* This file contains driver APIs to the irq subsystem.
*/
+#define pr_fmt(fmt) "genirq: " fmt
+
#include <linux/irq.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/sched.h>
+#include <linux/task_work.h>
#include "internals.h"
+#ifdef CONFIG_IRQ_FORCED_THREADING
+__read_mostly bool force_irqthreads;
+
+static int __init setup_forced_irqthreads(char *arg)
+{
+ force_irqthreads = true;
+ return 0;
+}
+early_param("threadirqs", setup_forced_irqthreads);
+#endif
+
/**
* synchronize_irq - wait for pending IRQ handlers (on other CPUs)
* @irq: interrupt number to wait for
void synchronize_irq(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
- unsigned int state;
+ bool inprogress;
if (!desc)
return;
* Wait until we're out of the critical section. This might
* give the wrong answer due to the lack of memory barriers.
*/
- while (desc->istate & IRQS_INPROGRESS)
+ while (irqd_irq_inprogress(&desc->irq_data))
cpu_relax();
/* Ok, that indicated we're done: double-check carefully. */
raw_spin_lock_irqsave(&desc->lock, flags);
- state = desc->istate;
+ inprogress = irqd_irq_inprogress(&desc->irq_data);
raw_spin_unlock_irqrestore(&desc->lock, flags);
/* Oops, that failed? */
- } while (state & IRQS_INPROGRESS);
+ } while (inprogress);
/*
* We made sure that no hardirq handler is running. Now verify
}
#ifdef CONFIG_GENERIC_PENDING_IRQ
-static inline bool irq_can_move_pcntxt(struct irq_desc *desc)
+static inline bool irq_can_move_pcntxt(struct irq_data *data)
{
- return irq_settings_can_move_pcntxt(desc);
+ return irqd_can_move_in_process_context(data);
}
-static inline bool irq_move_pending(struct irq_desc *desc)
+static inline bool irq_move_pending(struct irq_data *data)
{
- return irqd_is_setaffinity_pending(&desc->irq_data);
+ return irqd_is_setaffinity_pending(data);
}
static inline void
irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
cpumask_copy(mask, desc->pending_mask);
}
#else
-static inline bool irq_can_move_pcntxt(struct irq_desc *desc) { return true; }
-static inline bool irq_move_pending(struct irq_desc *desc) { return false; }
+static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
+static inline bool irq_move_pending(struct irq_data *data) { return false; }
static inline void
irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
static inline void
irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
#endif
-/**
- * irq_set_affinity - Set the irq affinity of a given irq
- * @irq: Interrupt to set affinity
- * @cpumask: cpumask
- *
- */
-int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
+int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
+ bool force)
{
- struct irq_desc *desc = irq_to_desc(irq);
- struct irq_chip *chip = desc->irq_data.chip;
- unsigned long flags;
+ struct irq_desc *desc = irq_data_to_desc(data);
+ struct irq_chip *chip = irq_data_get_irq_chip(data);
+ int ret;
+
+ ret = chip->irq_set_affinity(data, mask, false);
+ switch (ret) {
+ case IRQ_SET_MASK_OK:
+ cpumask_copy(data->affinity, mask);
+ case IRQ_SET_MASK_OK_NOCOPY:
+ irq_set_thread_affinity(desc);
+ ret = 0;
+ }
+
+ return ret;
+}
+
+int __irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask)
+{
+ struct irq_chip *chip = irq_data_get_irq_chip(data);
+ struct irq_desc *desc = irq_data_to_desc(data);
int ret = 0;
- if (!chip->irq_set_affinity)
+ if (!chip || !chip->irq_set_affinity)
return -EINVAL;
- raw_spin_lock_irqsave(&desc->lock, flags);
-
- if (irq_can_move_pcntxt(desc)) {
- ret = chip->irq_set_affinity(&desc->irq_data, mask, false);
- switch (ret) {
- case IRQ_SET_MASK_OK:
- cpumask_copy(desc->irq_data.affinity, mask);
- case IRQ_SET_MASK_OK_NOCOPY:
- irq_set_thread_affinity(desc);
- ret = 0;
- }
+ if (irq_can_move_pcntxt(data)) {
+ ret = irq_do_set_affinity(data, mask, false);
} else {
- irqd_set_move_pending(&desc->irq_data);
+ irqd_set_move_pending(data);
irq_copy_pending(desc, mask);
}
kref_get(&desc->affinity_notify->kref);
schedule_work(&desc->affinity_notify->work);
}
- irq_compat_set_affinity(desc);
- irqd_set(&desc->irq_data, IRQD_AFFINITY_SET);
- raw_spin_unlock_irqrestore(&desc->lock, flags);
+ irqd_set(data, IRQD_AFFINITY_SET);
+
return ret;
}
