diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/include/asm/irq.h | 18 | ||||
| -rw-r--r-- | arch/powerpc/kernel/irq.c | 97 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/xics.c | 11 |
3 files changed, 95 insertions, 31 deletions
diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h index a372f76836c2..0a5137676e1b 100644 --- a/arch/powerpc/include/asm/irq.h +++ b/arch/powerpc/include/asm/irq.h @@ -236,15 +236,27 @@ extern unsigned int irq_find_mapping(struct irq_host *host, extern unsigned int irq_create_direct_mapping(struct irq_host *host); /** - * irq_radix_revmap - Find a linux virq from a hw irq number. + * irq_radix_revmap_insert - Insert a hw irq to linux virq number mapping. + * @host: host owning this hardware interrupt + * @virq: linux irq number + * @hwirq: hardware irq number in that host space + * + * This is for use by irq controllers that use a radix tree reverse + * mapping for fast lookup. + */ +extern void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq, + irq_hw_number_t hwirq); + +/** + * irq_radix_revmap_lookup - Find a linux virq from a hw irq number. * @host: host owning this hardware interrupt * @hwirq: hardware irq number in that host space * * This is a fast path, for use by irq controller code that uses radix tree * revmaps */ -extern unsigned int irq_radix_revmap(struct irq_host *host, - irq_hw_number_t hwirq); +extern unsigned int irq_radix_revmap_lookup(struct irq_host *host, + irq_hw_number_t hwirq); /** * irq_linear_revmap - Find a linux virq from a hw irq number. diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index d972decf0324..2656924415da 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -441,6 +441,7 @@ 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; struct irq_map_entry irq_map[NR_IRQS]; static unsigned int irq_virq_count = NR_IRQS; static struct irq_host *irq_default_host; @@ -821,8 +822,12 @@ void irq_dispose_mapping(unsigned int virq) host->revmap_data.linear.revmap[hwirq] = NO_IRQ; break; case IRQ_HOST_MAP_TREE: - /* Check if radix tree allocated yet */ - if (host->revmap_data.tree.gfp_mask == 0) + /* + * Check if radix tree allocated yet, if not then nothing to + * remove. + */ + smp_rmb(); + if (revmap_trees_allocated < 1) break; irq_radix_wrlock(&flags); radix_tree_delete(&host->revmap_data.tree, hwirq); @@ -875,43 +880,62 @@ unsigned int irq_find_mapping(struct irq_host *host, EXPORT_SYMBOL_GPL(irq_find_mapping); -unsigned int irq_radix_revmap(struct irq_host *host, - irq_hw_number_t hwirq) +unsigned int irq_radix_revmap_lookup(struct irq_host *host, + irq_hw_number_t hwirq) { - struct radix_tree_root *tree; struct irq_map_entry *ptr; unsigned int virq; unsigned long flags; WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE); - /* Check if the radix tree exist yet. We test the value of - * the gfp_mask for that. Sneaky but saves another int in the - * structure. If not, we fallback to slow mode + /* + * Check if the radix tree exists and has bee initialized. + * If not, we fallback to slow mode */ - tree = &host->revmap_data.tree; - if (tree->gfp_mask == 0) + if (revmap_trees_allocated < 2) return irq_find_mapping(host, hwirq); /* Now try to resolve */ irq_radix_rdlock(&flags); - ptr = radix_tree_lookup(tree, hwirq); + ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq); irq_radix_rdunlock(flags); - /* Found it, return */ - if (ptr) { + /* + * If found in radix tree, then fine. + * Else fallback to linear lookup - this should not happen in practice + * as it means that we failed to insert the node in the radix tree. + */ + if (ptr) virq = ptr - irq_map; - return virq; - } + else + virq = irq_find_mapping(host, hwirq); + + return virq; +} + +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); + + /* + * Check if the radix tree exists yet. + * If not, then the irq will be inserted into the tree when it gets + * initialized. + */ + smp_rmb(); + if (revmap_trees_allocated < 1) + return; - /* If not there, try to insert it */ - virq = irq_find_mapping(host, hwirq); if (virq != NO_IRQ) { irq_radix_wrlock(&flags); - radix_tree_insert(tree, hwirq, &irq_map[virq]); + radix_tree_insert(&host->revmap_data.tree, hwirq, + &irq_map[virq]); irq_radix_wrunlock(flags); } - return virq; } unsigned int irq_linear_revmap(struct irq_host *host, @@ -1021,14 +1045,45 @@ static int irq_late_init(void) { struct irq_host *h; unsigned long flags; + unsigned int i; - irq_radix_wrlock(&flags); + /* + * No mutual exclusion with respect to accessors of the tree is needed + * here as the synchronization is done via the state variable + * revmap_trees_allocated. + */ list_for_each_entry(h, &irq_hosts, link) { if (h->revmap_type == IRQ_HOST_MAP_TREE) - INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC); + INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL); + } + + /* + * Make sure the radix trees inits are visible before setting + * the flag + */ + smp_wmb(); + revmap_trees_allocated = 1; + + /* + * Insert the reverse mapping for those interrupts already present + * in irq_map[]. + */ + irq_radix_wrlock(&flags); + 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); + /* + * Make sure the radix trees insertions are visible before setting + * the flag + */ + smp_wmb(); + revmap_trees_allocated = 2; + return 0; } arch_initcall(irq_late_init); diff --git a/arch/powerpc/platforms/pseries/xics.c b/arch/powerpc/platforms/pseries/xics.c index 0fc830f576f5..6b1a005cc0cc 100644 --- a/arch/powerpc/platforms/pseries/xics.c +++ b/arch/powerpc/platforms/pseries/xics.c @@ -310,12 +310,6 @@ static void xics_mask_irq(unsigned int virq) static unsigned int xics_startup(unsigned int virq) { - unsigned int irq; - - /* force a reverse mapping of the interrupt so it gets in the cache */ - irq = (unsigned int)irq_map[virq].hwirq; - irq_radix_revmap(xics_host, irq); - /* unmask it */ xics_unmask_irq(virq); return 0; @@ -346,7 +340,7 @@ static inline unsigned int xics_remap_irq(unsigned int vec) if (vec == XICS_IRQ_SPURIOUS) return NO_IRQ; - irq = irq_radix_revmap(xics_host, vec); + irq = irq_radix_revmap_lookup(xics_host, vec); if (likely(irq != NO_IRQ)) return irq; @@ -530,6 +524,9 @@ static int xics_host_map(struct irq_host *h, unsigned int virq, { pr_debug("xics: map virq %d, hwirq 0x%lx\n", virq, hw); + /* Insert the interrupt mapping into the radix tree for fast lookup */ + irq_radix_revmap_insert(xics_host, virq, hw); + get_irq_desc(virq)->status |= IRQ_LEVEL; set_irq_chip_and_handler(virq, xics_irq_chip, handle_fasteoi_irq); return 0; |
