diff options
| -rw-r--r-- | arch/powerpc/kernel/irq.c | 76 |
1 files changed, 11 insertions, 65 deletions
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 2656924415d..ac222d0ab12 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -439,9 +439,8 @@ void do_softirq(void) static LIST_HEAD(irq_hosts); static DEFINE_SPINLOCK(irq_big_lock); -static DEFINE_PER_CPU(unsigned int, irq_radix_reader); -static unsigned int irq_radix_writer; static unsigned int revmap_trees_allocated; +static DEFINE_MUTEX(revmap_trees_mutex); struct irq_map_entry irq_map[NR_IRQS]; static unsigned int irq_virq_count = NR_IRQS; static struct irq_host *irq_default_host; @@ -584,57 +583,6 @@ void irq_set_virq_count(unsigned int count) irq_virq_count = count; } -/* radix tree not lockless safe ! we use a brlock-type mecanism - * for now, until we can use a lockless radix tree - */ -static void irq_radix_wrlock(unsigned long *flags) -{ - unsigned int cpu, ok; - - spin_lock_irqsave(&irq_big_lock, *flags); - irq_radix_writer = 1; - smp_mb(); - do { - barrier(); - ok = 1; - for_each_possible_cpu(cpu) { - if (per_cpu(irq_radix_reader, cpu)) { - ok = 0; - break; - } - } - if (!ok) - cpu_relax(); - } while(!ok); -} - -static void irq_radix_wrunlock(unsigned long flags) -{ - smp_wmb(); - irq_radix_writer = 0; - spin_unlock_irqrestore(&irq_big_lock, flags); -} - -static void irq_radix_rdlock(unsigned long *flags) -{ - local_irq_save(*flags); - __get_cpu_var(irq_radix_reader) = 1; - smp_mb(); - if (likely(irq_radix_writer == 0)) - return; - __get_cpu_var(irq_radix_reader) = 0; - smp_wmb(); - spin_lock(&irq_big_lock); - __get_cpu_var(irq_radix_reader) = 1; - spin_unlock(&irq_big_lock); -} - -static void irq_radix_rdunlock(unsigned long flags) -{ - __get_cpu_var(irq_radix_reader) = 0; - local_irq_restore(flags); -} - static int irq_setup_virq(struct irq_host *host, unsigned int virq, irq_hw_number_t hwirq) { @@ -789,7 +737,6 @@ void irq_dispose_mapping(unsigned int virq) { struct irq_host *host; irq_hw_number_t hwirq; - unsigned long flags; if (virq == NO_IRQ) return; @@ -829,9 +776,9 @@ void irq_dispose_mapping(unsigned int virq) smp_rmb(); if (revmap_trees_allocated < 1) break; - irq_radix_wrlock(&flags); + mutex_lock(&revmap_trees_mutex); radix_tree_delete(&host->revmap_data.tree, hwirq); - irq_radix_wrunlock(flags); + mutex_unlock(&revmap_trees_mutex); break; } @@ -885,7 +832,6 @@ unsigned int irq_radix_revmap_lookup(struct irq_host *host, { struct irq_map_entry *ptr; unsigned int virq; - unsigned long flags; WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE); @@ -897,9 +843,11 @@ unsigned int irq_radix_revmap_lookup(struct irq_host *host, return irq_find_mapping(host, hwirq); /* Now try to resolve */ - irq_radix_rdlock(&flags); + /* + * No rcu_read_lock(ing) needed, the ptr returned can't go under us + * as it's referencing an entry in the static irq_map table. + */ ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq); - irq_radix_rdunlock(flags); /* * If found in radix tree, then fine. @@ -917,7 +865,6 @@ unsigned int irq_radix_revmap_lookup(struct irq_host *host, void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq, irq_hw_number_t hwirq) { - unsigned long flags; WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE); @@ -931,10 +878,10 @@ void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq, return; if (virq != NO_IRQ) { - irq_radix_wrlock(&flags); + mutex_lock(&revmap_trees_mutex); radix_tree_insert(&host->revmap_data.tree, hwirq, &irq_map[virq]); - irq_radix_wrunlock(flags); + mutex_unlock(&revmap_trees_mutex); } } @@ -1044,7 +991,6 @@ void irq_early_init(void) static int irq_late_init(void) { struct irq_host *h; - unsigned long flags; unsigned int i; /* @@ -1068,14 +1014,14 @@ static int irq_late_init(void) * Insert the reverse mapping for those interrupts already present * in irq_map[]. */ - irq_radix_wrlock(&flags); + mutex_lock(&revmap_trees_mutex); for (i = 0; i < irq_virq_count; i++) { if (irq_map[i].host && (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE)) radix_tree_insert(&irq_map[i].host->revmap_data.tree, irq_map[i].hwirq, &irq_map[i]); } - irq_radix_wrunlock(flags); + mutex_unlock(&revmap_trees_mutex); /* * Make sure the radix trees insertions are visible before setting |