[PATCH v2 0/6] ipipe-noarch: IRQ tracing, enabling, and lockdep fixes/cleanups

[PATCH v2 0/6] ipipe-noarch: IRQ tracing, enabling, and lockdep fixes/cleanups

[Jan Kiszka]

This included the patches from v1, the addition (patch 3), and the new
patches needed to add return codes and irq enabling to some services.

Jan

Jan Kiszka (6):
  ipipe: Restore trace_hardirqs_on_virt_caller
  ipipe: lockdep: Remove duplicate context checks
  ipipe: Add missing include for ipipe_root_only
  ipipe: Let ipipe_enable_irq return an error code
  ipipe: Activate IRQ in ipipe_enable_irq
  ipipe: Let ipipe_set_irq_affinity return an error

 include/linux/ipipe.h           |  6 +++---
 include/linux/kernel.h          |  1 +
 kernel/irq/chip.c               | 17 ++++++++++++-----
 kernel/locking/lockdep.c        |  6 ------
 kernel/trace/trace_preemptirq.c | 11 +++++++++++
 5 files changed, 27 insertions(+), 14 deletions(-)

-- 
2.16.4

[PATCH v2 1/6] ipipe: Restore trace_hardirqs_on_virt_caller

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

Lost in d7fc2c06edc9 ("lockdep: ipipe: exclude the head stage from IRQ
state tracing") but still needed by x86 at least.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 kernel/trace/trace_preemptirq.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/kernel/trace/trace_preemptirq.c b/kernel/trace/trace_preemptirq.c
index 3c482c02c1d9..19605695a6a2 100644
--- a/kernel/trace/trace_preemptirq.c
+++ b/kernel/trace/trace_preemptirq.c
@@ -66,6 +66,17 @@ __visible void trace_hardirqs_on_caller(unsigned long caller_addr)
 }
 EXPORT_SYMBOL(trace_hardirqs_on_caller);
 
+__visible void trace_hardirqs_on_virt_caller(unsigned long ip)
+{
+	/*
+	 * The IRQ tracing logic only applies to the root domain, and
+	 * must consider the virtual disable flag exclusively when
+	 * leaving an interrupt/fault context.
+	 */
+	if (ipipe_root_p && !irqs_disabled())
+		trace_hardirqs_on_caller(ip);
+}
+
 __visible void trace_hardirqs_on_virt(void)
 {
 	/*
-- 
2.16.4

[PATCH v2 2/6] ipipe: lockdep: Remove duplicate context checks

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

All callers of lockdep_hardirqs_on/off already filter out !ipipe_root_p.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 kernel/locking/lockdep.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 715fe8a49c2e..a2a8267788c6 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2841,9 +2841,6 @@ static void __trace_hardirqs_on_caller(unsigned long ip)
 
 void lockdep_hardirqs_on(unsigned long ip)
 {
-	if (!ipipe_root_p)
-		return;
-
 	if (unlikely(!debug_locks || current->lockdep_recursion))
 		return;
 
@@ -2890,9 +2887,6 @@ void lockdep_hardirqs_off(unsigned long ip)
 {
 	struct task_struct *curr;
 
-	if (!ipipe_root_p)
-		return;
-
 	curr = current;
 
 	if (unlikely(!debug_locks || current->lockdep_recursion))
-- 
2.16.4

[PATCH v2 3/6] ipipe: Add missing include for ipipe_root_only

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

Breaks in non-debug builds otherwise, e.g.
https://travis-ci.com/xenomai-ci/xenomai/jobs/212725223

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 include/linux/kernel.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 50b1e0c878e0..edd37052e585 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -14,6 +14,7 @@
 #include <linux/printk.h>
 #include <linux/build_bug.h>
 #include <asm/byteorder.h>
+#include <asm-generic/ipipe.h>
 #include <uapi/linux/kernel.h>
 
 #define USHRT_MAX	((u16)(~0U))
-- 
2.16.4

[PATCH v2 4/6] ipipe: Let ipipe_enable_irq return an error code

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

It's time to let ipipe_enable_irq return a proper error as it will gain
another function that may fail. Drop the WARN_ON_ONCE in favor of that.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 include/linux/ipipe.h |  2 +-
 kernel/irq/chip.c     | 12 +++++++-----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/include/linux/ipipe.h b/include/linux/ipipe.h
index b8a80eeade4f..f7c07a207093 100644
--- a/include/linux/ipipe.h
+++ b/include/linux/ipipe.h
@@ -475,7 +475,7 @@ static inline struct ipipe_threadinfo *ipipe_current_threadinfo(void)
 
 #define ipipe_task_threadinfo(p) (&task_thread_info(p)->ipipe_data)
 
-void ipipe_enable_irq(unsigned int irq);
+int ipipe_enable_irq(unsigned int irq);
 
 static inline void ipipe_disable_irq(unsigned int irq)
 {
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 6c279e065879..65d345b727be 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -1082,7 +1082,7 @@ __fixup_irq_handler(struct irq_desc *desc, irq_flow_handler_t handle, int is_cha
 	return handle;
 }
 