-int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
+/**
+ * irq_set_affinity - Set the irq affinity of a given irq
+ * @irq: Interrupt to set affinity
+ * @mask: cpumask
+ *
+ */
+int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
+ int ret;
if (!desc)
return -EINVAL;
raw_spin_lock_irqsave(&desc->lock, flags);
- desc->affinity_hint = m;
+ ret = __irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask);
raw_spin_unlock_irqrestore(&desc->lock, flags);
+ return ret;
+}
+int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
+{
+ unsigned long flags;
+ struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
+
+ if (!desc)
+ return -EINVAL;
+ desc->affinity_hint = m;
+ irq_put_desc_unlock(desc, flags);
return 0;
}
EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
goto out;
raw_spin_lock_irqsave(&desc->lock, flags);
- if (irq_move_pending(desc))
+ if (irq_move_pending(&desc->irq_data))
irq_get_pending(cpumask, desc);
else
cpumask_copy(cpumask, desc->irq_data.affinity);
static int
setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
{
- struct irq_chip *chip = irq_desc_get_chip(desc);
struct cpumask *set = irq_default_affinity;
- int ret;
+ int node = desc->irq_data.node;
/* Excludes PER_CPU and NO_BALANCE interrupts */
if (!irq_can_set_affinity(irq))
if (cpumask_intersects(desc->irq_data.affinity,
cpu_online_mask))
set = desc->irq_data.affinity;
- else {
- irq_compat_clr_affinity(desc);
+ else
irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
- }
}
cpumask_and(mask, cpu_online_mask, set);
- ret = chip->irq_set_affinity(&desc->irq_data, mask, false);
- switch (ret) {
- case IRQ_SET_MASK_OK:
- cpumask_copy(desc->irq_data.affinity, mask);
- case IRQ_SET_MASK_OK_NOCOPY:
- irq_set_thread_affinity(desc);
+ if (node != NUMA_NO_NODE) {
+ const struct cpumask *nodemask = cpumask_of_node(node);
+
+ /* make sure at least one of the cpus in nodemask is online */
+ if (cpumask_intersects(mask, nodemask))
+ cpumask_and(mask, mask, nodemask);
}
+ irq_do_set_affinity(&desc->irq_data, mask, false);
return 0;
}
#else
irq_disable(desc);
}
+static int __disable_irq_nosync(unsigned int irq)
+{
+ unsigned long flags;
+ struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
+
+ if (!desc)
+ return -EINVAL;
+ __disable_irq(desc, irq, false);
+ irq_put_desc_busunlock(desc, flags);
+ return 0;
+}
+
/**
* disable_irq_nosync - disable an irq without waiting
* @irq: Interrupt to disable
*/
void disable_irq_nosync(unsigned int irq)
{
- struct irq_desc *desc = irq_to_desc(irq);
- unsigned long flags;
-
- if (!desc)
- return;
-
- chip_bus_lock(desc);
- raw_spin_lock_irqsave(&desc->lock, flags);
- __disable_irq(desc, irq, false);
- raw_spin_unlock_irqrestore(&desc->lock, flags);
- chip_bus_sync_unlock(desc);
+ __disable_irq_nosync(irq);
}
EXPORT_SYMBOL(disable_irq_nosync);
*/
void disable_irq(unsigned int irq)
{
- struct irq_desc *desc = irq_to_desc(irq);
-
- if (!desc)
- return;
-
- disable_irq_nosync(irq);
- if (desc->action)
+ if (!__disable_irq_nosync(irq))
synchronize_irq(irq);
}
EXPORT_SYMBOL(disable_irq);
*/
void enable_irq(unsigned int irq)
{
- struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
+ struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
if (!desc)
return;
-
if (WARN(!desc->irq_data.chip,
KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
- return;
+ goto out;
- chip_bus_lock(desc);
- raw_spin_lock_irqsave(&desc->lock, flags);
__enable_irq(desc, irq, false);
- raw_spin_unlock_irqrestore(&desc->lock, flags);
- chip_bus_sync_unlock(desc);
+out:
+ irq_put_desc_busunlock(desc, flags);
}
EXPORT_SYMBOL(enable_irq);
struct irq_desc *desc = irq_to_desc(irq);
int ret = -ENXIO;
+ if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
+ return 0;
+
if (desc->irq_data.chip->irq_set_wake)
ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
*/
int irq_set_irq_wake(unsigned int irq, unsigned int on)
{
- struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
+ struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
int ret = 0;
+ if (!desc)
+ return -EINVAL;
+
/* wakeup-capable irqs can be shared between drivers that
* don't need to have the same sleep mode behaviors.
