linux/kernel/irq/irqdesc.c
Thomas Gleixner c16816acd0 genirq: Add protection against unsafe usage of generic_handle_irq()
In general calling generic_handle_irq() with interrupts disabled from non
interrupt context is harmless. For some interrupt controllers like the x86
trainwrecks this is outright dangerous as it might corrupt state if an
interrupt affinity change is pending.

Add infrastructure which allows to mark interrupts as unsafe and catch such
usage in generic_handle_irq().

Reported-by: sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lkml.kernel.org/r/20200306130623.590923677@linutronix.de
2020-03-08 11:06:40 +01:00

1022 lines
24 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* 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/core-api/genericirq.rst
*
*/
#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 <linux/sysfs.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 int __init irq_affinity_setup(char *str)
{
alloc_bootmem_cpumask_var(&irq_default_affinity);
cpulist_parse(str, irq_default_affinity);
/*
* Set at least the boot cpu. We don't want to end up with
* bugreports caused by random comandline masks
*/
cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
return 1;
}
__setup("irqaffinity=", irq_affinity_setup);
static void __init init_irq_default_affinity(void)
{
if (!cpumask_available(irq_default_affinity))
zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
if (cpumask_empty(irq_default_affinity))
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, int node)
{
if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
GFP_KERNEL, node))
return -ENOMEM;
#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
GFP_KERNEL, node)) {
free_cpumask_var(desc->irq_common_data.affinity);
return -ENOMEM;
}
#endif
#ifdef CONFIG_GENERIC_PENDING_IRQ
if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node)) {
#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
free_cpumask_var(desc->irq_common_data.effective_affinity);
#endif
free_cpumask_var(desc->irq_common_data.affinity);
return -ENOMEM;
}
#endif
return 0;
}
static void desc_smp_init(struct irq_desc *desc, int node,
const struct cpumask *affinity)
{
if (!affinity)
affinity = irq_default_affinity;
cpumask_copy(desc->irq_common_data.affinity, affinity);
#ifdef CONFIG_GENERIC_PENDING_IRQ
cpumask_clear(desc->pending_mask);
#endif
#ifdef CONFIG_NUMA
desc->irq_common_data.node = node;
#endif
}
#else
static inline int
alloc_masks(struct irq_desc *desc, int node) { return 0; }
static inline void
desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
#endif
static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
const struct cpumask *affinity, struct module *owner)
{
int cpu;
desc->irq_common_data.handler_data = NULL;
desc->irq_common_data.msi_desc = NULL;
desc->irq_data.common = &desc->irq_common_data;
desc->irq_data.irq = irq;
desc->irq_data.chip = &no_irq_chip;
desc->irq_data.chip_data = NULL;
irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
desc->handle_irq = handle_bad_irq;
desc->depth = 1;
desc->irq_count = 0;
desc->irqs_unhandled = 0;
desc->tot_count = 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, affinity);
}
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 void irq_kobj_release(struct kobject *kobj);
#ifdef CONFIG_SYSFS
static struct kobject *irq_kobj_base;
#define IRQ_ATTR_RO(_name) \
static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
static ssize_t per_cpu_count_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
int cpu, irq = desc->irq_data.irq;
ssize_t ret = 0;
char *p = "";
for_each_possible_cpu(cpu) {
unsigned int c = kstat_irqs_cpu(irq, cpu);
ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
p = ",";
}
ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
return ret;
}
IRQ_ATTR_RO(per_cpu_count);
static ssize_t chip_name_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
ssize_t ret = 0;
raw_spin_lock_irq(&desc->lock);
if (desc->irq_data.chip && desc->irq_data.chip->name) {
ret = scnprintf(buf, PAGE_SIZE, "%s\n",
desc->irq_data.chip->name);
}
raw_spin_unlock_irq(&desc->lock);
return ret;
}
IRQ_ATTR_RO(chip_name);
static ssize_t hwirq_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
ssize_t ret = 0;
raw_spin_lock_irq(&desc->lock);
if (desc->irq_data.domain)
ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
raw_spin_unlock_irq(&desc->lock);
return ret;
}
IRQ_ATTR_RO(hwirq);
static ssize_t type_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
ssize_t ret = 0;
raw_spin_lock_irq(&desc->lock);
ret = sprintf(buf, "%s\n",
irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
raw_spin_unlock_irq(&desc->lock);
return ret;
}
IRQ_ATTR_RO(type);
static ssize_t wakeup_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
ssize_t ret = 0;
raw_spin_lock_irq(&desc->lock);
ret = sprintf(buf, "%s\n",
irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
raw_spin_unlock_irq(&desc->lock);
return ret;
}
IRQ_ATTR_RO(wakeup);
static ssize_t name_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
ssize_t ret = 0;
raw_spin_lock_irq(&desc->lock);
if (desc->name)
ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
raw_spin_unlock_irq(&desc->lock);
return ret;
}
IRQ_ATTR_RO(name);
static ssize_t actions_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
struct irqaction *action;
ssize_t ret = 0;
char *p = "";
raw_spin_lock_irq(&desc->lock);
for (action = desc->action; action != NULL; action = action->next) {
ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
p, action->name);
p = ",";
}
raw_spin_unlock_irq(&desc->lock);
if (ret)
ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
return ret;
}
IRQ_ATTR_RO(actions);
static struct attribute *irq_attrs[] = {
&per_cpu_count_attr.attr,
&chip_name_attr.attr,
&hwirq_attr.attr,
&type_attr.attr,
&wakeup_attr.attr,
&name_attr.attr,
&actions_attr.attr,
NULL
};
ATTRIBUTE_GROUPS(irq);
static struct kobj_type irq_kobj_type = {
.release = irq_kobj_release,
.sysfs_ops = &kobj_sysfs_ops,
.default_groups = irq_groups,
};
static void irq_sysfs_add(int irq, struct irq_desc *desc)
{
if (irq_kobj_base) {
/*
* Continue even in case of failure as this is nothing
* crucial.
