/* * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar * Copyright (C) 2005-2006, Thomas Gleixner, Russell King * * This file contains the interrupt descriptor management code * * Detailed information is available in Documentation/DocBook/genericirq * */ #include <linux/irq.h> #include <linux/slab.h> #include <linux/module.h> #include <linux/interrupt.h> #include <linux/kernel_stat.h> #include <linux/radix-tree.h> #include <linux/bitmap.h> #include "internals.h" /* * lockdep: we want to handle all irq_desc locks as a single lock-class: */ static struct lock_class_key irq_desc_lock_class; #if defined(CONFIG_SMP) static void __init init_irq_default_affinity(void) { alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT); cpumask_setall(irq_default_affinity); } #else static void __init init_irq_default_affinity(void) { } #endif #ifdef CONFIG_SMP static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { if (!zalloc_cpumask_var_node(&desc->irq_data.affinity, gfp, node)) return -ENOMEM; #ifdef CONFIG_GENERIC_PENDING_IRQ if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) { free_cpumask_var(desc->irq_data.affinity); return -ENOMEM; } #endif return 0; } static void desc_smp_init(struct irq_desc *desc, int node) { desc->irq_data.node = node; cpumask_copy(desc->irq_data.affinity, irq_default_affinity); #ifdef CONFIG_GENERIC_PENDING_IRQ cpumask_clear(desc->pending_mask); #endif } static inline int desc_node(struct irq_desc *desc) { return desc->irq_data.node; } #else static inline int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; } static inline void desc_smp_init(struct irq_desc *desc, int node) { } static inline int desc_node(struct irq_desc *desc) { return 0; } #endif static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node, struct module *owner) { int cpu; desc->irq_data.irq = irq; desc->irq_data.chip = &no_irq_chip; desc->irq_data.chip_data = NULL; desc->irq_data.handler_data = NULL; desc->irq_data.msi_desc = NULL; irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS); irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED); desc->handle_irq = handle_bad_irq; desc->depth = 1; desc->irq_count = 0; desc->irqs_unhandled = 0; desc->name = NULL; desc->owner = owner; for_each_possible_cpu(cpu) *per_cpu_ptr(desc->kstat_irqs, cpu) = 0; desc_smp_init(desc, node); } int nr_irqs = NR_IRQS; EXPORT_SYMBOL_GPL(nr_irqs); static DEFINE_MUTEX(sparse_irq_lock); static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS); #ifdef CONFIG_SPARSE_IRQ static RADIX_TREE(irq_desc_tree, GFP_KERNEL); static void irq_insert_desc(unsigned int irq, struct irq_desc *desc) { radix_tree_insert(&irq_desc_tree, irq, desc); } struct irq_desc *irq_to_desc(unsigned int irq) { return radix_tree_lookup(&irq_desc_tree, irq); } static void delete_irq_desc(unsigned int irq) { radix_tree_delete(&irq_desc_tree, irq); } #ifdef CONFIG_SMP static void free_masks(struct irq_desc *desc) { #ifdef CONFIG_GENERIC_PENDING_IRQ free_cpumask_var(desc->pending_mask); #endif free_cpumask_var(desc->irq_data.affinity); } #else static inline void free_masks(struct irq_desc *desc) { } #endif static struct irq_desc *alloc_desc(int irq, int node, struct module *owner) { struct irq_desc *desc; gfp_t gfp = GFP_KERNEL; desc = kzalloc_node(sizeof(*desc), gfp, node); if (!desc) return NULL; /* allocate based on nr_cpu_ids */ desc->kstat_irqs = alloc_percpu(unsigned int); if (!desc->kstat_irqs) goto err_desc; if (alloc_masks(desc, gfp, node)) goto err_kstat; raw_spin_lock_init(&desc->lock); lockdep_set_class(&desc->lock, &irq_desc_lock_class); desc_set_defaults(irq, desc, node, owner); return