-void ipipe_enable_irq(unsigned int irq)
+int ipipe_enable_irq(unsigned int irq)
 {
 	struct irq_desc *desc;
 	struct irq_chip *chip;
@@ -1090,7 +1090,7 @@ void ipipe_enable_irq(unsigned int irq)
 
 	desc = irq_to_desc(irq);
 	if (desc == NULL)
-		return;
+		return -EINVAL;
 
 	chip = irq_desc_get_chip(desc);
 
@@ -1105,16 +1105,18 @@ void ipipe_enable_irq(unsigned int irq)
 		}
 		raw_spin_unlock_irqrestore(&desc->lock, flags);
 
-		return;
+		return 0;
 	}
 
-	if (WARN_ON_ONCE(chip->irq_enable == NULL && chip->irq_unmask == NULL))
-		return;
+	if (chip->irq_enable == NULL && chip->irq_unmask == NULL)
+		return -ENOSYS;
 
 	if (chip->irq_enable)
 		chip->irq_enable(&desc->irq_data);
 	else
 		chip->irq_unmask(&desc->irq_data);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(ipipe_enable_irq);
 
-- 
2.16.4

[PATCH v2 5/6] ipipe: Activate IRQ in ipipe_enable_irq

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

Likely needed since c942cee46bba which split enabling and startup.

This fixes unpopulated vectors in the IOAPIC on x86 at least, possibly
more.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 kernel/irq/chip.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 65d345b727be..22386e509f68 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -1087,6 +1087,7 @@ int ipipe_enable_irq(unsigned int irq)
 	struct irq_desc *desc;
 	struct irq_chip *chip;
 	unsigned long flags;
+	int err;
 
 	desc = irq_to_desc(irq);
 	if (desc == NULL)
@@ -1098,6 +1099,10 @@ int ipipe_enable_irq(unsigned int irq)
 
 		ipipe_root_only();
 
+		err = irq_activate(desc);
+		if (err)
+			return err;
+
 		raw_spin_lock_irqsave(&desc->lock, flags);
 		if (desc->istate & IPIPE_IRQS_NEEDS_STARTUP) {
 			desc->istate &= ~IPIPE_IRQS_NEEDS_STARTUP;
-- 
2.16.4

[PATCH v2 6/6] ipipe: Let ipipe_set_irq_affinity return an error

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

x86 may generate one, so change the signature.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 include/linux/ipipe.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/ipipe.h b/include/linux/ipipe.h
index f7c07a207093..45e8c87bff93 100644
--- a/include/linux/ipipe.h
+++ b/include/linux/ipipe.h
@@ -433,12 +433,12 @@ void ipipe_prepare_panic(void);
 #ifndef ipipe_smp_p
 #define ipipe_smp_p (1)
 #endif
-void ipipe_set_irq_affinity(unsigned int irq, cpumask_t cpumask);
+int ipipe_set_irq_affinity(unsigned int irq, cpumask_t cpumask);
 void ipipe_send_ipi(unsigned int ipi, cpumask_t cpumask);
 #else  /* !CONFIG_SMP */
 #define ipipe_smp_p (0)
 static inline
-void ipipe_set_irq_affinity(unsigned int irq, cpumask_t cpumask) { }
+int ipipe_set_irq_affinity(unsigned int irq, cpumask_t cpumask) { return 0; }
 static inline void ipipe_send_ipi(unsigned int ipi, cpumask_t cpumask) { }
 static inline void ipipe_disable_smp(void) { }
 #endif	/* CONFIG_SMP */
-- 
2.16.4

Re: [PATCH v2 0/6] ipipe-noarch: IRQ tracing, enabling, and lockdep fixes/cleanups

[Philippe Gerum]

On 7/11/19 9:56 PM, Jan Kiszka wrote:
> This included the patches from v1, the addition (patch 3), and the new
> patches needed to add return codes and irq enabling to some services.
> 
> Jan
> 
> Jan Kiszka (6):
>   ipipe: Restore trace_hardirqs_on_virt_caller
>   ipipe: lockdep: Remove duplicate context checks
>   ipipe: Add missing include for ipipe_root_only
>   ipipe: Let ipipe_enable_irq return an error code
>   ipipe: Activate IRQ in ipipe_enable_irq
>   ipipe: Let ipipe_set_irq_affinity return an error
> 
>  include/linux/ipipe.h           |  6 +++---
>  include/linux/kernel.h          |  1 +
>  kernel/irq/chip.c               | 17 ++++++++++++-----
>  kernel/locking/lockdep.c        |  6 ------
>  kernel/trace/trace_preemptirq.c | 11 +++++++++++
>  5 files changed, 27 insertions(+), 14 deletions(-)
> 

Applied, thanks.

-- 
Philippe.