*/
if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
pr_warn("Failed to add kobject for irq %d\n", irq);
}
}
static void irq_sysfs_del(struct irq_desc *desc)
{
/*
* If irq_sysfs_init() has not yet been invoked (early boot), then
* irq_kobj_base is NULL and the descriptor was never added.
* kobject_del() complains about a object with no parent, so make
* it conditional.
*/
if (irq_kobj_base)
kobject_del(&desc->kobj);
}
static int __init irq_sysfs_init(void)
{
struct irq_desc *desc;
int irq;
/* Prevent concurrent irq alloc/free */
irq_lock_sparse();
irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
if (!irq_kobj_base) {
irq_unlock_sparse();
return -ENOMEM;
}
/* Add the already allocated interrupts */
for_each_irq_desc(irq, desc)
irq_sysfs_add(irq, desc);
irq_unlock_sparse();
return 0;
}
postcore_initcall(irq_sysfs_init);
#else /* !CONFIG_SYSFS */
static struct kobj_type irq_kobj_type = {
.release = irq_kobj_release,
};
static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
static void irq_sysfs_del(struct irq_desc *desc) {}
#endif /* CONFIG_SYSFS */
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_common_data.affinity);
#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
free_cpumask_var(desc->irq_common_data.effective_affinity);
#endif
}
#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, unsigned int flags,
const struct cpumask *affinity,
struct module *owner)
{
struct irq_desc *desc;
desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, 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, node))
goto err_kstat;
raw_spin_lock_init(&desc->lock);
lockdep_set_class(&desc->lock, &irq_desc_lock_class);
mutex_init(&desc->request_mutex);
init_rcu_head(&desc->rcu);
desc_set_defaults(irq, desc, node, affinity, owner);
irqd_set(&desc->irq_data, flags);
kobject_init(&desc->kobj, &irq_kobj_type);
return desc;
err_kstat:
free_percpu(desc->kstat_irqs);
err_desc:
kfree(desc);
return NULL;
}
static void irq_kobj_release(struct kobject *kobj)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
free_masks(desc);
free_percpu(desc->kstat_irqs);
kfree(desc);
}
static void delayed_free_desc(struct rcu_head *rhp)
{
struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
kobject_put(&desc->kobj);
}
static void free_desc(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
irq_remove_debugfs_entry(desc);
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.
*
* The sysfs entry must be serialized against a concurrent
* irq_sysfs_init() as well.
*/
irq_sysfs_del(desc);
delete_irq_desc(irq);
/*
* We free the descriptor, masks and stat fields via RCU. That
* allows demultiplex interrupts to do rcu based management of
* the child interrupts.
* This also allows us to use rcu in kstat_irqs_usr().