*/
- chip_bus_lock(desc);
- raw_spin_lock_irqsave(&desc->lock, flags);
if (on) {
if (desc->wake_depth++ == 0) {
ret = set_irq_wake_real(irq, on);
irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
}
}
-
- raw_spin_unlock_irqrestore(&desc->lock, flags);
- chip_bus_sync_unlock(desc);
+ irq_put_desc_busunlock(desc, flags);
return ret;
}
EXPORT_SYMBOL(irq_set_irq_wake);
*/
int can_request_irq(unsigned int irq, unsigned long irqflags)
{
- struct irq_desc *desc = irq_to_desc(irq);
- struct irqaction *action;
unsigned long flags;
+ struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
+ int canrequest = 0;
if (!desc)
return 0;
- if (!irq_settings_can_request(desc))
- return 0;
-
- raw_spin_lock_irqsave(&desc->lock, flags);
- action = desc->action;
- if (action)
- if (irqflags & action->flags & IRQF_SHARED)
- action = NULL;
-
- raw_spin_unlock_irqrestore(&desc->lock, flags);
-
- return !action;
+ if (irq_settings_can_request(desc)) {
+ if (desc->action)
+ if (irqflags & desc->action->flags & IRQF_SHARED)
+ canrequest =1;
+ }
+ irq_put_desc_unlock(desc, flags);
+ return canrequest;
}
int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
* flow-types?
*/
pr_debug("No set_type function for IRQ %d (%s)\n", irq,
- chip ? (chip->name ? : "unknown") : "unknown");
+ chip ? (chip->name ? : "unknown") : "unknown");
return 0;
}
flags &= IRQ_TYPE_SENSE_MASK;
if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
- if (!(desc->istate & IRQS_MASKED))
+ if (!irqd_irq_masked(&desc->irq_data))
mask_irq(desc);
- if (!(desc->istate & IRQS_DISABLED))
+ if (!irqd_irq_disabled(&desc->irq_data))
unmask = 1;
}
irqd_set(&desc->irq_data, IRQD_LEVEL);
}
- if (chip != desc->irq_data.chip)
- irq_chip_set_defaults(desc->irq_data.chip);
ret = 0;
+ break;
default:
- pr_err("setting trigger mode %lu for irq %u failed (%pF)\n",
+ pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
flags, irq, chip->irq_set_type);
}
if (unmask)
static int irq_wait_for_interrupt(struct irqaction *action)
{
+ set_current_state(TASK_INTERRUPTIBLE);
+
while (!kthread_should_stop()) {
- set_current_state(TASK_INTERRUPTIBLE);
if (test_and_clear_bit(IRQTF_RUNTHREAD,
&action->thread_flags)) {
return 0;
}
schedule();
+ set_current_state(TASK_INTERRUPTIBLE);
}
+ __set_current_state(TASK_RUNNING);
return -1;
}
* handler finished. unmask if the interrupt has not been disabled and
* is marked MASKED.
*/
-static void irq_finalize_oneshot(unsigned int irq, struct irq_desc *desc)
+static void irq_finalize_oneshot(struct irq_desc *desc,
+ struct irqaction *action)
{
+ if (!(desc->istate & IRQS_ONESHOT))
+ return;
again:
chip_bus_lock(desc);
raw_spin_lock_irq(&desc->lock);
* on the other CPU. If we unmask the irq line then the
* interrupt can come in again and masks the line, leaves due
* to IRQS_INPROGRESS and the irq line is masked forever.
+ *
+ * This also serializes the state of shared oneshot handlers
+ * versus "desc->threads_onehsot |= action->thread_mask;" in
+ * irq_wake_thread(). See the comment there which explains the
+ * serialization.
