[PATCH AUTOSEL 6.1 03/15] powerpc: Check !irq instead of irq == NO_IRQ and remove NO_IRQ

[PATCH AUTOSEL 6.1 03/15] powerpc: Check !irq instead of irq == NO_IRQ and remove NO_IRQ

[Sasha Levin]

From: Christophe Leroy <christophe.leroy@csgroup.eu>

[ Upstream commit bab537805a10bdbf55b31324ba4a9599e0651e5e ]

NO_IRQ is a relic from the old days. It is not used anymore in core
functions. By the way, function irq_of_parse_and_map() returns value 0
on error.

In some drivers, NO_IRQ is erroneously used to check the return of
irq_of_parse_and_map().

It is not a real bug today because the only architectures using the
drivers being fixed by this patch define NO_IRQ as 0, but there are
architectures which define NO_IRQ as -1. If one day those
architectures start using the non fixed drivers, there will be a
problem.

Long time ago Linus advocated for not using NO_IRQ, see
https://lore.kernel.org/all/Pine.LNX.4.64.0511211150040.13959@g5.osdl.org

He re-iterated the same view recently in
https://lore.kernel.org/all/CAHk-=wg2Pkb9kbfbstbB91AJA2SF6cySbsgHG-iQMq56j3VTcA@mail.gmail.com

So test !irq instead of tesing irq == NO_IRQ.

All other usage of NO_IRQ for powerpc were removed in previous cycles so
the time has come to remove NO_IRQ completely for powerpc.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4b8d4f96140af01dec3a3330924dda8b2451c316.1674476798.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/include/asm/irq.h    | 3 ---
 arch/powerpc/platforms/44x/fsp2.c | 2 +-
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index 5c1516a5ba8f6..deadd2149426a 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -16,9 +16,6 @@
 
 extern atomic_t ppc_n_lost_interrupts;
 
-/* This number is used when no interrupt has been assigned */
-#define NO_IRQ			(0)
-
 /* Total number of virq in the platform */
 #define NR_IRQS		CONFIG_NR_IRQS
 
diff --git a/arch/powerpc/platforms/44x/fsp2.c b/arch/powerpc/platforms/44x/fsp2.c
index e2e4f6d8150d6..56d91dbef5770 100644
--- a/arch/powerpc/platforms/44x/fsp2.c
+++ b/arch/powerpc/platforms/44x/fsp2.c
@@ -205,7 +205,7 @@ static void __init node_irq_request(const char *compat, irq_handler_t errirq_han
 
 	for_each_compatible_node(np, NULL, compat) {
 		irq = irq_of_parse_and_map(np, 0);
-		if (irq == NO_IRQ) {
+		if (!irq) {
 			pr_err("device tree node %pOFn is missing a interrupt",
 			      np);
 			of_node_put(np);
-- 
2.39.2

[PATCH AUTOSEL 6.1 04/15] powerpc/64: Don't recurse irq replay

[Sasha Levin]

From: Nicholas Piggin <npiggin@gmail.com>

[ Upstream commit 5746ca131e2496ccd5bb4d7a0244d6c38070cbf5 ]

Interrupt handlers called by soft-pending irq replay code can run
softirqs, softirq replay enables and disables local irqs, which allows
interrupts to come in including soft-masked interrupts, and it can
cause pending irqs to be replayed again. That makes the soft irq replay
state machine and possible races more complicated and fragile than it
needs to be.

Use irq_enter/irq_exit around irq replay to prevent softirqs running
while interrupts are being replayed. Softirqs will now be run at the
irq_exit() call after all the irq replaying is done. This prevents irqs
being replayed while irqs are being replayed, and should hopefully make
things simpler and easier to think about and debug.

