[PATCH v2 00/44] cpuidle,rcu: Clean up the mess

[PATCH v2 00/44] cpuidle,rcu: Clean up the mess

[Peter Zijlstra]

Hi All!

At long last, a respin of the cpuidle vs rcu cleanup patches.

v1: https://lkml.kernel.org/r/20220608142723.103523089@infradead.org

These here patches clean up the mess that is cpuidle vs rcuidle.

At the end of the ride there's only on RCU_NONIDLE user left:

  arch/arm64/kernel/suspend.c:            RCU_NONIDLE(__cpu_suspend_exit());

and 'one' trace_*_rcuidle() user:

  kernel/trace/trace_preemptirq.c:                        trace_irq_enable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
  kernel/trace/trace_preemptirq.c:                        trace_irq_disable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
  kernel/trace/trace_preemptirq.c:                        trace_irq_enable_rcuidle(CALLER_ADDR0, caller_addr);
  kernel/trace/trace_preemptirq.c:                        trace_irq_disable_rcuidle(CALLER_ADDR0, caller_addr);
  kernel/trace/trace_preemptirq.c:                trace_preempt_enable_rcuidle(a0, a1);
  kernel/trace/trace_preemptirq.c:                trace_preempt_disable_rcuidle(a0, a1);

However this last is all in deprecated code that should be unused for GENERIC_ENTRY.

I've touched a lot of code that I can't test and I might've broken something by
accident. In particular the whole ARM cpuidle stuff was quite involved.

Please all; have a look where you haven't already.


New since v1:

 - rebase on top of Frederic's rcu-context-tracking rename fest
 - more omap goodness as per the last discusion (thanks Tony!)
 - removed one more RCU_NONIDLE() from arm64/risc-v perf code
 - ubsan/kasan fixes
 - intel_idle module-param for testing
 - a bunch of extra __always_inline, because compilers are silly.

---
 arch/alpha/kernel/process.c               |  1 -
 arch/alpha/kernel/vmlinux.lds.S           |  1 -
 arch/arc/kernel/process.c                 |  3 ++
 arch/arc/kernel/vmlinux.lds.S             |  1 -
 arch/arm/include/asm/vmlinux.lds.h        |  1 -
 arch/arm/kernel/process.c                 |  1 -
 arch/arm/kernel/smp.c                     |  6 +--
 arch/arm/mach-gemini/board-dt.c           |  3 +-
 arch/arm/mach-imx/cpuidle-imx6q.c         |  4 +-
 arch/arm/mach-imx/cpuidle-imx6sx.c        |  5 ++-
 arch/arm/mach-omap2/common.h              |  6 ++-
 arch/arm/mach-omap2/cpuidle34xx.c         | 16 +++++++-
 arch/arm/mach-omap2/cpuidle44xx.c         | 29 +++++++-------
 arch/arm/mach-omap2/omap-mpuss-lowpower.c | 12 +++++-
 arch/arm/mach-omap2/pm.h                  |  2 +-
 arch/arm/mach-omap2/pm24xx.c              | 51 +-----------------------
 arch/arm/mach-omap2/pm34xx.c              | 14 +++++--
 arch/arm/mach-omap2/pm44xx.c              |  2 +-
 arch/arm/mach-omap2/powerdomain.c         | 10 ++---
 arch/arm64/kernel/idle.c                  |  1 -
 arch/arm64/kernel/smp.c                   |  4 +-
 arch/arm64/kernel/vmlinux.lds.S           |  1 -
 arch/csky/kernel/process.c                |  1 -
 arch/csky/kernel/smp.c                    |  2 +-
 arch/csky/kernel/vmlinux.lds.S            |  1 -
 arch/hexagon/kernel/process.c             |  1 -
 arch/hexagon/kernel/vmlinux.lds.S         |  1 -
 arch/ia64/kernel/process.c                |  1 +
 arch/ia64/kernel/vmlinux.lds.S            |  1 -
 arch/loongarch/kernel/idle.c              |  1 +
 arch/loongarch/kernel/vmlinux.lds.S       |  1 -
 arch/m68k/kernel/vmlinux-nommu.lds        |  1 -
 arch/m68k/kernel/vmlinux-std.lds          |  1 -
 arch/m68k/kernel/vmlinux-sun3.lds         |  1 -
 arch/microblaze/kernel/process.c          |  1 -
 arch/microblaze/kernel/vmlinux.lds.S      |  1 -
 arch/mips/kernel/idle.c                   |  8 ++--
 arch/mips/kernel/vmlinux.lds.S            |  1 -
 arch/nios2/kernel/process.c               |  1 -
 arch/nios2/kernel/vmlinux.lds.S           |  1 -
 arch/openrisc/kernel/process.c            |  1 +
 arch/openrisc/kernel/vmlinux.lds.S        |  1 -
 arch/parisc/kernel/process.c              |  2 -
 arch/parisc/kernel/vmlinux.lds.S          |  1 -
 arch/powerpc/kernel/idle.c                |  5 +--
 arch/powerpc/kernel/vmlinux.lds.S         |  1 -
 arch/riscv/kernel/process.c               |  1 -
 arch/riscv/kernel/vmlinux-xip.lds.S       |  1 -
 arch/riscv/kernel/vmlinux.lds.S           |  1 -
 arch/s390/kernel/idle.c                   |  1 -
 arch/s390/kernel/vmlinux.lds.S            |  1 -
 arch/sh/kernel/idle.c                     |  1 +
 arch/sh/kernel/vmlinux.lds.S              |  1 -
 arch/sparc/kernel/leon_pmc.c              |  4 ++
 arch/sparc/kernel/process_32.c            |  1 -
 arch/sparc/kernel/process_64.c            |  3 +-
 arch/sparc/kernel/vmlinux.lds.S           |  1 -
 arch/um/kernel/dyn.lds.S                  |  1 -
 arch/um/kernel/process.c                  |  1 -
 arch/um/kernel/uml.lds.S                  |  1 -
 arch/x86/boot/compressed/vmlinux.lds.S    |  1 +
 arch/x86/coco/tdx/tdcall.S                | 15 +------
 arch/x86/coco/tdx/tdx.c                   | 25 ++++--------
 arch/x86/events/amd/brs.c                 | 13 +++----
 arch/x86/include/asm/fpu/xcr.h            |  4 +-
 arch/x86/include/asm/irqflags.h           | 11 ++----
 arch/x86/include/asm/mwait.h              | 14 +++----
 arch/x86/include/asm/nospec-branch.h      |  2 +-
 arch/x86/include/asm/paravirt.h           |  6 ++-
 arch/x86/include/asm/perf_event.h         |  2 +-
 arch/x86/include/asm/shared/io.h          |  4 +-
 arch/x86/include/asm/shared/tdx.h         |  1 -
 arch/x86/include/asm/special_insns.h      |  8 ++--
 arch/x86/include/asm/xen/hypercall.h      |  2 +-
 arch/x86/kernel/cpu/bugs.c                |  2 +-
 arch/x86/kernel/fpu/core.c                |  4 +-
 arch/x86/kernel/paravirt.c                | 14 ++++++-
 arch/x86/kernel/process.c                 | 65 +++++++++++++++----------------
 arch/x86/kernel/vmlinux.lds.S             |  1 -
 arch/x86/lib/memcpy_64.S                  |  5 +--
 arch/x86/lib/memmove_64.S                 |  4 +-
 arch/x86/lib/memset_64.S                  |  4 +-
 arch/x86/xen/enlighten_pv.c               |  2 +-
 arch/x86/xen/irq.c                        |  2 +-
 arch/xtensa/kernel/process.c              |  1 +
 arch/xtensa/kernel/vmlinux.lds.S          |  1 -
 drivers/acpi/processor_idle.c             | 36 ++++++++++-------
 drivers/base/power/runtime.c              | 24 ++++++------
 drivers/clk/clk.c                         |  8 ++--
 drivers/cpuidle/cpuidle-arm.c             |  1 +
 drivers/cpuidle/cpuidle-big_little.c      |  8 +++-
 drivers/cpuidle/cpuidle-mvebu-v7.c        |  7 ++++
 drivers/cpuidle/cpuidle-psci.c            | 10 +++--
 drivers/cpuidle/cpuidle-qcom-spm.c        |  1 +
 drivers/cpuidle/cpuidle-riscv-sbi.c       | 10 +++--
 drivers/cpuidle/cpuidle-tegra.c           | 21 +++++++---
 drivers/cpuidle/cpuidle.c                 | 21 +++++-----
 drivers/cpuidle/dt_idle_states.c          |  2 +-
 drivers/cpuidle/poll_state.c              | 10 ++++-
 drivers/idle/intel_idle.c                 | 19 +++++----
 drivers/perf/arm_pmu.c                    | 11 +-----
 drivers/perf/riscv_pmu_sbi.c              |  8 +---
 include/asm-generic/vmlinux.lds.h         |  9 ++---
 include/linux/compiler_types.h            |  8 +++-
 include/linux/cpu.h                       |  3 --
 include/linux/cpuidle.h                   | 34 ++++++++++++++++
 include/linux/cpumask.h                   |  4 +-
 include/linux/percpu-defs.h               |  2 +-
 include/linux/sched/idle.h                | 40 ++++++++++++++-----
 include/linux/thread_info.h               | 18 ++++++++-
 include/linux/tracepoint.h                | 13 ++++++-
 kernel/cpu_pm.c                           |  9 -----
 kernel/printk/printk.c                    |  2 +-
 kernel/sched/idle.c                       | 47 +++++++---------------
 kernel/time/tick-broadcast-hrtimer.c      | 29 ++++++--------
 kernel/time/tick-broadcast.c              |  6 ++-
 kernel/trace/trace.c                      |  3 ++
 lib/ubsan.c                               |  5 ++-
 mm/kasan/kasan.h                          |  4 ++
 mm/kasan/shadow.c                         | 38 ++++++++++++++++++
 tools/objtool/check.c                     | 17 ++++++++
 121 files changed, 511 insertions(+), 420 deletions(-)

[PATCH v2 01/44] x86/perf/amd: Remove tracing from perf_lopwr_cb()

[Peter Zijlstra]

The perf_lopwr_cb() is called from the idle routines; there is no RCU
there, we must not enter tracing.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/events/amd/brs.c         |   13 +++++--------
 arch/x86/include/asm/perf_event.h |    2 +-
 2 files changed, 6 insertions(+), 9 deletions(-)

--- a/arch/x86/events/amd/brs.c
+++ b/arch/x86/events/amd/brs.c
@@ -41,18 +41,15 @@ static inline unsigned int brs_to(int id
 	return MSR_AMD_SAMP_BR_FROM + 2 * idx + 1;
 }
 
-static inline void set_debug_extn_cfg(u64 val)
+static __always_inline void set_debug_extn_cfg(u64 val)
 {
 	/* bits[4:3] must always be set to 11b */
-	wrmsrl(MSR_AMD_DBG_EXTN_CFG, val | 3ULL << 3);
+	__wrmsr(MSR_AMD_DBG_EXTN_CFG, val | 3ULL << 3, val >> 32);
 }
 
-static inline u64 get_debug_extn_cfg(void)
+static __always_inline u64 get_debug_extn_cfg(void)
 {
-	u64 val;
-
-	rdmsrl(MSR_AMD_DBG_EXTN_CFG, val);
-	return val;
+	return __rdmsr(MSR_AMD_DBG_EXTN_CFG);
 }
 
 static bool __init amd_brs_detect(void)
@@ -338,7 +335,7 @@ void amd_pmu_brs_sched_task(struct perf_
  * called from ACPI processor_idle.c or acpi_pad.c
  * with interrupts disabled
  */
-void perf_amd_brs_lopwr_cb(bool lopwr_in)
+void noinstr perf_amd_brs_lopwr_cb(bool lopwr_in)
 {
 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	union amd_debug_extn_cfg cfg;
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -554,7 +554,7 @@ extern void perf_amd_brs_lopwr_cb(bool l
 
 DECLARE_STATIC_CALL(perf_lopwr_cb, perf_amd_brs_lopwr_cb);
 
-static inline void perf_lopwr_cb(bool lopwr_in)
+static __always_inline void perf_lopwr_cb(bool lopwr_in)
 {
 	static_call_mod(perf_lopwr_cb)(lopwr_in);
 }

[PATCH v2 02/44] x86/idle: Replace x86_idle with a static_call

[Peter Zijlstra]

Typical boot time setup; no need to suffer an indirect call for that.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 arch/x86/kernel/process.c |   50 +++++++++++++++++++++++++---------------------
 1 file changed, 28 insertions(+), 22 deletions(-)

--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -24,6 +24,7 @@
 #include <linux/cpuidle.h>
 #include <linux/acpi.h>
 #include <linux/elf-randomize.h>
+#include <linux/static_call.h>
 #include <trace/events/power.h>
 #include <linux/hw_breakpoint.h>
 #include <asm/cpu.h>
@@ -692,7 +693,23 @@ void __switch_to_xtra(struct task_struct
 unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
 EXPORT_SYMBOL(boot_option_idle_override);
 
-static void (*x86_idle)(void);
+/*
+ * We use this if we don't have any better idle routine..
+ */
+void __cpuidle default_idle(void)
+{
+	raw_safe_halt();
+}
+#if defined(CONFIG_APM_MODULE) || defined(CONFIG_HALTPOLL_CPUIDLE_MODULE)
+EXPORT_SYMBOL(default_idle);
+#endif
+
+DEFINE_STATIC_CALL_NULL(x86_idle, default_idle);
+
+static bool x86_idle_set(void)
+{
+	return !!static_call_query(x86_idle);
+}
 
 #ifndef CONFIG_SMP
 static inline void play_dead(void)
@@ -715,28 +732,17 @@ void arch_cpu_idle_dead(void)
 /*
  * Called from the generic idle code.
  */
-void arch_cpu_idle(void)
-{
-	x86_idle();
-}
-
-/*
- * We use this if we don't have any better idle routine..
- */
-void __cpuidle default_idle(void)
+void __cpuidle arch_cpu_idle(void)
 {
-	raw_safe_halt();
+	static_call(x86_idle)();
 }
-#if defined(CONFIG_APM_MODULE) || defined(CONFIG_HALTPOLL_CPUIDLE_MODULE)
-EXPORT_SYMBOL(default_idle);
-#endif
 
 #ifdef CONFIG_XEN
 bool xen_set_default_idle(void)
 {
-	bool ret = !!x86_idle;
+	bool ret = x86_idle_set();
 
-	x86_idle = default_idle;
+	static_call_update(x86_idle, default_idle);
 
 	return ret;
 }
@@ -859,20 +865,20 @@ void select_idle_routine(const struct cp
 	if (boot_option_idle_override == IDLE_POLL && smp_num_siblings > 1)
 		pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n");
 #endif
-	if (x86_idle || boot_option_idle_override == IDLE_POLL)
+	if (x86_idle_set() || boot_option_idle_override == IDLE_POLL)
 		return;
 
 	if (boot_cpu_has_bug(X86_BUG_AMD_E400)) {
 		pr_info("using AMD E400 aware idle routine\n");
-		x86_idle = amd_e400_idle;
+		static_call_update(x86_idle, amd_e400_idle);
 	} else if (prefer_mwait_c1_over_halt(c)) {
 		pr_info("using mwait in idle threads\n");
-		x86_idle = mwait_idle;
+		static_call_update(x86_idle, mwait_idle);
 	} else if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) {
 		pr_info("using TDX aware idle routine\n");
-		x86_idle = tdx_safe_halt;
+		static_call_update(x86_idle, tdx_safe_halt);
 	} else
-		x86_idle = default_idle;
+		static_call_update(x86_idle, default_idle);
 }
 
 void amd_e400_c1e_apic_setup(void)
@@ -925,7 +931,7 @@ static int __init idle_setup(char *str)
 		 * To continue to load the CPU idle driver, don't touch
 		 * the boot_option_idle_override.
 		 */
-		x86_idle = default_idle;
+		static_call_update(x86_idle, default_idle);
 		boot_option_idle_override = IDLE_HALT;
 	} else if (!strcmp(str, "nomwait")) {
 		/*

[PATCH v2 03/44] cpuidle/poll: Ensure IRQ state is invariant

[Peter Zijlstra]

cpuidle_state::enter() methods should be IRQ invariant

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/cpuidle/poll_state.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/cpuidle/poll_state.c
+++ b/drivers/cpuidle/poll_state.c
@@ -17,7 +17,7 @@ static int __cpuidle poll_idle(struct cp
 
 	dev->poll_time_limit = false;
 
-	local_irq_enable();
+	raw_local_irq_enable();
 	if (!current_set_polling_and_test()) {
 		unsigned int loop_count = 0;
 		u64 limit;
@@ -36,6 +36,8 @@ static int __cpuidle poll_idle(struct cp
 			}
 		}
 	}
+	raw_local_irq_disable();
+
 	current_clr_polling();
 
 	return index;

Re: [PATCH v2 03/44] cpuidle/poll: Ensure IRQ state is invariant

[Frederic Weisbecker]

On Mon, Sep 19, 2022 at 11:59:42AM +0200, Peter Zijlstra wrote:
> cpuidle_state::enter() methods should be IRQ invariant

Got a bit confused with the invariant thing since the first chunck I
see in this patch is a conversion to an non-traceable local_irq_enable().

Maybe just add a short mention about that and why?

Thanks.

> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>  drivers/cpuidle/poll_state.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> --- a/drivers/cpuidle/poll_state.c
> +++ b/drivers/cpuidle/poll_state.c
> @@ -17,7 +17,7 @@ static int __cpuidle poll_idle(struct cp
>  
>  	dev->poll_time_limit = false;
>  
> -	local_irq_enable();
> +	raw_local_irq_enable();
>  	if (!current_set_polling_and_test()) {
>  		unsigned int loop_count = 0;
>  		u64 limit;
> @@ -36,6 +36,8 @@ static int __cpuidle poll_idle(struct cp
>  			}
>  		}
>  	}
> +	raw_local_irq_disable();
> +
>  	current_clr_polling();
>  
>  	return index;
> 
> 

Re: [PATCH v2 03/44] cpuidle/poll: Ensure IRQ state is invariant

[Peter Zijlstra]

On Mon, Sep 19, 2022 at 03:19:27PM +0200, Frederic Weisbecker wrote:
> On Mon, Sep 19, 2022 at 11:59:42AM +0200, Peter Zijlstra wrote:
> > cpuidle_state::enter() methods should be IRQ invariant
> 
> Got a bit confused with the invariant thing since the first chunck I
> see in this patch is a conversion to an non-traceable local_irq_enable().
> 
> Maybe just add a short mention about that and why?

Changelog now reads:

---
Subject: cpuidle/poll: Ensure IRQ state is invariant
From: Peter Zijlstra <peterz@infradead.org>
Date: Tue May 31 15:43:32 CEST 2022

cpuidle_state::enter() methods should be IRQ invariant.

Additionally make sure to use raw_local_irq_*() methods since this
cpuidle callback will be called with RCU already disabled.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

Re: [PATCH v2 03/44] cpuidle/poll: Ensure IRQ state is invariant

[Frederic Weisbecker]

On Tue, Sep 20, 2022 at 10:57:00AM +0200, Peter Zijlstra wrote:
> On Mon, Sep 19, 2022 at 03:19:27PM +0200, Frederic Weisbecker wrote:
> > On Mon, Sep 19, 2022 at 11:59:42AM +0200, Peter Zijlstra wrote:
> > > cpuidle_state::enter() methods should be IRQ invariant
> > 
> > Got a bit confused with the invariant thing since the first chunck I
> > see in this patch is a conversion to an non-traceable local_irq_enable().
> > 
> > Maybe just add a short mention about that and why?
> 
> Changelog now reads:
> 
> ---
> Subject: cpuidle/poll: Ensure IRQ state is invariant
> From: Peter Zijlstra <peterz@infradead.org>
> Date: Tue May 31 15:43:32 CEST 2022
> 
> cpuidle_state::enter() methods should be IRQ invariant.
> 
> Additionally make sure to use raw_local_irq_*() methods since this
> cpuidle callback will be called with RCU already disabled.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>

Thanks!

[PATCH v2 04/44] cpuidle: Move IRQ state validation

[Peter Zijlstra]

Make cpuidle_enter_state() consistent with the s2idle variant and
verify ->enter() always returns with interrupts disabled.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 drivers/cpuidle/cpuidle.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -236,7 +236,11 @@ int cpuidle_enter_state(struct cpuidle_d
 	stop_critical_timings();
 	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
 		ct_idle_enter();
+
 	entered_state = target_state->enter(dev, drv, index);
+	if (WARN_ONCE(!irqs_disabled(), "%ps leaked IRQ state", target_state->enter))
+		raw_local_irq_disable();
+
 	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
 		ct_idle_exit();
 	start_critical_timings();
@@ -248,12 +252,8 @@ int cpuidle_enter_state(struct cpuidle_d
 	/* The cpu is no longer idle or about to enter idle. */
 	sched_idle_set_state(NULL);
 
-	if (broadcast) {
-		if (WARN_ON_ONCE(!irqs_disabled()))
-			local_irq_disable();
-
+	if (broadcast)
 		tick_broadcast_exit();
-	}
 
 	if (!cpuidle_state_is_coupled(drv, index))
 		local_irq_enable();

[PATCH v2 05/44] cpuidle,riscv: Push RCU-idle into driver

[Peter Zijlstra]

Doing RCU-idle outside the driver, only to then temporarily enable it
again, at least twice, before going idle is daft.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 drivers/cpuidle/cpuidle-riscv-sbi.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/cpuidle/cpuidle-riscv-sbi.c
+++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
@@ -116,12 +116,12 @@ static int __sbi_enter_domain_idle_state
 		return -1;
 
 	/* Do runtime PM to manage a hierarchical CPU toplogy. */
-	ct_irq_enter_irqson();
 	if (s2idle)
 		dev_pm_genpd_suspend(pd_dev);
 	else
 		pm_runtime_put_sync_suspend(pd_dev);
-	ct_irq_exit_irqson();
+
+	ct_idle_enter();
 
 	if (sbi_is_domain_state_available())
 		state = sbi_get_domain_state();
@@ -130,12 +130,12 @@ static int __sbi_enter_domain_idle_state
 
 	ret = sbi_suspend(state) ? -1 : idx;
 
-	ct_irq_enter_irqson();
+	ct_idle_exit();
+
 	if (s2idle)
 		dev_pm_genpd_resume(pd_dev);
 	else
 		pm_runtime_get_sync(pd_dev);
-	ct_irq_exit_irqson();
 
 	cpu_pm_exit();
 
@@ -246,6 +246,7 @@ static int sbi_dt_cpu_init_topology(stru
 	 * of a shared state for the domain, assumes the domain states are all
 	 * deeper states.
 	 */
+	drv->states[state_count - 1].flags |= CPUIDLE_FLAG_RCU_IDLE;
 	drv->states[state_count - 1].enter = sbi_enter_domain_idle_state;
 	drv->states[state_count - 1].enter_s2idle =
 					sbi_enter_s2idle_domain_idle_state;

Re: [PATCH v2 05/44] cpuidle,riscv: Push RCU-idle into driver

[Anup Patel]

On Mon, Sep 19, 2022 at 3:47 PM Peter Zijlstra <peterz@infradead.org> wrote:
>
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again, at least twice, before going idle is daft.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Looks good to me.

For RISC-V cpuidle:
Reviewed-by: Anup Patel <anup@brainfault.org>

Regards,
Anup


> ---
>  drivers/cpuidle/cpuidle-riscv-sbi.c |    9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> --- a/drivers/cpuidle/cpuidle-riscv-sbi.c
> +++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
> @@ -116,12 +116,12 @@ static int __sbi_enter_domain_idle_state
>                 return -1;
>
>         /* Do runtime PM to manage a hierarchical CPU toplogy. */
> -       ct_irq_enter_irqson();
>         if (s2idle)
>                 dev_pm_genpd_suspend(pd_dev);
>         else
>                 pm_runtime_put_sync_suspend(pd_dev);
> -       ct_irq_exit_irqson();
> +
> +       ct_idle_enter();
>
>         if (sbi_is_domain_state_available())
>                 state = sbi_get_domain_state();
> @@ -130,12 +130,12 @@ static int __sbi_enter_domain_idle_state
>
>         ret = sbi_suspend(state) ? -1 : idx;
>
> -       ct_irq_enter_irqson();
> +       ct_idle_exit();
> +
>         if (s2idle)
>                 dev_pm_genpd_resume(pd_dev);
>         else
>                 pm_runtime_get_sync(pd_dev);
> -       ct_irq_exit_irqson();
>
>         cpu_pm_exit();
>
> @@ -246,6 +246,7 @@ static int sbi_dt_cpu_init_topology(stru
>          * of a shared state for the domain, assumes the domain states are all
>          * deeper states.
>          */
> +       drv->states[state_count - 1].flags |= CPUIDLE_FLAG_RCU_IDLE;
>         drv->states[state_count - 1].enter = sbi_enter_domain_idle_state;
>         drv->states[state_count - 1].enter_s2idle =
>                                         sbi_enter_s2idle_domain_idle_state;
>
>

Re: [PATCH v2 05/44] cpuidle,riscv: Push RCU-idle into driver

[Frederic Weisbecker]

On Mon, Sep 19, 2022 at 11:59:44AM +0200, Peter Zijlstra wrote:
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again, at least twice, before going idle is daft.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>

[PATCH v2 06/44] cpuidle,tegra: Push RCU-idle into driver

[Peter Zijlstra]

Doing RCU-idle outside the driver, only to then temporarily enable it
again, at least twice, before going idle is daft.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 drivers/cpuidle/cpuidle-tegra.c |   21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

--- a/drivers/cpuidle/cpuidle-tegra.c
+++ b/drivers/cpuidle/cpuidle-tegra.c
@@ -180,9 +180,11 @@ static int tegra_cpuidle_state_enter(str
 	}
 
 	local_fiq_disable();
-	RCU_NONIDLE(tegra_pm_set_cpu_in_lp2());
+	tegra_pm_set_cpu_in_lp2();
 	cpu_pm_enter();
 
+	ct_idle_enter();
+
 	switch (index) {
 	case TEGRA_C7:
 		err = tegra_cpuidle_c7_enter();
@@ -197,8 +199,10 @@ static int tegra_cpuidle_state_enter(str
 		break;
 	}
 
+	ct_idle_exit();
+
 	cpu_pm_exit();
-	RCU_NONIDLE(tegra_pm_clear_cpu_in_lp2());
+	tegra_pm_clear_cpu_in_lp2();
 	local_fiq_enable();
 
 	return err ?: index;
@@ -226,6 +230,7 @@ static int tegra_cpuidle_enter(struct cp
 			       struct cpuidle_driver *drv,
 			       int index)
 {
+	bool do_rcu = drv->states[index].flags & CPUIDLE_FLAG_RCU_IDLE;
 	unsigned int cpu = cpu_logical_map(dev->cpu);
 	int ret;
 
@@ -233,9 +238,13 @@ static int tegra_cpuidle_enter(struct cp
 	if (dev->states_usage[index].disable)
 		return -1;
 
-	if (index == TEGRA_C1)
+	if (index == TEGRA_C1) {
+		if (do_rcu)
+			ct_idle_enter();
 		ret = arm_cpuidle_simple_enter(dev, drv, index);
-	else
+		if (do_rcu)
+			ct_idle_exit();
+	} else
 		ret = tegra_cpuidle_state_enter(dev, index, cpu);
 
 	if (ret < 0) {
@@ -285,7 +294,8 @@ static struct cpuidle_driver tegra_idle_
 			.exit_latency		= 2000,
 			.target_residency	= 2200,
 			.power_usage		= 100,
-			.flags			= CPUIDLE_FLAG_TIMER_STOP,
+			.flags			= CPUIDLE_FLAG_TIMER_STOP |
+						  CPUIDLE_FLAG_RCU_IDLE,
 			.name			= "C7",
 			.desc			= "CPU core powered off",
 		},
@@ -295,6 +305,7 @@ static struct cpuidle_driver tegra_idle_
 			.target_residency	= 10000,
 			.power_usage		= 0,
 			.flags			= CPUIDLE_FLAG_TIMER_STOP |
+						  CPUIDLE_FLAG_RCU_IDLE   |
 						  CPUIDLE_FLAG_COUPLED,
 			.name			= "CC6",
 			.desc			= "CPU cluster powered off",

Re: [PATCH v2 06/44] cpuidle,tegra: Push RCU-idle into driver

[Frederic Weisbecker]

On Mon, Sep 19, 2022 at 11:59:45AM +0200, Peter Zijlstra wrote:
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again, at least twice, before going idle is daft.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>

[PATCH v2 07/44] cpuidle,psci: Push RCU-idle into driver

[Peter Zijlstra]

Doing RCU-idle outside the driver, only to then temporarily enable it
again, at least twice, before going idle is daft.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 drivers/cpuidle/cpuidle-psci.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -69,12 +69,12 @@ static int __psci_enter_domain_idle_stat
 		return -1;
 
 	/* Do runtime PM to manage a hierarchical CPU toplogy. */
-	ct_irq_enter_irqson();
 	if (s2idle)
 		dev_pm_genpd_suspend(pd_dev);
 	else
 		pm_runtime_put_sync_suspend(pd_dev);
-	ct_irq_exit_irqson();
+
+	ct_idle_enter();
 
 	state = psci_get_domain_state();
 	if (!state)
@@ -82,12 +82,12 @@ static int __psci_enter_domain_idle_stat
 
 	ret = psci_cpu_suspend_enter(state) ? -1 : idx;
 
-	ct_irq_enter_irqson();
+	ct_idle_exit();
+
 	if (s2idle)
 		dev_pm_genpd_resume(pd_dev);
 	else
 		pm_runtime_get_sync(pd_dev);
-	ct_irq_exit_irqson();
 
 	cpu_pm_exit();
 
@@ -240,6 +240,7 @@ static int psci_dt_cpu_init_topology(str
 	 * of a shared state for the domain, assumes the domain states are all
 	 * deeper states.
 	 */
+	drv->states[state_count - 1].flags |= CPUIDLE_FLAG_RCU_IDLE;
 	drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
 	drv->states[state_count - 1].enter_s2idle = psci_enter_s2idle_domain_idle_state;
 	psci_cpuidle_use_cpuhp = true;

Re: [PATCH v2 07/44] cpuidle,psci: Push RCU-idle into driver

[Frederic Weisbecker]

On Mon, Sep 19, 2022 at 11:59:46AM +0200, Peter Zijlstra wrote:
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again, at least twice, before going idle is daft.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>

Re: [PATCH v2 07/44] cpuidle,psci: Push RCU-idle into driver

[Kajetan Puchalski]

On Mon, Sep 19, 2022 at 11:59:46AM +0200, Peter Zijlstra wrote:
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again, at least twice, before going idle is daft.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Tried it on Pixel 6 running psci_idle, looks good with no apparent issues.

Tested-by: Kajetan Puchalski <kajetan.puchalski@arm.com>

Re: [PATCH v2 07/44] cpuidle,psci: Push RCU-idle into driver

[Guo Ren]

Reviewed-by: Guo Ren <guoren@kernel.org>

On Mon, Sep 19, 2022 at 6:17 PM Peter Zijlstra <peterz@infradead.org> wrote:
>
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again, at least twice, before going idle is daft.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
>  drivers/cpuidle/cpuidle-psci.c |    9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> --- a/drivers/cpuidle/cpuidle-psci.c
> +++ b/drivers/cpuidle/cpuidle-psci.c
> @@ -69,12 +69,12 @@ static int __psci_enter_domain_idle_stat
>                 return -1;
>
>         /* Do runtime PM to manage a hierarchical CPU toplogy. */
> -       ct_irq_enter_irqson();
>         if (s2idle)
>                 dev_pm_genpd_suspend(pd_dev);
>         else
>                 pm_runtime_put_sync_suspend(pd_dev);
> -       ct_irq_exit_irqson();
> +
> +       ct_idle_enter();
>
>         state = psci_get_domain_state();
>         if (!state)
> @@ -82,12 +82,12 @@ static int __psci_enter_domain_idle_stat
>
>         ret = psci_cpu_suspend_enter(state) ? -1 : idx;
>
> -       ct_irq_enter_irqson();
> +       ct_idle_exit();
> +
>         if (s2idle)
>                 dev_pm_genpd_resume(pd_dev);
>         else
>                 pm_runtime_get_sync(pd_dev);
> -       ct_irq_exit_irqson();
>
>         cpu_pm_exit();
>
> @@ -240,6 +240,7 @@ static int psci_dt_cpu_init_topology(str
>          * of a shared state for the domain, assumes the domain states are all
>          * deeper states.
>          */
> +       drv->states[state_count - 1].flags |= CPUIDLE_FLAG_RCU_IDLE;
>         drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
>         drv->states[state_count - 1].enter_s2idle = psci_enter_s2idle_domain_idle_state;
>         psci_cpuidle_use_cpuhp = true;
>
>


-- 
Best Regards
 Guo Ren

[PATCH v2 08/44] cpuidle,imx6: Push RCU-idle into driver

[Peter Zijlstra]

Doing RCU-idle outside the driver, only to then temporarily enable it
again, at least twice, before going idle is daft.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/arm/mach-imx/cpuidle-imx6sx.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/arch/arm/mach-imx/cpuidle-imx6sx.c
+++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
@@ -47,7 +47,9 @@ static int imx6sx_enter_wait(struct cpui
 		cpu_pm_enter();
 		cpu_cluster_pm_enter();
 
+		ct_idle_enter();
 		cpu_suspend(0, imx6sx_idle_finish);
+		ct_idle_exit();
 
 		cpu_cluster_pm_exit();
 		cpu_pm_exit();
@@ -87,7 +89,8 @@ static struct cpuidle_driver imx6sx_cpui
 			 */
 			.exit_latency = 300,
 			.target_residency = 500,
-			.flags = CPUIDLE_FLAG_TIMER_STOP,
+			.flags = CPUIDLE_FLAG_TIMER_STOP |
+				 CPUIDLE_FLAG_RCU_IDLE,
 			.enter = imx6sx_enter_wait,
 			.name = "LOW-POWER-IDLE",
 			.desc = "ARM power off",

Re: [PATCH v2 08/44] cpuidle,imx6: Push RCU-idle into driver

[Frederic Weisbecker]

On Mon, Sep 19, 2022 at 11:59:47AM +0200, Peter Zijlstra wrote:
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again, at least twice, before going idle is daft.

Hmm, what ends up calling RCU_IDLE() here? Also what about
cpu_do_idle()?

Thanks.

> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
>  arch/arm/mach-imx/cpuidle-imx6sx.c |    5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> --- a/arch/arm/mach-imx/cpuidle-imx6sx.c
> +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
> @@ -47,7 +47,9 @@ static int imx6sx_enter_wait(struct cpui
>  		cpu_pm_enter();
>  		cpu_cluster_pm_enter();
>  
> +		ct_idle_enter();
>  		cpu_suspend(0, imx6sx_idle_finish);
> +		ct_idle_exit();
>  
>  		cpu_cluster_pm_exit();
>  		cpu_pm_exit();
> @@ -87,7 +89,8 @@ static struct cpuidle_driver imx6sx_cpui
>  			 */
>  			.exit_latency = 300,
>  			.target_residency = 500,
> -			.flags = CPUIDLE_FLAG_TIMER_STOP,
> +			.flags = CPUIDLE_FLAG_TIMER_STOP |
> +				 CPUIDLE_FLAG_RCU_IDLE,
>  			.enter = imx6sx_enter_wait,
>  			.name = "LOW-POWER-IDLE",
>  			.desc = "ARM power off",
> 
> 

Re: [PATCH v2 08/44] cpuidle,imx6: Push RCU-idle into driver

[Peter Zijlstra]

On Mon, Sep 19, 2022 at 04:21:23PM +0200, Frederic Weisbecker wrote:
> On Mon, Sep 19, 2022 at 11:59:47AM +0200, Peter Zijlstra wrote:
> > Doing RCU-idle outside the driver, only to then temporarily enable it
> > again, at least twice, before going idle is daft.
> 
> Hmm, what ends up calling RCU_IDLE() here? Also what about
> cpu_do_idle()?

Both cpu_pm_enter() and cpu_cluster_pm_enter() use ct_irq_enter_irqson()
which is another way to spell RCU_NONIDLE().

Re: [PATCH v2 08/44] cpuidle,imx6: Push RCU-idle into driver

[Peter Zijlstra]

On Mon, Sep 19, 2022 at 04:21:23PM +0200, Frederic Weisbecker wrote:
> On Mon, Sep 19, 2022 at 11:59:47AM +0200, Peter Zijlstra wrote:
> > Doing RCU-idle outside the driver, only to then temporarily enable it
> > again, at least twice, before going idle is daft.
> 
> Hmm, what ends up calling RCU_IDLE() here? Also what about
> cpu_do_idle()?

I've ammended patches 5-12 with a comment like:

Notably both cpu_pm_enter() and cpu_cluster_pm_enter() implicity
re-enable RCU.

(each noting the specific sites for the relevant patch).

Re: [PATCH v2 08/44] cpuidle,imx6: Push RCU-idle into driver

[Frederic Weisbecker]

On Tue, Sep 20, 2022 at 10:58:59AM +0200, Peter Zijlstra wrote:
> On Mon, Sep 19, 2022 at 04:21:23PM +0200, Frederic Weisbecker wrote:
> > On Mon, Sep 19, 2022 at 11:59:47AM +0200, Peter Zijlstra wrote:
> > > Doing RCU-idle outside the driver, only to then temporarily enable it
> > > again, at least twice, before going idle is daft.
> > 
> > Hmm, what ends up calling RCU_IDLE() here? Also what about
> > cpu_do_idle()?
> 
> I've ammended patches 5-12 with a comment like:
> 
> Notably both cpu_pm_enter() and cpu_cluster_pm_enter() implicity
> re-enable RCU.
> 
> (each noting the specific sites for the relevant patch).

Thanks!

Re: [PATCH v2 08/44] cpuidle,imx6: Push RCU-idle into driver

[Frederic Weisbecker]

On Mon, Sep 19, 2022 at 11:59:47AM +0200, Peter Zijlstra wrote:
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again, at least twice, before going idle is daft.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
>  arch/arm/mach-imx/cpuidle-imx6sx.c |    5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> --- a/arch/arm/mach-imx/cpuidle-imx6sx.c
> +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
> @@ -47,7 +47,9 @@ static int imx6sx_enter_wait(struct cpui
>  		cpu_pm_enter();
>  		cpu_cluster_pm_enter();
>  
> +		ct_idle_enter();
>  		cpu_suspend(0, imx6sx_idle_finish);
> +		ct_idle_exit();
>  
>  		cpu_cluster_pm_exit();
>  		cpu_pm_exit();
> @@ -87,7 +89,8 @@ static struct cpuidle_driver imx6sx_cpui
>  			 */
>  			.exit_latency = 300,
>  			.target_residency = 500,
> -			.flags = CPUIDLE_FLAG_TIMER_STOP,
> +			.flags = CPUIDLE_FLAG_TIMER_STOP |
> +				 CPUIDLE_FLAG_RCU_IDLE,
>  			.enter = imx6sx_enter_wait,

There is a second one below that also uses imx6sx_enter_wait.

Thanks.

>  			.name = "LOW-POWER-IDLE",
>  			.desc = "ARM power off",
> 
> 

Re: [PATCH v2 08/44] cpuidle,imx6: Push RCU-idle into driver

[Peter Zijlstra]

On Mon, Sep 19, 2022 at 04:49:41PM +0200, Frederic Weisbecker wrote:
> On Mon, Sep 19, 2022 at 11:59:47AM +0200, Peter Zijlstra wrote:
> > Doing RCU-idle outside the driver, only to then temporarily enable it
> > again, at least twice, before going idle is daft.
> > 
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > ---
> >  arch/arm/mach-imx/cpuidle-imx6sx.c |    5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > --- a/arch/arm/mach-imx/cpuidle-imx6sx.c
> > +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
> > @@ -47,7 +47,9 @@ static int imx6sx_enter_wait(struct cpui
> >  		cpu_pm_enter();
> >  		cpu_cluster_pm_enter();
> >  
> > +		ct_idle_enter();
> >  		cpu_suspend(0, imx6sx_idle_finish);
> > +		ct_idle_exit();
> >  
> >  		cpu_cluster_pm_exit();
> >  		cpu_pm_exit();
> > @@ -87,7 +89,8 @@ static struct cpuidle_driver imx6sx_cpui
> >  			 */
> >  			.exit_latency = 300,
> >  			.target_residency = 500,
> > -			.flags = CPUIDLE_FLAG_TIMER_STOP,
> > +			.flags = CPUIDLE_FLAG_TIMER_STOP |
> > +				 CPUIDLE_FLAG_RCU_IDLE,
> >  			.enter = imx6sx_enter_wait,
> 
> There is a second one below that also uses imx6sx_enter_wait.

Duh, thanks!

Re: [PATCH v2 08/44] cpuidle,imx6: Push RCU-idle into driver

[Peter Zijlstra]

On Mon, Sep 19, 2022 at 04:49:41PM +0200, Frederic Weisbecker wrote:
> On Mon, Sep 19, 2022 at 11:59:47AM +0200, Peter Zijlstra wrote:
> > Doing RCU-idle outside the driver, only to then temporarily enable it
> > again, at least twice, before going idle is daft.
> > 
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > ---
> >  arch/arm/mach-imx/cpuidle-imx6sx.c |    5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > --- a/arch/arm/mach-imx/cpuidle-imx6sx.c
> > +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
> > @@ -47,7 +47,9 @@ static int imx6sx_enter_wait(struct cpui
> >  		cpu_pm_enter();
> >  		cpu_cluster_pm_enter();
> >  
> > +		ct_idle_enter();
> >  		cpu_suspend(0, imx6sx_idle_finish);
> > +		ct_idle_exit();
> >  
> >  		cpu_cluster_pm_exit();
> >  		cpu_pm_exit();
> > @@ -87,7 +89,8 @@ static struct cpuidle_driver imx6sx_cpui
> >  			 */
> >  			.exit_latency = 300,
> >  			.target_residency = 500,
> > -			.flags = CPUIDLE_FLAG_TIMER_STOP,
> > +			.flags = CPUIDLE_FLAG_TIMER_STOP |
> > +				 CPUIDLE_FLAG_RCU_IDLE,
> >  			.enter = imx6sx_enter_wait,
> 
> There is a second one below that also uses imx6sx_enter_wait.

Oh, above you mean; but only @index==2 gets us into the whole PM crud.
@index==1 is fine afaict.

Re: [PATCH v2 08/44] cpuidle,imx6: Push RCU-idle into driver

[Frederic Weisbecker]

On Mon, Sep 19, 2022 at 05:03:04PM +0200, Peter Zijlstra wrote:
> On Mon, Sep 19, 2022 at 04:49:41PM +0200, Frederic Weisbecker wrote:
> > On Mon, Sep 19, 2022 at 11:59:47AM +0200, Peter Zijlstra wrote:
> > > Doing RCU-idle outside the driver, only to then temporarily enable it
> > > again, at least twice, before going idle is daft.
> > > 
> > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > > ---
> > >  arch/arm/mach-imx/cpuidle-imx6sx.c |    5 ++++-
> > >  1 file changed, 4 insertions(+), 1 deletion(-)
> > > 
> > > --- a/arch/arm/mach-imx/cpuidle-imx6sx.c
> > > +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
> > > @@ -47,7 +47,9 @@ static int imx6sx_enter_wait(struct cpui
> > >  		cpu_pm_enter();
> > >  		cpu_cluster_pm_enter();
> > >  
> > > +		ct_idle_enter();
> > >  		cpu_suspend(0, imx6sx_idle_finish);
> > > +		ct_idle_exit();
> > >  
> > >  		cpu_cluster_pm_exit();
> > >  		cpu_pm_exit();
> > > @@ -87,7 +89,8 @@ static struct cpuidle_driver imx6sx_cpui
> > >  			 */
> > >  			.exit_latency = 300,
> > >  			.target_residency = 500,
> > > -			.flags = CPUIDLE_FLAG_TIMER_STOP,
> > > +			.flags = CPUIDLE_FLAG_TIMER_STOP |
> > > +				 CPUIDLE_FLAG_RCU_IDLE,
> > >  			.enter = imx6sx_enter_wait,
> > 
> > There is a second one below that also uses imx6sx_enter_wait.
> 
> Oh, above you mean; but only @index==2 gets us into the whole PM crud.
> @index==1 is fine afaict.

Ah ok, got it, hence why you didn't touch cpu_do_idle()...
May need to comment that somewhere...

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>

Thanks!

[PATCH v2 09/44] cpuidle,omap3: Push RCU-idle into driver

[Peter Zijlstra]

Doing RCU-idle outside the driver, only to then teporarily enable it
again before going idle is daft.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/mach-omap2/cpuidle34xx.c |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)

--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -133,7 +133,9 @@ static int omap3_enter_idle(struct cpuid
 	}
 
 	/* Execute ARM wfi */
+	ct_idle_enter();
 	omap_sram_idle();
+	ct_idle_exit();
 
 	/*
 	 * Call idle CPU PM enter notifier chain to restore
@@ -265,6 +267,7 @@ static struct cpuidle_driver omap3_idle_
 	.owner            = THIS_MODULE,
 	.states = {
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 2 + 2,
 			.target_residency = 5,
@@ -272,6 +275,7 @@ static struct cpuidle_driver omap3_idle_
 			.desc		  = "MPU ON + CORE ON",
 		},
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 10 + 10,
 			.target_residency = 30,
@@ -279,6 +283,7 @@ static struct cpuidle_driver omap3_idle_
 			.desc		  = "MPU ON + CORE ON",
 		},
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 50 + 50,
 			.target_residency = 300,
@@ -286,6 +291,7 @@ static struct cpuidle_driver omap3_idle_
 			.desc		  = "MPU RET + CORE ON",
 		},
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 1500 + 1800,
 			.target_residency = 4000,
@@ -293,6 +299,7 @@ static struct cpuidle_driver omap3_idle_
 			.desc		  = "MPU OFF + CORE ON",
 		},
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 2500 + 7500,
 			.target_residency = 12000,
@@ -300,6 +307,7 @@ static struct cpuidle_driver omap3_idle_
 			.desc		  = "MPU RET + CORE RET",
 		},
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 3000 + 8500,
 			.target_residency = 15000,
@@ -307,6 +315,7 @@ static struct cpuidle_driver omap3_idle_
 			.desc		  = "MPU OFF + CORE RET",
 		},
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 10000 + 30000,
 			.target_residency = 30000,
@@ -328,6 +337,7 @@ static struct cpuidle_driver omap3430_id
 	.owner            = THIS_MODULE,
 	.states = {
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 110 + 162,
 			.target_residency = 5,
@@ -335,6 +345,7 @@ static struct cpuidle_driver omap3430_id
 			.desc		  = "MPU ON + CORE ON",
 		},
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 106 + 180,
 			.target_residency = 309,
@@ -342,6 +353,7 @@ static struct cpuidle_driver omap3430_id
 			.desc		  = "MPU ON + CORE ON",
 		},
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 107 + 410,
 			.target_residency = 46057,
@@ -349,6 +361,7 @@ static struct cpuidle_driver omap3430_id
 			.desc		  = "MPU RET + CORE ON",
 		},
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 121 + 3374,
 			.target_residency = 46057,
@@ -356,6 +369,7 @@ static struct cpuidle_driver omap3430_id
 			.desc		  = "MPU OFF + CORE ON",
 		},
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 855 + 1146,
 			.target_residency = 46057,
@@ -363,6 +377,7 @@ static struct cpuidle_driver omap3430_id
 			.desc		  = "MPU RET + CORE RET",
 		},
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 7580 + 4134,
 			.target_residency = 484329,
@@ -370,6 +385,7 @@ static struct cpuidle_driver omap3430_id
 			.desc		  = "MPU OFF + CORE RET",
 		},
 		{
+			.flags		  = CPUIDLE_FLAG_RCU_IDLE,
 			.enter		  = omap3_enter_idle_bm,
 			.exit_latency	  = 7505 + 15274,
 			.target_residency = 484329,

Re: [PATCH v2 09/44] cpuidle,omap3: Push RCU-idle into driver

[Frederic Weisbecker]

On Mon, Sep 19, 2022 at 11:59:48AM +0200, Peter Zijlstra wrote:
> Doing RCU-idle outside the driver, only to then teporarily enable it
> again before going idle is daft.

That doesn't tell where those calls are.

Thanks.

Re: [PATCH v2 09/44] cpuidle,omap3: Push RCU-idle into driver

[Peter Zijlstra]

On Mon, Sep 19, 2022 at 04:31:42PM +0200, Frederic Weisbecker wrote:
> On Mon, Sep 19, 2022 at 11:59:48AM +0200, Peter Zijlstra wrote:
> > Doing RCU-idle outside the driver, only to then teporarily enable it
> > again before going idle is daft.
> 
> That doesn't tell where those calls are.

cpu_pm_enter/exit and the power domain stuff, possibly also the clock
domain stuff. It's all over :/

I suppose I can add a blub and copy/paste it around the various patches
if you want.

Re: [PATCH v2 09/44] cpuidle,omap3: Push RCU-idle into driver

[Frederic Weisbecker]

On Mon, Sep 19, 2022 at 05:19:05PM +0200, Peter Zijlstra wrote:
> On Mon, Sep 19, 2022 at 04:31:42PM +0200, Frederic Weisbecker wrote:
> > On Mon, Sep 19, 2022 at 11:59:48AM +0200, Peter Zijlstra wrote:
> > > Doing RCU-idle outside the driver, only to then teporarily enable it
> > > again before going idle is daft.
> > 
> > That doesn't tell where those calls are.
> 
> cpu_pm_enter/exit and the power domain stuff, possibly also the clock
> domain stuff. It's all over :/
> 
> I suppose I can add a blub and copy/paste it around the various patches
> if you want.

Yes please, sorry I don't want to bother but, just for the sake of
git blame to report something useful in 5 years.

Thanks.

Re: [PATCH v2 09/44] cpuidle,omap3: Push RCU-idle into driver

[Frederic Weisbecker]

On Mon, Sep 19, 2022 at 11:59:48AM +0200, Peter Zijlstra wrote:
> Doing RCU-idle outside the driver, only to then teporarily enable it
> again before going idle is daft.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Reviewed-by: Tony Lindgren <tony@atomide.com>
> Tested-by: Tony Lindgren <tony@atomide.com>

Ok now with the cpu_pm_*() informations that makes sense:

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>

[PATCH v2 10/44] cpuidle,armada: Push RCU-idle into driver

[Peter Zijlstra]

Doing RCU-idle outside the driver, only to then temporarily enable it
again before going idle is daft.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 drivers/cpuidle/cpuidle-mvebu-v7.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/cpuidle/cpuidle-mvebu-v7.c
+++ b/drivers/cpuidle/cpuidle-mvebu-v7.c
@@ -36,7 +36,10 @@ static int mvebu_v7_enter_idle(struct cp
 	if (drv->states[index].flags & MVEBU_V7_FLAG_DEEP_IDLE)
 		deepidle = true;
 
+	ct_idle_enter();
 	ret = mvebu_v7_cpu_suspend(deepidle);
+	ct_idle_exit();
+
 	cpu_pm_exit();
 
 	if (ret)
@@ -49,6 +52,7 @@ static struct cpuidle_driver armadaxp_id
 	.name			= "armada_xp_idle",
 	.states[0]		= ARM_CPUIDLE_WFI_STATE,
 	.states[1]		= {
+		.flags			= CPUIDLE_FLAG_RCU_IDLE,
 		.enter			= mvebu_v7_enter_idle,
 		.exit_latency		= 100,
 		.power_usage		= 50,
@@ -57,6 +61,7 @@ static struct cpuidle_driver armadaxp_id
 		.desc			= "CPU power down",
 	},
 	.states[2]		= {
+		.flags			= CPUIDLE_FLAG_RCU_IDLE,
 		.enter			= mvebu_v7_enter_idle,
 		.exit_latency		= 1000,
 		.power_usage		= 5,
@@ -72,6 +77,7 @@ static struct cpuidle_driver armada370_i
 	.name			= "armada_370_idle",
 	.states[0]		= ARM_CPUIDLE_WFI_STATE,
 	.states[1]		= {
+		.flags			= CPUIDLE_FLAG_RCU_IDLE,
 		.enter			= mvebu_v7_enter_idle,
 		.exit_latency		= 100,
 		.power_usage		= 5,
@@ -87,6 +93,7 @@ static struct cpuidle_driver armada38x_i
 	.name			= "armada_38x_idle",
 	.states[0]		= ARM_CPUIDLE_WFI_STATE,
 	.states[1]		= {
+		.flags			= CPUIDLE_FLAG_RCU_IDLE,
 		.enter			= mvebu_v7_enter_idle,
 		.exit_latency		= 10,
 		.power_usage		= 5,

Re: [PATCH v2 10/44] cpuidle,armada: Push RCU-idle into driver

[Frederic Weisbecker]

On Mon, Sep 19, 2022 at 11:59:49AM +0200, Peter Zijlstra wrote:
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again before going idle is daft.

Ah wait, now I see, that's cpu_pm_enter()/cpu_pm_exit() -> cpu_pm_notify*() the culprits.
Might be worth adding a short note about that on your changelogs.

> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
>  drivers/cpuidle/cpuidle-mvebu-v7.c |    7 +++++++
>  1 file changed, 7 insertions(+)
> 
> --- a/drivers/cpuidle/cpuidle-mvebu-v7.c
> +++ b/drivers/cpuidle/cpuidle-mvebu-v7.c
> @@ -36,7 +36,10 @@ static int mvebu_v7_enter_idle(struct cp
>  	if (drv->states[index].flags & MVEBU_V7_FLAG_DEEP_IDLE)
>  		deepidle = true;
>  
> +	ct_idle_enter();
>  	ret = mvebu_v7_cpu_suspend(deepidle);
> +	ct_idle_exit();

And then yes of course:

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>

[PATCH v2 11/44] cpuidle,omap4: Push RCU-idle into driver

[Peter Zijlstra]

Doing RCU-idle outside the driver, only to then temporarily enable it
again, some *four* times, before going idle is daft.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/mach-omap2/cpuidle44xx.c |   29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

--- a/arch/arm/mach-omap2/cpuidle44xx.c
+++ b/arch/arm/mach-omap2/cpuidle44xx.c
@@ -105,7 +105,9 @@ static int omap_enter_idle_smp(struct cp
 	}
 	raw_spin_unlock_irqrestore(&mpu_lock, flag);
 
+	ct_idle_enter();
 	omap4_enter_lowpower(dev->cpu, cx->cpu_state);
+	ct_idle_exit();
 
 	raw_spin_lock_irqsave(&mpu_lock, flag);
 	if (cx->mpu_state_vote == num_online_cpus())
@@ -151,10 +153,10 @@ static int omap_enter_idle_coupled(struc
 				 (cx->mpu_logic_state == PWRDM_POWER_OFF);
 
 	/* Enter broadcast mode for periodic timers */
-	RCU_NONIDLE(tick_broadcast_enable());
+	tick_broadcast_enable();
 
 	/* Enter broadcast mode for one-shot timers */
-	RCU_NONIDLE(tick_broadcast_enter());
+	tick_broadcast_enter();
 
 	/*
 	 * Call idle CPU PM enter notifier chain so that
@@ -166,7 +168,7 @@ static int omap_enter_idle_coupled(struc
 
 	if (dev->cpu == 0) {
 		pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
-		RCU_NONIDLE(omap_set_pwrdm_state(mpu_pd, cx->mpu_state));
+		omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
 
 		/*
 		 * Call idle CPU cluster PM enter notifier chain
@@ -178,14 +180,16 @@ static int omap_enter_idle_coupled(struc
 				index = 0;
 				cx = state_ptr + index;
 				pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
-				RCU_NONIDLE(omap_set_pwrdm_state(mpu_pd, cx->mpu_state));
+				omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
 				mpuss_can_lose_context = 0;
 			}
 		}
 	}
 
+	ct_idle_enter();
 	omap4_enter_lowpower(dev->cpu, cx->cpu_state);
 	cpu_done[dev->cpu] = true;
+	ct_idle_exit();
 
 	/* Wakeup CPU1 only if it is not offlined */
 	if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
@@ -194,9 +198,9 @@ static int omap_enter_idle_coupled(struc
 		    mpuss_can_lose_context)
 			gic_dist_disable();
 
-		RCU_NONIDLE(clkdm_deny_idle(cpu_clkdm[1]));
-		RCU_NONIDLE(omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON));
-		RCU_NONIDLE(clkdm_allow_idle(cpu_clkdm[1]));
+		clkdm_deny_idle(cpu_clkdm[1]);
+		omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON);
+		clkdm_allow_idle(cpu_clkdm[1]);
 
 		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) &&
 		    mpuss_can_lose_context) {
@@ -222,7 +226,7 @@ static int omap_enter_idle_coupled(struc
 	cpu_pm_exit();
 
 cpu_pm_out:
-	RCU_NONIDLE(tick_broadcast_exit());
+	tick_broadcast_exit();
 
 fail:
 	cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
@@ -247,7 +251,8 @@ static struct cpuidle_driver omap4_idle_
 			/* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
 			.exit_latency = 328 + 440,
 			.target_residency = 960,
-			.flags = CPUIDLE_FLAG_COUPLED,
+			.flags = CPUIDLE_FLAG_COUPLED |
+				 CPUIDLE_FLAG_RCU_IDLE,
 			.enter = omap_enter_idle_coupled,
 			.name = "C2",
 			.desc = "CPUx OFF, MPUSS CSWR",
@@ -256,7 +261,8 @@ static struct cpuidle_driver omap4_idle_
 			/* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
 			.exit_latency = 460 + 518,
 			.target_residency = 1100,
-			.flags = CPUIDLE_FLAG_COUPLED,
+			.flags = CPUIDLE_FLAG_COUPLED |
+				 CPUIDLE_FLAG_RCU_IDLE,
 			.enter = omap_enter_idle_coupled,
 			.name = "C3",
 			.desc = "CPUx OFF, MPUSS OSWR",
@@ -282,7 +288,8 @@ static struct cpuidle_driver omap5_idle_
 			/* C2 - CPU0 RET + CPU1 RET + MPU CSWR */
 			.exit_latency = 48 + 60,
 			.target_residency = 100,
-			.flags = CPUIDLE_FLAG_TIMER_STOP,
+			.flags = CPUIDLE_FLAG_TIMER_STOP |
+				 CPUIDLE_FLAG_RCU_IDLE,
 			.enter = omap_enter_idle_smp,
 			.name = "C2",
 			.desc = "CPUx CSWR, MPUSS CSWR",

Re: [PATCH v2 11/44] cpuidle,omap4: Push RCU-idle into driver

[Frederic Weisbecker]

On Mon, Sep 19, 2022 at 11:59:50AM +0200, Peter Zijlstra wrote:
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again, some *four* times, before going idle is daft.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Reviewed-by: Tony Lindgren <tony@atomide.com>
> Tested-by: Tony Lindgren <tony@atomide.com>

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>

[PATCH v2 12/44] cpuidle,dt: Push RCU-idle into driver

[Peter Zijlstra]

Doing RCU-idle outside the driver, only to then temporarily enable it
again before going idle is daft.

Notably: this converts all dt_init_idle_driver() and
__CPU_PM_CPU_IDLE_ENTER() users for they are inextrably intertwined.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/arm/mach-omap2/cpuidle34xx.c    |    4 ++--
 drivers/acpi/processor_idle.c        |    2 ++
 drivers/cpuidle/cpuidle-arm.c        |    1 +
 drivers/cpuidle/cpuidle-big_little.c |    8 ++++++--
 drivers/cpuidle/cpuidle-psci.c       |    1 +
 drivers/cpuidle/cpuidle-qcom-spm.c   |    1 +
 drivers/cpuidle/cpuidle-riscv-sbi.c  |    1 +
 drivers/cpuidle/dt_idle_states.c     |    2 +-
 include/linux/cpuidle.h              |    4 ++++
 9 files changed, 19 insertions(+), 5 deletions(-)

--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -1200,6 +1200,8 @@ static int acpi_processor_setup_lpi_stat
 		state->target_residency = lpi->min_residency;
 		if (lpi->arch_flags)
 			state->flags |= CPUIDLE_FLAG_TIMER_STOP;
+		if (lpi->entry_method == ACPI_CSTATE_FFH)
+			state->flags |= CPUIDLE_FLAG_RCU_IDLE;
 		state->enter = acpi_idle_lpi_enter;
 		drv->safe_state_index = i;
 	}
--- a/drivers/cpuidle/cpuidle-arm.c
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -53,6 +53,7 @@ static struct cpuidle_driver arm_idle_dr
 	 * handler for idle state index 0.
 	 */
 	.states[0] = {
+		.flags			= CPUIDLE_FLAG_RCU_IDLE,
 		.enter                  = arm_enter_idle_state,
 		.exit_latency           = 1,
 		.target_residency       = 1,
--- a/drivers/cpuidle/cpuidle-big_little.c
+++ b/drivers/cpuidle/cpuidle-big_little.c
@@ -64,7 +64,8 @@ static struct cpuidle_driver bl_idle_lit
 		.enter			= bl_enter_powerdown,
 		.exit_latency		= 700,
 		.target_residency	= 2500,
-		.flags			= CPUIDLE_FLAG_TIMER_STOP,
+		.flags			= CPUIDLE_FLAG_TIMER_STOP |
+					  CPUIDLE_FLAG_RCU_IDLE,
 		.name			= "C1",
 		.desc			= "ARM little-cluster power down",
 	},
@@ -85,7 +86,8 @@ static struct cpuidle_driver bl_idle_big
 		.enter			= bl_enter_powerdown,
 		.exit_latency		= 500,
 		.target_residency	= 2000,
-		.flags			= CPUIDLE_FLAG_TIMER_STOP,
+		.flags			= CPUIDLE_FLAG_TIMER_STOP |
+					  CPUIDLE_FLAG_RCU_IDLE,
 		.name			= "C1",
 		.desc			= "ARM big-cluster power down",
 	},
@@ -124,11 +126,13 @@ static int bl_enter_powerdown(struct cpu
 				struct cpuidle_driver *drv, int idx)
 {
 	cpu_pm_enter();
+	ct_idle_enter();
 
 	cpu_suspend(0, bl_powerdown_finisher);
 
 	/* signals the MCPM core that CPU is out of low power state */
 	mcpm_cpu_powered_up();
+	ct_idle_exit();
 
 	cpu_pm_exit();
 
--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -357,6 +357,7 @@ static int psci_idle_init_cpu(struct dev
 	 * PSCI idle states relies on architectural WFI to be represented as
 	 * state index 0.
 	 */
+	drv->states[0].flags = CPUIDLE_FLAG_RCU_IDLE;
 	drv->states[0].enter = psci_enter_idle_state;
 	drv->states[0].exit_latency = 1;
 	drv->states[0].target_residency = 1;
--- a/drivers/cpuidle/cpuidle-qcom-spm.c
+++ b/drivers/cpuidle/cpuidle-qcom-spm.c
@@ -72,6 +72,7 @@ static struct cpuidle_driver qcom_spm_id
 	.owner = THIS_MODULE,
 	.states[0] = {
 		.enter			= spm_enter_idle_state,
+		.flags			= CPUIDLE_FLAG_RCU_IDLE,
 		.exit_latency		= 1,
 		.target_residency	= 1,
 		.power_usage		= UINT_MAX,
--- a/drivers/cpuidle/cpuidle-riscv-sbi.c
+++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
@@ -332,6 +332,7 @@ static int sbi_cpuidle_init_cpu(struct d
 	drv->cpumask = (struct cpumask *)cpumask_of(cpu);
 
 	/* RISC-V architectural WFI to be represented as state index 0. */
+	drv->states[0].flags = CPUIDLE_FLAG_RCU_IDLE;
 	drv->states[0].enter = sbi_cpuidle_enter_state;
 	drv->states[0].exit_latency = 1;
 	drv->states[0].target_residency = 1;
--- a/drivers/cpuidle/dt_idle_states.c
+++ b/drivers/cpuidle/dt_idle_states.c
@@ -77,7 +77,7 @@ static int init_state_node(struct cpuidl
 	if (err)
 		desc = state_node->name;
 
-	idle_state->flags = 0;
+	idle_state->flags = CPUIDLE_FLAG_RCU_IDLE;
 	if (of_property_read_bool(state_node, "local-timer-stop"))
 		idle_state->flags |= CPUIDLE_FLAG_TIMER_STOP;
 	/*
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -282,14 +282,18 @@ extern s64 cpuidle_governor_latency_req(
 	int __ret = 0;							\
 									\
 	if (!idx) {							\
+		ct_idle_enter();					\
 		cpu_do_idle();						\
+		ct_idle_exit();						\
 		return idx;						\
 	}								\
 									\
 	if (!is_retention)						\
 		__ret =  cpu_pm_enter();				\
 	if (!__ret) {							\
+		ct_idle_enter();					\
 		__ret = low_level_idle_enter(state);			\
+		ct_idle_exit();						\
 		if (!is_retention)					\
 			cpu_pm_exit();					\
 	}								\

Re: [PATCH v2 12/44] cpuidle,dt: Push RCU-idle into driver

[Ulf Hansson]

On Mon, 19 Sept 2022 at 12:18, Peter Zijlstra <peterz@infradead.org> wrote:
>
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again before going idle is daft.
>
> Notably: this converts all dt_init_idle_driver() and
> __CPU_PM_CPU_IDLE_ENTER() users for they are inextrably intertwined.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Kind regards
Uffe

> ---
>  arch/arm/mach-omap2/cpuidle34xx.c    |    4 ++--
>  drivers/acpi/processor_idle.c        |    2 ++
>  drivers/cpuidle/cpuidle-arm.c        |    1 +
>  drivers/cpuidle/cpuidle-big_little.c |    8 ++++++--
>  drivers/cpuidle/cpuidle-psci.c       |    1 +
>  drivers/cpuidle/cpuidle-qcom-spm.c   |    1 +
>  drivers/cpuidle/cpuidle-riscv-sbi.c  |    1 +
>  drivers/cpuidle/dt_idle_states.c     |    2 +-
>  include/linux/cpuidle.h              |    4 ++++
>  9 files changed, 19 insertions(+), 5 deletions(-)
>
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -1200,6 +1200,8 @@ static int acpi_processor_setup_lpi_stat
>                 state->target_residency = lpi->min_residency;
>                 if (lpi->arch_flags)
>                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
> +               if (lpi->entry_method == ACPI_CSTATE_FFH)
> +                       state->flags |= CPUIDLE_FLAG_RCU_IDLE;

I assume the state index here will never be 0?

If not, it may lead to that acpi_processor_ffh_lpi_enter() may trigger
CPU_PM_CPU_IDLE_ENTER_PARAM() to call ct_cpuidle_enter|exit() for an
idle-state that doesn't have the CPUIDLE_FLAG_RCU_IDLE bit set.

>                 state->enter = acpi_idle_lpi_enter;
>                 drv->safe_state_index = i;
>         }
> --- a/drivers/cpuidle/cpuidle-arm.c
> +++ b/drivers/cpuidle/cpuidle-arm.c
> @@ -53,6 +53,7 @@ static struct cpuidle_driver arm_idle_dr
>          * handler for idle state index 0.
>          */
>         .states[0] = {
> +               .flags                  = CPUIDLE_FLAG_RCU_IDLE,

Comparing arm64 and arm32 idle-states/idle-drivers, the $subject
series ends up setting the CPUIDLE_FLAG_RCU_IDLE for the ARM WFI idle
state (state zero), but only for the arm64 and psci cases (mostly
arm64). For arm32 we would need to update the ARM_CPUIDLE_WFI_STATE
too, as that is what most arm32 idle-drivers are using. My point is,
the code becomes a bit inconsistent.

Perhaps it's easier to avoid setting the CPUIDLE_FLAG_RCU_IDLE bit for
all of the ARM WFI idle states, for both arm64 and arm32?

>                 .enter                  = arm_enter_idle_state,
>                 .exit_latency           = 1,
>                 .target_residency       = 1,
> --- a/drivers/cpuidle/cpuidle-big_little.c
> +++ b/drivers/cpuidle/cpuidle-big_little.c
> @@ -64,7 +64,8 @@ static struct cpuidle_driver bl_idle_lit
>                 .enter                  = bl_enter_powerdown,
>                 .exit_latency           = 700,
>                 .target_residency       = 2500,
> -               .flags                  = CPUIDLE_FLAG_TIMER_STOP,
> +               .flags                  = CPUIDLE_FLAG_TIMER_STOP |
> +                                         CPUIDLE_FLAG_RCU_IDLE,
>                 .name                   = "C1",
>                 .desc                   = "ARM little-cluster power down",
>         },
> @@ -85,7 +86,8 @@ static struct cpuidle_driver bl_idle_big
>                 .enter                  = bl_enter_powerdown,
>                 .exit_latency           = 500,
>                 .target_residency       = 2000,
> -               .flags                  = CPUIDLE_FLAG_TIMER_STOP,
> +               .flags                  = CPUIDLE_FLAG_TIMER_STOP |
> +                                         CPUIDLE_FLAG_RCU_IDLE,
>                 .name                   = "C1",
>                 .desc                   = "ARM big-cluster power down",
>         },
> @@ -124,11 +126,13 @@ static int bl_enter_powerdown(struct cpu
>                                 struct cpuidle_driver *drv, int idx)
>  {
>         cpu_pm_enter();
> +       ct_idle_enter();
>
>         cpu_suspend(0, bl_powerdown_finisher);
>
>         /* signals the MCPM core that CPU is out of low power state */
>         mcpm_cpu_powered_up();
> +       ct_idle_exit();
>
>         cpu_pm_exit();
>
> --- a/drivers/cpuidle/cpuidle-psci.c
> +++ b/drivers/cpuidle/cpuidle-psci.c
> @@ -357,6 +357,7 @@ static int psci_idle_init_cpu(struct dev
>          * PSCI idle states relies on architectural WFI to be represented as
>          * state index 0.
>          */
> +       drv->states[0].flags = CPUIDLE_FLAG_RCU_IDLE;
>         drv->states[0].enter = psci_enter_idle_state;
>         drv->states[0].exit_latency = 1;
>         drv->states[0].target_residency = 1;
> --- a/drivers/cpuidle/cpuidle-qcom-spm.c
> +++ b/drivers/cpuidle/cpuidle-qcom-spm.c
> @@ -72,6 +72,7 @@ static struct cpuidle_driver qcom_spm_id
>         .owner = THIS_MODULE,
>         .states[0] = {
>                 .enter                  = spm_enter_idle_state,
> +               .flags                  = CPUIDLE_FLAG_RCU_IDLE,
>                 .exit_latency           = 1,
>                 .target_residency       = 1,
>                 .power_usage            = UINT_MAX,
> --- a/drivers/cpuidle/cpuidle-riscv-sbi.c
> +++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
> @@ -332,6 +332,7 @@ static int sbi_cpuidle_init_cpu(struct d
>         drv->cpumask = (struct cpumask *)cpumask_of(cpu);
>
>         /* RISC-V architectural WFI to be represented as state index 0. */
> +       drv->states[0].flags = CPUIDLE_FLAG_RCU_IDLE;
>         drv->states[0].enter = sbi_cpuidle_enter_state;
>         drv->states[0].exit_latency = 1;
>         drv->states[0].target_residency = 1;
> --- a/drivers/cpuidle/dt_idle_states.c
> +++ b/drivers/cpuidle/dt_idle_states.c
> @@ -77,7 +77,7 @@ static int init_state_node(struct cpuidl
>         if (err)
>                 desc = state_node->name;
>
> -       idle_state->flags = 0;
> +       idle_state->flags = CPUIDLE_FLAG_RCU_IDLE;
>         if (of_property_read_bool(state_node, "local-timer-stop"))
>                 idle_state->flags |= CPUIDLE_FLAG_TIMER_STOP;
>         /*
> --- a/include/linux/cpuidle.h
> +++ b/include/linux/cpuidle.h
> @@ -282,14 +282,18 @@ extern s64 cpuidle_governor_latency_req(
>         int __ret = 0;                                                  \
>                                                                         \
>         if (!idx) {                                                     \
> +               ct_idle_enter();                                        \

According to my comment above, we should then drop these calls to
ct_idle_enter and ct_idle_exit() here. Right?