*/
- if (unlikely(desc->istate & IRQS_INPROGRESS)) {
+ if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
raw_spin_unlock_irq(&desc->lock);
chip_bus_sync_unlock(desc);
cpu_relax();
goto again;
}
- if (!(desc->istate & IRQS_DISABLED) && (desc->istate & IRQS_MASKED)) {
- irq_compat_clr_masked(desc);
- desc->istate &= ~IRQS_MASKED;
- desc->irq_data.chip->irq_unmask(&desc->irq_data);
- }
+ /*
+ * Now check again, whether the thread should run. Otherwise
+ * we would clear the threads_oneshot bit of this thread which
+ * was just set.
+ */
+ if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
+ goto out_unlock;
+
+ desc->threads_oneshot &= ~action->thread_mask;
+
+ if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
+ irqd_irq_masked(&desc->irq_data))
+ unmask_irq(desc);
+
+out_unlock:
raw_spin_unlock_irq(&desc->lock);
chip_bus_sync_unlock(desc);
}
irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
#endif
+/*
+ * Interrupts which are not explicitely requested as threaded
+ * interrupts rely on the implicit bh/preempt disable of the hard irq
+ * context. So we need to disable bh here to avoid deadlocks and other
+ * side effects.
+ */
+static irqreturn_t
+irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
+{
+ irqreturn_t ret;
+
+ local_bh_disable();
+ ret = action->thread_fn(action->irq, action->dev_id);
+ irq_finalize_oneshot(desc, action);
+ local_bh_enable();
+ return ret;
+}
+
+/*
+ * Interrupts explicitely requested as threaded interupts want to be
+ * preemtible - many of them need to sleep and wait for slow busses to
+ * complete.
+ */
+static irqreturn_t irq_thread_fn(struct irq_desc *desc,
+ struct irqaction *action)
+{
+ irqreturn_t ret;
+
+ ret = action->thread_fn(action->irq, action->dev_id);
+ irq_finalize_oneshot(desc, action);
+ return ret;
+}
+
+static void wake_threads_waitq(struct irq_desc *desc)
+{
+ if (atomic_dec_and_test(&desc->threads_active) &&
+ waitqueue_active(&desc->wait_for_threads))
+ wake_up(&desc->wait_for_threads);
+}
+
+static void irq_thread_dtor(struct callback_head *unused)
+{
+ struct task_struct *tsk = current;
+ struct irq_desc *desc;
+ struct irqaction *action;
+
+ if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
+ return;
+
+ action = kthread_data(tsk);
+
+ pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
+ tsk->comm ? tsk->comm : "", tsk->pid, action->irq);
+
+
+ desc = irq_to_desc(action->irq);
+ /*
+ * If IRQTF_RUNTHREAD is set, we need to decrement
+ * desc->threads_active and wake possible waiters.
+ */
+ if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
+ wake_threads_waitq(desc);
+
+ /* Prevent a stale desc->threads_oneshot */
+ irq_finalize_oneshot(desc, action);
+}
+
/*
* Interrupt handler thread
*/
static int irq_thread(void *data)
{
+ struct callback_head on_exit_work;
static const struct sched_param param = {
.sched_priority = MAX_USER_RT_PRIO/2,
};
struct irqaction *action = data;
struct irq_desc *desc = irq_to_desc(action->irq);
- int wake, oneshot = desc->istate & IRQS_ONESHOT;
+ irqreturn_t (*handler_fn)(struct irq_desc *desc,
+ struct irqaction *action);
+
+ if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
+ &action->thread_flags))
+ handler_fn = irq_forced_thread_fn;
+ else
+ handler_fn = irq_thread_fn;
sched_setscheduler(current, SCHED_FIFO, ¶m);
- current->irqaction = action;
+
+ init_task_work(&on_exit_work, irq_thread_dtor);
+ task_work_add(current, &on_exit_work, false);
while (!irq_wait_for_interrupt(action)) {
+ irqreturn_t action_ret;
irq_thread_check_affinity(desc, action);
- atomic_inc(&desc->threads_active);
-
- raw_spin_lock_irq(&desc->lock);
- if (unlikely(desc->istate & IRQS_DISABLED)) {
- /*
- * CHECKME: We might need a dedicated
- * IRQ_THREAD_PENDING flag here, which
- * retriggers the thread in check_irq_resend()
- * but AFAICT IRQS_PENDING should be fine as it
- * retriggers the interrupt itself --- tglx
- */
- irq_compat_set_pending(desc);
- desc->istate |= IRQS_PENDING;
- raw_spin_unlock_irq(&desc->lock);
- } else {
- raw_spin_unlock_irq(&desc->lock);
-
- action->thread_fn(action->irq, action->dev_id);
-
- if (oneshot)
- irq_finalize_oneshot(action->irq, desc);
- }
-
- wake = atomic_dec_and_test(&desc->threads_active);
+ action_ret = handler_fn(desc, action);
+ if (!noirqdebug)
+ note_interrupt(action->irq, desc, action_ret);
- if (wake && waitqueue_active(&desc->wait_for_threads))
- wake_up(&desc->wait_for_threads);
+ wake_threads_waitq(desc);
}
/*
- * Clear irqaction. Otherwise exit_irq_thread() would make
- * fuzz about an active irq thread going into nirvana.