A new PACA_IRQ_REPLAYING is added to prevent asynchronous interrupt
handlers hard-enabling EE while pending irqs are being replayed, because
that causes new pending irqs to arrive which is also a complexity. This
means pending irqs won't be profiled quite so well because perf irqs
can't be taken.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230121102618.2824429-1-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/include/asm/hw_irq.h |   6 +-
 arch/powerpc/kernel/irq_64.c      | 101 +++++++++++++++++++-----------
 2 files changed, 70 insertions(+), 37 deletions(-)

diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index eb6d094083fd6..317659fdeacf2 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -36,15 +36,17 @@
 #define PACA_IRQ_DEC		0x08 /* Or FIT */
 #define PACA_IRQ_HMI		0x10
 #define PACA_IRQ_PMI		0x20
+#define PACA_IRQ_REPLAYING	0x40
 
 /*
  * Some soft-masked interrupts must be hard masked until they are replayed
  * (e.g., because the soft-masked handler does not clear the exception).
+ * Interrupt replay itself must remain hard masked too.
  */
 #ifdef CONFIG_PPC_BOOK3S
-#define PACA_IRQ_MUST_HARD_MASK	(PACA_IRQ_EE|PACA_IRQ_PMI)
+#define PACA_IRQ_MUST_HARD_MASK	(PACA_IRQ_EE|PACA_IRQ_PMI|PACA_IRQ_REPLAYING)
 #else
-#define PACA_IRQ_MUST_HARD_MASK	(PACA_IRQ_EE)
+#define PACA_IRQ_MUST_HARD_MASK	(PACA_IRQ_EE|PACA_IRQ_REPLAYING)
 #endif
 
 #endif /* CONFIG_PPC64 */
diff --git a/arch/powerpc/kernel/irq_64.c b/arch/powerpc/kernel/irq_64.c
index eb2b380e52a0d..9dc0ad3c533a8 100644
--- a/arch/powerpc/kernel/irq_64.c
+++ b/arch/powerpc/kernel/irq_64.c
@@ -70,22 +70,19 @@ int distribute_irqs = 1;
 
 static inline void next_interrupt(struct pt_regs *regs)
 {
-	/*
-	 * Softirq processing can enable/disable irqs, which will leave
-	 * MSR[EE] enabled and the soft mask set to IRQS_DISABLED. Fix
-	 * this up.
-	 */
-	if (!(local_paca->irq_happened & PACA_IRQ_HARD_DIS))
-		hard_irq_disable();
-	else
-		irq_soft_mask_set(IRQS_ALL_DISABLED);
+	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
+		WARN_ON(!(local_paca->irq_happened & PACA_IRQ_HARD_DIS));
+		WARN_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED);
+	}
 
 	/*
 	 * We are responding to the next interrupt, so interrupt-off
 	 * latencies should be reset here.
 	 */
+	lockdep_hardirq_exit();
 	trace_hardirqs_on();
 	trace_hardirqs_off();
+	lockdep_hardirq_enter();
 }
 
 static inline bool irq_happened_test_and_clear(u8 irq)
@@ -97,22 +94,11 @@ static inline bool irq_happened_test_and_clear(u8 irq)
 	return false;
 }
 
-void replay_soft_interrupts(void)
+static void __replay_soft_interrupts(void)
 {
 	struct pt_regs regs;
 
 	/*
-	 * Be careful here, calling these interrupt handlers can cause
-	 * softirqs to be raised, which they may run when calling irq_exit,
-	 * which will cause local_irq_enable() to be run, which can then
-	 * recurse into this function. Don't keep any state across
-	 * interrupt handler calls which may change underneath us.
-	 *
-	 * Softirqs can not be disabled over replay to stop this recursion
-	 * because interrupts taken in idle code may require RCU softirq
-	 * to run in the irq RCU tracking context. This is a hard problem
-	 * to fix without changes to the softirq or idle layer.
-	 *
 	 * We use local_paca rather than get_paca() to avoid all the
 	 * debug_smp_processor_id() business in this low level function.
 	 */
@@ -120,13 +106,20 @@ void replay_soft_interrupts(void)
 	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
 		WARN_ON_ONCE(mfmsr() & MSR_EE);
 		WARN_ON(!(local_paca->irq_happened & PACA_IRQ_HARD_DIS));
+		WARN_ON(local_paca->irq_happened & PACA_IRQ_REPLAYING);
 	}
 
+	/*
+	 * PACA_IRQ_REPLAYING prevents interrupt handlers from enabling
+	 * MSR[EE] to get PMIs, which can result in more IRQs becoming
+	 * pending.
+	 */
+	local_paca->irq_happened |= PACA_IRQ_REPLAYING;
+
 	ppc_save_regs(&regs);
 	regs.softe = IRQS_ENABLED;
 	regs.msr |= MSR_EE;
 
