--- /dev/null
+/*
+ * 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/export.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <linux/radix-tree.h>
+#include <linux/bitmap.h>
+#include <linux/irqdomain.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);
+}
+EXPORT_SYMBOL(irq_to_desc);
+
+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
+
+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, 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);
+
+ /*
+ * sparse_irq_lock protects also show_interrupts() and
+ * kstat_irq_usr(). Once we deleted the descriptor from the
+ * sparse tree we can free it. Access in proc will fail to
+ * lookup the descriptor.
+ */
+ 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;
+}
+EXPORT_SYMBOL(irq_to_desc);
+
+static void free_desc(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);
+}
+
+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;
+}
+
+void irq_mark_irq(unsigned int irq)
+{
+ mutex_lock(&sparse_irq_lock);
+ bitmap_set(allocated_irqs, irq, 1);
+ mutex_unlock(&sparse_irq_lock);
+}
+
+#ifdef CONFIG_GENERIC_IRQ_LEGACY
+void irq_init_desc(unsigned int irq)
+{
+ free_desc(irq);
+}
+#endif
+
+#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);
+
+#ifdef CONFIG_HANDLE_DOMAIN_IRQ
+/**
+ * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
+ * @domain: The domain where to perform the lookup
+ * @hwirq: The HW irq number to convert to a logical one
+ * @lookup: Whether to perform the domain lookup or not
+ * @regs: Register file coming from the low-level handling code
+ *
+ * Returns: 0 on success, or -EINVAL if conversion has failed
+ */
+int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
+ bool lookup, struct pt_regs *regs)
+{
+ struct pt_regs *old_regs = set_irq_regs(regs);
+ unsigned int irq = hwirq;
+ int ret = 0;
+
+ irq_enter();
+
+#ifdef CONFIG_IRQ_DOMAIN
+ if (lookup)
+ irq = irq_find_mapping(domain, hwirq);
+#endif
+
+ /*
+ * Some hardware gives randomly wrong interrupts. Rather
+ * than crashing, do something sensible.
+ */
+ if (unlikely(!irq || irq >= nr_irqs)) {
+ ack_bad_irq(irq);
+ ret = -EINVAL;
+ } else {
+ generic_handle_irq(irq);
+ }
+
+ irq_exit();
+ set_irq_regs(old_regs);
+ return ret;
+}
+#endif
+
+/* 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;
+ } else {
+ /*
+ * For interrupts which are freely allocated the
+ * architecture can force a lower bound to the @from
+ * argument. x86 uses this to exclude the GSI space.
+ */
+ from = arch_dynirq_lower_bound(from);
+ }
+
+ 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);
+
+#ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
+/**
+ * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
+ * @cnt: number of interrupts to allocate
+ * @node: node on which to allocate
+ *
+ * Returns an interrupt number > 0 or 0, if the allocation fails.
+ */
+unsigned int irq_alloc_hwirqs(int cnt, int node)
+{
+ int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL);
+
+ if (irq < 0)
+ return 0;
+
+ for (i = irq; cnt > 0; i++, cnt--) {
+ if (arch_setup_hwirq(i, node))
+ goto err;
+ irq_clear_status_flags(i, _IRQ_NOREQUEST);
+ }
+ return irq;
+
+err:
+ for (i--; i >= irq; i--) {
+ irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
+ arch_teardown_hwirq(i);
+ }
+ irq_free_descs(irq, cnt);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
+
+/**
+ * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
+ * @from: Free from irq number
+ * @cnt: number of interrupts to free
+ *
+ */
+void irq_free_hwirqs(unsigned int from, int cnt)
+{
+ int i, j;
+
+ for (i = from, j = cnt; j > 0; i++, j--) {
+ irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
+ arch_teardown_hwirq(i);
+ }
+ irq_free_descs(from, cnt);
+}
+EXPORT_SYMBOL_GPL(irq_free_hwirqs);
+#endif
+
+/**
+ * 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;
+}
+
+void kstat_incr_irq_this_cpu(unsigned int irq)
+{
+ kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
+}
+
+/**
+ * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
+ * @irq: The interrupt number
+ * @cpu: The cpu number
+ *
+ * Returns the sum of interrupt counts on @cpu since boot for
+ * @irq. The caller must ensure that the interrupt is not removed
+ * concurrently.
+ */
+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;
+}
+
+/**
+ * kstat_irqs - Get the statistics for an interrupt
+ * @irq: The interrupt number
+ *
+ * Returns the sum of interrupt counts on all cpus since boot for
+ * @irq. The caller must ensure that the interrupt is not removed
+ * concurrently.
+ */
+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;
+}
+
+/**
+ * kstat_irqs_usr - Get the statistics for an interrupt
+ * @irq: The interrupt number
+ *
+ * Returns the sum of interrupt counts on all cpus since boot for
+ * @irq. Contrary to kstat_irqs() this can be called from any
+ * preemptible context. It's protected against concurrent removal of
+ * an interrupt descriptor when sparse irqs are enabled.
+ */
+unsigned int kstat_irqs_usr(unsigned int irq)
+{
+ int sum;
+
+ irq_lock_sparse();
+ sum = kstat_irqs(irq);
+ irq_unlock_sparse();
+ return sum;
+}
Code Review / kvmfornfv.git / blobdiff