+ * This is the regular exit path. __free_irq() is stopping the
+ * thread via kthread_stop() after calling
+ * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
+ * oneshot mask bit can be set. We cannot verify that as we
+ * cannot touch the oneshot mask at this point anymore as
+ * __setup_irq() might have given out currents thread_mask
+ * again.
*/
- current->irqaction = NULL;
+ task_work_cancel(current, irq_thread_dtor);
return 0;
}
-/*
- * Called from do_exit()
- */
-void exit_irq_thread(void)
+static void irq_setup_forced_threading(struct irqaction *new)
{
- struct task_struct *tsk = current;
-
- if (!tsk->irqaction)
+ if (!force_irqthreads)
+ return;
+ if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
return;
- printk(KERN_ERR
- "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
- tsk->comm ? tsk->comm : "", tsk->pid, tsk->irqaction->irq);
+ new->flags |= IRQF_ONESHOT;
- /*
- * Set the THREAD DIED flag to prevent further wakeups of the
- * soon to be gone threaded handler.
- */
- set_bit(IRQTF_DIED, &tsk->irqaction->flags);
+ if (!new->thread_fn) {
+ set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
+ new->thread_fn = new->handler;
+ new->handler = irq_default_primary_handler;
+ }
}
/*
__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
{
struct irqaction *old, **old_ptr;
- const char *old_name = NULL;
- unsigned long flags;
+ unsigned long flags, thread_mask = 0;
int ret, nested, shared = 0;
cpumask_var_t mask;
if (desc->irq_data.chip == &no_irq_chip)
return -ENOSYS;
- /*
- * Some drivers like serial.c use request_irq() heavily,
- * so we have to be careful not to interfere with a
- * running system.
- */
- if (new->flags & IRQF_SAMPLE_RANDOM) {
- /*
- * This function might sleep, we want to call it first,
- * outside of the atomic block.
- * Yes, this might clear the entropy pool if the wrong
- * driver is attempted to be loaded, without actually
- * installing a new handler, but is this really a problem,
- * only the sysadmin is able to do this.
- */
- rand_initialize_irq(irq);
- }
-
- /* Oneshot interrupts are not allowed with shared */
- if ((new->flags & IRQF_ONESHOT) && (new->flags & IRQF_SHARED))
- return -EINVAL;
+ if (!try_module_get(desc->owner))
+ return -ENODEV;
/*
* Check whether the interrupt nests into another interrupt
*/
nested = irq_settings_is_nested_thread(desc);
if (nested) {
- if (!new->thread_fn)
- return -EINVAL;
+ if (!new->thread_fn) {
+ ret = -EINVAL;
+ goto out_mput;
+ }
/*
* Replace the primary handler which was provided from
* the driver for non nested interrupt handling by the
* dummy function which warns when called.
*/
new->handler = irq_nested_primary_handler;
+ } else {
+ if (irq_settings_can_thread(desc))
+ irq_setup_forced_threading(new);
}
/*
t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
new->name);
- if (IS_ERR(t))
- return PTR_ERR(t);
+ if (IS_ERR(t)) {
+ ret = PTR_ERR(t);
+ goto out_mput;
+ }
/*
* We keep the reference to the task struct even if
* the thread dies to avoid that the interrupt code
goto out_thread;
}
+ /*
+ * Drivers are often written to work w/o knowledge about the
+ * underlying irq chip implementation, so a request for a
+ * threaded irq without a primary hard irq context handler
+ * requires the ONESHOT flag to be set. Some irq chips like
+ * MSI based interrupts are per se one shot safe. Check the
+ * chip flags, so we can avoid the unmask dance at the end of
+ * the threaded handler for those.