desc; err_kstat: free_percpu(desc->kstat_irqs); err_desc: kfree(desc); return NULL; } static void free_desc(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); unregister_irq_proc(irq, desc); mutex_lock(&sparse_irq_lock); delete_irq_desc(irq); mutex_unlock(&sparse_irq_lock); free_masks(desc); free_percpu(desc->kstat_irqs); kfree(desc); } static int alloc_descs(unsigned int start, unsigned int cnt, int node, struct module *owner) { struct irq_desc *desc; int i; for (i = 0; i < cnt; i++) { desc = alloc_desc(start + i, node, owner); if (!desc) goto err; mutex_lock(&sparse_irq_lock); irq_insert_desc(start + i, desc); mutex_unlock(&sparse_irq_lock); } return start; err: for (i--; i >= 0; i--) free_desc(start + i); mutex_lock(&sparse_irq_lock); bitmap_clear(allocated_irqs, start, cnt); mutex_unlock(&sparse_irq_lock); return -ENOMEM; } static int irq_expand_nr_irqs(unsigned int nr) { if (nr > IRQ_BITMAP_BITS) return -ENOMEM; nr_irqs = nr; return 0; } int __init early_irq_init(void) { int i, initcnt, node = first_online_node; struct irq_desc *desc; init_irq_default_affinity(); /* Let arch update nr_irqs and return the nr of preallocated irqs */ initcnt = arch_probe_nr_irqs(); printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt); if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS)) nr_irqs = IRQ_BITMAP_BITS; if (WARN_ON(initcnt > IRQ_BITMAP_BITS)) initcnt = IRQ_BITMAP_BITS; if (initcnt > nr_irqs) nr_irqs = initcnt; for (i = 0; i < initcnt; i++) { desc = alloc_desc(i, node, NULL); set_bit(i, allocated_irqs); irq_insert_desc(i, desc); } return arch_early_irq_init(); } #else /* !CONFIG_SPARSE_IRQ */ struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { [0 ... NR_IRQS-1] = { .handle_irq = handle_bad_irq, .depth = 1, .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock), } }; int __init early_irq_init(void) { int count, i, node = first_online_node; struct irq_desc *desc; init_irq_default_affinity(); printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS); desc = irq_desc; count = ARRAY_SIZE(irq_desc); for (i = 0; i < count; i++) { desc[i].kstat_irqs = alloc_percpu(unsigned int); alloc_masks(&desc[i], GFP_KERNEL, node); raw_spin_lock_init(&desc[i].lock); lockdep_set_class(&desc[i].lock, &irq_desc_lock_class); desc_set_defaults(i, &desc[i], node, NULL); } return arch_early_irq_init(); } struct irq_desc *irq_to_desc(unsigned int irq) { return (irq < NR_IRQS) ? irq_desc + irq : NULL; } static void free_desc(unsigned int irq) { dynamic_irq_cleanup(irq); } static inline int alloc_descs(unsigned int start, unsigned int cnt, int node, struct module *owner) { u32 i; for (i = 0; i < cnt; i++) { struct irq_desc *desc = irq_to_desc(start + i); desc->owner = owner; } return start; } static int irq_expand_nr_irqs(unsigned int nr) { return -ENOMEM; } #endif /* !CONFIG_SPARSE_IRQ */ /** * generic_handle_irq - Invoke the handler for a particular irq * @irq: The irq number to handle * */ int generic_handle_irq(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); if (!desc) return -EINVAL; generic_handle_irq_desc(irq, desc); return 0; } EXPORT_SYMBOL_GPL(generic_handle_irq); /* Dynamic interrupt handling */ /** * irq_free_descs - free irq descriptors * @from: Start of descriptor range * @cnt: Number of consecutive irqs to free */ void irq_free_descs(unsigned int from, unsigned int cnt) { int i; if (from >= nr_irqs || (from + cnt) > nr_irqs) return; for (i = 0; i < cnt; i++) free_desc(from + i); mutex_lock(&sparse_irq_lock); bitmap_clear(allocated_irqs, from, cnt); mutex_unlock(&sparse_irq_lock); } EXPORT_SYMBOL_GPL(irq_free_descs); /** * irq_alloc_descs - allocate and initialize a range of irq descriptors * @irq: Allocate for specific irq number if irq >= 0 * @from: Start the search from this irq number * @cnt: Number of consecutive irqs to allocate. * @node: Preferred node on which the irq descriptor should be allocated * @owner: Owning module (can be NULL) * * Returns the first irq number or error code */ int __ref __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node, struct module *owner) { int start, ret; if (!cnt) return -EINVAL; if (irq >= 0) { if (from > irq) return -EINVAL; from = irq; } mutex_lock(&sparse_irq_lock); start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS, from, cnt, 0); ret = -EEXIST; if (irq >=0 && start != irq) goto err; if (start + cnt > nr_irqs) { ret = irq_expand_nr_irqs(start + cnt); if (ret) goto err; } bitmap_set(allocated_irqs, start, cnt); mutex_unlock(&sparse_irq_lock); return alloc_descs(start, cnt, node, owner); err: mutex_unlock(&sparse_irq_lock); return ret; } EXPORT_SYMBOL_GPL(__irq_alloc_descs); /** * irq_reserve_irqs - mark irqs allocated * @from: mark from irq number * @cnt: number of irqs to mark * * Returns 0 on success or an appropriate error code */ int irq_reserve_irqs(unsigned int from, unsigned int cnt) { unsigned int start; int ret = 0; if (!cnt || (from + cnt) > nr_irqs) return -EINVAL; mutex_lock(&sparse_irq_lock); start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0); if (start == from) bitmap_set(allocated_irqs, start, cnt); else ret = -EEXIST; mutex_unlock(&sparse_irq_lock); return ret; } /** * irq_get_next_irq - get next allocated irq number * @offset: where to start the search * * Returns next irq number after offset or nr_irqs if none is found. */ unsigned int irq_get_next_irq(unsigned int offset) { return find_next_bit(allocated_irqs, nr_irqs, offset); } struct irq_desc * __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus, unsigned int check) { struct irq_desc *desc = irq_to_desc(irq); if (desc) { if (check & _IRQ_DESC_CHECK) { if ((check & _IRQ_DESC_PERCPU) && !irq_settings_is_per_cpu_devid(desc)) return NULL; if (!(check & _IRQ_DESC_PERCPU) && irq_settings_is_per_cpu_devid(desc)) return NULL; } if (bus) chip_bus_lock(desc); raw_spin_lock_irqsave(&desc->lock, *flags); } return desc; } void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus) { raw_spin_unlock_irqrestore(&desc->lock, flags); if (bus) chip_bus_sync_unlock(desc); } int irq_set_percpu_devid(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); if (!desc) return -EINVAL; if (desc->percpu_enabled) return -EINVAL; desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL); if (!desc->percpu_enabled) return -ENOMEM; irq_set_percpu_devid_flags(irq); return 0; } /** * dynamic_irq_cleanup - cleanup a dynamically allocated irq * @irq: irq number to initialize */ void dynamic_irq_cleanup(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; raw_spin_lock_irqsave(&desc->lock, flags); desc_set_defaults(irq, desc, desc_node(desc), NULL); raw_spin_unlock_irqrestore(&desc->lock, flags); } unsigned int kstat_irqs_cpu(unsigned int irq, int cpu) { struct irq_desc *desc = irq_to_desc(irq); return desc && desc->kstat_irqs ? *per_cpu_ptr(desc->kstat_irqs, cpu) : 0; } unsigned int kstat_irqs(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); int cpu; int sum = 0; if (!desc || !desc->kstat_irqs) return 0; for_each_possible_cpu(cpu) sum += *per_cpu_ptr(desc->kstat_irqs, cpu); return sum; }