-again:
 	/*
 	 * Force the delivery of pending soft-disabled interrupts on PS3.
 	 * Any HV call will have this side effect.
@@ -175,13 +168,14 @@ void replay_soft_interrupts(void)
 		next_interrupt(&regs);
 	}
 
-	/*
-	 * Softirq processing can enable and disable interrupts, which can
-	 * result in new irqs becoming pending. Must keep looping until we
-	 * have cleared out all pending interrupts.
-	 */
-	if (local_paca->irq_happened & ~PACA_IRQ_HARD_DIS)
-		goto again;
+	local_paca->irq_happened &= ~PACA_IRQ_REPLAYING;
+}
+
+void replay_soft_interrupts(void)
+{
+	irq_enter(); /* See comment in arch_local_irq_restore */
+	__replay_soft_interrupts();
+	irq_exit();
 }
 
 #if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_PPC_KUAP)
@@ -200,13 +194,13 @@ static inline void replay_soft_interrupts_irqrestore(void)
 	if (kuap_state != AMR_KUAP_BLOCKED)
 		set_kuap(AMR_KUAP_BLOCKED);
 
-	replay_soft_interrupts();
+	__replay_soft_interrupts();
 
 	if (kuap_state != AMR_KUAP_BLOCKED)
 		set_kuap(kuap_state);
 }
 #else
-#define replay_soft_interrupts_irqrestore() replay_soft_interrupts()
+#define replay_soft_interrupts_irqrestore() __replay_soft_interrupts()
 #endif
 
 notrace void arch_local_irq_restore(unsigned long mask)
@@ -219,9 +213,13 @@ notrace void arch_local_irq_restore(unsigned long mask)
 		return;
 	}
 
-	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
-		WARN_ON_ONCE(in_nmi() || in_hardirq());
+	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
+		WARN_ON_ONCE(in_nmi());
+		WARN_ON_ONCE(in_hardirq());
+		WARN_ON_ONCE(local_paca->irq_happened & PACA_IRQ_REPLAYING);
+	}
 
+again:
 	/*
 	 * After the stb, interrupts are unmasked and there are no interrupts
 	 * pending replay. The restart sequence makes this atomic with
@@ -248,6 +246,12 @@ notrace void arch_local_irq_restore(unsigned long mask)
 	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
 		WARN_ON_ONCE(!(mfmsr() & MSR_EE));
 
+	/*
+	 * If we came here from the replay below, we might have a preempt
+	 * pending (due to preempt_enable_no_resched()). Have to check now.
+	 */
+	preempt_check_resched();
+
 	return;
 
 happened:
@@ -261,6 +265,7 @@ notrace void arch_local_irq_restore(unsigned long mask)
 		irq_soft_mask_set(IRQS_ENABLED);
 		local_paca->irq_happened = 0;
 		__hard_irq_enable();
+		preempt_check_resched();
 		return;
 	}
 
@@ -296,12 +301,38 @@ notrace void arch_local_irq_restore(unsigned long mask)
 	irq_soft_mask_set(IRQS_ALL_DISABLED);
 	trace_hardirqs_off();
 
+	/*
+	 * Now enter interrupt context. The interrupt handlers themselves
+	 * also call irq_enter/exit (which is okay, they can nest). But call
+	 * it here now to hold off softirqs until the below irq_exit(). If
+	 * we allowed replayed handlers to run softirqs, that enables irqs,
+	 * which must replay interrupts, which recurses in here and makes
+	 * things more complicated. The recursion is limited to 2, and it can
+	 * be made to work, but it's complicated.
+	 *
+	 * local_bh_disable can not be used here because interrupts taken in
+	 * idle are not in the right context (RCU, tick, etc) to run softirqs
+	 * so irq_enter must be called.
+	 */
+	irq_enter();
+
 	replay_soft_interrupts_irqrestore();
 