+ */
+ if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
+ new->flags &= ~IRQF_ONESHOT;
+
/*
* The following block of code has to be executed atomically
*/
* Can't share interrupts unless both agree to and are
* the same type (level, edge, polarity). So both flag
* fields must have IRQF_SHARED set and the bits which
- * set the trigger type must match.
+ * set the trigger type must match. Also all must
+ * agree on ONESHOT.
*/
if (!((old->flags & new->flags) & IRQF_SHARED) ||
- ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) {
- old_name = old->name;
+ ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
+ ((old->flags ^ new->flags) & IRQF_ONESHOT))
goto mismatch;
- }
/* All handlers must agree on per-cpuness */
if ((old->flags & IRQF_PERCPU) !=
/* add new interrupt at end of irq queue */
do {
+ /*
+ * Or all existing action->thread_mask bits,
+ * so we can find the next zero bit for this
+ * new action.
+ */
+ thread_mask |= old->thread_mask;
old_ptr = &old->next;
old = *old_ptr;
} while (old);
shared = 1;
}
- if (!shared) {
- irq_chip_set_defaults(desc->irq_data.chip);
+ /*
+ * Setup the thread mask for this irqaction for ONESHOT. For
+ * !ONESHOT irqs the thread mask is 0 so we can avoid a
+ * conditional in irq_wake_thread().
+ */
+ if (new->flags & IRQF_ONESHOT) {
+ /*
+ * Unlikely to have 32 resp 64 irqs sharing one line,
+ * but who knows.
+ */
+ if (thread_mask == ~0UL) {
+ ret = -EBUSY;
+ goto out_mask;
+ }
+ /*
+ * The thread_mask for the action is or'ed to
+ * desc->thread_active to indicate that the
+ * IRQF_ONESHOT thread handler has been woken, but not
+ * yet finished. The bit is cleared when a thread
+ * completes. When all threads of a shared interrupt
+ * line have completed desc->threads_active becomes
+ * zero and the interrupt line is unmasked. See
+ * handle.c:irq_wake_thread() for further information.
+ *
+ * If no thread is woken by primary (hard irq context)
+ * interrupt handlers, then desc->threads_active is
+ * also checked for zero to unmask the irq line in the
+ * affected hard irq flow handlers
+ * (handle_[fasteoi|level]_irq).
+ *
+ * The new action gets the first zero bit of
+ * thread_mask assigned. See the loop above which or's
+ * all existing action->thread_mask bits.
+ */
+ new->thread_mask = 1 << ffz(thread_mask);
+ } else if (new->handler == irq_default_primary_handler &&
+ !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
+ /*
+ * The interrupt was requested with handler = NULL, so
+ * we use the default primary handler for it. But it
+ * does not have the oneshot flag set. In combination
+ * with level interrupts this is deadly, because the
+ * default primary handler just wakes the thread, then
+ * the irq lines is reenabled, but the device still
+ * has the level irq asserted. Rinse and repeat....
+ *
+ * While this works for edge type interrupts, we play
+ * it safe and reject unconditionally because we can't
+ * say for sure which type this interrupt really
+ * has. The type flags are unreliable as the
+ * underlying chip implementation can override them.
