diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-15 15:07:35 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-15 15:07:35 (GMT) |
commit | 5f2434a66dfa4701b81b79a78eaf9c32da0f8839 (patch) | |
tree | 8c38f1fb0d0fbcd15e496df89be00ad8c4918a43 /arch/powerpc/kernel/irq.c | |
parent | 278429cff8809958d25415ba0ed32b59866ab1a8 (diff) | |
parent | 6dc6472581f693b5fc95aebedf67b4960fb85cf0 (diff) | |
download | linux-fsl-qoriq-5f2434a66dfa4701b81b79a78eaf9c32da0f8839.tar.xz |
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (158 commits)
powerpc: Fix CHRP PCI config access for indirect_pci
powerpc/chrp: Fix detection of Python PCI host bridge on IBM CHRPs
powerpc: Fix 32-bit SMP boot on CHRP
powerpc: Fix link errors on 32-bit machines using legacy DMA
powerpc/pci: Improve detection of unassigned bridge resources
hvc_console: Fix free_irq in spinlocked section
powerpc: Get USE_STRICT_MM_TYPECHECKS working again
powerpc: Reflect the used arguments in machine_init() prototype
powerpc: Fix DMA offset for non-coherent DMA
powerpc: fix fsl_upm nand driver modular build
powerpc/83xx: add NAND support for the MPC8360E-RDK boards
powerpc: FPGA support for GE Fanuc SBC610
i2c: MPC8349E-mITX Power Management and GPIO expander driver
powerpc: reserve two DMA channels for audio in MPC8610 HPCD device tree
powerpc: document the "fsl,ssi-dma-channel" compatible property
powerpc: disable CHRP and PMAC support in various defconfigs
OF: add fsl,mcu-mpc8349emitx to the exception list
powerpc/83xx: add DS1374 RTC support for the MPC837xE-MDS boards
powerpc: remove support for bootmem-allocated memory for the DIU driver
powerpc: remove non-dependent load fsl_booke PTE_64BIT
...
Diffstat (limited to 'arch/powerpc/kernel/irq.c')
-rw-r--r-- | arch/powerpc/kernel/irq.c | 169 |
1 files changed, 85 insertions, 84 deletions
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index d972dec..ac222d0 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -439,8 +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; @@ -583,57 +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) { @@ -788,7 +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; @@ -821,12 +769,16 @@ 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); + mutex_lock(&revmap_trees_mutex); radix_tree_delete(&host->revmap_data.tree, hwirq); - irq_radix_wrunlock(flags); + mutex_unlock(&revmap_trees_mutex); break; } @@ -875,43 +827,62 @@ 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); - irq_radix_rdunlock(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); - /* 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) +{ + + 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]); - irq_radix_wrunlock(flags); + mutex_lock(&revmap_trees_mutex); + radix_tree_insert(&host->revmap_data.tree, hwirq, + &irq_map[virq]); + mutex_unlock(&revmap_trees_mutex); } - return virq; } unsigned int irq_linear_revmap(struct irq_host *host, @@ -1020,14 +991,44 @@ void irq_early_init(void) 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[]. + */ + 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 + * the flag + */ + smp_wmb(); + revmap_trees_allocated = 2; return 0; } |