+	irq_exit();
+
+	if (unlikely(local_paca->irq_happened != PACA_IRQ_HARD_DIS)) {
+		/*
+		 * The softirq processing in irq_exit() may enable interrupts
+		 * temporarily, which can result in MSR[EE] being enabled and
+		 * more irqs becoming pending. Go around again if that happens.
+		 */
+		trace_hardirqs_on();
+		preempt_enable_no_resched();
+		goto again;
+	}
+
 	trace_hardirqs_on();
 	irq_soft_mask_set(IRQS_ENABLED);
-	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
-		WARN_ON(local_paca->irq_happened != PACA_IRQ_HARD_DIS);
 	local_paca->irq_happened = 0;
 	__hard_irq_enable();
 	preempt_enable();
-- 
2.39.2

[PATCH AUTOSEL 6.1 06/15] powerpc/iommu: fix memory leak with using debugfs_lookup()

[Sasha Levin]

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit b505063910c134778202dfad9332dfcecb76bab3 ]

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time.  To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230202141919.2298821-1-gregkh@linuxfoundation.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/iommu.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index caebe1431596e..ee95937bdaf14 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -67,11 +67,9 @@ static void iommu_debugfs_add(struct iommu_table *tbl)
 static void iommu_debugfs_del(struct iommu_table *tbl)
 {
 	char name[10];
-	struct dentry *liobn_entry;
 
 	sprintf(name, "%08lx", tbl->it_index);
-	liobn_entry = debugfs_lookup(name, iommu_debugfs_dir);
-	debugfs_remove(liobn_entry);
+	debugfs_lookup_and_remove(name, iommu_debugfs_dir);
 }
 #else
 static void iommu_debugfs_add(struct iommu_table *tbl){}
-- 
2.39.2

[PATCH AUTOSEL 6.1 08/15] powerpc/bpf/32: Only set a stack frame when necessary

[Sasha Levin]

From: Christophe Leroy <christophe.leroy@csgroup.eu>

[ Upstream commit d084dcf256bc4565b4b1af9b00297ac7b51c7049 ]

Until now a stack frame was set at all time due to the need
to keep tail call counter in the stack.

But since commit 89d21e259a94 ("powerpc/bpf/32: Fix Oops on tail call
tests") the tail call counter is passed via register r4. It is therefore
not necessary anymore to have a stack frame for that.

Just like PPC64, implement bpf_has_stack_frame() and only sets the frame
when needed.

The difference with PPC64 is that PPC32 doesn't have a redzone, so
the stack is required as soon as non volatile registers are used or
when tail call count is set up.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fix commit reference in change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/62d7b654a3cfe73d998697cb29bbc5ffd89bfdb1.1675245773.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/net/bpf_jit_comp32.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c
index a379b0ce19ffa..8643b2c8b76ef 100644
--- a/arch/powerpc/net/bpf_jit_comp32.c
+++ b/arch/powerpc/net/bpf_jit_comp32.c
@@ -79,6 +79,20 @@ static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg)
 #define SEEN_NVREG_FULL_MASK	0x0003ffff /* Non volatile registers r14-r31 */
 #define SEEN_NVREG_TEMP_MASK	0x00001e01 /* BPF_REG_5, BPF_REG_AX, TMP_REG */
 
+static inline bool bpf_has_stack_frame(struct codegen_context *ctx)
+{
+	/*
+	 * We only need a stack frame if:
+	 * - we call other functions (kernel helpers), or
+	 * - we use non volatile registers, or
+	 * - we use tail call counter
+	 * - the bpf program uses its stack area
+	 * The latter condition is deduced from the usage of BPF_REG_FP
+	 */
+	return ctx->seen & (SEEN_FUNC | SEEN_TAILCALL | SEEN_NVREG_FULL_MASK) ||
+	       bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP));
+}
+
 void bpf_jit_realloc_regs(struct codegen_context *ctx)
 {
 	unsigned int nvreg_mask;
@@ -118,7 +132,8 @@ void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
 
 #define BPF_TAILCALL_PROLOGUE_SIZE	4
 
-	EMIT(PPC_RAW_STWU(_R1, _R1, -BPF_PPC_STACKFRAME(ctx)));
+	if (bpf_has_stack_frame(ctx))
+		EMIT(PPC_RAW_STWU(_R1, _R1, -BPF_PPC_STACKFRAME(ctx)));
 
 	if (ctx->seen & SEEN_TAILCALL)
 		EMIT(PPC_RAW_STW(_R4, _R1, bpf_jit_stack_offsetof(ctx, BPF_PPC_TC)));
@@ -171,7 +186,8 @@ static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx
 		EMIT(PPC_RAW_LWZ(_R0, _R1, BPF_PPC_STACKFRAME(ctx) + PPC_LR_STKOFF));
 