+ */
+ pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
+ irq);
+ ret = -EINVAL;
+ goto out_mask;
+ }
+
+ if (!shared) {
init_waitqueue_head(&desc->wait_for_threads);
/* Setup the type (level, edge polarity) if configured: */
}
desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
- IRQS_INPROGRESS | IRQS_ONESHOT | \
- IRQS_WAITING);
+ IRQS_ONESHOT | IRQS_WAITING);
+ irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
if (new->flags & IRQF_PERCPU) {
irqd_set(&desc->irq_data, IRQD_PER_CPU);
desc->istate |= IRQS_ONESHOT;
if (irq_settings_can_autoenable(desc))
- irq_startup(desc);
+ irq_startup(desc, true);
else
/* Undo nested disables: */
desc->depth = 1;
if (nmsk != omsk)
/* hope the handler works with current trigger mode */
- pr_warning("IRQ %d uses trigger mode %u; requested %u\n",
+ pr_warning("irq %d uses trigger mode %u; requested %u\n",
irq, nmsk, omsk);
}
register_irq_proc(irq, desc);
new->dir = NULL;
register_handler_proc(irq, new);
+ free_cpumask_var(mask);
return 0;
mismatch:
-#ifdef CONFIG_DEBUG_SHIRQ
if (!(new->flags & IRQF_PROBE_SHARED)) {
- printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq);
- if (old_name)
- printk(KERN_ERR "current handler: %s\n", old_name);
+ pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
+ irq, new->flags, new->name, old->flags, old->name);
+#ifdef CONFIG_DEBUG_SHIRQ
dump_stack();
- }
#endif
+ }
ret = -EBUSY;
out_mask:
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
free_cpumask_var(mask);
out_thread:
- raw_spin_unlock_irqrestore(&desc->lock, flags);
if (new->thread) {
struct task_struct *t = new->thread;
new->thread = NULL;
- if (likely(!test_bit(IRQTF_DIED, &new->thread_flags)))
- kthread_stop(t);
+ kthread_stop(t);
put_task_struct(t);
}
+out_mput:
+ module_put(desc->owner);
return ret;
}
int retval;
struct irq_desc *desc = irq_to_desc(irq);
+ if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
+ return -EINVAL;
chip_bus_lock(desc);
retval = __setup_irq(irq, desc, act);
chip_bus_sync_unlock(desc);
}
EXPORT_SYMBOL_GPL(setup_irq);
- /*
+/*
* Internal function to unregister an irqaction - used to free
* regular and special interrupts that are part of the architecture.
*/
/* Found it - now remove it from the list of entries: */
*action_ptr = action->next;
- /* Currently used only by UML, might disappear one day: */
-#ifdef CONFIG_IRQ_RELEASE_METHOD
- if (desc->irq_data.chip->release)
- desc->irq_data.chip->release(irq, dev_id);
-#endif
-
/* If this was the last handler, shut down the IRQ line: */
if (!desc->action)
irq_shutdown(desc);
#endif
if (action->thread) {
- if (!test_bit(IRQTF_DIED, &action->thread_flags))
- kthread_stop(action->thread);
+ kthread_stop(action->thread);
put_task_struct(action->thread);
}
+ module_put(desc->owner);
return action;
}
*/
void remove_irq(unsigned int irq, struct irqaction *act)
{
- __free_irq(irq, act->dev_id);
+ struct irq_desc *desc = irq_to_desc(irq);
+
+ if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
+ __free_irq(irq, act->dev_id);
}
EXPORT_SYMBOL_GPL(remove_irq);
{
struct irq_desc *desc = irq_to_desc(irq);
- if (!desc)
+ if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
return;
#ifdef CONFIG_SMP
* and to set up the interrupt handler in the right order.
*
* If you want to set up a threaded irq handler for your device
- * then you need to supply @handler and @thread_fn. @handler ist
+ * then you need to supply @handler and @thread_fn. @handler is
* still called in hard interrupt context and has to check
* whether the interrupt originates from the device. If yes it
* needs to disable the interrupt on the device and return
* Flags:
*
* IRQF_SHARED Interrupt is shared
- * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
* IRQF_TRIGGER_* Specify active edge(s) or level
*
*/
if (!desc)
return -EINVAL;
- if (!irq_settings_can_request(desc))
+ if (!irq_settings_can_request(desc) ||
+ WARN_ON(irq_settings_is_per_cpu_devid(desc)))
return -EINVAL;
if (!handler) {
return !ret ? IRQC_IS_HARDIRQ : ret;
}
EXPORT_SYMBOL_GPL(request_any_context_irq);
+
+void enable_percpu_irq(unsigned int irq, unsigned int type)
+{
+ unsigned int cpu = smp_processor_id();
+ unsigned long flags;
+ struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
+
+ if (!desc)
+ return;
+
+ type &= IRQ_TYPE_SENSE_MASK;
+ if (type != IRQ_TYPE_NONE) {
+ int ret;
+
+ ret = __irq_set_trigger(desc, irq, type);
+
+ if (ret) {
+ WARN(1, "failed to set type for IRQ%d\n", irq);
+ goto out;
+ }
+ }
+
+ irq_percpu_enable(desc, cpu);
+out:
+ irq_put_desc_unlock(desc, flags);
+}
+
+void disable_percpu_irq(unsigned int irq)
+{
+ unsigned int cpu = smp_processor_id();
+ unsigned long flags;
+ struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
+
+ if (!desc)
+ return;
+
+ irq_percpu_disable(desc, cpu);
+ irq_put_desc_unlock(desc, flags);
+}
+
+/*
+ * Internal function to unregister a percpu irqaction.