>                 cpu_do_idle();                                          \
> +               ct_idle_exit();                                         \
>                 return idx;                                             \
>         }                                                               \
>                                                                         \
>         if (!is_retention)                                              \
>                 __ret =  cpu_pm_enter();                                \
>         if (!__ret) {                                                   \
> +               ct_idle_enter();                                        \
>                 __ret = low_level_idle_enter(state);                    \
> +               ct_idle_exit();                                         \
>                 if (!is_retention)                                      \
>                         cpu_pm_exit();                                  \
>         }                                                               \
>

Kind regards
Uffe

Re: [PATCH v2 12/44] cpuidle,dt: Push RCU-idle into driver

[Ulf Hansson]

On Tue, 4 Oct 2022 at 13:03, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> On Mon, 19 Sept 2022 at 12:18, Peter Zijlstra <peterz@infradead.org> wrote:
> >
> > Doing RCU-idle outside the driver, only to then temporarily enable it
> > again before going idle is daft.
> >
> > Notably: this converts all dt_init_idle_driver() and
> > __CPU_PM_CPU_IDLE_ENTER() users for they are inextrably intertwined.
> >
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
>
> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

This was not (yet) my intention. Please have a look at the comments I
provided below.

Kind regards
Uffe

>
> > ---
> >  arch/arm/mach-omap2/cpuidle34xx.c    |    4 ++--
> >  drivers/acpi/processor_idle.c        |    2 ++
> >  drivers/cpuidle/cpuidle-arm.c        |    1 +
> >  drivers/cpuidle/cpuidle-big_little.c |    8 ++++++--
> >  drivers/cpuidle/cpuidle-psci.c       |    1 +
> >  drivers/cpuidle/cpuidle-qcom-spm.c   |    1 +
> >  drivers/cpuidle/cpuidle-riscv-sbi.c  |    1 +
> >  drivers/cpuidle/dt_idle_states.c     |    2 +-
> >  include/linux/cpuidle.h              |    4 ++++
> >  9 files changed, 19 insertions(+), 5 deletions(-)
> >
> > --- a/drivers/acpi/processor_idle.c
> > +++ b/drivers/acpi/processor_idle.c
> > @@ -1200,6 +1200,8 @@ static int acpi_processor_setup_lpi_stat
> >                 state->target_residency = lpi->min_residency;
> >                 if (lpi->arch_flags)
> >                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
> > +               if (lpi->entry_method == ACPI_CSTATE_FFH)
> > +                       state->flags |= CPUIDLE_FLAG_RCU_IDLE;
>
> I assume the state index here will never be 0?
>
> If not, it may lead to that acpi_processor_ffh_lpi_enter() may trigger
> CPU_PM_CPU_IDLE_ENTER_PARAM() to call ct_cpuidle_enter|exit() for an
> idle-state that doesn't have the CPUIDLE_FLAG_RCU_IDLE bit set.
>
> >                 state->enter = acpi_idle_lpi_enter;
> >                 drv->safe_state_index = i;
> >         }
> > --- a/drivers/cpuidle/cpuidle-arm.c
> > +++ b/drivers/cpuidle/cpuidle-arm.c
> > @@ -53,6 +53,7 @@ static struct cpuidle_driver arm_idle_dr
> >          * handler for idle state index 0.
> >          */
> >         .states[0] = {
> > +               .flags                  = CPUIDLE_FLAG_RCU_IDLE,
>
> Comparing arm64 and arm32 idle-states/idle-drivers, the $subject
> series ends up setting the CPUIDLE_FLAG_RCU_IDLE for the ARM WFI idle
> state (state zero), but only for the arm64 and psci cases (mostly
> arm64). For arm32 we would need to update the ARM_CPUIDLE_WFI_STATE
> too, as that is what most arm32 idle-drivers are using. My point is,
> the code becomes a bit inconsistent.
>
> Perhaps it's easier to avoid setting the CPUIDLE_FLAG_RCU_IDLE bit for
> all of the ARM WFI idle states, for both arm64 and arm32?
>
> >                 .enter                  = arm_enter_idle_state,
> >                 .exit_latency           = 1,
> >                 .target_residency       = 1,
> > --- a/drivers/cpuidle/cpuidle-big_little.c
> > +++ b/drivers/cpuidle/cpuidle-big_little.c
> > @@ -64,7 +64,8 @@ static struct cpuidle_driver bl_idle_lit
> >                 .enter                  = bl_enter_powerdown,
> >                 .exit_latency           = 700,
> >                 .target_residency       = 2500,
> > -               .flags                  = CPUIDLE_FLAG_TIMER_STOP,
> > +               .flags                  = CPUIDLE_FLAG_TIMER_STOP |
> > +                                         CPUIDLE_FLAG_RCU_IDLE,
> >                 .name                   = "C1",
> >                 .desc                   = "ARM little-cluster power down",
> >         },
> > @@ -85,7 +86,8 @@ static struct cpuidle_driver bl_idle_big
> >                 .enter                  = bl_enter_powerdown,
> >                 .exit_latency           = 500,
> >                 .target_residency       = 2000,
> > -               .flags                  = CPUIDLE_FLAG_TIMER_STOP,
> > +               .flags                  = CPUIDLE_FLAG_TIMER_STOP |
> > +                                         CPUIDLE_FLAG_RCU_IDLE,
> >                 .name                   = "C1",
> >                 .desc                   = "ARM big-cluster power down",
> >         },
> > @@ -124,11 +126,13 @@ static int bl_enter_powerdown(struct cpu
> >                                 struct cpuidle_driver *drv, int idx)
> >  {
> >         cpu_pm_enter();
> > +       ct_idle_enter();
> >
> >         cpu_suspend(0, bl_powerdown_finisher);
> >
> >         /* signals the MCPM core that CPU is out of low power state */
> >         mcpm_cpu_powered_up();
> > +       ct_idle_exit();
> >
> >         cpu_pm_exit();
> >
> > --- a/drivers/cpuidle/cpuidle-psci.c
> > +++ b/drivers/cpuidle/cpuidle-psci.c
> > @@ -357,6 +357,7 @@ static int psci_idle_init_cpu(struct dev
> >          * PSCI idle states relies on architectural WFI to be represented as
> >          * state index 0.
> >          */
> > +       drv->states[0].flags = CPUIDLE_FLAG_RCU_IDLE;
> >         drv->states[0].enter = psci_enter_idle_state;
> >         drv->states[0].exit_latency = 1;
> >         drv->states[0].target_residency = 1;
> > --- a/drivers/cpuidle/cpuidle-qcom-spm.c
> > +++ b/drivers/cpuidle/cpuidle-qcom-spm.c
> > @@ -72,6 +72,7 @@ static struct cpuidle_driver qcom_spm_id
> >         .owner = THIS_MODULE,
> >         .states[0] = {
> >                 .enter                  = spm_enter_idle_state,
> > +               .flags                  = CPUIDLE_FLAG_RCU_IDLE,
> >                 .exit_latency           = 1,
> >                 .target_residency       = 1,
> >                 .power_usage            = UINT_MAX,
> > --- a/drivers/cpuidle/cpuidle-riscv-sbi.c
> > +++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
> > @@ -332,6 +332,7 @@ static int sbi_cpuidle_init_cpu(struct d
> >         drv->cpumask = (struct cpumask *)cpumask_of(cpu);
> >
> >         /* RISC-V architectural WFI to be represented as state index 0. */
> > +       drv->states[0].flags = CPUIDLE_FLAG_RCU_IDLE;
> >         drv->states[0].enter = sbi_cpuidle_enter_state;
> >         drv->states[0].exit_latency = 1;
> >         drv->states[0].target_residency = 1;
> > --- a/drivers/cpuidle/dt_idle_states.c
> > +++ b/drivers/cpuidle/dt_idle_states.c
> > @@ -77,7 +77,7 @@ static int init_state_node(struct cpuidl
> >         if (err)
> >                 desc = state_node->name;
> >
> > -       idle_state->flags = 0;
> > +       idle_state->flags = CPUIDLE_FLAG_RCU_IDLE;
> >         if (of_property_read_bool(state_node, "local-timer-stop"))
> >                 idle_state->flags |= CPUIDLE_FLAG_TIMER_STOP;
> >         /*
> > --- a/include/linux/cpuidle.h
> > +++ b/include/linux/cpuidle.h
> > @@ -282,14 +282,18 @@ extern s64 cpuidle_governor_latency_req(
> >         int __ret = 0;                                                  \
> >                                                                         \
> >         if (!idx) {                                                     \
> > +               ct_idle_enter();                                        \
>
> According to my comment above, we should then drop these calls to
> ct_idle_enter and ct_idle_exit() here. Right?
>
> >                 cpu_do_idle();                                          \
> > +               ct_idle_exit();                                         \
> >                 return idx;                                             \
> >         }                                                               \
> >                                                                         \
> >         if (!is_retention)                                              \
> >                 __ret =  cpu_pm_enter();                                \
> >         if (!__ret) {                                                   \
> > +               ct_idle_enter();                                        \
> >                 __ret = low_level_idle_enter(state);                    \
> > +               ct_idle_exit();                                         \
> >                 if (!is_retention)                                      \
> >                         cpu_pm_exit();                                  \
> >         }                                                               \
> >
>
> Kind regards
> Uffe

Re: [PATCH v2 12/44] cpuidle,dt: Push RCU-idle into driver

[Peter Zijlstra]

Sorry; things keep getting in the way of finishing this :/

As such, I need a bit of time to get on-track again..

On Tue, Oct 04, 2022 at 01:03:57PM +0200, Ulf Hansson wrote:

> > --- a/drivers/acpi/processor_idle.c
> > +++ b/drivers/acpi/processor_idle.c
> > @@ -1200,6 +1200,8 @@ static int acpi_processor_setup_lpi_stat
> >                 state->target_residency = lpi->min_residency;
> >                 if (lpi->arch_flags)
> >                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
> > +               if (lpi->entry_method == ACPI_CSTATE_FFH)
> > +                       state->flags |= CPUIDLE_FLAG_RCU_IDLE;
> 
> I assume the state index here will never be 0?
> 
> If not, it may lead to that acpi_processor_ffh_lpi_enter() may trigger
> CPU_PM_CPU_IDLE_ENTER_PARAM() to call ct_cpuidle_enter|exit() for an
> idle-state that doesn't have the CPUIDLE_FLAG_RCU_IDLE bit set.

I'm not quite sure I see how. AFAICT this condition above implies
acpi_processor_ffh_lpi_enter() gets called, no?

Which in turn is an unconditional __CPU_PM_CPU_IDLE_ENTER() user, so
even if idx==0, it ends up in ct_idle_{enter,exit}().

> 
> >                 state->enter = acpi_idle_lpi_enter;
> >                 drv->safe_state_index = i;
> >         }
> > --- a/drivers/cpuidle/cpuidle-arm.c
> > +++ b/drivers/cpuidle/cpuidle-arm.c
> > @@ -53,6 +53,7 @@ static struct cpuidle_driver arm_idle_dr
> >          * handler for idle state index 0.
> >          */
> >         .states[0] = {
> > +               .flags                  = CPUIDLE_FLAG_RCU_IDLE,
> 
> Comparing arm64 and arm32 idle-states/idle-drivers, the $subject
> series ends up setting the CPUIDLE_FLAG_RCU_IDLE for the ARM WFI idle
> state (state zero), but only for the arm64 and psci cases (mostly
> arm64). For arm32 we would need to update the ARM_CPUIDLE_WFI_STATE
> too, as that is what most arm32 idle-drivers are using. My point is,
> the code becomes a bit inconsistent.

True.

> Perhaps it's easier to avoid setting the CPUIDLE_FLAG_RCU_IDLE bit for
> all of the ARM WFI idle states, for both arm64 and arm32?

As per the below?

> 
> >                 .enter                  = arm_enter_idle_state,
> >                 .exit_latency           = 1,
> >                 .target_residency       = 1,

> > --- a/include/linux/cpuidle.h
> > +++ b/include/linux/cpuidle.h
> > @@ -282,14 +282,18 @@ extern s64 cpuidle_governor_latency_req(
> >         int __ret = 0;                                                  \
> >                                                                         \
> >         if (!idx) {                                                     \
> > +               ct_idle_enter();                                        \
> 
> According to my comment above, we should then drop these calls to
> ct_idle_enter and ct_idle_exit() here. Right?

Yes, if we ensure idx==0 never has RCU_IDLE set then these must be
removed.

> >                 cpu_do_idle();                                          \
> > +               ct_idle_exit();                                         \
> >                 return idx;                                             \
> >         }                                                               \
> >                                                                         \
> >         if (!is_retention)                                              \
> >                 __ret =  cpu_pm_enter();                                \
> >         if (!__ret) {                                                   \
> > +               ct_idle_enter();                                        \
> >                 __ret = low_level_idle_enter(state);                    \
> > +               ct_idle_exit();                                         \
> >                 if (!is_retention)                                      \
> >                         cpu_pm_exit();                                  \
> >         }                                                               \
> >

So the basic premise is that everything that needs RCU inside the idle
callback must set CPUIDLE_FLAG_RCU_IDLE and by doing that promise to
call ct_idle_{enter,exit}() themselves.

Setting RCU_IDLE is required when there is RCU usage, however even if
there is no RCU usage, setting RCU_IDLE is fine, as long as
ct_idle_{enter,exit}() then get called.


So does the below (delta) look better to you?

--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -1218,7 +1218,7 @@ static int acpi_processor_setup_lpi_stat
 		state->target_residency = lpi->min_residency;
 		if (lpi->arch_flags)
 			state->flags |= CPUIDLE_FLAG_TIMER_STOP;
-		if (lpi->entry_method == ACPI_CSTATE_FFH)
+		if (i != 0 && lpi->entry_method == ACPI_CSTATE_FFH)
 			state->flags |= CPUIDLE_FLAG_RCU_IDLE;
 		state->enter = acpi_idle_lpi_enter;
 		drv->safe_state_index = i;
--- a/drivers/cpuidle/cpuidle-arm.c
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -53,7 +53,7 @@ static struct cpuidle_driver arm_idle_dr
 	 * handler for idle state index 0.
 	 */
 	.states[0] = {
-		.flags			= CPUIDLE_FLAG_RCU_IDLE,
+		.flags			= 0,
 		.enter                  = arm_enter_idle_state,
 		.exit_latency           = 1,
 		.target_residency       = 1,
--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -357,7 +357,7 @@ static int psci_idle_init_cpu(struct dev
 	 * PSCI idle states relies on architectural WFI to be represented as
 	 * state index 0.
 	 */
-	drv->states[0].flags = CPUIDLE_FLAG_RCU_IDLE;
+	drv->states[0].flags = 0;
 	drv->states[0].enter = psci_enter_idle_state;
 	drv->states[0].exit_latency = 1;
 	drv->states[0].target_residency = 1;
--- a/drivers/cpuidle/cpuidle-qcom-spm.c
+++ b/drivers/cpuidle/cpuidle-qcom-spm.c
@@ -72,7 +72,7 @@ static struct cpuidle_driver qcom_spm_id
 	.owner = THIS_MODULE,
 	.states[0] = {
 		.enter			= spm_enter_idle_state,
-		.flags			= CPUIDLE_FLAG_RCU_IDLE,
+		.flags			= 0,
 		.exit_latency		= 1,
 		.target_residency	= 1,
 		.power_usage		= UINT_MAX,
--- a/drivers/cpuidle/cpuidle-riscv-sbi.c
+++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
@@ -337,7 +337,7 @@ static int sbi_cpuidle_init_cpu(struct d
 	drv->cpumask = (struct cpumask *)cpumask_of(cpu);
 
 	/* RISC-V architectural WFI to be represented as state index 0. */
-	drv->states[0].flags = CPUIDLE_FLAG_RCU_IDLE;
+	drv->states[0].flags = 0;
 	drv->states[0].enter = sbi_cpuidle_enter_state;
 	drv->states[0].exit_latency = 1;
 	drv->states[0].target_residency = 1;
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -282,9 +282,7 @@ extern s64 cpuidle_governor_latency_req(
 	int __ret = 0;							\
 									\
 	if (!idx) {							\
-		ct_idle_enter();					\
 		cpu_do_idle();						\
-		ct_idle_exit();						\
 		return idx;						\
 	}								\
 									\

Re: [PATCH v2 12/44] cpuidle,dt: Push RCU-idle into driver

[Ulf Hansson]

On Wed, 16 Nov 2022 at 16:29, Peter Zijlstra <peterz@infradead.org> wrote:
>
>
> Sorry; things keep getting in the way of finishing this :/
>
> As such, I need a bit of time to get on-track again..
>
> On Tue, Oct 04, 2022 at 01:03:57PM +0200, Ulf Hansson wrote:
>
> > > --- a/drivers/acpi/processor_idle.c
> > > +++ b/drivers/acpi/processor_idle.c
> > > @@ -1200,6 +1200,8 @@ static int acpi_processor_setup_lpi_stat
> > >                 state->target_residency = lpi->min_residency;
> > >                 if (lpi->arch_flags)
> > >                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
> > > +               if (lpi->entry_method == ACPI_CSTATE_FFH)
> > > +                       state->flags |= CPUIDLE_FLAG_RCU_IDLE;
> >
> > I assume the state index here will never be 0?
> >
> > If not, it may lead to that acpi_processor_ffh_lpi_enter() may trigger
> > CPU_PM_CPU_IDLE_ENTER_PARAM() to call ct_cpuidle_enter|exit() for an
> > idle-state that doesn't have the CPUIDLE_FLAG_RCU_IDLE bit set.
>
> I'm not quite sure I see how. AFAICT this condition above implies
> acpi_processor_ffh_lpi_enter() gets called, no?
>
> Which in turn is an unconditional __CPU_PM_CPU_IDLE_ENTER() user, so
> even if idx==0, it ends up in ct_idle_{enter,exit}().

Seems like I was overlooking something here, you are right, this
shouldn't really be a problem.

>
> >
> > >                 state->enter = acpi_idle_lpi_enter;
> > >                 drv->safe_state_index = i;
> > >         }
> > > --- a/drivers/cpuidle/cpuidle-arm.c
> > > +++ b/drivers/cpuidle/cpuidle-arm.c
> > > @@ -53,6 +53,7 @@ static struct cpuidle_driver arm_idle_dr
> > >          * handler for idle state index 0.
> > >          */
> > >         .states[0] = {
> > > +               .flags                  = CPUIDLE_FLAG_RCU_IDLE,
> >
> > Comparing arm64 and arm32 idle-states/idle-drivers, the $subject
> > series ends up setting the CPUIDLE_FLAG_RCU_IDLE for the ARM WFI idle
> > state (state zero), but only for the arm64 and psci cases (mostly
> > arm64). For arm32 we would need to update the ARM_CPUIDLE_WFI_STATE
> > too, as that is what most arm32 idle-drivers are using. My point is,
> > the code becomes a bit inconsistent.
>
> True.
>
> > Perhaps it's easier to avoid setting the CPUIDLE_FLAG_RCU_IDLE bit for
> > all of the ARM WFI idle states, for both arm64 and arm32?
>
> As per the below?
>
> >
> > >                 .enter                  = arm_enter_idle_state,
> > >                 .exit_latency           = 1,
> > >                 .target_residency       = 1,
>
> > > --- a/include/linux/cpuidle.h
> > > +++ b/include/linux/cpuidle.h
> > > @@ -282,14 +282,18 @@ extern s64 cpuidle_governor_latency_req(
> > >         int __ret = 0;                                                  \
> > >                                                                         \
> > >         if (!idx) {                                                     \
> > > +               ct_idle_enter();                                        \
> >
> > According to my comment above, we should then drop these calls to
> > ct_idle_enter and ct_idle_exit() here. Right?
>
> Yes, if we ensure idx==0 never has RCU_IDLE set then these must be
> removed.
>
> > >                 cpu_do_idle();                                          \
> > > +               ct_idle_exit();                                         \
> > >                 return idx;                                             \
> > >         }                                                               \
> > >                                                                         \
> > >         if (!is_retention)                                              \
> > >                 __ret =  cpu_pm_enter();                                \
> > >         if (!__ret) {                                                   \
> > > +               ct_idle_enter();                                        \
> > >                 __ret = low_level_idle_enter(state);                    \
> > > +               ct_idle_exit();                                         \
> > >                 if (!is_retention)                                      \
> > >                         cpu_pm_exit();                                  \
> > >         }                                                               \
> > >
>
> So the basic premise is that everything that needs RCU inside the idle
> callback must set CPUIDLE_FLAG_RCU_IDLE and by doing that promise to
> call ct_idle_{enter,exit}() themselves.
>
> Setting RCU_IDLE is required when there is RCU usage, however even if
> there is no RCU usage, setting RCU_IDLE is fine, as long as
> ct_idle_{enter,exit}() then get called.

Right, I was thinking that it could make sense to shrink the window
for users getting this wrong. In other words, we shouldn't set the
CPUIDLE_FLAG_RCU_IDLE unless we really need to.

And as I said, consistent behaviour is also nice to have.

>
>
> So does the below (delta) look better to you?

Yes, it does!

Although, one minor comment below.

>
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -1218,7 +1218,7 @@ static int acpi_processor_setup_lpi_stat
>                 state->target_residency = lpi->min_residency;
>                 if (lpi->arch_flags)
>                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
> -               if (lpi->entry_method == ACPI_CSTATE_FFH)
> +               if (i != 0 && lpi->entry_method == ACPI_CSTATE_FFH)
>                         state->flags |= CPUIDLE_FLAG_RCU_IDLE;
>                 state->enter = acpi_idle_lpi_enter;
>                 drv->safe_state_index = i;
> --- a/drivers/cpuidle/cpuidle-arm.c
> +++ b/drivers/cpuidle/cpuidle-arm.c
> @@ -53,7 +53,7 @@ static struct cpuidle_driver arm_idle_dr
>          * handler for idle state index 0.
>          */
>         .states[0] = {
> -               .flags                  = CPUIDLE_FLAG_RCU_IDLE,
> +               .flags                  = 0,

Nitpick: I don't think we need to explicitly clear the flag, as it
should already be zeroed by the compiler from its static declaration.
Right?

>                 .enter                  = arm_enter_idle_state,
>                 .exit_latency           = 1,
>                 .target_residency       = 1,
> --- a/drivers/cpuidle/cpuidle-psci.c
> +++ b/drivers/cpuidle/cpuidle-psci.c
> @@ -357,7 +357,7 @@ static int psci_idle_init_cpu(struct dev
>          * PSCI idle states relies on architectural WFI to be represented as
>          * state index 0.
>          */
> -       drv->states[0].flags = CPUIDLE_FLAG_RCU_IDLE;
> +       drv->states[0].flags = 0;
>         drv->states[0].enter = psci_enter_idle_state;
>         drv->states[0].exit_latency = 1;
>         drv->states[0].target_residency = 1;
> --- a/drivers/cpuidle/cpuidle-qcom-spm.c
> +++ b/drivers/cpuidle/cpuidle-qcom-spm.c
> @@ -72,7 +72,7 @@ static struct cpuidle_driver qcom_spm_id
>         .owner = THIS_MODULE,
>         .states[0] = {
>                 .enter                  = spm_enter_idle_state,
> -               .flags                  = CPUIDLE_FLAG_RCU_IDLE,
> +               .flags                  = 0,
>                 .exit_latency           = 1,
>                 .target_residency       = 1,
>                 .power_usage            = UINT_MAX,
> --- a/drivers/cpuidle/cpuidle-riscv-sbi.c
> +++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
> @@ -337,7 +337,7 @@ static int sbi_cpuidle_init_cpu(struct d
>         drv->cpumask = (struct cpumask *)cpumask_of(cpu);
>
>         /* RISC-V architectural WFI to be represented as state index 0. */
> -       drv->states[0].flags = CPUIDLE_FLAG_RCU_IDLE;
> +       drv->states[0].flags = 0;
>         drv->states[0].enter = sbi_cpuidle_enter_state;
>         drv->states[0].exit_latency = 1;
>         drv->states[0].target_residency = 1;
> --- a/include/linux/cpuidle.h
> +++ b/include/linux/cpuidle.h
> @@ -282,9 +282,7 @@ extern s64 cpuidle_governor_latency_req(
>         int __ret = 0;                                                  \
>                                                                         \
>         if (!idx) {                                                     \
> -               ct_idle_enter();                                        \
>                 cpu_do_idle();                                          \
> -               ct_idle_exit();                                         \
>                 return idx;                                             \
>         }                                                               \
>                                                                         \

Kind regards
Uffe

[PATCH v2 13/44] cpuidle: Fix ct_idle_*() usage

[Peter Zijlstra]

The whole disable-RCU, enable-IRQS dance is very intricate since
changing IRQ state is traced, which depends on RCU.

Add two helpers for the cpuidle case that mirror the entry code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/arm/mach-imx/cpuidle-imx6q.c    |    4 +--
 arch/arm/mach-imx/cpuidle-imx6sx.c   |    4 +--
 arch/arm/mach-omap2/cpuidle34xx.c    |    4 +--
 arch/arm/mach-omap2/cpuidle44xx.c    |    8 +++---
 drivers/acpi/processor_idle.c        |    8 ++++--
 drivers/cpuidle/cpuidle-big_little.c |    4 +--
 drivers/cpuidle/cpuidle-mvebu-v7.c   |    4 +--
 drivers/cpuidle/cpuidle-psci.c       |    4 +--
 drivers/cpuidle/cpuidle-riscv-sbi.c  |    4 +--
 drivers/cpuidle/cpuidle-tegra.c      |    8 +++---
 drivers/cpuidle/cpuidle.c            |   11 ++++----
 include/linux/cpuidle.h              |   38 ++++++++++++++++++++++++++---
 kernel/sched/idle.c                  |   45 ++++++++++-------------------------
 kernel/time/tick-broadcast.c         |    6 +++-
 14 files changed, 86 insertions(+), 66 deletions(-)

--- a/arch/arm/mach-imx/cpuidle-imx6q.c
+++ b/arch/arm/mach-imx/cpuidle-imx6q.c
@@ -25,9 +25,9 @@ static int imx6q_enter_wait(struct cpuid
 		imx6_set_lpm(WAIT_UNCLOCKED);
 	raw_spin_unlock(&cpuidle_lock);
 
-	ct_idle_enter();
+	ct_cpuidle_enter();
 	cpu_do_idle();
-	ct_idle_exit();
+	ct_cpuidle_exit();
 
 	raw_spin_lock(&cpuidle_lock);
 	if (num_idle_cpus-- == num_online_cpus())
--- a/arch/arm/mach-imx/cpuidle-imx6sx.c
+++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
@@ -47,9 +47,9 @@ static int imx6sx_enter_wait(struct cpui
 		cpu_pm_enter();
 		cpu_cluster_pm_enter();
 
-		ct_idle_enter();
+		ct_cpuidle_enter();
 		cpu_suspend(0, imx6sx_idle_finish);
-		ct_idle_exit();
+		ct_cpuidle_exit();
 
 		cpu_cluster_pm_exit();
 		cpu_pm_exit();
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -133,9 +133,9 @@ static int omap3_enter_idle(struct cpuid
 	}
 
 	/* Execute ARM wfi */
-	ct_idle_enter();
+	ct_cpuidle_enter();
 	omap_sram_idle();
-	ct_idle_exit();
+	ct_cpuidle_exit();
 
 	/*
 	 * Call idle CPU PM enter notifier chain to restore
--- a/arch/arm/mach-omap2/cpuidle44xx.c
+++ b/arch/arm/mach-omap2/cpuidle44xx.c
@@ -105,9 +105,9 @@ static int omap_enter_idle_smp(struct cp
 	}
 	raw_spin_unlock_irqrestore(&mpu_lock, flag);
 
-	ct_idle_enter();
+	ct_cpuidle_enter();
 	omap4_enter_lowpower(dev->cpu, cx->cpu_state);
-	ct_idle_exit();
+	ct_cpuidle_exit();
 
 	raw_spin_lock_irqsave(&mpu_lock, flag);
 	if (cx->mpu_state_vote == num_online_cpus())
@@ -186,10 +186,10 @@ static int omap_enter_idle_coupled(struc
 		}
 	}
 
-	ct_idle_enter();
+	ct_cpuidle_enter();
 	omap4_enter_lowpower(dev->cpu, cx->cpu_state);
 	cpu_done[dev->cpu] = true;
-	ct_idle_exit();
+	ct_cpuidle_exit();
 
 	/* Wakeup CPU1 only if it is not offlined */
 	if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -627,6 +627,8 @@ static int __cpuidle acpi_idle_enter_bm(
 	 */
 	bool dis_bm = pr->flags.bm_control;
 
+	instrumentation_begin();
+
 	/* If we can skip BM, demote to a safe state. */
 	if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
 		dis_bm = false;
@@ -648,11 +650,11 @@ static int __cpuidle acpi_idle_enter_bm(
 		raw_spin_unlock(&c3_lock);
 	}
 
-	ct_idle_enter();
+	ct_cpuidle_enter();
 
 	acpi_idle_do_entry(cx);
 
-	ct_idle_exit();
+	ct_cpuidle_exit();
 
 	/* Re-enable bus master arbitration */
 	if (dis_bm) {
@@ -662,6 +664,8 @@ static int __cpuidle acpi_idle_enter_bm(
 		raw_spin_unlock(&c3_lock);
 	}
 
+	instrumentation_end();
+
 	return index;
 }
 
--- a/drivers/cpuidle/cpuidle-big_little.c
+++ b/drivers/cpuidle/cpuidle-big_little.c
@@ -126,13 +126,13 @@ static int bl_enter_powerdown(struct cpu
 				struct cpuidle_driver *drv, int idx)
 {
 	cpu_pm_enter();
-	ct_idle_enter();
+	ct_cpuidle_enter();
 
 	cpu_suspend(0, bl_powerdown_finisher);
 
 	/* signals the MCPM core that CPU is out of low power state */
 	mcpm_cpu_powered_up();
-	ct_idle_exit();
+	ct_cpuidle_exit();
 
 	cpu_pm_exit();
 
--- a/drivers/cpuidle/cpuidle-mvebu-v7.c
+++ b/drivers/cpuidle/cpuidle-mvebu-v7.c
@@ -36,9 +36,9 @@ static int mvebu_v7_enter_idle(struct cp
 	if (drv->states[index].flags & MVEBU_V7_FLAG_DEEP_IDLE)
 		deepidle = true;
 
-	ct_idle_enter();
+	ct_cpuidle_enter();
 	ret = mvebu_v7_cpu_suspend(deepidle);
-	ct_idle_exit();
+	ct_cpuidle_exit();
 
 	cpu_pm_exit();
 
--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -74,7 +74,7 @@ static int __psci_enter_domain_idle_stat
 	else
 		pm_runtime_put_sync_suspend(pd_dev);
 
-	ct_idle_enter();
+	ct_cpuidle_enter();
 
 	state = psci_get_domain_state();
 	if (!state)
@@ -82,7 +82,7 @@ static int __psci_enter_domain_idle_stat
 
 	ret = psci_cpu_suspend_enter(state) ? -1 : idx;
 
-	ct_idle_exit();
+	ct_cpuidle_exit();
 
 	if (s2idle)
 		dev_pm_genpd_resume(pd_dev);
--- a/drivers/cpuidle/cpuidle-riscv-sbi.c
+++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
@@ -121,7 +121,7 @@ static int __sbi_enter_domain_idle_state
 	else
 		pm_runtime_put_sync_suspend(pd_dev);
 
-	ct_idle_enter();
+	ct_cpuidle_enter();
 
 	if (sbi_is_domain_state_available())
 		state = sbi_get_domain_state();
@@ -130,7 +130,7 @@ static int __sbi_enter_domain_idle_state
 
 	ret = sbi_suspend(state) ? -1 : idx;
 
-	ct_idle_exit();
+	ct_cpuidle_exit();
 
 	if (s2idle)
 		dev_pm_genpd_resume(pd_dev);
--- a/drivers/cpuidle/cpuidle-tegra.c
+++ b/drivers/cpuidle/cpuidle-tegra.c
@@ -183,7 +183,7 @@ static int tegra_cpuidle_state_enter(str
 	tegra_pm_set_cpu_in_lp2();
 	cpu_pm_enter();
 
-	ct_idle_enter();
+	ct_cpuidle_enter();
 
 	switch (index) {
 	case TEGRA_C7:
@@ -199,7 +199,7 @@ static int tegra_cpuidle_state_enter(str
 		break;
 	}
 
-	ct_idle_exit();
+	ct_cpuidle_exit();
 
 	cpu_pm_exit();
 	tegra_pm_clear_cpu_in_lp2();
@@ -240,10 +240,10 @@ static int tegra_cpuidle_enter(struct cp
 
 	if (index == TEGRA_C1) {
 		if (do_rcu)
-			ct_idle_enter();
+			ct_cpuidle_enter();
 		ret = arm_cpuidle_simple_enter(dev, drv, index);
 		if (do_rcu)
-			ct_idle_exit();
+			ct_cpuidle_exit();
 	} else
 		ret = tegra_cpuidle_state_enter(dev, index, cpu);
 