 	/* Tear down our stack frame */
-	EMIT(PPC_RAW_ADDI(_R1, _R1, BPF_PPC_STACKFRAME(ctx)));
+	if (bpf_has_stack_frame(ctx))
+		EMIT(PPC_RAW_ADDI(_R1, _R1, BPF_PPC_STACKFRAME(ctx)));
 
 	if (ctx->seen & SEEN_FUNC)
 		EMIT(PPC_RAW_MTLR(_R0));
-- 
2.39.2

[PATCH AUTOSEL 6.1 09/15] powerpc/64: Fix task_cpu in early boot when booting non-zero cpuid

[Sasha Levin]

From: Nicholas Piggin <npiggin@gmail.com>

[ Upstream commit 9fa24404f5044967753a6cd3e5e36f57686bec6e ]

powerpc/64 can boot on a non-zero SMP processor id. Initially, the boot
CPU is said to be "assumed to be 0" until early_init_devtree() discovers
the id from the device tree. That is not a good description because the
assumption can be wrong and that has to be handled, the better
description is that 0 is used as a placeholder, and things are fixed
after the real id is discovered.

smp_processor_id() is set to the boot cpuid, but task_cpu(current) is
not, which causes the smp_processor_id() == task_cpu(current) invariant
to be broken until init_idle() in sched_init().

This is quite fragile and could lead to subtle bugs in future. One bug
is that validate_sp_size uses task_cpu() to get the process stack, so
any stack trace from the booting CPU between early_init_devtree()
and sched_init() will have problems. Early on paca_ptrs[0] will be
poisoned, so that can cause machine checks dereferencing that memory
in real mode. Later, validating the current stack pointer against the
idle task of a different secondary will probably cause no stack trace
to be printed.

Fix this by setting thread_info->cpu right after smp_processor_id() is
set to the boot cpuid.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fix SMP=n build as reported by sfr]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221216115930.2667772-3-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/setup_64.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index a0dee7354fe6b..a43865e0fb4bf 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -396,6 +396,11 @@ void __init early_setup(unsigned long dt_ptr)
 	}
 	fixup_boot_paca(paca_ptrs[boot_cpuid]);
 	setup_paca(paca_ptrs[boot_cpuid]); /* install the paca into registers */
+	// smp_processor_id() now reports boot_cpuid
+
+#ifdef CONFIG_SMP
+	task_thread_info(current)->cpu = boot_cpuid; // fix task_cpu(current)
+#endif
 
 	/*
 	 * Configure exception handlers. This include setting up trampolines
-- 
2.39.2

[PATCH AUTOSEL 6.1 10/15] powerpc/64: Move paca allocation to early_setup()

[Sasha Levin]

From: Nicholas Piggin <npiggin@gmail.com>

[ Upstream commit dc222fa7737212fe0da513e5b8937c156d02225d ]

The early paca and boot cpuid dance is complicated and currently does
not quite work as expected for boot cpuid != 0 cases.

early_init_devtree() currently allocates the paca_ptrs and boot cpuid
paca, but until that returns and early_setup() calls setup_paca(), this
thread is currently still executing with smp_processor_id() == 0.

One problem this causes is the paca_ptrs[smp_processor_id()] pointer is
poisoned, so valid_emergency_stack() (any backtrace) and any similar
users will crash.

Another is that the hardware id which is set here will not be returned
by get_hard_smp_processor_id(smp_processor_id()), but it would work
correctly for boot_cpuid == 0, which could lead to difficult to
reproduce or find bugs. The hard id does not seem to be used by the rest
of early_init_devtree(), it just looks like all this code might have
been put here to allocate somewhere to store boot CPU hardware id while
scanning the devtree.

Rearrange things so the hwid is put in a global variable like
boot_cpuid, and do all the paca allocation and boot paca setup in the
64-bit early_setup() after we have everything ready to go.