*/
call_rcu(&desc->rcu, delayed_free_desc);
}
static int alloc_descs(unsigned int start, unsigned int cnt, int node,
const struct irq_affinity_desc *affinity,
struct module *owner)
{
struct irq_desc *desc;
int i;
/* Validate affinity mask(s) */
if (affinity) {
for (i = 0; i < cnt; i++) {
if (cpumask_empty(&affinity[i].mask))
return -EINVAL;
}
}
for (i = 0; i < cnt; i++) {
const struct cpumask *mask = NULL;
unsigned int flags = 0;
if (affinity) {
if (affinity->is_managed) {
flags = IRQD_AFFINITY_MANAGED |
IRQD_MANAGED_SHUTDOWN;
}
mask = &affinity->mask;
node = cpu_to_node(cpumask_first(mask));
affinity++;
}
desc = alloc_desc(start + i, node, flags, mask, owner);
if (!desc)
goto err;
irq_insert_desc(start + i, desc);
irq_sysfs_add(start + i, desc);
irq_add_debugfs_entry(start + i, desc);
}
bitmap_set(allocated_irqs, start, cnt);
return start;
err:
for (i--; i >= 0; i--)
free_desc(start + i);
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, preallocated irqs: %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, 0, NULL, 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], node);
raw_spin_lock_init(&desc[i].lock);
lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
mutex_init(&desc[i].request_mutex);
desc_set_defaults(i, &desc[i], node, NULL, 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, irq_desc_get_node(desc), NULL, NULL);
raw_spin_unlock_irqrestore(&desc->lock, flags);
}
static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
const struct irq_affinity_desc *affinity,
struct module *owner)
{
u32 i;
for (i = 0; i < cnt; i++) {
struct irq_desc *desc = irq_to_desc(start + i);
desc->owner = owner;
}
bitmap_set(allocated_irqs, start, cnt);
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);
struct irq_data *data;
if (!desc)
return -EINVAL;
data = irq_desc_get_irq_data(desc);
if (WARN_ON_ONCE(!in_irq() && handle_enforce_irqctx(data)))
return -EPERM;
generic_handle_irq_desc(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;
}
#ifdef CONFIG_IRQ_DOMAIN
/**
* handle_domain_nmi - 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
* @regs: Register file coming from the low-level handling code
*
* This function must be called from an NMI context.
*
* Returns: 0 on success, or -EINVAL if conversion has failed
*/
int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
unsigned int irq;
int ret = 0;
/*
* NMI context needs to be setup earlier in order to deal with tracing.
*/
WARN_ON(!in_nmi());
irq = irq_find_mapping(domain, hwirq);
/*
* ack_bad_irq is not NMI-safe, just report
* an invalid interrupt.
*/
if (likely(irq))
generic_handle_irq(irq);
else
ret = -EINVAL;
set_irq_regs(old_regs);
return ret;
}
#endif
#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;
mutex_lock(&sparse_irq_lock);
for (i = 0; i < cnt; i++)
free_desc(from + i);
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)
* @affinity: Optional pointer to an affinity mask array of size @cnt which
* hints where the irq descriptors should be allocated and which
* default affinities to use
*
* 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, const struct irq_affinity_desc *affinity)
{
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 unlock;
if (start + cnt > nr_irqs) {
ret = irq_expand_nr_irqs(start + cnt);
if (ret)
goto unlock;
}
ret = alloc_descs(start, cnt, node, affinity, owner);
unlock:
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, 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)
__releases(&desc->lock)
{
raw_spin_unlock_irqrestore(&desc->lock, flags);
if (bus)
chip_bus_sync_unlock(desc);
}
int irq_set_percpu_devid_partition(unsigned int irq,
const struct cpumask *affinity)
{
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;
if (affinity)
desc->percpu_affinity = affinity;
else
desc->percpu_affinity = cpu_possible_mask;
irq_set_percpu_devid_flags(irq);
return 0;
}
int irq_set_percpu_devid(unsigned int irq)
{
return irq_set_percpu_devid_partition(irq, NULL);
}
int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
{
struct irq_desc *desc = irq_to_desc(irq);
if (!desc || !desc->percpu_enabled)
return -EINVAL;
if (affinity)
cpumask_copy(affinity, desc->percpu_affinity);
return 0;
}
EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
void kstat_incr_irq_this_cpu(unsigned int irq)
{
kstat_incr_irqs_this_cpu(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;
}
static bool irq_is_nmi(struct irq_desc *desc)
{
return desc->istate & IRQS_NMI;
}
/**
* 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);
unsigned int sum = 0;
int cpu;
if (!desc || !desc->kstat_irqs)
return 0;
if (!irq_settings_is_per_cpu_devid(desc) &&
!irq_settings_is_per_cpu(desc) &&
!irq_is_nmi(desc))
return desc->tot_count;
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 context.
* It uses rcu since a concurrent removal of an interrupt descriptor is
* observing an rcu grace period before delayed_free_desc()/irq_kobj_release().
*/
unsigned int kstat_irqs_usr(unsigned int irq)
{
unsigned int sum;
rcu_read_lock();
sum = kstat_irqs(irq);
rcu_read_unlock();
return sum;
}