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -14,6 +14,7 @@
 #include <linux/mutex.h>
 #include <linux/sched.h>
 #include <linux/sched/clock.h>
+#include <linux/sched/idle.h>
 #include <linux/notifier.h>
 #include <linux/pm_qos.h>
 #include <linux/cpu.h>
@@ -152,12 +153,12 @@ static void enter_s2idle_proper(struct c
 	 */
 	stop_critical_timings();
 	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
-		ct_idle_enter();
+		ct_cpuidle_enter();
 	target_state->enter_s2idle(dev, drv, index);
 	if (WARN_ON_ONCE(!irqs_disabled()))
-		local_irq_disable();
+		raw_local_irq_disable();
 	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
-		ct_idle_exit();
+		ct_cpuidle_exit();
 	tick_unfreeze();
 	start_critical_timings();
 
@@ -235,14 +236,14 @@ int cpuidle_enter_state(struct cpuidle_d
 
 	stop_critical_timings();
 	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
-		ct_idle_enter();
+		ct_cpuidle_enter();
 
 	entered_state = target_state->enter(dev, drv, index);
 	if (WARN_ONCE(!irqs_disabled(), "%ps leaked IRQ state", target_state->enter))
 		raw_local_irq_disable();
 
 	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
-		ct_idle_exit();
+		ct_cpuidle_exit();
 	start_critical_timings();
 
 	sched_clock_idle_wakeup_event();
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -14,6 +14,7 @@
 #include <linux/percpu.h>
 #include <linux/list.h>
 #include <linux/hrtimer.h>
+#include <linux/context_tracking.h>
 
 #define CPUIDLE_STATE_MAX	10
 #define CPUIDLE_NAME_LEN	16
@@ -115,6 +116,35 @@ struct cpuidle_device {
 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
 
+static __always_inline void ct_cpuidle_enter(void)
+{
+	lockdep_assert_irqs_disabled();
+	/*
+	 * Idle is allowed to (temporary) enable IRQs. It
+	 * will return with IRQs disabled.
+	 *
+	 * Trace IRQs enable here, then switch off RCU, and have
+	 * arch_cpu_idle() use raw_local_irq_enable(). Note that
+	 * ct_idle_enter() relies on lockdep IRQ state, so switch that
+	 * last -- this is very similar to the entry code.
+	 */
+	trace_hardirqs_on_prepare();
+	lockdep_hardirqs_on_prepare();
+	instrumentation_end();
+	ct_idle_enter();
+	lockdep_hardirqs_on(_THIS_IP_);
+}
+
+static __always_inline void ct_cpuidle_exit(void)
+{
+	/*
+	 * Carefully undo the above.
+	 */
+	lockdep_hardirqs_off(_THIS_IP_);
+	ct_idle_exit();
+	instrumentation_begin();
+}
+
 /****************************
  * CPUIDLE DRIVER INTERFACE *
  ****************************/
@@ -282,18 +312,18 @@ extern s64 cpuidle_governor_latency_req(
 	int __ret = 0;							\
 									\
 	if (!idx) {							\
-		ct_idle_enter();					\
+		ct_cpuidle_enter();					\
 		cpu_do_idle();						\
-		ct_idle_exit();						\
+		ct_cpuidle_exit();					\
 		return idx;						\
 	}								\
 									\
 	if (!is_retention)						\
 		__ret =  cpu_pm_enter();				\
 	if (!__ret) {							\
-		ct_idle_enter();					\
+		ct_cpuidle_enter();					\
 		__ret = low_level_idle_enter(state);			\
-		ct_idle_exit();						\
+		ct_cpuidle_exit();					\
 		if (!is_retention)					\
 			cpu_pm_exit();					\
 	}								\
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -51,18 +51,22 @@ __setup("hlt", cpu_idle_nopoll_setup);
 
 static noinline int __cpuidle cpu_idle_poll(void)
 {
+	instrumentation_begin();
 	trace_cpu_idle(0, smp_processor_id());
 	stop_critical_timings();
-	ct_idle_enter();
-	local_irq_enable();
+	ct_cpuidle_enter();
 
+	raw_local_irq_enable();
 	while (!tif_need_resched() &&
 	       (cpu_idle_force_poll || tick_check_broadcast_expired()))
 		cpu_relax();
+	raw_local_irq_disable();
 
-	ct_idle_exit();
+	ct_cpuidle_exit();
 	start_critical_timings();
 	trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
+	local_irq_enable();
+	instrumentation_end();
 
 	return 1;
 }
@@ -85,44 +89,21 @@ void __weak arch_cpu_idle(void)
  */
 void __cpuidle default_idle_call(void)
 {
-	if (current_clr_polling_and_test()) {
-		local_irq_enable();
-	} else {
-
+	instrumentation_begin();
+	if (!current_clr_polling_and_test()) {
 		trace_cpu_idle(1, smp_processor_id());
 		stop_critical_timings();
 
-		/*
-		 * arch_cpu_idle() is supposed to enable IRQs, however
-		 * we can't do that because of RCU and tracing.
-		 *
-		 * Trace IRQs enable here, then switch off RCU, and have
-		 * arch_cpu_idle() use raw_local_irq_enable(). Note that
-		 * ct_idle_enter() relies on lockdep IRQ state, so switch that
-		 * last -- this is very similar to the entry code.
-		 */
-		trace_hardirqs_on_prepare();
-		lockdep_hardirqs_on_prepare();
-		ct_idle_enter();
-		lockdep_hardirqs_on(_THIS_IP_);
-
+		ct_cpuidle_enter();
 		arch_cpu_idle();
-
-		/*
-		 * OK, so IRQs are enabled here, but RCU needs them disabled to
-		 * turn itself back on.. funny thing is that disabling IRQs
-		 * will cause tracing, which needs RCU. Jump through hoops to
-		 * make it 'work'.
-		 */
 		raw_local_irq_disable();
-		lockdep_hardirqs_off(_THIS_IP_);
-		ct_idle_exit();
-		lockdep_hardirqs_on(_THIS_IP_);
-		raw_local_irq_enable();
+		ct_cpuidle_exit();
 
 		start_critical_timings();
 		trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
 	}
+	local_irq_enable();
+	instrumentation_end();
 }
 
 static int call_cpuidle_s2idle(struct cpuidle_driver *drv,
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -622,9 +622,13 @@ struct cpumask *tick_get_broadcast_onesh
  * to avoid a deep idle transition as we are about to get the
  * broadcast IPI right away.
  */
-int tick_check_broadcast_expired(void)
+noinstr int tick_check_broadcast_expired(void)
 {
+#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H
+	return arch_test_bit(smp_processor_id(), cpumask_bits(tick_broadcast_force_mask));
+#else
 	return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask);
+#endif
 }
 
 /*

[PATCH v2 14/44] cpuidle,cpu_pm: Remove RCU fiddling from cpu_pm_{enter,exit}()

[Peter Zijlstra]

All callers should still have RCU enabled.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
 kernel/cpu_pm.c |    9 ---------
 1 file changed, 9 deletions(-)

--- a/kernel/cpu_pm.c
+++ b/kernel/cpu_pm.c
@@ -30,16 +30,9 @@ static int cpu_pm_notify(enum cpu_pm_eve
 {
 	int ret;
 
-	/*
-	 * This introduces a RCU read critical section, which could be
-	 * disfunctional in cpu idle. Copy RCU_NONIDLE code to let RCU know
-	 * this.
-	 */
-	ct_irq_enter_irqson();
 	rcu_read_lock();
 	ret = raw_notifier_call_chain(&cpu_pm_notifier.chain, event, NULL);
 	rcu_read_unlock();
-	ct_irq_exit_irqson();
 
 	return notifier_to_errno(ret);
 }
@@ -49,11 +42,9 @@ static int cpu_pm_notify_robust(enum cpu
 	unsigned long flags;
 	int ret;
 
-	ct_irq_enter_irqson();
 	raw_spin_lock_irqsave(&cpu_pm_notifier.lock, flags);
 	ret = raw_notifier_call_chain_robust(&cpu_pm_notifier.chain, event_up, event_down, NULL);
 	raw_spin_unlock_irqrestore(&cpu_pm_notifier.lock, flags);
-	ct_irq_exit_irqson();
 
 	return notifier_to_errno(ret);
 }

Re: [PATCH v2 14/44] cpuidle,cpu_pm: Remove RCU fiddling from cpu_pm_{enter,exit}()

[Ulf Hansson]

On Mon, 19 Sept 2022 at 12:17, Peter Zijlstra <peterz@infradead.org> wrote:
>
> All callers should still have RCU enabled.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Acked-by: Mark Rutland <mark.rutland@arm.com>

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Kind regards
Uffe

> ---
>  kernel/cpu_pm.c |    9 ---------
>  1 file changed, 9 deletions(-)
>
> --- a/kernel/cpu_pm.c
> +++ b/kernel/cpu_pm.c
> @@ -30,16 +30,9 @@ static int cpu_pm_notify(enum cpu_pm_eve
>  {
>         int ret;
>
> -       /*
> -        * This introduces a RCU read critical section, which could be
> -        * disfunctional in cpu idle. Copy RCU_NONIDLE code to let RCU know
> -        * this.
> -        */
> -       ct_irq_enter_irqson();
>         rcu_read_lock();
>         ret = raw_notifier_call_chain(&cpu_pm_notifier.chain, event, NULL);
>         rcu_read_unlock();
> -       ct_irq_exit_irqson();
>
>         return notifier_to_errno(ret);
>  }
> @@ -49,11 +42,9 @@ static int cpu_pm_notify_robust(enum cpu
>         unsigned long flags;
>         int ret;
>
> -       ct_irq_enter_irqson();
>         raw_spin_lock_irqsave(&cpu_pm_notifier.lock, flags);
>         ret = raw_notifier_call_chain_robust(&cpu_pm_notifier.chain, event_up, event_down, NULL);
>         raw_spin_unlock_irqrestore(&cpu_pm_notifier.lock, flags);
> -       ct_irq_exit_irqson();
>
>         return notifier_to_errno(ret);
>  }
>
>

[PATCH v2 15/44] acpi_idle: Remove tracing

[Peter Zijlstra]

All the idle routines are called with RCU disabled, as such there must
not be any tracing inside.

While there; clean-up the io-port idle thing.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 drivers/acpi/processor_idle.c |   24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -108,8 +108,8 @@ static const struct dmi_system_id proces
 static void __cpuidle acpi_safe_halt(void)
 {
 	if (!tif_need_resched()) {
-		safe_halt();
-		local_irq_disable();
+		raw_safe_halt();
+		raw_local_irq_disable();
 	}
 }
 
@@ -524,16 +524,21 @@ static int acpi_idle_bm_check(void)
 	return bm_status;
 }
 
-static void wait_for_freeze(void)
+static __cpuidle void io_idle(unsigned long addr)
 {
+	/* IO port based C-state */
+	inb(addr);
+
 #ifdef	CONFIG_X86
 	/* No delay is needed if we are in guest */
 	if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
 		return;
 #endif
-	/* Dummy wait op - must do something useless after P_LVL2 read
-	   because chipsets cannot guarantee that STPCLK# signal
-	   gets asserted in time to freeze execution properly. */
+	/*
+	 * Dummy wait op - must do something useless after P_LVL2 read
+	 * because chipsets cannot guarantee that STPCLK# signal
+	 * gets asserted in time to freeze execution properly.
+	 */
 	inl(acpi_gbl_FADT.xpm_timer_block.address);
 }
 
@@ -553,9 +558,7 @@ static void __cpuidle acpi_idle_do_entry
 	} else if (cx->entry_method == ACPI_CSTATE_HALT) {
 		acpi_safe_halt();
 	} else {
-		/* IO port based C-state */
-		inb(cx->address);
-		wait_for_freeze();
+		io_idle(cx->address);
 	}
 
 	perf_lopwr_cb(false);
@@ -577,8 +580,7 @@ static int acpi_idle_play_dead(struct cp
 		if (cx->entry_method == ACPI_CSTATE_HALT)
 			safe_halt();
 		else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
-			inb(cx->address);
-			wait_for_freeze();
+			io_idle(cx->address);
 		} else
 			return -ENODEV;
 

[PATCH v2 16/44] cpuidle: Annotate poll_idle()

[Peter Zijlstra]

The __cpuidle functions will become a noinstr class, as such they need
explicit annotations.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/cpuidle/poll_state.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/cpuidle/poll_state.c
+++ b/drivers/cpuidle/poll_state.c
@@ -13,7 +13,10 @@
 static int __cpuidle poll_idle(struct cpuidle_device *dev,
 			       struct cpuidle_driver *drv, int index)
 {
-	u64 time_start = local_clock();
+	u64 time_start;
+
+	instrumentation_begin();
+	time_start = local_clock();
 
 	dev->poll_time_limit = false;
 
@@ -39,6 +42,7 @@ static int __cpuidle poll_idle(struct cp
 	raw_local_irq_disable();
 
 	current_clr_polling();
+	instrumentation_end();
 
 	return index;
 }

[PATCH v2 17/44] objtool/idle: Validate __cpuidle code as noinstr

[Peter Zijlstra]

Idle code is very like entry code in that RCU isn't available. As
such, add a little validation.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
 arch/alpha/kernel/vmlinux.lds.S      |    1 -
 arch/arc/kernel/vmlinux.lds.S        |    1 -
 arch/arm/include/asm/vmlinux.lds.h   |    1 -
 arch/arm64/kernel/vmlinux.lds.S      |    1 -
 arch/csky/kernel/vmlinux.lds.S       |    1 -
 arch/hexagon/kernel/vmlinux.lds.S    |    1 -
 arch/ia64/kernel/vmlinux.lds.S       |    1 -
 arch/loongarch/kernel/vmlinux.lds.S  |    1 -
 arch/m68k/kernel/vmlinux-nommu.lds   |    1 -
 arch/m68k/kernel/vmlinux-std.lds     |    1 -
 arch/m68k/kernel/vmlinux-sun3.lds    |    1 -
 arch/microblaze/kernel/vmlinux.lds.S |    1 -
 arch/mips/kernel/vmlinux.lds.S       |    1 -
 arch/nios2/kernel/vmlinux.lds.S      |    1 -
 arch/openrisc/kernel/vmlinux.lds.S   |    1 -
 arch/parisc/kernel/vmlinux.lds.S     |    1 -
 arch/powerpc/kernel/vmlinux.lds.S    |    1 -
 arch/riscv/kernel/vmlinux-xip.lds.S  |    1 -
 arch/riscv/kernel/vmlinux.lds.S      |    1 -
 arch/s390/kernel/vmlinux.lds.S       |    1 -
 arch/sh/kernel/vmlinux.lds.S         |    1 -
 arch/sparc/kernel/vmlinux.lds.S      |    1 -
 arch/um/kernel/dyn.lds.S             |    1 -
 arch/um/kernel/uml.lds.S             |    1 -
 arch/x86/include/asm/irqflags.h      |   11 ++++-------
 arch/x86/include/asm/mwait.h         |    2 +-
 arch/x86/kernel/vmlinux.lds.S        |    1 -
 arch/xtensa/kernel/vmlinux.lds.S     |    1 -
 include/asm-generic/vmlinux.lds.h    |    9 +++------
 include/linux/compiler_types.h       |    8 ++++++--
 include/linux/cpu.h                  |    3 ---
 tools/objtool/check.c                |   13 +++++++++++++
 32 files changed, 27 insertions(+), 45 deletions(-)

--- a/arch/alpha/kernel/vmlinux.lds.S
+++ b/arch/alpha/kernel/vmlinux.lds.S
@@ -27,7 +27,6 @@ SECTIONS
 		HEAD_TEXT
 		TEXT_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		*(.fixup)
 		*(.gnu.warning)
--- a/arch/arc/kernel/vmlinux.lds.S
+++ b/arch/arc/kernel/vmlinux.lds.S
@@ -85,7 +85,6 @@ SECTIONS
 		_stext = .;
 		TEXT_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		IRQENTRY_TEXT
--- a/arch/arm/include/asm/vmlinux.lds.h
+++ b/arch/arm/include/asm/vmlinux.lds.h
@@ -96,7 +96,6 @@
 		SOFTIRQENTRY_TEXT					\
 		TEXT_TEXT						\
 		SCHED_TEXT						\
-		CPUIDLE_TEXT						\
 		LOCK_TEXT						\
 		KPROBES_TEXT						\
 		ARM_STUBS_TEXT						\
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -163,7 +163,6 @@ SECTIONS
 			ENTRY_TEXT
 			TEXT_TEXT
 			SCHED_TEXT
-			CPUIDLE_TEXT
 			LOCK_TEXT
 			KPROBES_TEXT
 			HYPERVISOR_TEXT
--- a/arch/csky/kernel/vmlinux.lds.S
+++ b/arch/csky/kernel/vmlinux.lds.S
@@ -38,7 +38,6 @@ SECTIONS
 		SOFTIRQENTRY_TEXT
 		TEXT_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		*(.fixup)
--- a/arch/hexagon/kernel/vmlinux.lds.S
+++ b/arch/hexagon/kernel/vmlinux.lds.S
@@ -41,7 +41,6 @@ SECTIONS
 		IRQENTRY_TEXT
 		SOFTIRQENTRY_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		*(.fixup)
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -51,7 +51,6 @@ SECTIONS {
 		__end_ivt_text = .;
 		TEXT_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		IRQENTRY_TEXT
--- a/arch/loongarch/kernel/vmlinux.lds.S
+++ b/arch/loongarch/kernel/vmlinux.lds.S
@@ -41,7 +41,6 @@ SECTIONS
 	.text : {
 		TEXT_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		IRQENTRY_TEXT
--- a/arch/m68k/kernel/vmlinux-nommu.lds
+++ b/arch/m68k/kernel/vmlinux-nommu.lds
@@ -48,7 +48,6 @@ SECTIONS {
 		IRQENTRY_TEXT
 		SOFTIRQENTRY_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		*(.fixup)
 		. = ALIGN(16);
--- a/arch/m68k/kernel/vmlinux-std.lds
+++ b/arch/m68k/kernel/vmlinux-std.lds
@@ -19,7 +19,6 @@ SECTIONS
 	IRQENTRY_TEXT
 	SOFTIRQENTRY_TEXT
 	SCHED_TEXT
-	CPUIDLE_TEXT
 	LOCK_TEXT
 	*(.fixup)
 	*(.gnu.warning)
--- a/arch/m68k/kernel/vmlinux-sun3.lds
+++ b/arch/m68k/kernel/vmlinux-sun3.lds
@@ -19,7 +19,6 @@ SECTIONS
 	IRQENTRY_TEXT
 	SOFTIRQENTRY_TEXT
 	SCHED_TEXT
-	CPUIDLE_TEXT
 	LOCK_TEXT
 	*(.fixup)
 	*(.gnu.warning)
--- a/arch/microblaze/kernel/vmlinux.lds.S
+++ b/arch/microblaze/kernel/vmlinux.lds.S
@@ -36,7 +36,6 @@ SECTIONS {
 		EXIT_TEXT
 		EXIT_CALL
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		IRQENTRY_TEXT
--- a/arch/mips/kernel/vmlinux.lds.S
+++ b/arch/mips/kernel/vmlinux.lds.S
@@ -61,7 +61,6 @@ SECTIONS
 	.text : {
 		TEXT_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		IRQENTRY_TEXT
--- a/arch/nios2/kernel/vmlinux.lds.S
+++ b/arch/nios2/kernel/vmlinux.lds.S
@@ -24,7 +24,6 @@ SECTIONS
 	.text : {
 		TEXT_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		IRQENTRY_TEXT
 		SOFTIRQENTRY_TEXT
--- a/arch/openrisc/kernel/vmlinux.lds.S
+++ b/arch/openrisc/kernel/vmlinux.lds.S
@@ -52,7 +52,6 @@ SECTIONS
           _stext = .;
 	  TEXT_TEXT
 	  SCHED_TEXT
-	  CPUIDLE_TEXT
 	  LOCK_TEXT
 	  KPROBES_TEXT
 	  IRQENTRY_TEXT
--- a/arch/parisc/kernel/vmlinux.lds.S
+++ b/arch/parisc/kernel/vmlinux.lds.S
@@ -86,7 +86,6 @@ SECTIONS
 		TEXT_TEXT
 		LOCK_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		KPROBES_TEXT
 		IRQENTRY_TEXT
 		SOFTIRQENTRY_TEXT
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -107,7 +107,6 @@ SECTIONS
 #endif
 		NOINSTR_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		IRQENTRY_TEXT
--- a/arch/riscv/kernel/vmlinux-xip.lds.S
+++ b/arch/riscv/kernel/vmlinux-xip.lds.S
@@ -39,7 +39,6 @@ SECTIONS
 		_stext = .;
 		TEXT_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		ENTRY_TEXT
--- a/arch/riscv/kernel/vmlinux.lds.S
+++ b/arch/riscv/kernel/vmlinux.lds.S
@@ -42,7 +42,6 @@ SECTIONS
 		_stext = .;
 		TEXT_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		ENTRY_TEXT
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -42,7 +42,6 @@ SECTIONS
 		HEAD_TEXT
 		TEXT_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		IRQENTRY_TEXT
--- a/arch/sh/kernel/vmlinux.lds.S
+++ b/arch/sh/kernel/vmlinux.lds.S
@@ -29,7 +29,6 @@ SECTIONS
 		HEAD_TEXT
 		TEXT_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		IRQENTRY_TEXT
--- a/arch/sparc/kernel/vmlinux.lds.S
+++ b/arch/sparc/kernel/vmlinux.lds.S
@@ -50,7 +50,6 @@ SECTIONS
 		HEAD_TEXT
 		TEXT_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		IRQENTRY_TEXT
--- a/arch/um/kernel/dyn.lds.S
+++ b/arch/um/kernel/dyn.lds.S
@@ -74,7 +74,6 @@ SECTIONS
     _stext = .;
     TEXT_TEXT
     SCHED_TEXT
-    CPUIDLE_TEXT
     LOCK_TEXT
     IRQENTRY_TEXT
     SOFTIRQENTRY_TEXT
--- a/arch/um/kernel/uml.lds.S
+++ b/arch/um/kernel/uml.lds.S
@@ -35,7 +35,6 @@ SECTIONS
     _stext = .;
     TEXT_TEXT
     SCHED_TEXT
-    CPUIDLE_TEXT
     LOCK_TEXT
     IRQENTRY_TEXT
     SOFTIRQENTRY_TEXT
--- a/arch/x86/include/asm/irqflags.h
+++ b/arch/x86/include/asm/irqflags.h
@@ -8,9 +8,6 @@
 
 #include <asm/nospec-branch.h>
 
-/* Provide __cpuidle; we can't safely include <linux/cpu.h> */
-#define __cpuidle __section(".cpuidle.text")
-
 /*
  * Interrupt control:
  */
@@ -45,13 +42,13 @@ static __always_inline void native_irq_e
 	asm volatile("sti": : :"memory");
 }
 
-static inline __cpuidle void native_safe_halt(void)
+static __always_inline void native_safe_halt(void)
 {
 	mds_idle_clear_cpu_buffers();
 	asm volatile("sti; hlt": : :"memory");
 }
 
-static inline __cpuidle void native_halt(void)
+static __always_inline void native_halt(void)
 {
 	mds_idle_clear_cpu_buffers();
 	asm volatile("hlt": : :"memory");
@@ -84,7 +81,7 @@ static __always_inline void arch_local_i
  * Used in the idle loop; sti takes one instruction cycle
  * to complete:
  */
-static inline __cpuidle void arch_safe_halt(void)
+static __always_inline void arch_safe_halt(void)
 {
 	native_safe_halt();
 }
@@ -93,7 +90,7 @@ static inline __cpuidle void arch_safe_h
  * Used when interrupts are already enabled or to
  * shutdown the processor:
  */
-static inline __cpuidle void halt(void)
+static __always_inline void halt(void)
 {
 	native_halt();
 }
--- a/arch/x86/include/asm/mwait.h
+++ b/arch/x86/include/asm/mwait.h
@@ -104,7 +104,7 @@ static inline void __sti_mwait(unsigned
  * New with Core Duo processors, MWAIT can take some hints based on CPU
  * capability.
  */
-static inline void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
+static __always_inline void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
 {
 	if (static_cpu_has_bug(X86_BUG_MONITOR) || !current_set_polling_and_test()) {
 		if (static_cpu_has_bug(X86_BUG_CLFLUSH_MONITOR)) {
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -129,7 +129,6 @@ SECTIONS
 		HEAD_TEXT
 		TEXT_TEXT
 		SCHED_TEXT
-		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
 		ALIGN_ENTRY_TEXT_BEGIN
--- a/arch/xtensa/kernel/vmlinux.lds.S
+++ b/arch/xtensa/kernel/vmlinux.lds.S
@@ -125,7 +125,6 @@ SECTIONS
     ENTRY_TEXT
     TEXT_TEXT
     SCHED_TEXT
-    CPUIDLE_TEXT
     LOCK_TEXT
     *(.fixup)
   }
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -559,6 +559,9 @@
 		ALIGN_FUNCTION();					\
 		__noinstr_text_start = .;				\
 		*(.noinstr.text)					\
+		__cpuidle_text_start = .;				\
+		*(.cpuidle.text)					\
+		__cpuidle_text_end = .;					\
 		__noinstr_text_end = .;
 
 /*
@@ -600,12 +603,6 @@
 		*(.spinlock.text)					\
 		__lock_text_end = .;
 
-#define CPUIDLE_TEXT							\
-		ALIGN_FUNCTION();					\
-		__cpuidle_text_start = .;				\
-		*(.cpuidle.text)					\
-		__cpuidle_text_end = .;
-
 #define KPROBES_TEXT							\
 		ALIGN_FUNCTION();					\
 		__kprobes_text_start = .;				\
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -227,10 +227,14 @@ struct ftrace_likely_data {
 #endif
 
 /* Section for code which can't be instrumented at all */
-#define noinstr								\
-	noinline notrace __attribute((__section__(".noinstr.text")))	\
+#define __noinstr_section(section)					\
+	noinline notrace __attribute((__section__(section)))		\
 	__no_kcsan __no_sanitize_address __no_profile __no_sanitize_coverage
 
+#define noinstr __noinstr_section(".noinstr.text")
+
+#define __cpuidle __noinstr_section(".cpuidle.text")
+
 #endif /* __KERNEL__ */
 
 #endif /* __ASSEMBLY__ */
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -176,9 +176,6 @@ void __noreturn cpu_startup_entry(enum c
 
 void cpu_idle_poll_ctrl(bool enable);
 
-/* Attach to any functions which should be considered cpuidle. */
-#define __cpuidle	__section(".cpuidle.text")
-
 bool cpu_in_idle(unsigned long pc);
 
 void arch_cpu_idle(void);
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -377,6 +377,7 @@ static int decode_instructions(struct ob
 
 		if (!strcmp(sec->name, ".noinstr.text") ||
 		    !strcmp(sec->name, ".entry.text") ||
+		    !strcmp(sec->name, ".cpuidle.text") ||
 		    !strncmp(sec->name, ".text.__x86.", 12))
 			sec->noinstr = true;
 
@@ -3187,6 +3188,12 @@ static inline bool noinstr_call_dest(str
 		return true;
 
 	/*
+	 * If the symbol is a static_call trampoline, we can't tell.
+	 */
+	if (func->static_call_tramp)
+		return true;
+
+	/*
 	 * The __ubsan_handle_*() calls are like WARN(), they only happen when
 	 * something 'BAD' happened. At the risk of taking the machine down,
 	 * let them proceed to get the message out.
@@ -3932,6 +3939,12 @@ static int validate_noinstr_sections(str
 	if (sec) {
 		warnings += validate_section(file, sec);
 		warnings += validate_unwind_hints(file, sec);
+	}
+
+	sec = find_section_by_name(file->elf, ".cpuidle.text");
+	if (sec) {
+		warnings += validate_section(file, sec);
+		warnings += validate_unwind_hints(file, sec);
 	}
 
 	return warnings;

[PATCH v2 18/44] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE *again*

[Peter Zijlstra]

  vmlinux.o: warning: objtool: intel_idle_irq+0x10c: call to trace_hardirqs_off() leaves .noinstr.text section

As per commit 32d4fd5751ea ("cpuidle,intel_idle: Fix
CPUIDLE_FLAG_IRQ_ENABLE"):

  "must not have tracing in idle functions"

Clearly people can't read and tinker along until splat dissapears.
This straight up reverts commit d295ad34f236 ("intel_idle: Fix false
positive RCU splats due to incorrect hardirqs state").

It doesn't re-introduce the problem because preceding patches fixed it
properly.

Fixes: d295ad34f236 ("intel_idle: Fix false positive RCU splats due to incorrect hardirqs state")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 drivers/idle/intel_idle.c |    8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -168,13 +168,7 @@ static __cpuidle int intel_idle_irq(stru
 
 	raw_local_irq_enable();
 	ret = __intel_idle(dev, drv, index);
-
-	/*
-	 * The lockdep hardirqs state may be changed to 'on' with timer
-	 * tick interrupt followed by __do_softirq(). Use local_irq_disable()
-	 * to keep the hardirqs state correct.
-	 */
-	local_irq_disable();
+	raw_local_irq_disable();
 
 	return ret;
 }

[PATCH v2 19/44] cpuidle,intel_idle: Fix CPUIDLE_FLAG_INIT_XSTATE

[Peter Zijlstra]

vmlinux.o: warning: objtool: intel_idle_s2idle+0xd5: call to fpu_idle_fpregs() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_xstate+0x11: call to fpu_idle_fpregs() leaves .noinstr.text section
vmlinux.o: warning: objtool: fpu_idle_fpregs+0x9: call to xfeatures_in_use() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/include/asm/fpu/xcr.h       |    4 ++--
 arch/x86/include/asm/special_insns.h |    2 +-
 arch/x86/kernel/fpu/core.c           |    4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

--- a/arch/x86/include/asm/fpu/xcr.h
+++ b/arch/x86/include/asm/fpu/xcr.h
@@ -5,7 +5,7 @@
 #define XCR_XFEATURE_ENABLED_MASK	0x00000000
 #define XCR_XFEATURE_IN_USE_MASK	0x00000001
 
-static inline u64 xgetbv(u32 index)
+static __always_inline u64 xgetbv(u32 index)
 {
 	u32 eax, edx;
 
@@ -27,7 +27,7 @@ static inline void xsetbv(u32 index, u64
  *
  * Callers should check X86_FEATURE_XGETBV1.
  */
-static inline u64 xfeatures_in_use(void)
+static __always_inline u64 xfeatures_in_use(void)
 {
 	return xgetbv(XCR_XFEATURE_IN_USE_MASK);
 }
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -295,7 +295,7 @@ static inline int enqcmds(void __iomem *
 	return 0;
 }
 
-static inline void tile_release(void)
+static __always_inline void tile_release(void)
 {
 	/*
 	 * Instruction opcode for TILERELEASE; supported in binutils
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -856,12 +856,12 @@ int fpu__exception_code(struct fpu *fpu,
  * Initialize register state that may prevent from entering low-power idle.
  * This function will be invoked from the cpuidle driver only when needed.
  */
-void fpu_idle_fpregs(void)
+noinstr void fpu_idle_fpregs(void)
 {
 	/* Note: AMX_TILE being enabled implies XGETBV1 support */
 	if (cpu_feature_enabled(X86_FEATURE_AMX_TILE) &&
 	    (xfeatures_in_use() & XFEATURE_MASK_XTILE)) {
 		tile_release();
-		fpregs_deactivate(&current->thread.fpu);
+		__this_cpu_write(fpu_fpregs_owner_ctx, NULL);
 	}
 }

[PATCH v2 20/44] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IBRS

[Peter Zijlstra]

vmlinux.o: warning: objtool: intel_idle_ibrs+0x17: call to spec_ctrl_current() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_ibrs+0x27: call to wrmsrl.constprop.0() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/kernel/cpu/bugs.c |    2 +-
 drivers/idle/intel_idle.c  |    4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -79,7 +79,7 @@ void write_spec_ctrl_current(u64 val, bo
 		wrmsrl(MSR_IA32_SPEC_CTRL, val);
 }
 
-u64 spec_ctrl_current(void)
+noinstr u64 spec_ctrl_current(void)
 {
 	return this_cpu_read(x86_spec_ctrl_current);
 }
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -181,12 +181,12 @@ static __cpuidle int intel_idle_ibrs(str
 	int ret;
 
 	if (smt_active)
-		wrmsrl(MSR_IA32_SPEC_CTRL, 0);
+		native_wrmsrl(MSR_IA32_SPEC_CTRL, 0);
 
 	ret = __intel_idle(dev, drv, index);
 
 	if (smt_active)
-		wrmsrl(MSR_IA32_SPEC_CTRL, spec_ctrl);
+		native_wrmsrl(MSR_IA32_SPEC_CTRL, spec_ctrl);
 
 	return ret;
 }

[PATCH v2 21/44] arch/idle: Change arch_cpu_idle() IRQ behaviour

[Peter Zijlstra]

Current arch_cpu_idle() is called with IRQs disabled, but will return
with IRQs enabled.

However, the very first thing the generic code does after calling
arch_cpu_idle() is raw_local_irq_disable(). This means that
architectures that can idle with IRQs disabled end up doing a
pointless 'enable-disable' dance.