The paca_ptrs[0] re-poisoning code in early_setup does not seem to have
ever worked, because paca_ptrs[0] was never not-poisoned when boot_cpuid
is not 0.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fix build error on 32-bit]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221216115930.2667772-4-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/include/asm/paca.h    |  1 -
 arch/powerpc/include/asm/smp.h     |  1 +
 arch/powerpc/kernel/prom.c         | 12 +++---------
 arch/powerpc/kernel/setup-common.c |  4 ++++
 arch/powerpc/kernel/setup_64.c     | 11 +++++------
 5 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 09f1790d0ae16..0ab3511a47d77 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -295,7 +295,6 @@ extern void free_unused_pacas(void);
 
 #else /* CONFIG_PPC64 */
 
-static inline void allocate_paca_ptrs(void) { }
 static inline void allocate_paca(int cpu) { }
 static inline void free_unused_pacas(void) { }
 
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index f63505d74932b..6c6cb53d70458 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -26,6 +26,7 @@
 #include <asm/percpu.h>
 
 extern int boot_cpuid;
+extern int boot_cpu_hwid; /* PPC64 only */
 extern int spinning_secondaries;
 extern u32 *cpu_to_phys_id;
 extern bool coregroup_enabled;
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 1eed87d954ba8..8537c354c560b 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -366,8 +366,8 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
 	    be32_to_cpu(intserv[found_thread]));
 	boot_cpuid = found;
 
-	// Pass the boot CPU's hard CPU id back to our caller
-	*((u32 *)data) = be32_to_cpu(intserv[found_thread]);
+	if (IS_ENABLED(CONFIG_PPC64))
+		boot_cpu_hwid = be32_to_cpu(intserv[found_thread]);
 
 	/*
 	 * PAPR defines "logical" PVR values for cpus that
@@ -751,7 +751,6 @@ static inline void save_fscr_to_task(void) {}
 
 void __init early_init_devtree(void *params)
 {
-	u32 boot_cpu_hwid;
 	phys_addr_t limit;
 
 	DBG(" -> early_init_devtree(%px)\n", params);
@@ -847,7 +846,7 @@ void __init early_init_devtree(void *params)
 	/* Retrieve CPU related informations from the flat tree
 	 * (altivec support, boot CPU ID, ...)
 	 */
-	of_scan_flat_dt(early_init_dt_scan_cpus, &boot_cpu_hwid);
+	of_scan_flat_dt(early_init_dt_scan_cpus, NULL);
 	if (boot_cpuid < 0) {
 		printk("Failed to identify boot CPU !\n");
 		BUG();
@@ -864,11 +863,6 @@ void __init early_init_devtree(void *params)
 
 	mmu_early_init_devtree();
 
-	// NB. paca is not installed until later in early_setup()
-	allocate_paca_ptrs();
-	allocate_paca(boot_cpuid);
-	set_hard_smp_processor_id(boot_cpuid, boot_cpu_hwid);
-
 #ifdef CONFIG_PPC_POWERNV
 	/* Scan and build the list of machine check recoverable ranges */
 	of_scan_flat_dt(early_init_dt_scan_recoverable_ranges, NULL);
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 6d041993a45dc..efb301a4987ca 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -86,6 +86,10 @@ EXPORT_SYMBOL(machine_id);
 int boot_cpuid = -1;
 EXPORT_SYMBOL_GPL(boot_cpuid);
 
+#ifdef CONFIG_PPC64
+int boot_cpu_hwid = -1;
+#endif
+
 /*
  * These are used in binfmt_elf.c to put aux entries on the stack
  * for each elf executable being started.
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index a43865e0fb4bf..b2e0d3ce4261c 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -385,15 +385,14 @@ void __init early_setup(unsigned long dt_ptr)
 	/*
 	 * Do early initialization using the flattened device
 	 * tree, such as retrieving the physical memory map or
-	 * calculating/retrieving the hash table size.
+	 * calculating/retrieving the hash table size, discover
+	 * boot_cpuid and boot_cpu_hwid.
 	 */
 	early_init_devtree(__va(dt_ptr));
 
-	/* Now we know the logical id of our boot cpu, setup the paca. */
-	if (boot_cpuid != 0) {
-		/* Poison paca_ptrs[0] again if it's not the boot cpu */
-		memset(&paca_ptrs[0], 0x88, sizeof(paca_ptrs[0]));
-	}
+	allocate_paca_ptrs();
+	allocate_paca(boot_cpuid);
+	set_hard_smp_processor_id(boot_cpuid, boot_cpu_hwid);
 	fixup_boot_paca(paca_ptrs[boot_cpuid]);
 	setup_paca(paca_ptrs[boot_cpuid]); /* install the paca into registers */
 	// smp_processor_id() now reports boot_cpuid
-- 
2.39.2