+ */
+static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ struct irqaction *action;
+ unsigned long flags;
+
+ WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
+
+ if (!desc)
+ return NULL;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+
+ action = desc->action;
+ if (!action || action->percpu_dev_id != dev_id) {
+ WARN(1, "Trying to free already-free IRQ %d\n", irq);
+ goto bad;
+ }
+
+ if (!cpumask_empty(desc->percpu_enabled)) {
+ WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
+ irq, cpumask_first(desc->percpu_enabled));
+ goto bad;
+ }
+
+ /* Found it - now remove it from the list of entries: */
+ desc->action = NULL;
+
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+
+ unregister_handler_proc(irq, action);
+
+ module_put(desc->owner);
+ return action;
+
+bad:
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+ return NULL;
+}
+
+/**
+ * remove_percpu_irq - free a per-cpu interrupt
+ * @irq: Interrupt line to free
+ * @act: irqaction for the interrupt
+ *
+ * Used to remove interrupts statically setup by the early boot process.
+ */
+void remove_percpu_irq(unsigned int irq, struct irqaction *act)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+
+ if (desc && irq_settings_is_per_cpu_devid(desc))
+ __free_percpu_irq(irq, act->percpu_dev_id);
+}
+
+/**
+ * free_percpu_irq - free an interrupt allocated with request_percpu_irq
+ * @irq: Interrupt line to free
+ * @dev_id: Device identity to free
+ *
+ * Remove a percpu interrupt handler. The handler is removed, but
+ * the interrupt line is not disabled. This must be done on each
+ * CPU before calling this function. The function does not return
+ * until any executing interrupts for this IRQ have completed.
+ *
+ * This function must not be called from interrupt context.
+ */
+void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+
+ if (!desc || !irq_settings_is_per_cpu_devid(desc))
+ return;
+
+ chip_bus_lock(desc);
+ kfree(__free_percpu_irq(irq, dev_id));
+ chip_bus_sync_unlock(desc);
+}
+
+/**
+ * setup_percpu_irq - setup a per-cpu interrupt
+ * @irq: Interrupt line to setup
+ * @act: irqaction for the interrupt
+ *
+ * Used to statically setup per-cpu interrupts in the early boot process.
+ */
+int setup_percpu_irq(unsigned int irq, struct irqaction *act)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ int retval;
+
+ if (!desc || !irq_settings_is_per_cpu_devid(desc))
+ return -EINVAL;
+ chip_bus_lock(desc);
+ retval = __setup_irq(irq, desc, act);
+ chip_bus_sync_unlock(desc);
+
+ return retval;
+}
+
+/**
+ * request_percpu_irq - allocate a percpu interrupt line
+ * @irq: Interrupt line to allocate
+ * @handler: Function to be called when the IRQ occurs.
+ * @devname: An ascii name for the claiming device
+ * @dev_id: A percpu cookie passed back to the handler function
+ *
+ * This call allocates interrupt resources, but doesn't
+ * automatically enable the interrupt. It has to be done on each
+ * CPU using enable_percpu_irq().
+ *
+ * Dev_id must be globally unique. It is a per-cpu variable, and
+ * the handler gets called with the interrupted CPU's instance of
+ * that variable.
+ */
+int request_percpu_irq(unsigned int irq, irq_handler_t handler,
+ const char *devname, void __percpu *dev_id)
+{
+ struct irqaction *action;
+ struct irq_desc *desc;
+ int retval;
+
+ if (!dev_id)
+ return -EINVAL;
+
+ desc = irq_to_desc(irq);
+ if (!desc || !irq_settings_can_request(desc) ||
+ !irq_settings_is_per_cpu_devid(desc))
+ return -EINVAL;
+
+ action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
+ if (!action)
+ return -ENOMEM;
+
+ action->handler = handler;
+ action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
+ action->name = devname;
+ action->percpu_dev_id = dev_id;
+
+ chip_bus_lock(desc);
+ retval = __setup_irq(irq, desc, action);
+ chip_bus_sync_unlock(desc);
+
+ if (retval)
+ kfree(action);
+
+ return retval;
+}
Code Review / linux-3.10.git / blobdiff