Therefore, push this IRQ disabling into the idle function, meaning
that those architectures can avoid the pointless IRQ state flipping.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Acked-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 arch/alpha/kernel/process.c      |    1 -
 arch/arc/kernel/process.c        |    3 +++
 arch/arm/kernel/process.c        |    1 -
 arch/arm/mach-gemini/board-dt.c  |    3 ++-
 arch/arm64/kernel/idle.c         |    1 -
 arch/csky/kernel/process.c       |    1 -
 arch/csky/kernel/smp.c           |    2 +-
 arch/hexagon/kernel/process.c    |    1 -
 arch/ia64/kernel/process.c       |    1 +
 arch/loongarch/kernel/idle.c     |    1 +
 arch/microblaze/kernel/process.c |    1 -
 arch/mips/kernel/idle.c          |    8 +++-----
 arch/nios2/kernel/process.c      |    1 -
 arch/openrisc/kernel/process.c   |    1 +
 arch/parisc/kernel/process.c     |    2 --
 arch/powerpc/kernel/idle.c       |    5 ++---
 arch/riscv/kernel/process.c      |    1 -
 arch/s390/kernel/idle.c          |    1 -
 arch/sh/kernel/idle.c            |    1 +
 arch/sparc/kernel/leon_pmc.c     |    4 ++++
 arch/sparc/kernel/process_32.c   |    1 -
 arch/sparc/kernel/process_64.c   |    3 ++-
 arch/um/kernel/process.c         |    1 -
 arch/x86/coco/tdx/tdx.c          |    3 +++
 arch/x86/kernel/process.c        |   15 ++++-----------
 arch/xtensa/kernel/process.c     |    1 +
 kernel/sched/idle.c              |    2 --
 27 files changed, 29 insertions(+), 37 deletions(-)

--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -57,7 +57,6 @@ EXPORT_SYMBOL(pm_power_off);
 void arch_cpu_idle(void)
 {
 	wtint(0);
-	raw_local_irq_enable();
 }
 
 void arch_cpu_idle_dead(void)
--- a/arch/arc/kernel/process.c
+++ b/arch/arc/kernel/process.c
@@ -114,6 +114,8 @@ void arch_cpu_idle(void)
 		"sleep %0	\n"
 		:
 		:"I"(arg)); /* can't be "r" has to be embedded const */
+
+	raw_local_irq_disable();
 }
 
 #else	/* ARC700 */
@@ -122,6 +124,7 @@ void arch_cpu_idle(void)
 {
 	/* sleep, but enable both set E1/E2 (levels of interrupts) before committing */
 	__asm__ __volatile__("sleep 0x3	\n");
+	raw_local_irq_disable();
 }
 
 #endif
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -78,7 +78,6 @@ void arch_cpu_idle(void)
 		arm_pm_idle();
 	else
 		cpu_do_idle();
-	raw_local_irq_enable();
 }
 
 void arch_cpu_idle_prepare(void)
--- a/arch/arm/mach-gemini/board-dt.c
+++ b/arch/arm/mach-gemini/board-dt.c
@@ -42,8 +42,9 @@ static void gemini_idle(void)
 	 */
 
 	/* FIXME: Enabling interrupts here is racy! */
-	local_irq_enable();
+	raw_local_irq_enable();
 	cpu_do_idle();
+	raw_local_irq_disable();
 }
 
 static void __init gemini_init_machine(void)
--- a/arch/arm64/kernel/idle.c
+++ b/arch/arm64/kernel/idle.c
@@ -42,5 +42,4 @@ void noinstr arch_cpu_idle(void)
 	 * tricks
 	 */
 	cpu_do_idle();
-	raw_local_irq_enable();
 }
--- a/arch/csky/kernel/process.c
+++ b/arch/csky/kernel/process.c
@@ -100,6 +100,5 @@ void arch_cpu_idle(void)
 #ifdef CONFIG_CPU_PM_STOP
 	asm volatile("stop\n");
 #endif
-	raw_local_irq_enable();
 }
 #endif
--- a/arch/csky/kernel/smp.c
+++ b/arch/csky/kernel/smp.c
@@ -309,7 +309,7 @@ void arch_cpu_idle_dead(void)
 	while (!secondary_stack)
 		arch_cpu_idle();
 
-	local_irq_disable();
+	raw_local_irq_disable();
 
 	asm volatile(
 		"mov	sp, %0\n"
--- a/arch/hexagon/kernel/process.c
+++ b/arch/hexagon/kernel/process.c
@@ -44,7 +44,6 @@ void arch_cpu_idle(void)
 {
 	__vmwait();
 	/*  interrupts wake us up, but irqs are still disabled */
-	raw_local_irq_enable();
 }
 
 /*
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -242,6 +242,7 @@ void arch_cpu_idle(void)
 		(*mark_idle)(1);
 
 	raw_safe_halt();
+	raw_local_irq_disable();
 
 	if (mark_idle)
 		(*mark_idle)(0);
--- a/arch/loongarch/kernel/idle.c
+++ b/arch/loongarch/kernel/idle.c
@@ -13,4 +13,5 @@ void __cpuidle arch_cpu_idle(void)
 {
 	raw_local_irq_enable();
 	__arch_cpu_idle(); /* idle instruction needs irq enabled */
+	raw_local_irq_disable();
 }
--- a/arch/microblaze/kernel/process.c
+++ b/arch/microblaze/kernel/process.c
@@ -140,5 +140,4 @@ int dump_fpu(struct pt_regs *regs, elf_f
 
 void arch_cpu_idle(void)
 {
-       raw_local_irq_enable();
 }
--- a/arch/mips/kernel/idle.c
+++ b/arch/mips/kernel/idle.c
@@ -33,13 +33,13 @@ static void __cpuidle r3081_wait(void)
 {
 	unsigned long cfg = read_c0_conf();
 	write_c0_conf(cfg | R30XX_CONF_HALT);
-	raw_local_irq_enable();
 }
 
 void __cpuidle r4k_wait(void)
 {
 	raw_local_irq_enable();
 	__r4k_wait();
+	raw_local_irq_disable();
 }
 
 /*
@@ -57,7 +57,6 @@ void __cpuidle r4k_wait_irqoff(void)
 		"	.set	arch=r4000	\n"
 		"	wait			\n"
 		"	.set	pop		\n");
-	raw_local_irq_enable();
 }
 
 /*
@@ -77,7 +76,6 @@ static void __cpuidle rm7k_wait_irqoff(v
 		"	wait						\n"
 		"	mtc0	$1, $12		# stalls until W stage	\n"
 		"	.set	pop					\n");
-	raw_local_irq_enable();
 }
 
 /*
@@ -103,6 +101,8 @@ static void __cpuidle au1k_wait(void)
 	"	nop				\n"
 	"	.set	pop			\n"
 	: : "r" (au1k_wait), "r" (c0status));
+
+	raw_local_irq_disable();
 }
 
 static int __initdata nowait;
@@ -245,8 +245,6 @@ void arch_cpu_idle(void)
 {
 	if (cpu_wait)
 		cpu_wait();
-	else
-		raw_local_irq_enable();
 }
 
 #ifdef CONFIG_CPU_IDLE
--- a/arch/nios2/kernel/process.c
+++ b/arch/nios2/kernel/process.c
@@ -33,7 +33,6 @@ EXPORT_SYMBOL(pm_power_off);
 
 void arch_cpu_idle(void)
 {
-	raw_local_irq_enable();
 }
 
 /*
--- a/arch/openrisc/kernel/process.c
+++ b/arch/openrisc/kernel/process.c
@@ -102,6 +102,7 @@ void arch_cpu_idle(void)
 	raw_local_irq_enable();
 	if (mfspr(SPR_UPR) & SPR_UPR_PMP)
 		mtspr(SPR_PMR, mfspr(SPR_PMR) | SPR_PMR_DME);
+	raw_local_irq_disable();
 }
 
 void (*pm_power_off)(void) = NULL;
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -187,8 +187,6 @@ void arch_cpu_idle_dead(void)
 
 void __cpuidle arch_cpu_idle(void)
 {
-	raw_local_irq_enable();
-
 	/* nop on real hardware, qemu will idle sleep. */
 	asm volatile("or %%r10,%%r10,%%r10\n":::);
 }
--- a/arch/powerpc/kernel/idle.c
+++ b/arch/powerpc/kernel/idle.c
@@ -51,10 +51,9 @@ void arch_cpu_idle(void)
 		 * Some power_save functions return with
 		 * interrupts enabled, some don't.
 		 */
-		if (irqs_disabled())
-			raw_local_irq_enable();
+		if (!irqs_disabled())
+			raw_local_irq_disable();
 	} else {
-		raw_local_irq_enable();
 		/*
 		 * Go into low thread priority and possibly
 		 * low power mode.
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -39,7 +39,6 @@ extern asmlinkage void ret_from_kernel_t
 void arch_cpu_idle(void)
 {
 	cpu_do_idle();
-	raw_local_irq_enable();
 }
 
 void __show_regs(struct pt_regs *regs)
--- a/arch/s390/kernel/idle.c
+++ b/arch/s390/kernel/idle.c
@@ -66,7 +66,6 @@ void arch_cpu_idle(void)
 	idle->idle_count++;
 	account_idle_time(cputime_to_nsecs(idle_time));
 	raw_write_seqcount_end(&idle->seqcount);
-	raw_local_irq_enable();
 }
 
 static ssize_t show_idle_count(struct device *dev,
--- a/arch/sh/kernel/idle.c
+++ b/arch/sh/kernel/idle.c
@@ -25,6 +25,7 @@ void default_idle(void)
 	raw_local_irq_enable();
 	/* Isn't this racy ? */
 	cpu_sleep();
+	raw_local_irq_disable();
 	clear_bl_bit();
 }
 
--- a/arch/sparc/kernel/leon_pmc.c
+++ b/arch/sparc/kernel/leon_pmc.c
@@ -57,6 +57,8 @@ static void pmc_leon_idle_fixup(void)
 		"lda	[%0] %1, %%g0\n"
 		:
 		: "r"(address), "i"(ASI_LEON_BYPASS));
+
+	raw_local_irq_disable();
 }
 
 /*
@@ -70,6 +72,8 @@ static void pmc_leon_idle(void)
 
 	/* For systems without power-down, this will be no-op */
 	__asm__ __volatile__ ("wr	%g0, %asr19\n\t");
+
+	raw_local_irq_disable();
 }
 
 /* Install LEON Power Down function */
--- a/arch/sparc/kernel/process_32.c
+++ b/arch/sparc/kernel/process_32.c
@@ -71,7 +71,6 @@ void arch_cpu_idle(void)
 {
 	if (sparc_idle)
 		(*sparc_idle)();
-	raw_local_irq_enable();
 }
 
 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -59,7 +59,6 @@ void arch_cpu_idle(void)
 {
 	if (tlb_type != hypervisor) {
 		touch_nmi_watchdog();
-		raw_local_irq_enable();
 	} else {
 		unsigned long pstate;
 
@@ -90,6 +89,8 @@ void arch_cpu_idle(void)
 			"wrpr %0, %%g0, %%pstate"
 			: "=&r" (pstate)
 			: "i" (PSTATE_IE));
+
+		raw_local_irq_disable();
 	}
 }
 
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -217,7 +217,6 @@ void arch_cpu_idle(void)
 {
 	cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
 	um_idle_sleep();
-	raw_local_irq_enable();
 }
 
 int __cant_sleep(void) {
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -223,6 +223,9 @@ void __cpuidle tdx_safe_halt(void)
 	 */
 	if (__halt(irq_disabled, do_sti))
 		WARN_ONCE(1, "HLT instruction emulation failed\n");
+
+	/* XXX I can't make sense of what @do_sti actually does */
+	raw_local_irq_disable();
 }
 
 static int read_msr(struct pt_regs *regs, struct ve_info *ve)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -701,6 +701,7 @@ EXPORT_SYMBOL(boot_option_idle_override)
 void __cpuidle default_idle(void)
 {
 	raw_safe_halt();
+	raw_local_irq_disable();
 }
 #if defined(CONFIG_APM_MODULE) || defined(CONFIG_HALTPOLL_CPUIDLE_MODULE)
 EXPORT_SYMBOL(default_idle);
@@ -806,13 +807,7 @@ static void amd_e400_idle(void)
 
 	default_idle();
 
-	/*
-	 * The switch back from broadcast mode needs to be called with
-	 * interrupts disabled.
-	 */
-	raw_local_irq_disable();
 	tick_broadcast_exit();
-	raw_local_irq_enable();
 }
 
 /*
@@ -870,12 +865,10 @@ static __cpuidle void mwait_idle(void)
 		}
 
 		__monitor((void *)&current_thread_info()->flags, 0, 0);
-		if (!need_resched())
+		if (!need_resched()) {
 			__sti_mwait(0, 0);
-		else
-			raw_local_irq_enable();
-	} else {
-		raw_local_irq_enable();
+			raw_local_irq_disable();
+		}
 	}
 	__current_clr_polling();
 }
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -183,6 +183,7 @@ void coprocessor_flush_release_all(struc
 void arch_cpu_idle(void)
 {
 	platform_idle();
+	raw_local_irq_disable();
 }
 
 /*
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -79,7 +79,6 @@ void __weak arch_cpu_idle_dead(void) { }
 void __weak arch_cpu_idle(void)
 {
 	cpu_idle_force_poll = 1;
-	raw_local_irq_enable();
 }
 
 /**
@@ -96,7 +95,6 @@ void __cpuidle default_idle_call(void)
 
 		ct_cpuidle_enter();
 		arch_cpu_idle();
-		raw_local_irq_disable();
 		ct_cpuidle_exit();
 
 		start_critical_timings();

Re: [PATCH v2 21/44] arch/idle: Change arch_cpu_idle() IRQ behaviour

[Guo Ren]

On Mon, Sep 19, 2022 at 6:18 PM Peter Zijlstra <peterz@infradead.org> wrote:
>
> Current arch_cpu_idle() is called with IRQs disabled, but will return
> with IRQs enabled.
>
> However, the very first thing the generic code does after calling
> arch_cpu_idle() is raw_local_irq_disable(). This means that
> architectures that can idle with IRQs disabled end up doing a
> pointless 'enable-disable' dance.
>
> Therefore, push this IRQ disabling into the idle function, meaning
> that those architectures can avoid the pointless IRQ state flipping.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
> Acked-by: Mark Rutland <mark.rutland@arm.com> [arm64]
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>  arch/alpha/kernel/process.c      |    1 -
>  arch/arc/kernel/process.c        |    3 +++
>  arch/arm/kernel/process.c        |    1 -
>  arch/arm/mach-gemini/board-dt.c  |    3 ++-
>  arch/arm64/kernel/idle.c         |    1 -
>  arch/csky/kernel/process.c       |    1 -
>  arch/csky/kernel/smp.c           |    2 +-
>  arch/hexagon/kernel/process.c    |    1 -
>  arch/ia64/kernel/process.c       |    1 +
>  arch/loongarch/kernel/idle.c     |    1 +
>  arch/microblaze/kernel/process.c |    1 -
>  arch/mips/kernel/idle.c          |    8 +++-----
>  arch/nios2/kernel/process.c      |    1 -
>  arch/openrisc/kernel/process.c   |    1 +
>  arch/parisc/kernel/process.c     |    2 --
>  arch/powerpc/kernel/idle.c       |    5 ++---
>  arch/riscv/kernel/process.c      |    1 -
>  arch/s390/kernel/idle.c          |    1 -
>  arch/sh/kernel/idle.c            |    1 +
>  arch/sparc/kernel/leon_pmc.c     |    4 ++++
>  arch/sparc/kernel/process_32.c   |    1 -
>  arch/sparc/kernel/process_64.c   |    3 ++-
>  arch/um/kernel/process.c         |    1 -
>  arch/x86/coco/tdx/tdx.c          |    3 +++
>  arch/x86/kernel/process.c        |   15 ++++-----------
>  arch/xtensa/kernel/process.c     |    1 +
>  kernel/sched/idle.c              |    2 --
>  27 files changed, 29 insertions(+), 37 deletions(-)
>
> --- a/arch/alpha/kernel/process.c
> +++ b/arch/alpha/kernel/process.c
> @@ -57,7 +57,6 @@ EXPORT_SYMBOL(pm_power_off);
>  void arch_cpu_idle(void)
>  {
>         wtint(0);
> -       raw_local_irq_enable();
>  }
>
>  void arch_cpu_idle_dead(void)
> --- a/arch/arc/kernel/process.c
> +++ b/arch/arc/kernel/process.c
> @@ -114,6 +114,8 @@ void arch_cpu_idle(void)
>                 "sleep %0       \n"
>                 :
>                 :"I"(arg)); /* can't be "r" has to be embedded const */
> +
> +       raw_local_irq_disable();
>  }
>
>  #else  /* ARC700 */
> @@ -122,6 +124,7 @@ void arch_cpu_idle(void)
>  {
>         /* sleep, but enable both set E1/E2 (levels of interrupts) before committing */
>         __asm__ __volatile__("sleep 0x3 \n");
> +       raw_local_irq_disable();
>  }
>
>  #endif
> --- a/arch/arm/kernel/process.c
> +++ b/arch/arm/kernel/process.c
> @@ -78,7 +78,6 @@ void arch_cpu_idle(void)
>                 arm_pm_idle();
>         else
>                 cpu_do_idle();
> -       raw_local_irq_enable();
>  }
>
>  void arch_cpu_idle_prepare(void)
> --- a/arch/arm/mach-gemini/board-dt.c
> +++ b/arch/arm/mach-gemini/board-dt.c
> @@ -42,8 +42,9 @@ static void gemini_idle(void)
>          */
>
>         /* FIXME: Enabling interrupts here is racy! */
> -       local_irq_enable();
> +       raw_local_irq_enable();
>         cpu_do_idle();
> +       raw_local_irq_disable();
>  }
>
>  static void __init gemini_init_machine(void)
> --- a/arch/arm64/kernel/idle.c
> +++ b/arch/arm64/kernel/idle.c
> @@ -42,5 +42,4 @@ void noinstr arch_cpu_idle(void)
>          * tricks
>          */
>         cpu_do_idle();
> -       raw_local_irq_enable();
>  }
> --- a/arch/csky/kernel/process.c
> +++ b/arch/csky/kernel/process.c
> @@ -100,6 +100,5 @@ void arch_cpu_idle(void)
>  #ifdef CONFIG_CPU_PM_STOP
>         asm volatile("stop\n");
>  #endif
> -       raw_local_irq_enable();
Acked-by: Guo Ren <guoren@kernel.org>

>  }
>  #endif
> --- a/arch/csky/kernel/smp.c
> +++ b/arch/csky/kernel/smp.c
> @@ -309,7 +309,7 @@ void arch_cpu_idle_dead(void)
>         while (!secondary_stack)
>                 arch_cpu_idle();
>
> -       local_irq_disable();
> +       raw_local_irq_disable();
Acked-by ..., because:

                local_irq_disable();

                if (cpu_is_offline(cpu)) {
                        tick_nohz_idle_stop_tick();
                        cpuhp_report_idle_dead();
                        arch_cpu_idle_dead();
                }

>
>         asm volatile(
>                 "mov    sp, %0\n"
> --- a/arch/hexagon/kernel/process.c
> +++ b/arch/hexagon/kernel/process.c
> @@ -44,7 +44,6 @@ void arch_cpu_idle(void)
>  {
>         __vmwait();
>         /*  interrupts wake us up, but irqs are still disabled */
> -       raw_local_irq_enable();
>  }
>
>  /*
> --- a/arch/ia64/kernel/process.c
> +++ b/arch/ia64/kernel/process.c
> @@ -242,6 +242,7 @@ void arch_cpu_idle(void)
>                 (*mark_idle)(1);
>
>         raw_safe_halt();
> +       raw_local_irq_disable();
>
>         if (mark_idle)
>                 (*mark_idle)(0);
> --- a/arch/loongarch/kernel/idle.c
> +++ b/arch/loongarch/kernel/idle.c
> @@ -13,4 +13,5 @@ void __cpuidle arch_cpu_idle(void)
>  {
>         raw_local_irq_enable();
>         __arch_cpu_idle(); /* idle instruction needs irq enabled */
> +       raw_local_irq_disable();
>  }
> --- a/arch/microblaze/kernel/process.c
> +++ b/arch/microblaze/kernel/process.c
> @@ -140,5 +140,4 @@ int dump_fpu(struct pt_regs *regs, elf_f
>
>  void arch_cpu_idle(void)
>  {
> -       raw_local_irq_enable();
>  }
> --- a/arch/mips/kernel/idle.c
> +++ b/arch/mips/kernel/idle.c
> @@ -33,13 +33,13 @@ static void __cpuidle r3081_wait(void)
>  {
>         unsigned long cfg = read_c0_conf();
>         write_c0_conf(cfg | R30XX_CONF_HALT);
> -       raw_local_irq_enable();
>  }
>
>  void __cpuidle r4k_wait(void)
>  {
>         raw_local_irq_enable();
>         __r4k_wait();
> +       raw_local_irq_disable();
>  }
>
>  /*
> @@ -57,7 +57,6 @@ void __cpuidle r4k_wait_irqoff(void)
>                 "       .set    arch=r4000      \n"
>                 "       wait                    \n"
>                 "       .set    pop             \n");
> -       raw_local_irq_enable();
>  }
>
>  /*
> @@ -77,7 +76,6 @@ static void __cpuidle rm7k_wait_irqoff(v
>                 "       wait                                            \n"
>                 "       mtc0    $1, $12         # stalls until W stage  \n"
>                 "       .set    pop                                     \n");
> -       raw_local_irq_enable();
>  }
>
>  /*
> @@ -103,6 +101,8 @@ static void __cpuidle au1k_wait(void)
>         "       nop                             \n"
>         "       .set    pop                     \n"
>         : : "r" (au1k_wait), "r" (c0status));
> +
> +       raw_local_irq_disable();
>  }
>
>  static int __initdata nowait;
> @@ -245,8 +245,6 @@ void arch_cpu_idle(void)
>  {
>         if (cpu_wait)
>                 cpu_wait();
> -       else
> -               raw_local_irq_enable();
>  }
>
>  #ifdef CONFIG_CPU_IDLE
> --- a/arch/nios2/kernel/process.c
> +++ b/arch/nios2/kernel/process.c
> @@ -33,7 +33,6 @@ EXPORT_SYMBOL(pm_power_off);
>
>  void arch_cpu_idle(void)
>  {
> -       raw_local_irq_enable();
>  }
>
>  /*
> --- a/arch/openrisc/kernel/process.c
> +++ b/arch/openrisc/kernel/process.c
> @@ -102,6 +102,7 @@ void arch_cpu_idle(void)
>         raw_local_irq_enable();
>         if (mfspr(SPR_UPR) & SPR_UPR_PMP)
>                 mtspr(SPR_PMR, mfspr(SPR_PMR) | SPR_PMR_DME);
> +       raw_local_irq_disable();
>  }
>
>  void (*pm_power_off)(void) = NULL;
> --- a/arch/parisc/kernel/process.c
> +++ b/arch/parisc/kernel/process.c
> @@ -187,8 +187,6 @@ void arch_cpu_idle_dead(void)
>
>  void __cpuidle arch_cpu_idle(void)
>  {
> -       raw_local_irq_enable();
> -
>         /* nop on real hardware, qemu will idle sleep. */
>         asm volatile("or %%r10,%%r10,%%r10\n":::);
>  }
> --- a/arch/powerpc/kernel/idle.c
> +++ b/arch/powerpc/kernel/idle.c
> @@ -51,10 +51,9 @@ void arch_cpu_idle(void)
>                  * Some power_save functions return with
>                  * interrupts enabled, some don't.
>                  */
> -               if (irqs_disabled())
> -                       raw_local_irq_enable();
> +               if (!irqs_disabled())
> +                       raw_local_irq_disable();
>         } else {
> -               raw_local_irq_enable();
>                 /*
>                  * Go into low thread priority and possibly
>                  * low power mode.
> --- a/arch/riscv/kernel/process.c
> +++ b/arch/riscv/kernel/process.c
> @@ -39,7 +39,6 @@ extern asmlinkage void ret_from_kernel_t
>  void arch_cpu_idle(void)
>  {
>         cpu_do_idle();
> -       raw_local_irq_enable();
>  }
>
>  void __show_regs(struct pt_regs *regs)
> --- a/arch/s390/kernel/idle.c
> +++ b/arch/s390/kernel/idle.c
> @@ -66,7 +66,6 @@ void arch_cpu_idle(void)
>         idle->idle_count++;
>         account_idle_time(cputime_to_nsecs(idle_time));
>         raw_write_seqcount_end(&idle->seqcount);
> -       raw_local_irq_enable();
>  }
>
>  static ssize_t show_idle_count(struct device *dev,
> --- a/arch/sh/kernel/idle.c
> +++ b/arch/sh/kernel/idle.c
> @@ -25,6 +25,7 @@ void default_idle(void)
>         raw_local_irq_enable();
>         /* Isn't this racy ? */
>         cpu_sleep();
> +       raw_local_irq_disable();
>         clear_bl_bit();
>  }
>
> --- a/arch/sparc/kernel/leon_pmc.c
> +++ b/arch/sparc/kernel/leon_pmc.c
> @@ -57,6 +57,8 @@ static void pmc_leon_idle_fixup(void)
>                 "lda    [%0] %1, %%g0\n"
>                 :
>                 : "r"(address), "i"(ASI_LEON_BYPASS));
> +
> +       raw_local_irq_disable();
>  }
>
>  /*
> @@ -70,6 +72,8 @@ static void pmc_leon_idle(void)
>
>         /* For systems without power-down, this will be no-op */
>         __asm__ __volatile__ ("wr       %g0, %asr19\n\t");
> +
> +       raw_local_irq_disable();
>  }
>
>  /* Install LEON Power Down function */
> --- a/arch/sparc/kernel/process_32.c
> +++ b/arch/sparc/kernel/process_32.c
> @@ -71,7 +71,6 @@ void arch_cpu_idle(void)
>  {
>         if (sparc_idle)
>                 (*sparc_idle)();
> -       raw_local_irq_enable();
>  }
>
>  /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
> --- a/arch/sparc/kernel/process_64.c
> +++ b/arch/sparc/kernel/process_64.c
> @@ -59,7 +59,6 @@ void arch_cpu_idle(void)
>  {
>         if (tlb_type != hypervisor) {
>                 touch_nmi_watchdog();
> -               raw_local_irq_enable();
>         } else {
>                 unsigned long pstate;
>
> @@ -90,6 +89,8 @@ void arch_cpu_idle(void)
>                         "wrpr %0, %%g0, %%pstate"
>                         : "=&r" (pstate)
>                         : "i" (PSTATE_IE));
> +
> +               raw_local_irq_disable();
>         }
>  }
>
> --- a/arch/um/kernel/process.c
> +++ b/arch/um/kernel/process.c
> @@ -217,7 +217,6 @@ void arch_cpu_idle(void)
>  {
>         cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
>         um_idle_sleep();
> -       raw_local_irq_enable();
>  }
>
>  int __cant_sleep(void) {
> --- a/arch/x86/coco/tdx/tdx.c
> +++ b/arch/x86/coco/tdx/tdx.c
> @@ -223,6 +223,9 @@ void __cpuidle tdx_safe_halt(void)
>          */
>         if (__halt(irq_disabled, do_sti))
>                 WARN_ONCE(1, "HLT instruction emulation failed\n");
> +
> +       /* XXX I can't make sense of what @do_sti actually does */
> +       raw_local_irq_disable();
>  }
>
>  static int read_msr(struct pt_regs *regs, struct ve_info *ve)
> --- a/arch/x86/kernel/process.c
> +++ b/arch/x86/kernel/process.c
> @@ -701,6 +701,7 @@ EXPORT_SYMBOL(boot_option_idle_override)
>  void __cpuidle default_idle(void)
>  {
>         raw_safe_halt();
> +       raw_local_irq_disable();
>  }
>  #if defined(CONFIG_APM_MODULE) || defined(CONFIG_HALTPOLL_CPUIDLE_MODULE)
>  EXPORT_SYMBOL(default_idle);
> @@ -806,13 +807,7 @@ static void amd_e400_idle(void)
>
>         default_idle();
>
> -       /*
> -        * The switch back from broadcast mode needs to be called with
> -        * interrupts disabled.
> -        */
> -       raw_local_irq_disable();
>         tick_broadcast_exit();
> -       raw_local_irq_enable();
>  }
>
>  /*
> @@ -870,12 +865,10 @@ static __cpuidle void mwait_idle(void)
>                 }
>
>                 __monitor((void *)&current_thread_info()->flags, 0, 0);
> -               if (!need_resched())
> +               if (!need_resched()) {
>                         __sti_mwait(0, 0);
> -               else
> -                       raw_local_irq_enable();
> -       } else {
> -               raw_local_irq_enable();
> +                       raw_local_irq_disable();
> +               }
>         }
>         __current_clr_polling();
>  }
> --- a/arch/xtensa/kernel/process.c
> +++ b/arch/xtensa/kernel/process.c
> @@ -183,6 +183,7 @@ void coprocessor_flush_release_all(struc
>  void arch_cpu_idle(void)
>  {
>         platform_idle();
> +       raw_local_irq_disable();
>  }
>
>  /*
> --- a/kernel/sched/idle.c
> +++ b/kernel/sched/idle.c
> @@ -79,7 +79,6 @@ void __weak arch_cpu_idle_dead(void) { }
>  void __weak arch_cpu_idle(void)
>  {
>         cpu_idle_force_poll = 1;
> -       raw_local_irq_enable();
>  }
>
>  /**
> @@ -96,7 +95,6 @@ void __cpuidle default_idle_call(void)
>
>                 ct_cpuidle_enter();
>                 arch_cpu_idle();
> -               raw_local_irq_disable();
>                 ct_cpuidle_exit();
>
>                 start_critical_timings();
>
>


-- 
Best Regards
 Guo Ren

[PATCH v2 22/44] x86/tdx: Remove TDX_HCALL_ISSUE_STI

[Peter Zijlstra]

Now that arch_cpu_idle() is expected to return with IRQs disabled,
avoid the useless STI/CLI dance.

Per the specs this is supposed to work, but nobody has yet relied up
this behaviour so broken implementations are possible.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/coco/tdx/tdcall.S        |   13 -------------
 arch/x86/coco/tdx/tdx.c           |   23 ++++-------------------
 arch/x86/include/asm/shared/tdx.h |    1 -
 3 files changed, 4 insertions(+), 33 deletions(-)

--- a/arch/x86/coco/tdx/tdcall.S
+++ b/arch/x86/coco/tdx/tdcall.S
@@ -139,19 +139,6 @@ SYM_FUNC_START(__tdx_hypercall)
 
 	movl $TDVMCALL_EXPOSE_REGS_MASK, %ecx
 
-	/*
-	 * For the idle loop STI needs to be called directly before the TDCALL
-	 * that enters idle (EXIT_REASON_HLT case). STI instruction enables
-	 * interrupts only one instruction later. If there is a window between
-	 * STI and the instruction that emulates the HALT state, there is a
-	 * chance for interrupts to happen in this window, which can delay the
-	 * HLT operation indefinitely. Since this is the not the desired
-	 * result, conditionally call STI before TDCALL.
-	 */
-	testq $TDX_HCALL_ISSUE_STI, %rsi
-	jz .Lskip_sti
-	sti
-.Lskip_sti:
 	tdcall
 
 	/*
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -169,7 +169,7 @@ static int ve_instr_len(struct ve_info *
 	}
 }
 
-static u64 __cpuidle __halt(const bool irq_disabled, const bool do_sti)
+static u64 __cpuidle __halt(const bool irq_disabled)
 {
 	struct tdx_hypercall_args args = {
 		.r10 = TDX_HYPERCALL_STANDARD,
@@ -189,20 +189,14 @@ static u64 __cpuidle __halt(const bool i
 	 * can keep the vCPU in virtual HLT, even if an IRQ is
 	 * pending, without hanging/breaking the guest.
 	 */
-	return __tdx_hypercall(&args, do_sti ? TDX_HCALL_ISSUE_STI : 0);
+	return __tdx_hypercall(&args, 0);
 }
 
 static int handle_halt(struct ve_info *ve)
 {
-	/*
-	 * Since non safe halt is mainly used in CPU offlining
-	 * and the guest will always stay in the halt state, don't
-	 * call the STI instruction (set do_sti as false).
-	 */
 	const bool irq_disabled = irqs_disabled();
-	const bool do_sti = false;
 
-	if (__halt(irq_disabled, do_sti))
+	if (__halt(irq_disabled))
 		return -EIO;
 
 	return ve_instr_len(ve);
@@ -210,22 +204,13 @@ static int handle_halt(struct ve_info *v
 
 void __cpuidle tdx_safe_halt(void)
 {
-	 /*
-	  * For do_sti=true case, __tdx_hypercall() function enables
-	  * interrupts using the STI instruction before the TDCALL. So
-	  * set irq_disabled as false.
-	  */
 	const bool irq_disabled = false;
-	const bool do_sti = true;
 
 	/*
 	 * Use WARN_ONCE() to report the failure.
 	 */
-	if (__halt(irq_disabled, do_sti))
+	if (__halt(irq_disabled))
 		WARN_ONCE(1, "HLT instruction emulation failed\n");
-
-	/* XXX I can't make sense of what @do_sti actually does */
-	raw_local_irq_disable();
 }
 
 static int read_msr(struct pt_regs *regs, struct ve_info *ve)
--- a/arch/x86/include/asm/shared/tdx.h
+++ b/arch/x86/include/asm/shared/tdx.h
@@ -8,7 +8,6 @@
 #define TDX_HYPERCALL_STANDARD  0
 
 #define TDX_HCALL_HAS_OUTPUT	BIT(0)
-#define TDX_HCALL_ISSUE_STI	BIT(1)
 
 #define TDX_CPUID_LEAF_ID	0x21
 #define TDX_IDENT		"IntelTDX    "

[PATCH v2 23/44] arm,smp: Remove trace_.*_rcuidle() usage

[Peter Zijlstra]

None of these functions should ever be ran with RCU disabled anymore.

Specifically, do_handle_IPI() is only called from handle_IPI() which
explicitly does irq_enter()/irq_exit() which ensures RCU is watching.

The problem with smp_cross_call() was, per commit 7c64cc0531fa ("arm: Use
_rcuidle for smp_cross_call() tracepoints"), that
cpuidle_enter_state_coupled() already had RCU disabled, but that's
long been fixed by commit 1098582a0f6c ("sched,idle,rcu: Push rcu_idle
deeper into the idle path").

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/arm/kernel/smp.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -639,7 +639,7 @@ static void do_handle_IPI(int ipinr)
 	unsigned int cpu = smp_processor_id();
 
 	if ((unsigned)ipinr < NR_IPI)
-		trace_ipi_entry_rcuidle(ipi_types[ipinr]);
+		trace_ipi_entry(ipi_types[ipinr]);
 
 	switch (ipinr) {
 	case IPI_WAKEUP:
@@ -686,7 +686,7 @@ static void do_handle_IPI(int ipinr)
 	}
 
 	if ((unsigned)ipinr < NR_IPI)
-		trace_ipi_exit_rcuidle(ipi_types[ipinr]);
+		trace_ipi_exit(ipi_types[ipinr]);
 }
 
 /* Legacy version, should go away once all irqchips have been converted */
@@ -709,7 +709,7 @@ static irqreturn_t ipi_handler(int irq,
 
 static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
 {
-	trace_ipi_raise_rcuidle(target, ipi_types[ipinr]);
+	trace_ipi_raise(target, ipi_types[ipinr]);
 	__ipi_send_mask(ipi_desc[ipinr], target);
 }
 

Re: [PATCH v2 23/44] arm,smp: Remove trace_.*_rcuidle() usage

[Ulf Hansson]

On Mon, 19 Sept 2022 at 12:18, Peter Zijlstra <peterz@infradead.org> wrote:
>
> None of these functions should ever be ran with RCU disabled anymore.
>
> Specifically, do_handle_IPI() is only called from handle_IPI() which
> explicitly does irq_enter()/irq_exit() which ensures RCU is watching.
>
> The problem with smp_cross_call() was, per commit 7c64cc0531fa ("arm: Use
> _rcuidle for smp_cross_call() tracepoints"), that
> cpuidle_enter_state_coupled() already had RCU disabled, but that's
> long been fixed by commit 1098582a0f6c ("sched,idle,rcu: Push rcu_idle
> deeper into the idle path").
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

FWIW:

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Kind regards
Uffe

> ---
>  arch/arm/kernel/smp.c |    6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> --- a/arch/arm/kernel/smp.c
> +++ b/arch/arm/kernel/smp.c
> @@ -639,7 +639,7 @@ static void do_handle_IPI(int ipinr)
>         unsigned int cpu = smp_processor_id();
>
>         if ((unsigned)ipinr < NR_IPI)
> -               trace_ipi_entry_rcuidle(ipi_types[ipinr]);
> +               trace_ipi_entry(ipi_types[ipinr]);
>
>         switch (ipinr) {
>         case IPI_WAKEUP:
> @@ -686,7 +686,7 @@ static void do_handle_IPI(int ipinr)
>         }
>
>         if ((unsigned)ipinr < NR_IPI)
> -               trace_ipi_exit_rcuidle(ipi_types[ipinr]);
> +               trace_ipi_exit(ipi_types[ipinr]);
>  }
>
>  /* Legacy version, should go away once all irqchips have been converted */
> @@ -709,7 +709,7 @@ static irqreturn_t ipi_handler(int irq,
>
>  static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
>  {
> -       trace_ipi_raise_rcuidle(target, ipi_types[ipinr]);
> +       trace_ipi_raise(target, ipi_types[ipinr]);
>         __ipi_send_mask(ipi_desc[ipinr], target);
>  }
>
>
>
> _______________________________________________
> Virtualization mailing list
> Virtualization@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/virtualization

[PATCH v2 24/44] arm64,smp: Remove trace_.*_rcuidle() usage

[Peter Zijlstra]

Ever since commit d3afc7f12987 ("arm64: Allow IPIs to be handled as
normal interrupts") this function is called in regular IRQ context.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kernel/smp.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -865,7 +865,7 @@ static void do_handle_IPI(int ipinr)
 	unsigned int cpu = smp_processor_id();
 
 	if ((unsigned)ipinr < NR_IPI)
-		trace_ipi_entry_rcuidle(ipi_types[ipinr]);
+		trace_ipi_entry(ipi_types[ipinr]);
 
 	switch (ipinr) {
 	case IPI_RESCHEDULE:
@@ -914,7 +914,7 @@ static void do_handle_IPI(int ipinr)
 	}
 
 	if ((unsigned)ipinr < NR_IPI)
-		trace_ipi_exit_rcuidle(ipi_types[ipinr]);
+		trace_ipi_exit(ipi_types[ipinr]);
 }
 
 static irqreturn_t ipi_handler(int irq, void *data)

[PATCH v2 25/44] printk: Remove trace_.*_rcuidle() usage

[Peter Zijlstra]

The problem, per commit fc98c3c8c9dc ("printk: use rcuidle console
tracepoint"), was printk usage from the cpuidle path where RCU was
already disabled.

