Hi Thomas,
Any status on this one?
Cheers!
>-----Original Message-----
>From: Iyer, Sundar
>Sent: Thursday, July 05, 2012 2:46 PM
>To: t...@linutronix.de
>Cc: linux-kernel@vger.kernel.org; ar...@linux.intel.com; let...@linux-sh.org;
>Iyer,
>Sundar; Monroy, German
>Subject: [PATCH v4] x86/irq: handle chained interrupts during IRQ migration
>
>Chained interrupt handlers dont have an irqaction and hence are not handled
>during
>migrating interrupts when some cores go offline.
>
>Handle this by introducing a irq_is_chained() check which is based on the the
>CHAINED
>flag being set for such interrupts. fixup_irq() can then handle such
>interrupts and not
>skip them over.
>
>---
>v1: use accessors instead of new variables to identify chained irqs
>v2: use a mask of NOREQUEST, NOPROBE, and NOTHREAD accessor flags as per
>Paul M
>v3: use a new accessor called IRQ_CHAINED instead of the mask in v2
>v4: rebase against tip/irq/core branch
>
>Signed-off-by: Sundar Iyer <sundar.i...@intel.com>
>Reviewed-by: Yang, Fei <fei.y...@intel.com>
>Tested-by: Ng, Cheon-woei <cheon-woei...@intel.com>
>---
> arch/x86/kernel/irq.c | 10 ++++++----
> include/linux/irq.h | 1 +
> include/linux/irqdesc.h | 7 +++++++
> kernel/irq/chip.c | 1 +
> kernel/irq/settings.h | 8 ++++++++
> 5 files changed, 23 insertions(+), 4 deletions(-)
>
>diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index
>3dafc60..352de40 100644
>--- a/arch/x86/kernel/irq.c
>+++ b/arch/x86/kernel/irq.c
>@@ -255,10 +255,12 @@ void fixup_irqs(void)
>
> data = irq_desc_get_irq_data(desc);
> affinity = data->affinity;
>- if (!irq_has_action(irq) || irqd_is_per_cpu(data) ||
>- cpumask_subset(affinity, cpu_online_mask)) {
>- raw_spin_unlock(&desc->lock);
>- continue;
>+ /* include IRQs who have no action, but are chained */
>+ if ((!irq_has_action(irq) && !irq_is_chained(irq)) ||
>+ irqd_is_per_cpu(data) ||
>+ cpumask_subset(affinity, cpu_online_mask)) {
>+ raw_spin_unlock(&desc->lock);
>+ continue;
> }
>
> /*
>diff --git a/include/linux/irq.h b/include/linux/irq.h index 61f5cec..531fa31
>100644
>--- a/include/linux/irq.h
>+++ b/include/linux/irq.h
>@@ -97,6 +97,7 @@ enum {
> IRQ_NESTED_THREAD = (1 << 15),
> IRQ_NOTHREAD = (1 << 16),
> IRQ_PER_CPU_DEVID = (1 << 17),
>+ IRQ_CHAINED = (1 << 18),
> };
>
> #define IRQF_MODIFY_MASK \
>diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index
>f1e2527..785d608
>100644
>--- a/include/linux/irqdesc.h
>+++ b/include/linux/irqdesc.h
>@@ -123,6 +123,13 @@ static inline int irq_has_action(unsigned int irq)
> return desc->action != NULL;
> }
>
>+/* Test to see if the IRQ is chained */ static inline int
>+irq_is_chained(unsigned int irq) {
>+ struct irq_desc *desc = irq_to_desc(irq);
>+ return desc->status_use_accessors & IRQ_CHAINED; }
>+
> /* caller has locked the irq_desc and both params are valid */ static inline
> void
>__irq_set_handler_locked(unsigned int irq,
> irq_flow_handler_t handler)
>diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index eebd6d5..41e0208
>100644
>--- a/kernel/irq/chip.c
>+++ b/kernel/irq/chip.c
>@@ -657,6 +657,7 @@ __irq_set_handler(unsigned int irq, irq_flow_handler_t
>handle, int
>is_chained,
> irq_settings_set_noprobe(desc);
> irq_settings_set_norequest(desc);
> irq_settings_set_nothread(desc);
>+ irq_settings_set_chained(desc);
> irq_startup(desc, true);
> }
> out:
>diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h index
>1162f10..bb8e167 100644
>--- a/kernel/irq/settings.h
>+++ b/kernel/irq/settings.h
>@@ -15,6 +15,7 @@ enum {
> _IRQ_NESTED_THREAD = IRQ_NESTED_THREAD,
> _IRQ_PER_CPU_DEVID = IRQ_PER_CPU_DEVID,
> _IRQF_MODIFY_MASK = IRQF_MODIFY_MASK,
>+ _IRQ_CHAINED = IRQ_CHAINED,
> };
>
> #define IRQ_PER_CPU GOT_YOU_MORON
>@@ -28,6 +29,7 @@ enum {
> #define IRQ_PER_CPU_DEVID GOT_YOU_MORON
> #undef IRQF_MODIFY_MASK
> #define IRQF_MODIFY_MASK GOT_YOU_MORON
>+#define IRQ_CHAINED GOT_YOU_MORON
>
> static inline void
> irq_settings_clr_and_set(struct irq_desc *desc, u32 clr, u32 set) @@ -147,3
> +149,9 @@
>static inline bool irq_settings_is_nested_thread(struct irq_desc *desc) {
> return desc->status_use_accessors & _IRQ_NESTED_THREAD; }
>+
>+static inline bool irq_settings_set_chained(struct irq_desc *desc) {
>+ return desc->status_use_accessors |= _IRQ_CHAINED; }
>+
>--
>1.7.0.4
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