Messages in this thread Patch in this message | | | From | Pingfan Liu <> | Subject | [PATCH 8/9] irq: make irq_lock_sparse() independent of CONFIG_SPARSE_IRQ | Date | Wed, 20 Apr 2022 22:05:20 +0800 |
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Even in the case of non-sparse irq, the callsite of for_each_active_irq() in irq_debugfs_init() still cares about the sync of allocated_irqs bitmap. Otherwise irq_debugfs_init() may show some disappeared irq if the irq is disactived by other driver in parallel.
As there are only a few callsites of irq_lock_sparse() in the cold path, which means the slight performance drops can be ignored. Hence moving irq_lock_sparse() out of CONFIG_SPARSE_IRQ to protect both irq_desc and allocated_irqs bitmap, instead of making irq_lock_sparse() dependent on GENERIC_IRQ_DEBUGFS.
Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Marc Zyngier <maz@kernel.org> Cc: Wolfram Sang <wsa+renesas@sang-engineering.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Mark Rutland <mark.rutland@arm.com> To: linux-kernel@vger.kernel.org --- include/linux/irqdesc.h | 6 ++---- kernel/irq/irqdesc.c | 20 ++++++++++---------- 2 files changed, 12 insertions(+), 14 deletions(-)
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index a77584593f7d..6c01231fec00 100644 --- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -104,12 +104,10 @@ struct irq_desc { const char *name; } ____cacheline_internodealigned_in_smp; -#ifdef CONFIG_SPARSE_IRQ extern void irq_lock_sparse(void); extern void irq_unlock_sparse(void); -#else -static inline void irq_lock_sparse(void) { } -static inline void irq_unlock_sparse(void) { } + +#ifndef CONFIG_SPARSE_IRQ extern struct irq_desc irq_desc[NR_IRQS]; #endif diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 9feedaa08430..a5cefd7c9ef7 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -375,16 +375,6 @@ static void free_masks(struct irq_desc *desc) static inline void free_masks(struct irq_desc *desc) { } #endif -void irq_lock_sparse(void) -{ - mutex_lock(&sparse_irq_lock); -} - -void irq_unlock_sparse(void) -{ - mutex_unlock(&sparse_irq_lock); -} - static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags, const struct cpumask *affinity, struct module *owner) @@ -721,6 +711,16 @@ int generic_handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq) } #endif +void irq_lock_sparse(void) +{ + mutex_lock(&sparse_irq_lock); +} + +void irq_unlock_sparse(void) +{ + mutex_unlock(&sparse_irq_lock); +} + /* Dynamic interrupt handling */ /** -- 2.31.1
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