Per the patches earlier in this series, this is no longer the case.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Petr Mladek <pmladek@suse.com>
---
 kernel/printk/printk.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2238,7 +2238,7 @@ static u16 printk_sprint(char *text, u16
 		}
 	}
 
-	trace_console_rcuidle(text, text_len);
+	trace_console(text, text_len);
 
 	return text_len;
 }

Re: [PATCH v2 25/44] printk: Remove trace_.*_rcuidle() usage

[Sergey Senozhatsky]

On (22/09/19 12:00), Peter Zijlstra wrote:
> The problem, per commit fc98c3c8c9dc ("printk: use rcuidle console
> tracepoint"), was printk usage from the cpuidle path where RCU was
> already disabled.
> 
> Per the patches earlier in this series, this is no longer the case.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
> Acked-by: Petr Mladek <pmladek@suse.com>

Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org>

[PATCH v2 26/44] time/tick-broadcast: Remove RCU_NONIDLE usage

[Peter Zijlstra]

No callers left that have already disabled RCU.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
 kernel/time/tick-broadcast-hrtimer.c |   29 ++++++++++++-----------------
 1 file changed, 12 insertions(+), 17 deletions(-)

--- a/kernel/time/tick-broadcast-hrtimer.c
+++ b/kernel/time/tick-broadcast-hrtimer.c
@@ -56,25 +56,20 @@ static int bc_set_next(ktime_t expires,
 	 * hrtimer callback function is currently running, then
 	 * hrtimer_start() cannot move it and the timer stays on the CPU on
 	 * which it is assigned at the moment.
+	 */
+	hrtimer_start(&bctimer, expires, HRTIMER_MODE_ABS_PINNED_HARD);
+	/*
+	 * The core tick broadcast mode expects bc->bound_on to be set
+	 * correctly to prevent a CPU which has the broadcast hrtimer
+	 * armed from going deep idle.
 	 *
-	 * As this can be called from idle code, the hrtimer_start()
-	 * invocation has to be wrapped with RCU_NONIDLE() as
-	 * hrtimer_start() can call into tracing.
+	 * As tick_broadcast_lock is held, nothing can change the cpu
+	 * base which was just established in hrtimer_start() above. So
+	 * the below access is safe even without holding the hrtimer
+	 * base lock.
 	 */
-	RCU_NONIDLE( {
-		hrtimer_start(&bctimer, expires, HRTIMER_MODE_ABS_PINNED_HARD);
-		/*
-		 * The core tick broadcast mode expects bc->bound_on to be set
-		 * correctly to prevent a CPU which has the broadcast hrtimer
-		 * armed from going deep idle.
-		 *
-		 * As tick_broadcast_lock is held, nothing can change the cpu
-		 * base which was just established in hrtimer_start() above. So
-		 * the below access is safe even without holding the hrtimer
-		 * base lock.
-		 */
-		bc->bound_on = bctimer.base->cpu_base->cpu;
-	} );
+	bc->bound_on = bctimer.base->cpu_base->cpu;
+
 	return 0;
 }
 

[PATCH v2 27/44] cpuidle,sched: Remove annotations from TIF_{POLLING_NRFLAG,NEED_RESCHED}

[Peter Zijlstra]

vmlinux.o: warning: objtool: mwait_idle+0x5: call to current_set_polling_and_test() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_processor_ffh_cstate_enter+0xc5: call to current_set_polling_and_test() leaves .noinstr.text section
vmlinux.o: warning: objtool: cpu_idle_poll.isra.0+0x73: call to test_ti_thread_flag() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle+0xbc: call to current_set_polling_and_test() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_irq+0xea: call to current_set_polling_and_test() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_s2idle+0xb4: call to current_set_polling_and_test() leaves .noinstr.text section

vmlinux.o: warning: objtool: intel_idle+0xa6: call to current_clr_polling() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_irq+0xbf: call to current_clr_polling() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_s2idle+0xa1: call to current_clr_polling() leaves .noinstr.text section

vmlinux.o: warning: objtool: mwait_idle+0xe: call to __current_set_polling() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_processor_ffh_cstate_enter+0xc5: call to __current_set_polling() leaves .noinstr.text section
vmlinux.o: warning: objtool: cpu_idle_poll.isra.0+0x73: call to test_ti_thread_flag() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle+0xbc: call to __current_set_polling() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_irq+0xea: call to __current_set_polling() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_s2idle+0xb4: call to __current_set_polling() leaves .noinstr.text section

vmlinux.o: warning: objtool: cpu_idle_poll.isra.0+0x73: call to test_ti_thread_flag() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_s2idle+0x73: call to test_ti_thread_flag.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_irq+0x91: call to test_ti_thread_flag.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle+0x78: call to test_ti_thread_flag.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_safe_halt+0xf: call to test_ti_thread_flag.constprop.0() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 include/linux/sched/idle.h  |   40 ++++++++++++++++++++++++++++++----------
 include/linux/thread_info.h |   18 +++++++++++++++++-
 2 files changed, 47 insertions(+), 11 deletions(-)

--- a/include/linux/sched/idle.h
+++ b/include/linux/sched/idle.h
@@ -23,12 +23,37 @@ static inline void wake_up_if_idle(int c
  */
 #ifdef TIF_POLLING_NRFLAG
 
-static inline void __current_set_polling(void)
+#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_ATOMIC_H
+
+static __always_inline void __current_set_polling(void)
 {
-	set_thread_flag(TIF_POLLING_NRFLAG);
+	arch_set_bit(TIF_POLLING_NRFLAG,
+		     (unsigned long *)(&current_thread_info()->flags));
 }
 
-static inline bool __must_check current_set_polling_and_test(void)
+static __always_inline void __current_clr_polling(void)
+{
+	arch_clear_bit(TIF_POLLING_NRFLAG,
+		       (unsigned long *)(&current_thread_info()->flags));
+}
+
+#else
+
+static __always_inline void __current_set_polling(void)
+{
+	set_bit(TIF_POLLING_NRFLAG,
+		(unsigned long *)(&current_thread_info()->flags));
+}
+
+static __always_inline void __current_clr_polling(void)
+{
+	clear_bit(TIF_POLLING_NRFLAG,
+		  (unsigned long *)(&current_thread_info()->flags));
+}
+
+#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_ATOMIC_H */
+
+static __always_inline bool __must_check current_set_polling_and_test(void)
 {
 	__current_set_polling();
 
@@ -41,12 +66,7 @@ static inline bool __must_check current_
 	return unlikely(tif_need_resched());
 }
 
-static inline void __current_clr_polling(void)
-{
-	clear_thread_flag(TIF_POLLING_NRFLAG);
-}
-
-static inline bool __must_check current_clr_polling_and_test(void)
+static __always_inline bool __must_check current_clr_polling_and_test(void)
 {
 	__current_clr_polling();
 
@@ -73,7 +93,7 @@ static inline bool __must_check current_
 }
 #endif
 
-static inline void current_clr_polling(void)
+static __always_inline void current_clr_polling(void)
 {
 	__current_clr_polling();
 
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -177,7 +177,23 @@ static __always_inline unsigned long rea
 	clear_ti_thread_flag(task_thread_info(t), TIF_##fl)
 #endif /* !CONFIG_GENERIC_ENTRY */
 
-#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
+#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H
+
+static __always_inline bool tif_need_resched(void)
+{
+	return arch_test_bit(TIF_NEED_RESCHED,
+			     (unsigned long *)(&current_thread_info()->flags));
+}
+
+#else
+
+static __always_inline bool tif_need_resched(void)
+{
+	return test_bit(TIF_NEED_RESCHED,
+			(unsigned long *)(&current_thread_info()->flags));
+}
+
+#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H */
 
 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
 static inline int arch_within_stack_frames(const void * const stack,

[PATCH v2 28/44] cpuidle,mwait: Make noinstr clean

[Peter Zijlstra]

vmlinux.o: warning: objtool: intel_idle_s2idle+0x6e: call to __monitor.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_irq+0x8c: call to __monitor.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle+0x73: call to __monitor.constprop.0() leaves .noinstr.text section

vmlinux.o: warning: objtool: mwait_idle+0x88: call to clflush() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/include/asm/mwait.h         |   12 ++++++------
 arch/x86/include/asm/special_insns.h |    2 +-
 2 files changed, 7 insertions(+), 7 deletions(-)

--- a/arch/x86/include/asm/mwait.h
+++ b/arch/x86/include/asm/mwait.h
@@ -25,7 +25,7 @@
 #define TPAUSE_C01_STATE		1
 #define TPAUSE_C02_STATE		0
 
-static inline void __monitor(const void *eax, unsigned long ecx,
+static __always_inline void __monitor(const void *eax, unsigned long ecx,
 			     unsigned long edx)
 {
 	/* "monitor %eax, %ecx, %edx;" */
@@ -33,7 +33,7 @@ static inline void __monitor(const void
 		     :: "a" (eax), "c" (ecx), "d"(edx));
 }
 
-static inline void __monitorx(const void *eax, unsigned long ecx,
+static __always_inline void __monitorx(const void *eax, unsigned long ecx,
 			      unsigned long edx)
 {
 	/* "monitorx %eax, %ecx, %edx;" */
@@ -41,7 +41,7 @@ static inline void __monitorx(const void
 		     :: "a" (eax), "c" (ecx), "d"(edx));
 }
 
-static inline void __mwait(unsigned long eax, unsigned long ecx)
+static __always_inline void __mwait(unsigned long eax, unsigned long ecx)
 {
 	mds_idle_clear_cpu_buffers();
 
@@ -76,8 +76,8 @@ static inline void __mwait(unsigned long
  * EAX                     (logical) address to monitor
  * ECX                     #GP if not zero
  */
-static inline void __mwaitx(unsigned long eax, unsigned long ebx,
-			    unsigned long ecx)
+static __always_inline void __mwaitx(unsigned long eax, unsigned long ebx,
+				     unsigned long ecx)
 {
 	/* No MDS buffer clear as this is AMD/HYGON only */
 
@@ -86,7 +86,7 @@ static inline void __mwaitx(unsigned lon
 		     :: "a" (eax), "b" (ebx), "c" (ecx));
 }
 
-static inline void __sti_mwait(unsigned long eax, unsigned long ecx)
+static __always_inline void __sti_mwait(unsigned long eax, unsigned long ecx)
 {
 	mds_idle_clear_cpu_buffers();
 	/* "mwait %eax, %ecx;" */
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -196,7 +196,7 @@ static inline void load_gs_index(unsigne
 
 #endif /* CONFIG_PARAVIRT_XXL */
 
-static inline void clflush(volatile void *__p)
+static __always_inline void clflush(volatile void *__p)
 {
 	asm volatile("clflush %0" : "+m" (*(volatile char __force *)__p));
 }

[PATCH v2 29/44] cpuidle,tdx: Make tdx noinstr clean

[Peter Zijlstra]

vmlinux.o: warning: objtool: __halt+0x2c: call to hcall_func.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: __halt+0x3f: call to __tdx_hypercall() leaves .noinstr.text section
vmlinux.o: warning: objtool: __tdx_hypercall+0x66: call to __tdx_hypercall_failed() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/boot/compressed/vmlinux.lds.S |    1 +
 arch/x86/coco/tdx/tdcall.S             |    2 ++
 arch/x86/coco/tdx/tdx.c                |    5 +++--
 3 files changed, 6 insertions(+), 2 deletions(-)

--- a/arch/x86/boot/compressed/vmlinux.lds.S
+++ b/arch/x86/boot/compressed/vmlinux.lds.S
@@ -34,6 +34,7 @@ SECTIONS
 		_text = .; 	/* Text */
 		*(.text)
 		*(.text.*)
+		*(.noinstr.text)
 		_etext = . ;
 	}
 	.rodata : {
--- a/arch/x86/coco/tdx/tdcall.S
+++ b/arch/x86/coco/tdx/tdcall.S
@@ -31,6 +31,8 @@
 					  TDX_R12 | TDX_R13 | \
 					  TDX_R14 | TDX_R15 )
 
+.section .noinstr.text, "ax"
+
 /*
  * __tdx_module_call()  - Used by TDX guests to request services from
  * the TDX module (does not include VMM services) using TDCALL instruction.
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -53,8 +53,9 @@ static inline u64 _tdx_hypercall(u64 fn,
 }
 
 /* Called from __tdx_hypercall() for unrecoverable failure */
-void __tdx_hypercall_failed(void)
+noinstr void __tdx_hypercall_failed(void)
 {
+	instrumentation_begin();
 	panic("TDVMCALL failed. TDX module bug?");
 }
 
@@ -64,7 +65,7 @@ void __tdx_hypercall_failed(void)
  * Reusing the KVM EXIT_REASON macros makes it easier to connect the host and
  * guest sides of these calls.
  */
-static u64 hcall_func(u64 exit_reason)
+static __always_inline u64 hcall_func(u64 exit_reason)
 {
 	return exit_reason;
 }

[PATCH v2 30/44] cpuidle,xenpv: Make more PARAVIRT_XXL noinstr clean

[Peter Zijlstra]

vmlinux.o: warning: objtool: acpi_idle_enter_s2idle+0xde: call to wbinvd() leaves .noinstr.text section
vmlinux.o: warning: objtool: default_idle+0x4: call to arch_safe_halt() leaves .noinstr.text section
vmlinux.o: warning: objtool: xen_safe_halt+0xa: call to HYPERVISOR_sched_op.constprop.0() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
---
 arch/x86/include/asm/paravirt.h      |    6 ++++--
 arch/x86/include/asm/special_insns.h |    4 ++--
 arch/x86/include/asm/xen/hypercall.h |    2 +-
 arch/x86/kernel/paravirt.c           |   14 ++++++++++++--
 arch/x86/xen/enlighten_pv.c          |    2 +-
 arch/x86/xen/irq.c                   |    2 +-
 6 files changed, 21 insertions(+), 9 deletions(-)

--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -168,7 +168,7 @@ static inline void __write_cr4(unsigned
 	PVOP_VCALL1(cpu.write_cr4, x);
 }
 
-static inline void arch_safe_halt(void)
+static __always_inline void arch_safe_halt(void)
 {
 	PVOP_VCALL0(irq.safe_halt);
 }
@@ -178,7 +178,9 @@ static inline void halt(void)
 	PVOP_VCALL0(irq.halt);
 }
 
-static inline void wbinvd(void)
+extern noinstr void pv_native_wbinvd(void);
+
+static __always_inline void wbinvd(void)
 {
 	PVOP_ALT_VCALL0(cpu.wbinvd, "wbinvd", ALT_NOT(X86_FEATURE_XENPV));
 }
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -115,7 +115,7 @@ static inline void wrpkru(u32 pkru)
 }
 #endif
 
-static inline void native_wbinvd(void)
+static __always_inline void native_wbinvd(void)
 {
 	asm volatile("wbinvd": : :"memory");
 }
@@ -179,7 +179,7 @@ static inline void __write_cr4(unsigned
 	native_write_cr4(x);
 }
 
-static inline void wbinvd(void)
+static __always_inline void wbinvd(void)
 {
 	native_wbinvd();
 }
--- a/arch/x86/include/asm/xen/hypercall.h
+++ b/arch/x86/include/asm/xen/hypercall.h
@@ -382,7 +382,7 @@ MULTI_stack_switch(struct multicall_entr
 }
 #endif
 
-static inline int
+static __always_inline int
 HYPERVISOR_sched_op(int cmd, void *arg)
 {
 	return _hypercall2(int, sched_op, cmd, arg);
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -233,6 +233,11 @@ static noinstr void pv_native_set_debugr
 	native_set_debugreg(regno, val);
 }
 
+noinstr void pv_native_wbinvd(void)
+{
+	native_wbinvd();
+}
+
 static noinstr void pv_native_irq_enable(void)
 {
 	native_irq_enable();
@@ -242,6 +247,11 @@ static noinstr void pv_native_irq_disabl
 {
 	native_irq_disable();
 }
+
+static noinstr void pv_native_safe_halt(void)
+{
+	native_safe_halt();
+}
 #endif
 
 enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
@@ -273,7 +283,7 @@ struct paravirt_patch_template pv_ops =
 	.cpu.read_cr0		= native_read_cr0,
 	.cpu.write_cr0		= native_write_cr0,
 	.cpu.write_cr4		= native_write_cr4,
-	.cpu.wbinvd		= native_wbinvd,
+	.cpu.wbinvd		= pv_native_wbinvd,
 	.cpu.read_msr		= native_read_msr,
 	.cpu.write_msr		= native_write_msr,
 	.cpu.read_msr_safe	= native_read_msr_safe,
@@ -307,7 +317,7 @@ struct paravirt_patch_template pv_ops =
 	.irq.save_fl		= __PV_IS_CALLEE_SAVE(native_save_fl),
 	.irq.irq_disable	= __PV_IS_CALLEE_SAVE(pv_native_irq_disable),
 	.irq.irq_enable		= __PV_IS_CALLEE_SAVE(pv_native_irq_enable),
-	.irq.safe_halt		= native_safe_halt,
+	.irq.safe_halt		= pv_native_safe_halt,
 	.irq.halt		= native_halt,
 #endif /* CONFIG_PARAVIRT_XXL */
 
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1019,7 +1019,7 @@ static const typeof(pv_ops) xen_cpu_ops
 
 		.write_cr4 = xen_write_cr4,
 
-		.wbinvd = native_wbinvd,
+		.wbinvd = pv_native_wbinvd,
 
 		.read_msr = xen_read_msr,
 		.write_msr = xen_write_msr,
--- a/arch/x86/xen/irq.c
+++ b/arch/x86/xen/irq.c
@@ -24,7 +24,7 @@ noinstr void xen_force_evtchn_callback(v
 	(void)HYPERVISOR_xen_version(0, NULL);
 }
 
-static void xen_safe_halt(void)
+static noinstr void xen_safe_halt(void)
 {
 	/* Blocking includes an implicit local_irq_enable(). */
 	if (HYPERVISOR_sched_op(SCHEDOP_block, NULL) != 0)

Re: [PATCH v2 30/44] cpuidle,xenpv: Make more PARAVIRT_XXL noinstr clean

[Juergen Gross]

[-- Attachment #1.1.1: Type: text/plain, Size: 573 bytes --]

On 19.09.22 12:00, Peter Zijlstra wrote:
> vmlinux.o: warning: objtool: acpi_idle_enter_s2idle+0xde: call to wbinvd() leaves .noinstr.text section
> vmlinux.o: warning: objtool: default_idle+0x4: call to arch_safe_halt() leaves .noinstr.text section
> vmlinux.o: warning: objtool: xen_safe_halt+0xa: call to HYPERVISOR_sched_op.constprop.0() leaves .noinstr.text section
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Reviewed-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen


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[PATCH v2 31/44] cpuidle,nospec: Make noinstr clean

[Peter Zijlstra]

vmlinux.o: warning: objtool: mwait_idle+0x47: call to mds_idle_clear_cpu_buffers() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_processor_ffh_cstate_enter+0xa2: call to mds_idle_clear_cpu_buffers() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle+0x91: call to mds_idle_clear_cpu_buffers() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_s2idle+0x8c: call to mds_idle_clear_cpu_buffers() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_irq+0xaa: call to mds_idle_clear_cpu_buffers() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/include/asm/nospec-branch.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -310,7 +310,7 @@ static __always_inline void mds_user_cle
  *
  * Clear CPU buffers if the corresponding static key is enabled
  */
-static inline void mds_idle_clear_cpu_buffers(void)
+static __always_inline void mds_idle_clear_cpu_buffers(void)
 {
 	if (static_branch_likely(&mds_idle_clear))
 		mds_clear_cpu_buffers();

[PATCH v2 32/44] cpuidle,acpi: Make noinstr clean

[Peter Zijlstra]

vmlinux.o: warning: objtool: io_idle+0xc: call to __inb.isra.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_idle_enter+0xfe: call to num_online_cpus() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_idle_enter+0x115: call to acpi_idle_fallback_to_c1.isra.0() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 arch/x86/include/asm/shared/io.h |    4 ++--
 drivers/acpi/processor_idle.c    |    2 +-
 include/linux/cpumask.h          |    4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

--- a/arch/x86/include/asm/shared/io.h
+++ b/arch/x86/include/asm/shared/io.h
@@ -5,13 +5,13 @@
 #include <linux/types.h>
 
 #define BUILDIO(bwl, bw, type)						\
-static inline void __out##bwl(type value, u16 port)			\
+static __always_inline void __out##bwl(type value, u16 port)		\
 {									\
 	asm volatile("out" #bwl " %" #bw "0, %w1"			\
 		     : : "a"(value), "Nd"(port));			\
 }									\
 									\
-static inline type __in##bwl(u16 port)					\
+static __always_inline type __in##bwl(u16 port)				\
 {									\
 	type value;							\
 	asm volatile("in" #bwl " %w1, %" #bw "0"			\
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -593,7 +593,7 @@ static int acpi_idle_play_dead(struct cp
 	return 0;
 }
 
-static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
+static __always_inline bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 {
 	return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 		!(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -908,9 +908,9 @@ static inline const struct cpumask *get_
  * concurrent CPU hotplug operations unless invoked from a cpuhp_lock held
  * region.
  */
-static inline unsigned int num_online_cpus(void)
+static __always_inline unsigned int num_online_cpus(void)
 {
-	return atomic_read(&__num_online_cpus);
+	return arch_atomic_read(&__num_online_cpus);
 }
 #define num_possible_cpus()	cpumask_weight(cpu_possible_mask)
 #define num_present_cpus()	cpumask_weight(cpu_present_mask)

[PATCH v2 33/44] ftrace: WARN on rcuidle

[Peter Zijlstra]

CONFIG_GENERIC_ENTRY disallows any and all tracing when RCU isn't
enabled.

XXX if s390 (the only other GENERIC_ENTRY user as of this writing)
isn't comfortable with this, we could switch to
HAVE_NOINSTR_VALIDATION which is x86_64 only atm.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 include/linux/tracepoint.h |   13 ++++++++++++-
 kernel/trace/trace.c       |    3 +++
 2 files changed, 15 insertions(+), 1 deletion(-)

--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -178,6 +178,16 @@ static inline struct tracepoint *tracepo
 #endif /* CONFIG_HAVE_STATIC_CALL */
 
 /*
+ * CONFIG_GENERIC_ENTRY archs are expected to have sanitized entry and idle
+ * code that disallow any/all tracing/instrumentation when RCU isn't watching.
+ */
+#ifdef CONFIG_GENERIC_ENTRY
+#define RCUIDLE_COND(rcuidle)	(rcuidle)
+#else
+#define RCUIDLE_COND(rcuidle)	(rcuidle && in_nmi())
+#endif
+
+/*
  * it_func[0] is never NULL because there is at least one element in the array
  * when the array itself is non NULL.
  */
@@ -189,7 +199,8 @@ static inline struct tracepoint *tracepo
 			return;						\
 									\
 		/* srcu can't be used from NMI */			\
-		WARN_ON_ONCE(rcuidle && in_nmi());			\
+		if (WARN_ON_ONCE(RCUIDLE_COND(rcuidle)))		\
+			return;						\
 									\
 		/* keep srcu and sched-rcu usage consistent */		\
 		preempt_disable_notrace();				\
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3104,6 +3104,9 @@ void __trace_stack(struct trace_array *t
 		return;
 	}
 
+	if (WARN_ON_ONCE(IS_ENABLED(CONFIG_GENERIC_ENTRY)))
+		return;
+
 	/*
 	 * When an NMI triggers, RCU is enabled via ct_nmi_enter(),
 	 * but if the above rcu_is_watching() failed, then the NMI

Re: [PATCH v2 33/44] ftrace: WARN on rcuidle

[Steven Rostedt]

Nit, the subject should have "tracing:" an not "ftrace:" as the former
encompasses the tracing infrastructure and the latter is for the function
hook part of that.

On Mon, 19 Sep 2022 12:00:12 +0200
Peter Zijlstra <peterz@infradead.org> wrote:

> CONFIG_GENERIC_ENTRY disallows any and all tracing when RCU isn't
> enabled.
> 
> XXX if s390 (the only other GENERIC_ENTRY user as of this writing)
> isn't comfortable with this, we could switch to
> HAVE_NOINSTR_VALIDATION which is x86_64 only atm.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
>  include/linux/tracepoint.h |   13 ++++++++++++-
>  kernel/trace/trace.c       |    3 +++
>  2 files changed, 15 insertions(+), 1 deletion(-)
> 
> --- a/include/linux/tracepoint.h
> +++ b/include/linux/tracepoint.h
> @@ -178,6 +178,16 @@ static inline struct tracepoint *tracepo
>  #endif /* CONFIG_HAVE_STATIC_CALL */
>  
>  /*
> + * CONFIG_GENERIC_ENTRY archs are expected to have sanitized entry and idle
> + * code that disallow any/all tracing/instrumentation when RCU isn't watching.
> + */
> +#ifdef CONFIG_GENERIC_ENTRY
> +#define RCUIDLE_COND(rcuidle)	(rcuidle)
> +#else

Should probably move the below comment to here:

 /* srcu can't be used from NMI */

> +#define RCUIDLE_COND(rcuidle)	(rcuidle && in_nmi())
> +#endif
> +
> +/*
>   * it_func[0] is never NULL because there is at least one element in the array
>   * when the array itself is non NULL.
>   */
> @@ -189,7 +199,8 @@ static inline struct tracepoint *tracepo
>  			return;						\
>  									\
>  		/* srcu can't be used from NMI */			\

And remove the above.

-- Steve

> -		WARN_ON_ONCE(rcuidle && in_nmi());			\
> +		if (WARN_ON_ONCE(RCUIDLE_COND(rcuidle)))		\
> +			return;						\
>  									\
>  		/* keep srcu and sched-rcu usage consistent */		\
>  		preempt_disable_notrace();				\
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -3104,6 +3104,9 @@ void __trace_stack(struct trace_array *t
>  		return;
>  	}
>  
> +	if (WARN_ON_ONCE(IS_ENABLED(CONFIG_GENERIC_ENTRY)))
> +		return;
> +
>  	/*
>  	 * When an NMI triggers, RCU is enabled via ct_nmi_enter(),
>  	 * but if the above rcu_is_watching() failed, then the NMI
> 

Re: [PATCH v2 33/44] ftrace: WARN on rcuidle

[Mark Rutland]

On Mon, Sep 19, 2022 at 12:00:12PM +0200, Peter Zijlstra wrote:
> CONFIG_GENERIC_ENTRY disallows any and all tracing when RCU isn't
> enabled.
> 
> XXX if s390 (the only other GENERIC_ENTRY user as of this writing)
> isn't comfortable with this, we could switch to
> HAVE_NOINSTR_VALIDATION which is x86_64 only atm.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
>  include/linux/tracepoint.h |   13 ++++++++++++-
>  kernel/trace/trace.c       |    3 +++
>  2 files changed, 15 insertions(+), 1 deletion(-)
> 
> --- a/include/linux/tracepoint.h
> +++ b/include/linux/tracepoint.h
> @@ -178,6 +178,16 @@ static inline struct tracepoint *tracepo
>  #endif /* CONFIG_HAVE_STATIC_CALL */
>  
>  /*
> + * CONFIG_GENERIC_ENTRY archs are expected to have sanitized entry and idle
> + * code that disallow any/all tracing/instrumentation when RCU isn't watching.
> + */
> +#ifdef CONFIG_GENERIC_ENTRY
> +#define RCUIDLE_COND(rcuidle)	(rcuidle)
> +#else
> +#define RCUIDLE_COND(rcuidle)	(rcuidle && in_nmi())
> +#endif

Could we make this depend on ARCH_WANTS_NO_INSTR instead?

That'll allow arm64 to check this even though we're not using the generic entry
code (and there's lots of work necessary to make that possible...).

Thanks,
Mark.

> +
> +/*
>   * it_func[0] is never NULL because there is at least one element in the array
>   * when the array itself is non NULL.
>   */
> @@ -189,7 +199,8 @@ static inline struct tracepoint *tracepo
>  			return;						\
>  									\
>  		/* srcu can't be used from NMI */			\
> -		WARN_ON_ONCE(rcuidle && in_nmi());			\
> +		if (WARN_ON_ONCE(RCUIDLE_COND(rcuidle)))		\
> +			return;						\
>  									\
>  		/* keep srcu and sched-rcu usage consistent */		\
>  		preempt_disable_notrace();				\
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -3104,6 +3104,9 @@ void __trace_stack(struct trace_array *t
>  		return;
>  	}
>  
> +	if (WARN_ON_ONCE(IS_ENABLED(CONFIG_GENERIC_ENTRY)))
> +		return;
> +
>  	/*
>  	 * When an NMI triggers, RCU is enabled via ct_nmi_enter(),
>  	 * but if the above rcu_is_watching() failed, then the NMI
> 
> 

[PATCH v2 34/44] cpuidle,omap3: Use WFI for omap3_pm_idle()

[Peter Zijlstra]

arch_cpu_idle() is a very simple idle interface and exposes only a
single idle state and is expected to not require RCU and not do any
tracing/instrumentation.

As such, omap_sram_idle() is not a valid implementation. Replace it
with the simple (shallow) omap3_do_wfi() call. Leaving the more
complicated idle states for the cpuidle driver.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/mach-omap2/pm34xx.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -294,7 +294,7 @@ static void omap3_pm_idle(void)
 	if (omap_irq_pending())
 		return;
 
-	omap_sram_idle();
+	omap3_do_wfi();
 }
 
 #ifdef CONFIG_SUSPEND

[PATCH v2 35/44] cpuidle,omap3: Push RCU-idle into omap_sram_idle()

[Peter Zijlstra]

OMAP3 uses full SoC suspend modes as idle states, as such it needs the
whole power-domain and clock-domain code from the idle path.

All that code is not suitable to run with RCU disabled, as such push
RCU-idle deeper still.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/mach-omap2/cpuidle34xx.c |    4 +---
 arch/arm/mach-omap2/pm.h          |    2 +-
 arch/arm/mach-omap2/pm34xx.c      |   12 ++++++++++--
 3 files changed, 12 insertions(+), 6 deletions(-)

--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -133,9 +133,7 @@ static int omap3_enter_idle(struct cpuid
 	}
 
 	/* Execute ARM wfi */
-	ct_cpuidle_enter();
-	omap_sram_idle();
-	ct_cpuidle_exit();
+	omap_sram_idle(true);
 
 	/*
 	 * Call idle CPU PM enter notifier chain to restore
--- a/arch/arm/mach-omap2/pm.h
+++ b/arch/arm/mach-omap2/pm.h
@@ -29,7 +29,7 @@ static inline int omap4_idle_init(void)
 
 extern void *omap3_secure_ram_storage;
 extern void omap3_pm_off_mode_enable(int);
-extern void omap_sram_idle(void);
+extern void omap_sram_idle(bool rcuidle);
 extern int omap_pm_clkdms_setup(struct clockdomain *clkdm, void *unused);
 
 #if defined(CONFIG_PM_OPP)
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -26,6 +26,7 @@
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/of.h>
+#include <linux/cpuidle.h>
 
 #include <trace/events/power.h>
 
@@ -174,7 +175,7 @@ static int omap34xx_do_sram_idle(unsigne
 	return 0;
 }
 
-void omap_sram_idle(void)
+void omap_sram_idle(bool rcuidle)
 {
 	/* Variable to tell what needs to be saved and restored
 	 * in omap_sram_idle*/
@@ -254,11 +255,18 @@ void omap_sram_idle(void)
 	 */
 	if (save_state)
 		omap34xx_save_context(omap3_arm_context);
+
+	if (rcuidle)
+		ct_cpuidle_enter();
+
 	if (save_state == 1 || save_state == 3)
 		cpu_suspend(save_state, omap34xx_do_sram_idle);
 	else
 		omap34xx_do_sram_idle(save_state);
 
+	if (rcuidle)
+		ct_cpuidle_exit();
+
 	/* Restore normal SDRC POWER settings */
 	if (cpu_is_omap3430() && omap_rev() >= OMAP3430_REV_ES3_0 &&
 	    (omap_type() == OMAP2_DEVICE_TYPE_EMU ||
@@ -316,7 +324,7 @@ static int omap3_pm_suspend(void)
 
 	omap3_intc_suspend();
 
-	omap_sram_idle();
+	omap_sram_idle(false);
 
 restore:
 	/* Restore next_pwrsts */

[PATCH v2 36/44] cpuidle,omap4: Push RCU-idle into omap4_enter_lowpower()

[Peter Zijlstra]

From: Tony Lindgren <tony@atomide.com>

OMAP4 uses full SoC suspend modes as idle states, as such it needs the
whole power-domain and clock-domain code from the idle path.