[PATCH AUTOSEL 6.1 11/15] powerpc/kcsan: Exclude udelay to prevent recursive instrumentation

[Sasha Levin]

From: Rohan McLure <rmclure@linux.ibm.com>

[ Upstream commit 2a7ce82dc46c591c9244057d89a6591c9639b9b9 ]

In order for KCSAN to increase its likelihood of observing a data race,
it sets a watchpoint on memory accesses and stalls, allowing for
detection of conflicting accesses by other kernel threads or interrupts.

Stalls are implemented by injecting a call to udelay in instrumented code.
To prevent recursive instrumentation, exclude udelay from being instrumented.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230206021801.105268-3-rmclure@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/time.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index f157552d79b38..285159e65a3ba 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -374,7 +374,7 @@ void vtime_flush(struct task_struct *tsk)
 #define calc_cputime_factors()
 #endif
 
-void __delay(unsigned long loops)
+void __no_kcsan __delay(unsigned long loops)
 {
 	unsigned long start;
 
@@ -395,7 +395,7 @@ void __delay(unsigned long loops)
 }
 EXPORT_SYMBOL(__delay);
 
-void udelay(unsigned long usecs)
+void __no_kcsan udelay(unsigned long usecs)
 {
 	__delay(tb_ticks_per_usec * usecs);
 }
-- 
2.39.2

[PATCH AUTOSEL 6.1 13/15] macintosh: windfarm: Use unsigned type for 1-bit bitfields

[Sasha Levin]

From: Nathan Chancellor <nathan@kernel.org>

[ Upstream commit 748ea32d2dbd813d3bd958117bde5191182f909a ]

Clang warns:

  drivers/macintosh/windfarm_lm75_sensor.c:63:14: error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
                  lm->inited = 1;
                             ^ ~

  drivers/macintosh/windfarm_smu_sensors.c:356:19: error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
                  pow->fake_volts = 1;
                                  ^ ~
  drivers/macintosh/windfarm_smu_sensors.c:368:18: error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
                  pow->quadratic = 1;
                                 ^ ~

There is no bug here since no code checks the actual value of these
fields, just whether or not they are zero (boolean context), but this
can be easily fixed by switching to an unsigned type.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230215-windfarm-wsingle-bit-bitfield-constant-conversion-v1-1-26415072e855@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/macintosh/windfarm_lm75_sensor.c | 4 ++--
 drivers/macintosh/windfarm_smu_sensors.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/macintosh/windfarm_lm75_sensor.c b/drivers/macintosh/windfarm_lm75_sensor.c
index 204661c8e918f..9dd80837a759a 100644
--- a/drivers/macintosh/windfarm_lm75_sensor.c
+++ b/drivers/macintosh/windfarm_lm75_sensor.c
@@ -33,8 +33,8 @@
 #endif
 
 struct wf_lm75_sensor {
-	int			ds1775 : 1;
-	int			inited : 1;
+	unsigned int		ds1775 : 1;
+	unsigned int		inited : 1;
 	struct i2c_client	*i2c;
 	struct wf_sensor	sens;
 };
diff --git a/drivers/macintosh/windfarm_smu_sensors.c b/drivers/macintosh/windfarm_smu_sensors.c
index 00c6fe25fcba0..2bdb73b34d291 100644
--- a/drivers/macintosh/windfarm_smu_sensors.c
+++ b/drivers/macintosh/windfarm_smu_sensors.c
@@ -274,8 +274,8 @@ struct smu_cpu_power_sensor {
 	struct list_head	link;
 	struct wf_sensor	*volts;
 	struct wf_sensor	*amps;
-	int			fake_volts : 1;
-	int			quadratic : 1;
+	unsigned int		fake_volts : 1;
+	unsigned int		quadratic : 1;
 	struct wf_sensor	sens;
 };
 #define to_smu_cpu_power(c) container_of(c, struct smu_cpu_power_sensor, sens)
-- 
2.39.2