All that code is not suitable to run with RCU disabled, as such push
RCU-idle deeper still.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/Yqcv6crSNKuSWoTu@atomide.com
---
 arch/arm/mach-omap2/common.h              |    6 ++++--
 arch/arm/mach-omap2/cpuidle44xx.c         |    8 ++------
 arch/arm/mach-omap2/omap-mpuss-lowpower.c |   12 +++++++++++-
 arch/arm/mach-omap2/pm44xx.c              |    2 +-
 4 files changed, 18 insertions(+), 10 deletions(-)

--- a/arch/arm/mach-omap2/common.h
+++ b/arch/arm/mach-omap2/common.h
@@ -284,11 +284,13 @@ extern u32 omap4_get_cpu1_ns_pa_addr(voi
 
 #if defined(CONFIG_SMP) && defined(CONFIG_PM)
 extern int omap4_mpuss_init(void);
-extern int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state);
+extern int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state,
+				bool rcuidle);
 extern int omap4_hotplug_cpu(unsigned int cpu, unsigned int power_state);
 #else
 static inline int omap4_enter_lowpower(unsigned int cpu,
-					unsigned int power_state)
+					unsigned int power_state,
+					bool rcuidle)
 {
 	cpu_do_idle();
 	return 0;
--- a/arch/arm/mach-omap2/cpuidle44xx.c
+++ b/arch/arm/mach-omap2/cpuidle44xx.c
@@ -105,9 +105,7 @@ static int omap_enter_idle_smp(struct cp
 	}
 	raw_spin_unlock_irqrestore(&mpu_lock, flag);
 
-	ct_cpuidle_enter();
-	omap4_enter_lowpower(dev->cpu, cx->cpu_state);
-	ct_cpuidle_exit();
+	omap4_enter_lowpower(dev->cpu, cx->cpu_state, true);
 
 	raw_spin_lock_irqsave(&mpu_lock, flag);
 	if (cx->mpu_state_vote == num_online_cpus())
@@ -186,10 +184,8 @@ static int omap_enter_idle_coupled(struc
 		}
 	}
 
-	ct_cpuidle_enter();
-	omap4_enter_lowpower(dev->cpu, cx->cpu_state);
+	omap4_enter_lowpower(dev->cpu, cx->cpu_state, true);
 	cpu_done[dev->cpu] = true;
-	ct_cpuidle_exit();
 
 	/* Wakeup CPU1 only if it is not offlined */
 	if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
--- a/arch/arm/mach-omap2/omap-mpuss-lowpower.c
+++ b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
@@ -33,6 +33,7 @@
  * and first to wake-up when MPUSS low power states are excercised
  */
 
+#include <linux/cpuidle.h>
 #include <linux/kernel.h>
 #include <linux/io.h>
 #include <linux/errno.h>
@@ -214,6 +215,7 @@ static void __init save_l2x0_context(voi
  * of OMAP4 MPUSS subsystem
  * @cpu : CPU ID
  * @power_state: Low power state.
+ * @rcuidle: RCU needs to be idled
  *
  * MPUSS states for the context save:
  * save_state =
@@ -222,7 +224,8 @@ static void __init save_l2x0_context(voi
  *	2 - CPUx L1 and logic lost + GIC lost: MPUSS OSWR
  *	3 - CPUx L1 and logic lost + GIC + L2 lost: DEVICE OFF
  */
-int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
+int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state,
+			 bool rcuidle)
 {
 	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu);
 	unsigned int save_state = 0, cpu_logic_state = PWRDM_POWER_RET;
@@ -268,6 +271,10 @@ int omap4_enter_lowpower(unsigned int cp
 	cpu_clear_prev_logic_pwrst(cpu);
 	pwrdm_set_next_pwrst(pm_info->pwrdm, power_state);
 	pwrdm_set_logic_retst(pm_info->pwrdm, cpu_logic_state);
+
+	if (rcuidle)
+		ct_cpuidle_enter();
+
 	set_cpu_wakeup_addr(cpu, __pa_symbol(omap_pm_ops.resume));
 	omap_pm_ops.scu_prepare(cpu, power_state);
 	l2x0_pwrst_prepare(cpu, save_state);
@@ -283,6 +290,9 @@ int omap4_enter_lowpower(unsigned int cp
 	if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) && cpu)
 		gic_dist_enable();
 
+	if (rcuidle)
+		ct_cpuidle_exit();
+
 	/*
 	 * Restore the CPUx power state to ON otherwise CPUx
 	 * power domain can transitions to programmed low power
--- a/arch/arm/mach-omap2/pm44xx.c
+++ b/arch/arm/mach-omap2/pm44xx.c
@@ -76,7 +76,7 @@ static int omap4_pm_suspend(void)
 	 * domain CSWR is not supported by hardware.
 	 * More details can be found in OMAP4430 TRM section 4.3.4.2.
 	 */
-	omap4_enter_lowpower(cpu_id, cpu_suspend_state);
+	omap4_enter_lowpower(cpu_id, cpu_suspend_state, false);
 
 	/* Restore next powerdomain state */
 	list_for_each_entry(pwrst, &pwrst_list, node) {

[PATCH v2 37/44] arm,omap2: Use WFI for omap2_pm_idle()

[Peter Zijlstra]

arch_cpu_idle() is a very simple idle interface and exposes only a
single idle state and is expected to not require RCU and not do any
tracing/instrumentation.

As such, omap2_pm_idle() is not a valid implementation. Replace it
with a simple (shallow) omap2_do_wfi() call.

Omap2 doesn't have a cpuidle driver; but adding one would be the
recourse to (re)gain the other idle states.

Suggested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/arm/mach-omap2/pm24xx.c |   51 +------------------------------------------
 1 file changed, 2 insertions(+), 49 deletions(-)

--- a/arch/arm/mach-omap2/pm24xx.c
+++ b/arch/arm/mach-omap2/pm24xx.c
@@ -116,50 +116,12 @@ static int omap2_enter_full_retention(vo
 
 static int sti_console_enabled;
 
-static int omap2_allow_mpu_retention(void)
-{
-	if (!omap2xxx_cm_mpu_retention_allowed())
-		return 0;
-	if (sti_console_enabled)
-		return 0;
-
-	return 1;
-}
-
-static void omap2_enter_mpu_retention(void)
+static void omap2_do_wfi(void)
 {
 	const int zero = 0;
 
-	/* The peripherals seem not to be able to wake up the MPU when
-	 * it is in retention mode. */
-	if (omap2_allow_mpu_retention()) {
-		/* REVISIT: These write to reserved bits? */
-		omap_prm_clear_mod_irqs(CORE_MOD, PM_WKST1, ~0);
-		omap_prm_clear_mod_irqs(CORE_MOD, OMAP24XX_PM_WKST2, ~0);
-		omap_prm_clear_mod_irqs(WKUP_MOD, PM_WKST, ~0);
-
-		/* Try to enter MPU retention */
-		pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_RET);
-
-	} else {
-		/* Block MPU retention */
-		pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_ON);
-	}
-
 	/* WFI */
 	asm("mcr p15, 0, %0, c7, c0, 4" : : "r" (zero) : "memory", "cc");
-
-	pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_ON);
-}
-
-static int omap2_can_sleep(void)
-{
-	if (omap2xxx_cm_fclks_active())
-		return 0;
-	if (__clk_is_enabled(osc_ck))
-		return 0;
-
-	return 1;
 }
 
 static void omap2_pm_idle(void)
@@ -169,16 +131,7 @@ static void omap2_pm_idle(void)
 	if (omap_irq_pending())
 		return;
 
-	error = cpu_cluster_pm_enter();
-	if (error || !omap2_can_sleep()) {
-		omap2_enter_mpu_retention();
-		goto out_cpu_cluster_pm;
-	}
-
-	omap2_enter_full_retention();
-
-out_cpu_cluster_pm:
-	cpu_cluster_pm_exit();
+	omap2_do_wfi();
 }
 
 static void __init prcm_setup_regs(void)

Re: [PATCH v2 37/44] arm,omap2: Use WFI for omap2_pm_idle()

[Tony Lindgren]

* Peter Zijlstra <peterz@infradead.org> [220919 10:09]:
> arch_cpu_idle() is a very simple idle interface and exposes only a
> single idle state and is expected to not require RCU and not do any
> tracing/instrumentation.
> 
> As such, omap2_pm_idle() is not a valid implementation. Replace it
> with a simple (shallow) omap2_do_wfi() call.
> 
> Omap2 doesn't have a cpuidle driver; but adding one would be the
> recourse to (re)gain the other idle states.

Looks good to me thanks:

Acked-by: Tony Lindgren <tony@atomide.com>

[PATCH v2 38/44] cpuidle,powerdomain: Remove trace_.*_rcuidle()

[Peter Zijlstra]

OMAP was the one and only user.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/arm/mach-omap2/powerdomain.c |   10 +++++-----
 drivers/base/power/runtime.c      |   24 ++++++++++++------------
 2 files changed, 17 insertions(+), 17 deletions(-)

--- a/arch/arm/mach-omap2/powerdomain.c
+++ b/arch/arm/mach-omap2/powerdomain.c
@@ -187,9 +187,9 @@ static int _pwrdm_state_switch(struct po
 			trace_state = (PWRDM_TRACE_STATES_FLAG |
 				       ((next & OMAP_POWERSTATE_MASK) << 8) |
 				       ((prev & OMAP_POWERSTATE_MASK) << 0));
-			trace_power_domain_target_rcuidle(pwrdm->name,
-							  trace_state,
-							  raw_smp_processor_id());
+			trace_power_domain_target(pwrdm->name,
+						  trace_state,
+						  raw_smp_processor_id());
 		}
 		break;
 	default:
@@ -541,8 +541,8 @@ int pwrdm_set_next_pwrst(struct powerdom
 
 	if (arch_pwrdm && arch_pwrdm->pwrdm_set_next_pwrst) {
 		/* Trace the pwrdm desired target state */
-		trace_power_domain_target_rcuidle(pwrdm->name, pwrst,
-						  raw_smp_processor_id());
+		trace_power_domain_target(pwrdm->name, pwrst,
+					  raw_smp_processor_id());
 		/* Program the pwrdm desired target state */
 		ret = arch_pwrdm->pwrdm_set_next_pwrst(pwrdm, pwrst);
 	}
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -442,7 +442,7 @@ static int rpm_idle(struct device *dev,
 	int (*callback)(struct device *);
 	int retval;
 
-	trace_rpm_idle_rcuidle(dev, rpmflags);
+	trace_rpm_idle(dev, rpmflags);
 	retval = rpm_check_suspend_allowed(dev);
 	if (retval < 0)
 		;	/* Conditions are wrong. */
@@ -481,7 +481,7 @@ static int rpm_idle(struct device *dev,
 			dev->power.request_pending = true;
 			queue_work(pm_wq, &dev->power.work);
 		}
-		trace_rpm_return_int_rcuidle(dev, _THIS_IP_, 0);
+		trace_rpm_return_int(dev, _THIS_IP_, 0);
 		return 0;
 	}
 
@@ -493,7 +493,7 @@ static int rpm_idle(struct device *dev,
 	wake_up_all(&dev->power.wait_queue);
 
  out:
-	trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
+	trace_rpm_return_int(dev, _THIS_IP_, retval);
 	return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO);
 }
 
@@ -557,7 +557,7 @@ static int rpm_suspend(struct device *de
 	struct device *parent = NULL;
 	int retval;
 
-	trace_rpm_suspend_rcuidle(dev, rpmflags);
+	trace_rpm_suspend(dev, rpmflags);
 
  repeat:
 	retval = rpm_check_suspend_allowed(dev);
@@ -708,7 +708,7 @@ static int rpm_suspend(struct device *de
 	}
 
  out:
-	trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
+	trace_rpm_return_int(dev, _THIS_IP_, retval);
 
 	return retval;
 
@@ -760,7 +760,7 @@ static int rpm_resume(struct device *dev
 	struct device *parent = NULL;
 	int retval = 0;
 
-	trace_rpm_resume_rcuidle(dev, rpmflags);
+	trace_rpm_resume(dev, rpmflags);
 
  repeat:
 	if (dev->power.runtime_error) {
@@ -925,7 +925,7 @@ static int rpm_resume(struct device *dev
 		spin_lock_irq(&dev->power.lock);
 	}
 
-	trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
+	trace_rpm_return_int(dev, _THIS_IP_, retval);
 
 	return retval;
 }
@@ -1081,7 +1081,7 @@ int __pm_runtime_idle(struct device *dev
 		if (retval < 0) {
 			return retval;
 		} else if (retval > 0) {
-			trace_rpm_usage_rcuidle(dev, rpmflags);
+			trace_rpm_usage(dev, rpmflags);
 			return 0;
 		}
 	}
@@ -1119,7 +1119,7 @@ int __pm_runtime_suspend(struct device *
 		if (retval < 0) {
 			return retval;
 		} else if (retval > 0) {
-			trace_rpm_usage_rcuidle(dev, rpmflags);
+			trace_rpm_usage(dev, rpmflags);
 			return 0;
 		}
 	}
@@ -1202,7 +1202,7 @@ int pm_runtime_get_if_active(struct devi
 	} else {
 		retval = atomic_inc_not_zero(&dev->power.usage_count);
 	}
-	trace_rpm_usage_rcuidle(dev, 0);
+	trace_rpm_usage(dev, 0);
 	spin_unlock_irqrestore(&dev->power.lock, flags);
 
 	return retval;
@@ -1566,7 +1566,7 @@ void pm_runtime_allow(struct device *dev
 	if (ret == 0)
 		rpm_idle(dev, RPM_AUTO | RPM_ASYNC);
 	else if (ret > 0)
-		trace_rpm_usage_rcuidle(dev, RPM_AUTO | RPM_ASYNC);
+		trace_rpm_usage(dev, RPM_AUTO | RPM_ASYNC);
 
  out:
 	spin_unlock_irq(&dev->power.lock);
@@ -1635,7 +1635,7 @@ static void update_autosuspend(struct de
 			atomic_inc(&dev->power.usage_count);
 			rpm_resume(dev, 0);
 		} else {
-			trace_rpm_usage_rcuidle(dev, 0);
+			trace_rpm_usage(dev, 0);
 		}
 	}
 

Re: [PATCH v2 38/44] cpuidle,powerdomain: Remove trace_.*_rcuidle()

[Ulf Hansson]

On Mon, 19 Sept 2022 at 12:17, Peter Zijlstra <peterz@infradead.org> wrote:
>
> OMAP was the one and only user.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

There are changes to the runtime PM core as part of $subject patch.
Perhaps move those parts into a separate patch? In any case, the code
looks good to me.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Kind regards
Uffe

> ---
>  arch/arm/mach-omap2/powerdomain.c |   10 +++++-----
>  drivers/base/power/runtime.c      |   24 ++++++++++++------------
>  2 files changed, 17 insertions(+), 17 deletions(-)
>
> --- a/arch/arm/mach-omap2/powerdomain.c
> +++ b/arch/arm/mach-omap2/powerdomain.c
> @@ -187,9 +187,9 @@ static int _pwrdm_state_switch(struct po
>                         trace_state = (PWRDM_TRACE_STATES_FLAG |
>                                        ((next & OMAP_POWERSTATE_MASK) << 8) |
>                                        ((prev & OMAP_POWERSTATE_MASK) << 0));
> -                       trace_power_domain_target_rcuidle(pwrdm->name,
> -                                                         trace_state,
> -                                                         raw_smp_processor_id());
> +                       trace_power_domain_target(pwrdm->name,
> +                                                 trace_state,
> +                                                 raw_smp_processor_id());
>                 }
>                 break;
>         default:
> @@ -541,8 +541,8 @@ int pwrdm_set_next_pwrst(struct powerdom
>
>         if (arch_pwrdm && arch_pwrdm->pwrdm_set_next_pwrst) {
>                 /* Trace the pwrdm desired target state */
> -               trace_power_domain_target_rcuidle(pwrdm->name, pwrst,
> -                                                 raw_smp_processor_id());
> +               trace_power_domain_target(pwrdm->name, pwrst,
> +                                         raw_smp_processor_id());
>                 /* Program the pwrdm desired target state */
>                 ret = arch_pwrdm->pwrdm_set_next_pwrst(pwrdm, pwrst);
>         }
> --- a/drivers/base/power/runtime.c
> +++ b/drivers/base/power/runtime.c
> @@ -442,7 +442,7 @@ static int rpm_idle(struct device *dev,
>         int (*callback)(struct device *);
>         int retval;
>
> -       trace_rpm_idle_rcuidle(dev, rpmflags);
> +       trace_rpm_idle(dev, rpmflags);
>         retval = rpm_check_suspend_allowed(dev);
>         if (retval < 0)
>                 ;       /* Conditions are wrong. */
> @@ -481,7 +481,7 @@ static int rpm_idle(struct device *dev,
>                         dev->power.request_pending = true;
>                         queue_work(pm_wq, &dev->power.work);
>                 }
> -               trace_rpm_return_int_rcuidle(dev, _THIS_IP_, 0);
> +               trace_rpm_return_int(dev, _THIS_IP_, 0);
>                 return 0;
>         }
>
> @@ -493,7 +493,7 @@ static int rpm_idle(struct device *dev,
>         wake_up_all(&dev->power.wait_queue);
>
>   out:
> -       trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
> +       trace_rpm_return_int(dev, _THIS_IP_, retval);
>         return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO);
>  }
>
> @@ -557,7 +557,7 @@ static int rpm_suspend(struct device *de
>         struct device *parent = NULL;
>         int retval;
>
> -       trace_rpm_suspend_rcuidle(dev, rpmflags);
> +       trace_rpm_suspend(dev, rpmflags);
>
>   repeat:
>         retval = rpm_check_suspend_allowed(dev);
> @@ -708,7 +708,7 @@ static int rpm_suspend(struct device *de
>         }
>
>   out:
> -       trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
> +       trace_rpm_return_int(dev, _THIS_IP_, retval);
>
>         return retval;
>
> @@ -760,7 +760,7 @@ static int rpm_resume(struct device *dev
>         struct device *parent = NULL;
>         int retval = 0;
>
> -       trace_rpm_resume_rcuidle(dev, rpmflags);
> +       trace_rpm_resume(dev, rpmflags);
>
>   repeat:
>         if (dev->power.runtime_error) {
> @@ -925,7 +925,7 @@ static int rpm_resume(struct device *dev
>                 spin_lock_irq(&dev->power.lock);
>         }
>
> -       trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
> +       trace_rpm_return_int(dev, _THIS_IP_, retval);
>
>         return retval;
>  }
> @@ -1081,7 +1081,7 @@ int __pm_runtime_idle(struct device *dev
>                 if (retval < 0) {
>                         return retval;
>                 } else if (retval > 0) {
> -                       trace_rpm_usage_rcuidle(dev, rpmflags);
> +                       trace_rpm_usage(dev, rpmflags);
>                         return 0;
>                 }
>         }
> @@ -1119,7 +1119,7 @@ int __pm_runtime_suspend(struct device *
>                 if (retval < 0) {
>                         return retval;
>                 } else if (retval > 0) {
> -                       trace_rpm_usage_rcuidle(dev, rpmflags);
> +                       trace_rpm_usage(dev, rpmflags);
>                         return 0;
>                 }
>         }
> @@ -1202,7 +1202,7 @@ int pm_runtime_get_if_active(struct devi
>         } else {
>                 retval = atomic_inc_not_zero(&dev->power.usage_count);
>         }
> -       trace_rpm_usage_rcuidle(dev, 0);
> +       trace_rpm_usage(dev, 0);
>         spin_unlock_irqrestore(&dev->power.lock, flags);
>
>         return retval;
> @@ -1566,7 +1566,7 @@ void pm_runtime_allow(struct device *dev
>         if (ret == 0)
>                 rpm_idle(dev, RPM_AUTO | RPM_ASYNC);
>         else if (ret > 0)
> -               trace_rpm_usage_rcuidle(dev, RPM_AUTO | RPM_ASYNC);
> +               trace_rpm_usage(dev, RPM_AUTO | RPM_ASYNC);
>
>   out:
>         spin_unlock_irq(&dev->power.lock);
> @@ -1635,7 +1635,7 @@ static void update_autosuspend(struct de
>                         atomic_inc(&dev->power.usage_count);
>                         rpm_resume(dev, 0);
>                 } else {
> -                       trace_rpm_usage_rcuidle(dev, 0);
> +                       trace_rpm_usage(dev, 0);
>                 }
>         }
>
>
>
> _______________________________________________
> Virtualization mailing list
> Virtualization@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/virtualization

[PATCH v2 39/44] cpuidle,clk: Remove trace_.*_rcuidle()

[Peter Zijlstra]

OMAP was the one and only user.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 drivers/clk/clk.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -978,12 +978,12 @@ static void clk_core_disable(struct clk_
 	if (--core->enable_count > 0)
 		return;
 
-	trace_clk_disable_rcuidle(core);
+	trace_clk_disable(core);
 
 	if (core->ops->disable)
 		core->ops->disable(core->hw);
 
-	trace_clk_disable_complete_rcuidle(core);
+	trace_clk_disable_complete(core);
 
 	clk_core_disable(core->parent);
 }
@@ -1037,12 +1037,12 @@ static int clk_core_enable(struct clk_co
 		if (ret)
 			return ret;
 
-		trace_clk_enable_rcuidle(core);
+		trace_clk_enable(core);
 
 		if (core->ops->enable)
 			ret = core->ops->enable(core->hw);
 
-		trace_clk_enable_complete_rcuidle(core);
+		trace_clk_enable_complete(core);
 
 		if (ret) {
 			clk_core_disable(core->parent);

Re: [PATCH v2 39/44] cpuidle,clk: Remove trace_.*_rcuidle()

[Ulf Hansson]

On Mon, 19 Sept 2022 at 12:17, Peter Zijlstra <peterz@infradead.org> wrote:
>
> OMAP was the one and only user.

OMAP? :-)

>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Kind regards
Uffe

> ---
>  drivers/clk/clk.c |    8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -978,12 +978,12 @@ static void clk_core_disable(struct clk_
>         if (--core->enable_count > 0)
>                 return;
>
> -       trace_clk_disable_rcuidle(core);
> +       trace_clk_disable(core);
>
>         if (core->ops->disable)
>                 core->ops->disable(core->hw);
>
> -       trace_clk_disable_complete_rcuidle(core);
> +       trace_clk_disable_complete(core);
>
>         clk_core_disable(core->parent);
>  }
> @@ -1037,12 +1037,12 @@ static int clk_core_enable(struct clk_co
>                 if (ret)
>                         return ret;
>
> -               trace_clk_enable_rcuidle(core);
> +               trace_clk_enable(core);
>
>                 if (core->ops->enable)
>                         ret = core->ops->enable(core->hw);
>
> -               trace_clk_enable_complete_rcuidle(core);
> +               trace_clk_enable_complete(core);
>
>                 if (ret) {
>                         clk_core_disable(core->parent);
>
>
> _______________________________________________
> Virtualization mailing list
> Virtualization@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/virtualization

[PATCH v2 40/44] ubsan: Fix objtool UACCESS warns

[Peter Zijlstra]

clang-14 allyesconfig gives:

vmlinux.o: warning: objtool: emulator_cmpxchg_emulated+0x705: call to __ubsan_handle_load_invalid_value() with UACCESS enabled
vmlinux.o: warning: objtool: paging64_update_accessed_dirty_bits+0x39e: call to __ubsan_handle_load_invalid_value() with UACCESS enabled
vmlinux.o: warning: objtool: paging32_update_accessed_dirty_bits+0x390: call to __ubsan_handle_load_invalid_value() with UACCESS enabled
vmlinux.o: warning: objtool: ept_update_accessed_dirty_bits+0x43f: call to __ubsan_handle_load_invalid_value() with UACCESS enabled

Add the required eflags save/restore and whitelist the thing.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 lib/ubsan.c           |    5 ++++-
 tools/objtool/check.c |    1 +
 2 files changed, 5 insertions(+), 1 deletion(-)

--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -340,9 +340,10 @@ void __ubsan_handle_load_invalid_value(v
 {
 	struct invalid_value_data *data = _data;
 	char val_str[VALUE_LENGTH];
+	unsigned long ua_flags = user_access_save();
 
 	if (suppress_report(&data->location))
-		return;
+		goto out;
 
 	ubsan_prologue(&data->location, "invalid-load");
 
@@ -352,6 +353,8 @@ void __ubsan_handle_load_invalid_value(v
 		val_str, data->type->type_name);
 
 	ubsan_epilogue();
+out:
+	user_access_restore(ua_flags);
 }
 EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
 
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1068,6 +1068,7 @@ static const char *uaccess_safe_builtin[
 	"__ubsan_handle_type_mismatch",
 	"__ubsan_handle_type_mismatch_v1",
 	"__ubsan_handle_shift_out_of_bounds",
+	"__ubsan_handle_load_invalid_value",
 	/* misc */
 	"csum_partial_copy_generic",
 	"copy_mc_fragile",

[PATCH v2 41/44] intel_idle: Add force_irq_on module param

[Peter Zijlstra]

For testing purposes.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 drivers/idle/intel_idle.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -1787,6 +1787,9 @@ static bool __init intel_idle_verify_cst
 	return true;
 }
 
+static bool force_irq_on __read_mostly;
+module_param(force_irq_on, bool, 0444);
+
 static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
 {
 	int cstate;
@@ -1838,8 +1841,10 @@ static void __init intel_idle_init_cstat
 		/* Structure copy. */
 		drv->states[drv->state_count] = cpuidle_state_table[cstate];
 
-		if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_IRQ_ENABLE)
+		if ((cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_IRQ_ENABLE) || force_irq_on) {
+			printk("intel_idle: forced intel_idle_irq for state %d\n", cstate);
 			drv->states[drv->state_count].enter = intel_idle_irq;
+		}
 
 		if (cpu_feature_enabled(X86_FEATURE_KERNEL_IBRS) &&
 		    cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_IBRS) {

[PATCH v2 42/44] entry,kasan,x86: Disallow overriding mem*() functions

[Peter Zijlstra]

KASAN cannot just hijack the mem*() functions, it needs to emit
__asan_mem*() variants if it wants instrumentation (other sanitizers
already do this).

vmlinux.o: warning: objtool: sync_regs+0x24: call to memcpy() leaves .noinstr.text section
vmlinux.o: warning: objtool: vc_switch_off_ist+0xbe: call to memcpy() leaves .noinstr.text section
vmlinux.o: warning: objtool: fixup_bad_iret+0x36: call to memset() leaves .noinstr.text section
vmlinux.o: warning: objtool: __sev_get_ghcb+0xa0: call to memcpy() leaves .noinstr.text section
vmlinux.o: warning: objtool: __sev_put_ghcb+0x35: call to memcpy() leaves .noinstr.text section

Remove the weak aliases to ensure nobody hijacks these functions and
add them to the noinstr section.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/lib/memcpy_64.S  |    5 ++---
 arch/x86/lib/memmove_64.S |    4 +++-
 arch/x86/lib/memset_64.S  |    4 +++-
 mm/kasan/kasan.h          |    4 ++++
 mm/kasan/shadow.c         |   38 ++++++++++++++++++++++++++++++++++++++
 tools/objtool/check.c     |    3 +++
 6 files changed, 53 insertions(+), 5 deletions(-)

--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -7,7 +7,7 @@
 #include <asm/alternative.h>
 #include <asm/export.h>
 
-.pushsection .noinstr.text, "ax"
+.section .noinstr.text, "ax"
 
 /*
  * We build a jump to memcpy_orig by default which gets NOPped out on
@@ -42,7 +42,7 @@ SYM_FUNC_START(__memcpy)
 SYM_FUNC_END(__memcpy)
 EXPORT_SYMBOL(__memcpy)
 
-SYM_FUNC_ALIAS_WEAK(memcpy, __memcpy)
+SYM_FUNC_ALIAS(memcpy, __memcpy)
 EXPORT_SYMBOL(memcpy)
 
 /*
@@ -183,4 +183,3 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
 	RET
 SYM_FUNC_END(memcpy_orig)
 
-.popsection
--- a/arch/x86/lib/memmove_64.S
+++ b/arch/x86/lib/memmove_64.S
@@ -13,6 +13,8 @@
 
 #undef memmove
 
+.section .noinstr.text, "ax"
+
 /*
  * Implement memmove(). This can handle overlap between src and dst.
  *
@@ -213,5 +215,5 @@ SYM_FUNC_START(__memmove)
 SYM_FUNC_END(__memmove)
 EXPORT_SYMBOL(__memmove)
 
-SYM_FUNC_ALIAS_WEAK(memmove, __memmove)
+SYM_FUNC_ALIAS(memmove, __memmove)
 EXPORT_SYMBOL(memmove)
--- a/arch/x86/lib/memset_64.S
+++ b/arch/x86/lib/memset_64.S
@@ -6,6 +6,8 @@
 #include <asm/alternative.h>
 #include <asm/export.h>
 
+.section .noinstr.text, "ax"
+
 /*
  * ISO C memset - set a memory block to a byte value. This function uses fast
  * string to get better performance than the original function. The code is
@@ -43,7 +45,7 @@ SYM_FUNC_START(__memset)
 SYM_FUNC_END(__memset)
 EXPORT_SYMBOL(__memset)
 
-SYM_FUNC_ALIAS_WEAK(memset, __memset)
+SYM_FUNC_ALIAS(memset, __memset)
 EXPORT_SYMBOL(memset)
 
 /*
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -551,6 +551,10 @@ void __asan_set_shadow_f3(const void *ad
 void __asan_set_shadow_f5(const void *addr, size_t size);
 void __asan_set_shadow_f8(const void *addr, size_t size);
 
+void *__asan_memset(void *addr, int c, size_t len);
+void *__asan_memmove(void *dest, const void *src, size_t len);
+void *__asan_memcpy(void *dest, const void *src, size_t len);
+
 void __hwasan_load1_noabort(unsigned long addr);
 void __hwasan_store1_noabort(unsigned long addr);
 void __hwasan_load2_noabort(unsigned long addr);
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -38,6 +38,12 @@ bool __kasan_check_write(const volatile
 }
 EXPORT_SYMBOL(__kasan_check_write);
 
+#ifndef CONFIG_GENERIC_ENTRY
+/*
+ * CONFIG_GENERIC_ENTRY relies on compiler emitted mem*() calls to not be
+ * instrumented. KASAN enabled toolchains should emit __asan_mem*() functions
+ * for the sites they want to instrument.
+ */
 #undef memset
 void *memset(void *addr, int c, size_t len)
 {
@@ -68,6 +74,38 @@ void *memcpy(void *dest, const void *src
 
 	return __memcpy(dest, src, len);
 }
+#endif
+
+void *__asan_memset(void *addr, int c, size_t len)
+{
+	if (!kasan_check_range((unsigned long)addr, len, true, _RET_IP_))
+		return NULL;
+
+	return __memset(addr, c, len);
+}
+EXPORT_SYMBOL(__asan_memset);
+
+#ifdef __HAVE_ARCH_MEMMOVE
+void *__asan_memmove(void *dest, const void *src, size_t len)
+{
+	if (!kasan_check_range((unsigned long)src, len, false, _RET_IP_) ||
+	    !kasan_check_range((unsigned long)dest, len, true, _RET_IP_))
+		return NULL;
+
+	return __memmove(dest, src, len);
+}
+EXPORT_SYMBOL(__asan_memmove);
+#endif
+
+void *__asan_memcpy(void *dest, const void *src, size_t len)
+{
+	if (!kasan_check_range((unsigned long)src, len, false, _RET_IP_) ||
+	    !kasan_check_range((unsigned long)dest, len, true, _RET_IP_))
+		return NULL;
+
+	return __memcpy(dest, src, len);
+}
+EXPORT_SYMBOL(__asan_memcpy);
 
 void kasan_poison(const void *addr, size_t size, u8 value, bool init)
 {
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -956,6 +956,9 @@ static const char *uaccess_safe_builtin[
 	"__asan_store16_noabort",
 	"__kasan_check_read",
 	"__kasan_check_write",
+	"__asan_memset",
+	"__asan_memmove",
+	"__asan_memcpy",
 	/* KASAN in-line */
 	"__asan_report_load_n_noabort",
 	"__asan_report_load1_noabort",

[PATCH v2 43/44] sched: Always inline __this_cpu_preempt_check()

[Peter Zijlstra]

vmlinux.o: warning: objtool: in_entry_stack+0x9: call to __this_cpu_preempt_check() leaves .noinstr.text section
vmlinux.o: warning: objtool: default_do_nmi+0x10: call to __this_cpu_preempt_check() leaves .noinstr.text section
vmlinux.o: warning: objtool: fpu_idle_fpregs+0x41: call to __this_cpu_preempt_check() leaves .noinstr.text section
vmlinux.o: warning: objtool: kvm_read_and_reset_apf_flags+0x1: call to __this_cpu_preempt_check() leaves .noinstr.text section
vmlinux.o: warning: objtool: lockdep_hardirqs_on+0xb0: call to __this_cpu_preempt_check() leaves .noinstr.text section
vmlinux.o: warning: objtool: lockdep_hardirqs_off+0xae: call to __this_cpu_preempt_check() leaves .noinstr.text section
vmlinux.o: warning: objtool: irqentry_nmi_enter+0x69: call to __this_cpu_preempt_check() leaves .noinstr.text section
vmlinux.o: warning: objtool: irqentry_nmi_exit+0x32: call to __this_cpu_preempt_check() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_processor_ffh_cstate_enter+0x9: call to __this_cpu_preempt_check() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_idle_enter+0x43: call to __this_cpu_preempt_check() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_idle_enter_s2idle+0x45: call to __this_cpu_preempt_check() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 include/linux/percpu-defs.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -310,7 +310,7 @@ extern void __bad_size_call_parameter(vo
 #ifdef CONFIG_DEBUG_PREEMPT
 extern void __this_cpu_preempt_check(const char *op);
 #else
-static inline void __this_cpu_preempt_check(const char *op) { }
+static __always_inline void __this_cpu_preempt_check(const char *op) { }
 #endif
 
 #define __pcpu_size_call_return(stem, variable)				\

[PATCH v2 44/44] arm64,riscv,perf: Remove RCU_NONIDLE() usage

[Peter Zijlstra]

The PM notifiers should no longer be ran with RCU disabled (per the
previous patches), as such this hack is no longer required either.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 drivers/perf/arm_pmu.c       |   11 +----------
 drivers/perf/riscv_pmu_sbi.c |    8 +-------
 2 files changed, 2 insertions(+), 17 deletions(-)

--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -762,17 +762,8 @@ static void cpu_pm_pmu_setup(struct arm_
 		case CPU_PM_ENTER_FAILED:
 			 /*
 			  * Restore and enable the counter.
-			  * armpmu_start() indirectly calls
-			  *
-			  * perf_event_update_userpage()
-			  *
-			  * that requires RCU read locking to be functional,
-			  * wrap the call within RCU_NONIDLE to make the
-			  * RCU subsystem aware this cpu is not idle from
-			  * an RCU perspective for the armpmu_start() call
-			  * duration.
 			  */
-			RCU_NONIDLE(armpmu_start(event, PERF_EF_RELOAD));
+			armpmu_start(event, PERF_EF_RELOAD);
 			break;
 		default:
 			break;
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -747,14 +747,8 @@ static int riscv_pm_pmu_notify(struct no
 		case CPU_PM_ENTER_FAILED:
 			/*
 			 * Restore and enable the counter.
-			 *
-			 * Requires RCU read locking to be functional,
-			 * wrap the call within RCU_NONIDLE to make the
-			 * RCU subsystem aware this cpu is not idle from
-			 * an RCU perspective for the riscv_pmu_start() call
-			 * duration.
 			 */
-			RCU_NONIDLE(riscv_pmu_start(event, PERF_EF_RELOAD));
+			riscv_pmu_start(event, PERF_EF_RELOAD);
 			break;
 		default:
 			break;

Re: [PATCH v2 00/44] cpuidle,rcu: Clean up the mess

[Rafael J. Wysocki]

On Mon, Sep 19, 2022 at 12:17 PM Peter Zijlstra <peterz@infradead.org> wrote:
>
> Hi All!
>
> At long last, a respin of the cpuidle vs rcu cleanup patches.
>
> v1: https://lkml.kernel.org/r/20220608142723.103523089@infradead.org
>
> These here patches clean up the mess that is cpuidle vs rcuidle.
>
> At the end of the ride there's only on RCU_NONIDLE user left:
>
>   arch/arm64/kernel/suspend.c:            RCU_NONIDLE(__cpu_suspend_exit());
>
> and 'one' trace_*_rcuidle() user:
>
>   kernel/trace/trace_preemptirq.c:                        trace_irq_enable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
>   kernel/trace/trace_preemptirq.c:                        trace_irq_disable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
>   kernel/trace/trace_preemptirq.c:                        trace_irq_enable_rcuidle(CALLER_ADDR0, caller_addr);
>   kernel/trace/trace_preemptirq.c:                        trace_irq_disable_rcuidle(CALLER_ADDR0, caller_addr);
>   kernel/trace/trace_preemptirq.c:                trace_preempt_enable_rcuidle(a0, a1);
>   kernel/trace/trace_preemptirq.c:                trace_preempt_disable_rcuidle(a0, a1);
>
> However this last is all in deprecated code that should be unused for GENERIC_ENTRY.
>
> I've touched a lot of code that I can't test and I might've broken something by
> accident. In particular the whole ARM cpuidle stuff was quite involved.
>
> Please all; have a look where you haven't already.
>
>
> New since v1:
>
>  - rebase on top of Frederic's rcu-context-tracking rename fest
>  - more omap goodness as per the last discusion (thanks Tony!)
>  - removed one more RCU_NONIDLE() from arm64/risc-v perf code
>  - ubsan/kasan fixes
>  - intel_idle module-param for testing
>  - a bunch of extra __always_inline, because compilers are silly.

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

for the whole set and let me know if you want me to merge any of these
through cpuidle.

Thanks!

>
> ---
>  arch/alpha/kernel/process.c               |  1 -
>  arch/alpha/kernel/vmlinux.lds.S           |  1 -
>  arch/arc/kernel/process.c                 |  3 ++
>  arch/arc/kernel/vmlinux.lds.S             |  1 -
>  arch/arm/include/asm/vmlinux.lds.h        |  1 -
>  arch/arm/kernel/process.c                 |  1 -
>  arch/arm/kernel/smp.c                     |  6 +--
>  arch/arm/mach-gemini/board-dt.c           |  3 +-
>  arch/arm/mach-imx/cpuidle-imx6q.c         |  4 +-
>  arch/arm/mach-imx/cpuidle-imx6sx.c        |  5 ++-
>  arch/arm/mach-omap2/common.h              |  6 ++-
>  arch/arm/mach-omap2/cpuidle34xx.c         | 16 +++++++-
>  arch/arm/mach-omap2/cpuidle44xx.c         | 29 +++++++-------
>  arch/arm/mach-omap2/omap-mpuss-lowpower.c | 12 +++++-
>  arch/arm/mach-omap2/pm.h                  |  2 +-
>  arch/arm/mach-omap2/pm24xx.c              | 51 +-----------------------
>  arch/arm/mach-omap2/pm34xx.c              | 14 +++++--
>  arch/arm/mach-omap2/pm44xx.c              |  2 +-
>  arch/arm/mach-omap2/powerdomain.c         | 10 ++---
>  arch/arm64/kernel/idle.c                  |  1 -
>  arch/arm64/kernel/smp.c                   |  4 +-
>  arch/arm64/kernel/vmlinux.lds.S           |  1 -
>  arch/csky/kernel/process.c                |  1 -
>  arch/csky/kernel/smp.c                    |  2 +-
>  arch/csky/kernel/vmlinux.lds.S            |  1 -
>  arch/hexagon/kernel/process.c             |  1 -
>  arch/hexagon/kernel/vmlinux.lds.S         |  1 -
>  arch/ia64/kernel/process.c                |  1 +
>  arch/ia64/kernel/vmlinux.lds.S            |  1 -
>  arch/loongarch/kernel/idle.c              |  1 +
>  arch/loongarch/kernel/vmlinux.lds.S       |  1 -
>  arch/m68k/kernel/vmlinux-nommu.lds        |  1 -
>  arch/m68k/kernel/vmlinux-std.lds          |  1 -
>  arch/m68k/kernel/vmlinux-sun3.lds         |  1 -
>  arch/microblaze/kernel/process.c          |  1 -
>  arch/microblaze/kernel/vmlinux.lds.S      |  1 -
>  arch/mips/kernel/idle.c                   |  8 ++--
>  arch/mips/kernel/vmlinux.lds.S            |  1 -
>  arch/nios2/kernel/process.c               |  1 -
>  arch/nios2/kernel/vmlinux.lds.S           |  1 -
>  arch/openrisc/kernel/process.c            |  1 +
>  arch/openrisc/kernel/vmlinux.lds.S        |  1 -
>  arch/parisc/kernel/process.c              |  2 -
>  arch/parisc/kernel/vmlinux.lds.S          |  1 -
>  arch/powerpc/kernel/idle.c                |  5 +--
>  arch/powerpc/kernel/vmlinux.lds.S         |  1 -
>  arch/riscv/kernel/process.c               |  1 -
>  arch/riscv/kernel/vmlinux-xip.lds.S       |  1 -
>  arch/riscv/kernel/vmlinux.lds.S           |  1 -
>  arch/s390/kernel/idle.c                   |  1 -
>  arch/s390/kernel/vmlinux.lds.S            |  1 -
>  arch/sh/kernel/idle.c                     |  1 +
>  arch/sh/kernel/vmlinux.lds.S              |  1 -
>  arch/sparc/kernel/leon_pmc.c              |  4 ++
>  arch/sparc/kernel/process_32.c            |  1 -
>  arch/sparc/kernel/process_64.c            |  3 +-
>  arch/sparc/kernel/vmlinux.lds.S           |  1 -
>  arch/um/kernel/dyn.lds.S                  |  1 -
>  arch/um/kernel/process.c                  |  1 -
>  arch/um/kernel/uml.lds.S                  |  1 -
>  arch/x86/boot/compressed/vmlinux.lds.S    |  1 +
>  arch/x86/coco/tdx/tdcall.S                | 15 +------
>  arch/x86/coco/tdx/tdx.c                   | 25 ++++--------
>  arch/x86/events/amd/brs.c                 | 13 +++----
>  arch/x86/include/asm/fpu/xcr.h            |  4 +-
>  arch/x86/include/asm/irqflags.h           | 11 ++----
>  arch/x86/include/asm/mwait.h              | 14 +++----
>  arch/x86/include/asm/nospec-branch.h      |  2 +-
>  arch/x86/include/asm/paravirt.h           |  6 ++-
>  arch/x86/include/asm/perf_event.h         |  2 +-
>  arch/x86/include/asm/shared/io.h          |  4 +-
>  arch/x86/include/asm/shared/tdx.h         |  1 -
>  arch/x86/include/asm/special_insns.h      |  8 ++--
>  arch/x86/include/asm/xen/hypercall.h      |  2 +-
>  arch/x86/kernel/cpu/bugs.c                |  2 +-
>  arch/x86/kernel/fpu/core.c                |  4 +-
>  arch/x86/kernel/paravirt.c                | 14 ++++++-
>  arch/x86/kernel/process.c                 | 65 +++++++++++++++----------------
>  arch/x86/kernel/vmlinux.lds.S             |  1 -
>  arch/x86/lib/memcpy_64.S                  |  5 +--
>  arch/x86/lib/memmove_64.S                 |  4 +-
>  arch/x86/lib/memset_64.S                  |  4 +-
>  arch/x86/xen/enlighten_pv.c               |  2 +-
>  arch/x86/xen/irq.c                        |  2 +-
>  arch/xtensa/kernel/process.c              |  1 +
>  arch/xtensa/kernel/vmlinux.lds.S          |  1 -
>  drivers/acpi/processor_idle.c             | 36 ++++++++++-------
>  drivers/base/power/runtime.c              | 24 ++++++------
>  drivers/clk/clk.c                         |  8 ++--
>  drivers/cpuidle/cpuidle-arm.c             |  1 +
>  drivers/cpuidle/cpuidle-big_little.c      |  8 +++-
>  drivers/cpuidle/cpuidle-mvebu-v7.c        |  7 ++++
>  drivers/cpuidle/cpuidle-psci.c            | 10 +++--
>  drivers/cpuidle/cpuidle-qcom-spm.c        |  1 +
>  drivers/cpuidle/cpuidle-riscv-sbi.c       | 10 +++--
>  drivers/cpuidle/cpuidle-tegra.c           | 21 +++++++---
>  drivers/cpuidle/cpuidle.c                 | 21 +++++-----
>  drivers/cpuidle/dt_idle_states.c          |  2 +-
>  drivers/cpuidle/poll_state.c              | 10 ++++-
>  drivers/idle/intel_idle.c                 | 19 +++++----
>  drivers/perf/arm_pmu.c                    | 11 +-----
>  drivers/perf/riscv_pmu_sbi.c              |  8 +---
>  include/asm-generic/vmlinux.lds.h         |  9 ++---
>  include/linux/compiler_types.h            |  8 +++-
>  include/linux/cpu.h                       |  3 --
>  include/linux/cpuidle.h                   | 34 ++++++++++++++++
>  include/linux/cpumask.h                   |  4 +-
>  include/linux/percpu-defs.h               |  2 +-
>  include/linux/sched/idle.h                | 40 ++++++++++++++-----
>  include/linux/thread_info.h               | 18 ++++++++-
>  include/linux/tracepoint.h                | 13 ++++++-
>  kernel/cpu_pm.c                           |  9 -----
>  kernel/printk/printk.c                    |  2 +-
>  kernel/sched/idle.c                       | 47 +++++++---------------
>  kernel/time/tick-broadcast-hrtimer.c      | 29 ++++++--------
>  kernel/time/tick-broadcast.c              |  6 ++-
>  kernel/trace/trace.c                      |  3 ++
>  lib/ubsan.c                               |  5 ++-
>  mm/kasan/kasan.h                          |  4 ++
>  mm/kasan/shadow.c                         | 38 ++++++++++++++++++
>  tools/objtool/check.c                     | 17 ++++++++
>  121 files changed, 511 insertions(+), 420 deletions(-)
>

Re: [PATCH v2 00/44] cpuidle,rcu: Clean up the mess

[Frederic Weisbecker]

On Mon, Sep 19, 2022 at 11:59:39AM +0200, Peter Zijlstra wrote:
> Hi All!
> 
> At long last, a respin of the cpuidle vs rcu cleanup patches.
> 
> v1: https://lkml.kernel.org/r/20220608142723.103523089@infradead.org
> 
> These here patches clean up the mess that is cpuidle vs rcuidle.
> 
> At the end of the ride there's only on RCU_NONIDLE user left:
> 
>   arch/arm64/kernel/suspend.c:            RCU_NONIDLE(__cpu_suspend_exit());
> 
> and 'one' trace_*_rcuidle() user:
> 
>   kernel/trace/trace_preemptirq.c:                        trace_irq_enable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
>   kernel/trace/trace_preemptirq.c:                        trace_irq_disable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
>   kernel/trace/trace_preemptirq.c:                        trace_irq_enable_rcuidle(CALLER_ADDR0, caller_addr);
>   kernel/trace/trace_preemptirq.c:                        trace_irq_disable_rcuidle(CALLER_ADDR0, caller_addr);
>   kernel/trace/trace_preemptirq.c:                trace_preempt_enable_rcuidle(a0, a1);
>   kernel/trace/trace_preemptirq.c:                trace_preempt_disable_rcuidle(a0, a1);
> 
> However this last is all in deprecated code that should be unused for GENERIC_ENTRY.
> 
> I've touched a lot of code that I can't test and I might've broken something by
> accident. In particular the whole ARM cpuidle stuff was quite involved.
> 
> Please all; have a look where you haven't already.
> 
> 
> New since v1:
> 
>  - rebase on top of Frederic's rcu-context-tracking rename fest
>  - more omap goodness as per the last discusion (thanks Tony!)
>  - removed one more RCU_NONIDLE() from arm64/risc-v perf code
>  - ubsan/kasan fixes
>  - intel_idle module-param for testing
>  - a bunch of extra __always_inline, because compilers are silly.

Except for those I have already tagged as Reviewed:

Acked-by: Frederic Weisbecker <frederic@kernel.org>

Thanks for the hard work!

Re: [PATCH v2 00/44] cpuidle,rcu: Clean up the mess

[Peter Zijlstra]

Because Nadav asked about tracing/kprobing idle, I had another go around
and noticed not all functions calling ct_cpuidle_enter are __cpuidle.

Basically all cpuidle_driver::enter functions should be __cpuidle; i'll
do that audit shortly.

For now this is ct_cpuidle_enter / CPU_IDLE_ENTER users.

---
--- a/arch/arm/mach-imx/cpuidle-imx6q.c
+++ b/arch/arm/mach-imx/cpuidle-imx6q.c
@@ -17,8 +17,8 @@
 static int num_idle_cpus = 0;
 static DEFINE_RAW_SPINLOCK(cpuidle_lock);
 
-static int imx6q_enter_wait(struct cpuidle_device *dev,
-			    struct cpuidle_driver *drv, int index)
+static __cpuidle int imx6q_enter_wait(struct cpuidle_device *dev,
+				      struct cpuidle_driver *drv, int index)
 {
 	raw_spin_lock(&cpuidle_lock);
 	if (++num_idle_cpus == num_online_cpus())
--- a/arch/arm/mach-imx/cpuidle-imx6sx.c
+++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
@@ -30,8 +30,8 @@ static int imx6sx_idle_finish(unsigned l
 	return 0;
 }
 
-static int imx6sx_enter_wait(struct cpuidle_device *dev,
-			    struct cpuidle_driver *drv, int index)
+static __cpuidle int imx6sx_enter_wait(struct cpuidle_device *dev,
+				       struct cpuidle_driver *drv, int index)
 {
 	imx6_set_lpm(WAIT_UNCLOCKED);
 
--- a/arch/arm/mach-omap2/omap-mpuss-lowpower.c
+++ b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
@@ -224,8 +224,8 @@ static void __init save_l2x0_context(voi
  *	2 - CPUx L1 and logic lost + GIC lost: MPUSS OSWR
  *	3 - CPUx L1 and logic lost + GIC + L2 lost: DEVICE OFF
  */
-int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state,
-			 bool rcuidle)
+__cpuidle int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state,
+				   bool rcuidle)
 {
 	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu);
 	unsigned int save_state = 0, cpu_logic_state = PWRDM_POWER_RET;
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -175,7 +175,7 @@ static int omap34xx_do_sram_idle(unsigne
 	return 0;
 }
 
-void omap_sram_idle(bool rcuidle)
+__cpuidle void omap_sram_idle(bool rcuidle)
 {
 	/* Variable to tell what needs to be saved and restored
 	 * in omap_sram_idle*/
--- a/arch/arm64/kernel/cpuidle.c
+++ b/arch/arm64/kernel/cpuidle.c
@@ -62,7 +62,7 @@ int acpi_processor_ffh_lpi_probe(unsigne
 	return psci_acpi_cpu_init_idle(cpu);
 }
 
-int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
+__cpuidle int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
 {
 	u32 state = lpi->address;
 
--- a/drivers/cpuidle/cpuidle-arm.c
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -31,8 +31,8 @@
  * Called from the CPUidle framework to program the device to the
  * specified target state selected by the governor.
  */
-static int arm_enter_idle_state(struct cpuidle_device *dev,
-				struct cpuidle_driver *drv, int idx)
+static __cpuidle int arm_enter_idle_state(struct cpuidle_device *dev,
+					  struct cpuidle_driver *drv, int idx)
 {
 	/*
 	 * Pass idle state index to arm_cpuidle_suspend which in turn
--- a/drivers/cpuidle/cpuidle-big_little.c
+++ b/drivers/cpuidle/cpuidle-big_little.c
@@ -122,8 +122,8 @@ static int notrace bl_powerdown_finisher
  * Called from the CPUidle framework to program the device to the
  * specified target state selected by the governor.
  */
-static int bl_enter_powerdown(struct cpuidle_device *dev,
-				struct cpuidle_driver *drv, int idx)
+static __cpuidle int bl_enter_powerdown(struct cpuidle_device *dev,
+					struct cpuidle_driver *drv, int idx)
 {
 	cpu_pm_enter();
 	ct_cpuidle_enter();
--- a/drivers/cpuidle/cpuidle-mvebu-v7.c
+++ b/drivers/cpuidle/cpuidle-mvebu-v7.c
@@ -25,9 +25,9 @@
 
 static int (*mvebu_v7_cpu_suspend)(int);
 
-static int mvebu_v7_enter_idle(struct cpuidle_device *dev,
-				struct cpuidle_driver *drv,
-				int index)
+static __cpuidle int mvebu_v7_enter_idle(struct cpuidle_device *dev,
+					 struct cpuidle_driver *drv,
+					 int index)
 {
 	int ret;
 	bool deepidle = false;
--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -49,14 +49,9 @@ static inline u32 psci_get_domain_state(
 	return __this_cpu_read(domain_state);
 }
 
-static inline int psci_enter_state(int idx, u32 state)
-{
-	return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state);
-}
-
-static int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
-					  struct cpuidle_driver *drv, int idx,
-					  bool s2idle)
+static __cpuidle int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
+						    struct cpuidle_driver *drv, int idx,
+						    bool s2idle)
 {
 	struct psci_cpuidle_data *data = this_cpu_ptr(&psci_cpuidle_data);
 	u32 *states = data->psci_states;
@@ -192,12 +187,12 @@ static void psci_idle_init_cpuhp(void)
 		pr_warn("Failed %d while setup cpuhp state\n", err);
 }
 
-static int psci_enter_idle_state(struct cpuidle_device *dev,
-				struct cpuidle_driver *drv, int idx)
+static __cpuidle int psci_enter_idle_state(struct cpuidle_device *dev,
+					   struct cpuidle_driver *drv, int idx)
 {
 	u32 *state = __this_cpu_read(psci_cpuidle_data.psci_states);
 
-	return psci_enter_state(idx, state[idx]);
+	return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state[idx]);
 }
 
 static const struct of_device_id psci_idle_state_match[] = {
--- a/drivers/cpuidle/cpuidle-qcom-spm.c
+++ b/drivers/cpuidle/cpuidle-qcom-spm.c
@@ -58,8 +58,8 @@ static int qcom_cpu_spc(struct spm_drive
 	return ret;
 }
 
-static int spm_enter_idle_state(struct cpuidle_device *dev,
-				struct cpuidle_driver *drv, int idx)
+static __cpuidle int spm_enter_idle_state(struct cpuidle_device *dev,
+					  struct cpuidle_driver *drv, int idx)
 {
 	struct cpuidle_qcom_spm_data *data = container_of(drv, struct cpuidle_qcom_spm_data,
 							  cpuidle_driver);
--- a/drivers/cpuidle/cpuidle-riscv-sbi.c
+++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
@@ -93,17 +93,17 @@ static int sbi_suspend(u32 state)
 		return sbi_suspend_finisher(state, 0, 0);
 }
 
-static int sbi_cpuidle_enter_state(struct cpuidle_device *dev,
-				   struct cpuidle_driver *drv, int idx)
+static __cpuidle int sbi_cpuidle_enter_state(struct cpuidle_device *dev,
+					     struct cpuidle_driver *drv, int idx)
 {
 	u32 *states = __this_cpu_read(sbi_cpuidle_data.states);
 
 	return CPU_PM_CPU_IDLE_ENTER_PARAM(sbi_suspend, idx, states[idx]);
 }
 
-static int __sbi_enter_domain_idle_state(struct cpuidle_device *dev,
-					  struct cpuidle_driver *drv, int idx,
-					  bool s2idle)
+static __cpuidle int __sbi_enter_domain_idle_state(struct cpuidle_device *dev,
+						   struct cpuidle_driver *drv, int idx,
+						   bool s2idle)
 {
 	struct sbi_cpuidle_data *data = this_cpu_ptr(&sbi_cpuidle_data);
 	u32 *states = data->states;
--- a/drivers/cpuidle/cpuidle-tegra.c
+++ b/drivers/cpuidle/cpuidle-tegra.c
@@ -160,8 +160,8 @@ static int tegra_cpuidle_coupled_barrier
 	return 0;
 }
 
-static int tegra_cpuidle_state_enter(struct cpuidle_device *dev,
-				     int index, unsigned int cpu)
+static __cpuidle int tegra_cpuidle_state_enter(struct cpuidle_device *dev,
+					       int index, unsigned int cpu)
 {
 	int err;
 
@@ -226,9 +226,9 @@ static int tegra_cpuidle_adjust_state_in
 	return index;
 }
 
-static int tegra_cpuidle_enter(struct cpuidle_device *dev,
-			       struct cpuidle_driver *drv,
-			       int index)
+static __cpuidle int tegra_cpuidle_enter(struct cpuidle_device *dev,
+					 struct cpuidle_driver *drv,
+					 int index)
 {
 	bool do_rcu = drv->states[index].flags & CPUIDLE_FLAG_RCU_IDLE;
 	unsigned int cpu = cpu_logical_map(dev->cpu);
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -137,11 +137,13 @@ int cpuidle_find_deepest_state(struct cp
 }
 
 #ifdef CONFIG_SUSPEND
-static void enter_s2idle_proper(struct cpuidle_driver *drv,
-				struct cpuidle_device *dev, int index)
+static __cpuidle void enter_s2idle_proper(struct cpuidle_driver *drv,
+					  struct cpuidle_device *dev, int index)
 {
-	ktime_t time_start, time_end;
 	struct cpuidle_state *target_state = &drv->states[index];
+	ktime_t time_start, time_end;
+
+	instrumentation_begin();
 
 	time_start = ns_to_ktime(local_clock());
 
@@ -152,13 +154,18 @@ static void enter_s2idle_proper(struct c
 	 * suspended is generally unsafe.
 	 */
 	stop_critical_timings();
-	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
+	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) {
 		ct_cpuidle_enter();
+		/* Annotate away the indirect call */
+		instrumentation_begin();
+	}
 	target_state->enter_s2idle(dev, drv, index);
 	if (WARN_ON_ONCE(!irqs_disabled()))
 		raw_local_irq_disable();
-	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
+	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) {
+		instrumentation_end();
 		ct_cpuidle_exit();
+	}
 	tick_unfreeze();
 	start_critical_timings();
 
@@ -166,6 +173,7 @@ static void enter_s2idle_proper(struct c
 
 	dev->states_usage[index].s2idle_time += ktime_us_delta(time_end, time_start);
 	dev->states_usage[index].s2idle_usage++;
+	instrumentation_end();
 }
 
 /**
@@ -200,8 +208,9 @@ int cpuidle_enter_s2idle(struct cpuidle_
  * @drv: cpuidle driver for this cpu
  * @index: index into the states table in @drv of the state to enter
  */
-int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
-			int index)
+__cpuidle int cpuidle_enter_state(struct cpuidle_device *dev,
+				  struct cpuidle_driver *drv,
+				  int index)
 {
 	int entered_state;
 
@@ -209,6 +218,8 @@ int cpuidle_enter_state(struct cpuidle_d
 	bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP);
 	ktime_t time_start, time_end;
 
+	instrumentation_begin();
+
 	/*
 	 * Tell the time framework to switch to a broadcast timer because our
 	 * local timer will be shut down.  If a local timer is used from another
@@ -235,15 +246,21 @@ int cpuidle_enter_state(struct cpuidle_d
 	time_start = ns_to_ktime(local_clock());
 
 	stop_critical_timings();
-	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
+	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) {
 		ct_cpuidle_enter();
+		/* Annotate away the indirect call */
+		instrumentation_begin();
+	}
 
 	entered_state = target_state->enter(dev, drv, index);
+
 	if (WARN_ONCE(!irqs_disabled(), "%ps leaked IRQ state", target_state->enter))
 		raw_local_irq_disable();
 
-	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
+	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) {
+		instrumentation_end();
 		ct_cpuidle_exit();
+	}
 	start_critical_timings();
 
 	sched_clock_idle_wakeup_event();
@@ -306,6 +323,8 @@ int cpuidle_enter_state(struct cpuidle_d
 		dev->states_usage[index].rejected++;
 	}
 
+	instrumentation_end();
+
 	return entered_state;
 }
 

Re: [PATCH v2 00/44] cpuidle,rcu: Clean up the mess

[Tony Lindgren]

Hi,

* Peter Zijlstra <peterz@infradead.org> [220919 10:08]:
> Hi All!
> 
> At long last, a respin of the cpuidle vs rcu cleanup patches.
> 
> v1: https://lkml.kernel.org/r/20220608142723.103523089@infradead.org
> 
> These here patches clean up the mess that is cpuidle vs rcuidle.

I just gave these a quick test and things still work for me. The old
omap3 off mode during idle still works. No more need to play the
whack the mole game with RCU-idle :) I did not test on x86, or on other
ARMs, but considering the test pretty much covered the all the
affected RCU-idle related paths, where suitable, feel free to add:

Tested-by: Tony Lindgren <tony@atomide.com>

Re: [PATCH v2 00/44] cpuidle,rcu: Clean up the mess

[Ulf Hansson]

On Mon, 19 Sept 2022 at 12:18, Peter Zijlstra <peterz@infradead.org> wrote:
>
> Hi All!
>
> At long last, a respin of the cpuidle vs rcu cleanup patches.
>
> v1: https://lkml.kernel.org/r/20220608142723.103523089@infradead.org
>
> These here patches clean up the mess that is cpuidle vs rcuidle.
>
> At the end of the ride there's only on RCU_NONIDLE user left:
>
>   arch/arm64/kernel/suspend.c:            RCU_NONIDLE(__cpu_suspend_exit());
>
> and 'one' trace_*_rcuidle() user:
>
>   kernel/trace/trace_preemptirq.c:                        trace_irq_enable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
>   kernel/trace/trace_preemptirq.c:                        trace_irq_disable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
>   kernel/trace/trace_preemptirq.c:                        trace_irq_enable_rcuidle(CALLER_ADDR0, caller_addr);
>   kernel/trace/trace_preemptirq.c:                        trace_irq_disable_rcuidle(CALLER_ADDR0, caller_addr);
>   kernel/trace/trace_preemptirq.c:                trace_preempt_enable_rcuidle(a0, a1);
>   kernel/trace/trace_preemptirq.c:                trace_preempt_disable_rcuidle(a0, a1);
>
> However this last is all in deprecated code that should be unused for GENERIC_ENTRY.
>
> I've touched a lot of code that I can't test and I might've broken something by
> accident. In particular the whole ARM cpuidle stuff was quite involved.
>
> Please all; have a look where you haven't already.
>
>
> New since v1:
>
>  - rebase on top of Frederic's rcu-context-tracking rename fest
>  - more omap goodness as per the last discusion (thanks Tony!)
>  - removed one more RCU_NONIDLE() from arm64/risc-v perf code
>  - ubsan/kasan fixes
>  - intel_idle module-param for testing
>  - a bunch of extra __always_inline, because compilers are silly.
>
> ---
>  arch/alpha/kernel/process.c               |  1 -
>  arch/alpha/kernel/vmlinux.lds.S           |  1 -
>  arch/arc/kernel/process.c                 |  3 ++
>  arch/arc/kernel/vmlinux.lds.S             |  1 -
>  arch/arm/include/asm/vmlinux.lds.h        |  1 -
>  arch/arm/kernel/process.c                 |  1 -
>  arch/arm/kernel/smp.c                     |  6 +--
>  arch/arm/mach-gemini/board-dt.c           |  3 +-
>  arch/arm/mach-imx/cpuidle-imx6q.c         |  4 +-
>  arch/arm/mach-imx/cpuidle-imx6sx.c        |  5 ++-
>  arch/arm/mach-omap2/common.h              |  6 ++-
>  arch/arm/mach-omap2/cpuidle34xx.c         | 16 +++++++-
>  arch/arm/mach-omap2/cpuidle44xx.c         | 29 +++++++-------
>  arch/arm/mach-omap2/omap-mpuss-lowpower.c | 12 +++++-
>  arch/arm/mach-omap2/pm.h                  |  2 +-
>  arch/arm/mach-omap2/pm24xx.c              | 51 +-----------------------
>  arch/arm/mach-omap2/pm34xx.c              | 14 +++++--
>  arch/arm/mach-omap2/pm44xx.c              |  2 +-
>  arch/arm/mach-omap2/powerdomain.c         | 10 ++---
>  arch/arm64/kernel/idle.c                  |  1 -
>  arch/arm64/kernel/smp.c                   |  4 +-
>  arch/arm64/kernel/vmlinux.lds.S           |  1 -
>  arch/csky/kernel/process.c                |  1 -
>  arch/csky/kernel/smp.c                    |  2 +-
>  arch/csky/kernel/vmlinux.lds.S            |  1 -
>  arch/hexagon/kernel/process.c             |  1 -
>  arch/hexagon/kernel/vmlinux.lds.S         |  1 -
>  arch/ia64/kernel/process.c                |  1 +
>  arch/ia64/kernel/vmlinux.lds.S            |  1 -
>  arch/loongarch/kernel/idle.c              |  1 +
>  arch/loongarch/kernel/vmlinux.lds.S       |  1 -
>  arch/m68k/kernel/vmlinux-nommu.lds        |  1 -
>  arch/m68k/kernel/vmlinux-std.lds          |  1 -
>  arch/m68k/kernel/vmlinux-sun3.lds         |  1 -
>  arch/microblaze/kernel/process.c          |  1 -
>  arch/microblaze/kernel/vmlinux.lds.S      |  1 -
>  arch/mips/kernel/idle.c                   |  8 ++--
>  arch/mips/kernel/vmlinux.lds.S            |  1 -
>  arch/nios2/kernel/process.c               |  1 -
>  arch/nios2/kernel/vmlinux.lds.S           |  1 -
>  arch/openrisc/kernel/process.c            |  1 +
>  arch/openrisc/kernel/vmlinux.lds.S        |  1 -
>  arch/parisc/kernel/process.c              |  2 -
>  arch/parisc/kernel/vmlinux.lds.S          |  1 -
>  arch/powerpc/kernel/idle.c                |  5 +--
>  arch/powerpc/kernel/vmlinux.lds.S         |  1 -
>  arch/riscv/kernel/process.c               |  1 -
>  arch/riscv/kernel/vmlinux-xip.lds.S       |  1 -
>  arch/riscv/kernel/vmlinux.lds.S           |  1 -
>  arch/s390/kernel/idle.c                   |  1 -
>  arch/s390/kernel/vmlinux.lds.S            |  1 -
>  arch/sh/kernel/idle.c                     |  1 +
>  arch/sh/kernel/vmlinux.lds.S              |  1 -
>  arch/sparc/kernel/leon_pmc.c              |  4 ++
>  arch/sparc/kernel/process_32.c            |  1 -
>  arch/sparc/kernel/process_64.c            |  3 +-
>  arch/sparc/kernel/vmlinux.lds.S           |  1 -
>  arch/um/kernel/dyn.lds.S                  |  1 -
>  arch/um/kernel/process.c                  |  1 -
>  arch/um/kernel/uml.lds.S                  |  1 -
>  arch/x86/boot/compressed/vmlinux.lds.S    |  1 +
>  arch/x86/coco/tdx/tdcall.S                | 15 +------
>  arch/x86/coco/tdx/tdx.c                   | 25 ++++--------
>  arch/x86/events/amd/brs.c                 | 13 +++----
>  arch/x86/include/asm/fpu/xcr.h            |  4 +-
>  arch/x86/include/asm/irqflags.h           | 11 ++----
>  arch/x86/include/asm/mwait.h              | 14 +++----
>  arch/x86/include/asm/nospec-branch.h      |  2 +-
>  arch/x86/include/asm/paravirt.h           |  6 ++-
>  arch/x86/include/asm/perf_event.h         |  2 +-
>  arch/x86/include/asm/shared/io.h          |  4 +-
>  arch/x86/include/asm/shared/tdx.h         |  1 -
>  arch/x86/include/asm/special_insns.h      |  8 ++--
>  arch/x86/include/asm/xen/hypercall.h      |  2 +-
>  arch/x86/kernel/cpu/bugs.c                |  2 +-
>  arch/x86/kernel/fpu/core.c                |  4 +-
>  arch/x86/kernel/paravirt.c                | 14 ++++++-
>  arch/x86/kernel/process.c                 | 65 +++++++++++++++----------------
>  arch/x86/kernel/vmlinux.lds.S             |  1 -
>  arch/x86/lib/memcpy_64.S                  |  5 +--
>  arch/x86/lib/memmove_64.S                 |  4 +-
>  arch/x86/lib/memset_64.S                  |  4 +-
>  arch/x86/xen/enlighten_pv.c               |  2 +-
>  arch/x86/xen/irq.c                        |  2 +-
>  arch/xtensa/kernel/process.c              |  1 +
>  arch/xtensa/kernel/vmlinux.lds.S          |  1 -
>  drivers/acpi/processor_idle.c             | 36 ++++++++++-------
>  drivers/base/power/runtime.c              | 24 ++++++------
>  drivers/clk/clk.c                         |  8 ++--
>  drivers/cpuidle/cpuidle-arm.c             |  1 +
>  drivers/cpuidle/cpuidle-big_little.c      |  8 +++-
>  drivers/cpuidle/cpuidle-mvebu-v7.c        |  7 ++++
>  drivers/cpuidle/cpuidle-psci.c            | 10 +++--
>  drivers/cpuidle/cpuidle-qcom-spm.c        |  1 +
>  drivers/cpuidle/cpuidle-riscv-sbi.c       | 10 +++--
>  drivers/cpuidle/cpuidle-tegra.c           | 21 +++++++---
>  drivers/cpuidle/cpuidle.c                 | 21 +++++-----
>  drivers/cpuidle/dt_idle_states.c          |  2 +-
>  drivers/cpuidle/poll_state.c              | 10 ++++-
>  drivers/idle/intel_idle.c                 | 19 +++++----
>  drivers/perf/arm_pmu.c                    | 11 +-----
>  drivers/perf/riscv_pmu_sbi.c              |  8 +---
>  include/asm-generic/vmlinux.lds.h         |  9 ++---
>  include/linux/compiler_types.h            |  8 +++-
>  include/linux/cpu.h                       |  3 --
>  include/linux/cpuidle.h                   | 34 ++++++++++++++++
>  include/linux/cpumask.h                   |  4 +-
>  include/linux/percpu-defs.h               |  2 +-
>  include/linux/sched/idle.h                | 40 ++++++++++++++-----
>  include/linux/thread_info.h               | 18 ++++++++-
>  include/linux/tracepoint.h                | 13 ++++++-
>  kernel/cpu_pm.c                           |  9 -----
>  kernel/printk/printk.c                    |  2 +-
>  kernel/sched/idle.c                       | 47 +++++++---------------
>  kernel/time/tick-broadcast-hrtimer.c      | 29 ++++++--------
>  kernel/time/tick-broadcast.c              |  6 ++-
>  kernel/trace/trace.c                      |  3 ++
>  lib/ubsan.c                               |  5 ++-
>  mm/kasan/kasan.h                          |  4 ++
>  mm/kasan/shadow.c                         | 38 ++++++++++++++++++
>  tools/objtool/check.c                     | 17 ++++++++
>  121 files changed, 511 insertions(+), 420 deletions(-)

Thanks for cleaning up the situation!

I have applied this on a plain v6.0 (only one patch had a minor
conflict) and tested this on an ARM64 Dragonboard 410c, which uses
cpuidle-psci and the cpuidle-psci-domain. I didn't observe any
problems, so feel free to add:

Tested-by: Ulf Hansson <ulf.hansson@linaro.org>

Kind regards
Uffe