From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt
---
kernel/kernel/irq/manage.c | 591 +++++++++++++++++++++++++++++++++++++++++++++++++++-------
1 files changed, 517 insertions(+), 74 deletions(-)
diff --git a/kernel/kernel/irq/manage.c b/kernel/kernel/irq/manage.c
index 39d6bc9..02ecab8 100644
--- a/kernel/kernel/irq/manage.c
+++ b/kernel/kernel/irq/manage.c
@@ -18,12 +18,13 @@
#include <linux/sched.h>
#include <linux/sched/rt.h>
#include <linux/sched/task.h>
+#include <linux/sched/isolation.h>
#include <uapi/linux/sched/types.h>
#include <linux/task_work.h>
#include "internals.h"
-#ifdef CONFIG_IRQ_FORCED_THREADING
+#if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT)
__read_mostly bool force_irqthreads;
EXPORT_SYMBOL_GPL(force_irqthreads);
@@ -222,16 +223,70 @@
{
struct irq_desc *desc = irq_data_to_desc(data);
struct irq_chip *chip = irq_data_get_irq_chip(data);
+ const struct cpumask *prog_mask;
int ret;
+
+ static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
+ static struct cpumask tmp_mask;
if (!chip || !chip->irq_set_affinity)
return -EINVAL;
- ret = chip->irq_set_affinity(data, mask, force);
+ raw_spin_lock(&tmp_mask_lock);
+ /*
+ * If this is a managed interrupt and housekeeping is enabled on
+ * it check whether the requested affinity mask intersects with
+ * a housekeeping CPU. If so, then remove the isolated CPUs from
+ * the mask and just keep the housekeeping CPU(s). This prevents
+ * the affinity setter from routing the interrupt to an isolated
+ * CPU to avoid that I/O submitted from a housekeeping CPU causes
+ * interrupts on an isolated one.
+ *
+ * If the masks do not intersect or include online CPU(s) then
+ * keep the requested mask. The isolated target CPUs are only
+ * receiving interrupts when the I/O operation was submitted
+ * directly from them.
+ *
+ * If all housekeeping CPUs in the affinity mask are offline, the
+ * interrupt will be migrated by the CPU hotplug code once a
+ * housekeeping CPU which belongs to the affinity mask comes
+ * online.
+ */
+ if (irqd_affinity_is_managed(data) &&
+ housekeeping_enabled(HK_FLAG_MANAGED_IRQ)) {
+ const struct cpumask *hk_mask;
+
+ hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ);
+
+ cpumask_and(&tmp_mask, mask, hk_mask);
+ if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
+ prog_mask = mask;
+ else
+ prog_mask = &tmp_mask;
+ } else {
+ prog_mask = mask;
+ }
+
+ /*
+ * Make sure we only provide online CPUs to the irqchip,
+ * unless we are being asked to force the affinity (in which
+ * case we do as we are told).
+ */
+ cpumask_and(&tmp_mask, prog_mask, cpu_online_mask);
+ if (!force && !cpumask_empty(&tmp_mask))
+ ret = chip->irq_set_affinity(data, &tmp_mask, force);
+ else if (force)
+ ret = chip->irq_set_affinity(data, mask, force);
+ else
+ ret = -EINVAL;
+
+ raw_spin_unlock(&tmp_mask_lock);
+
switch (ret) {
case IRQ_SET_MASK_OK:
case IRQ_SET_MASK_OK_DONE:
cpumask_copy(desc->irq_common_data.affinity, mask);
+ fallthrough;
case IRQ_SET_MASK_OK_NOCOPY:
irq_validate_effective_affinity(data);
irq_set_thread_affinity(desc);
@@ -240,6 +295,7 @@
return ret;
}
+EXPORT_SYMBOL_GPL(irq_do_set_affinity);
#ifdef CONFIG_GENERIC_PENDING_IRQ
static inline int irq_set_affinity_pending(struct irq_data *data,
@@ -345,7 +401,6 @@
raw_spin_unlock_irqrestore(&desc->lock, flags);
return ret;
}
-EXPORT_SYMBOL_GPL(__irq_set_affinity);
int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
{
@@ -409,7 +464,7 @@
/* The release function is promised process context */
might_sleep();
- if (!desc)
+ if (!desc || desc->istate & IRQS_NMI)
return -EINVAL;
/* Complete initialisation of *notify */
@@ -612,6 +667,21 @@
}
EXPORT_SYMBOL_GPL(disable_hardirq);
+/**
+ * disable_nmi_nosync - disable an nmi without waiting
+ * @irq: Interrupt to disable
+ *
+ * Disable the selected interrupt line. Disables and enables are
+ * nested.
+ * The interrupt to disable must have been requested through request_nmi.
+ * Unlike disable_nmi(), this function does not ensure existing
+ * instances of the IRQ handler have completed before returning.
+ */
+void disable_nmi_nosync(unsigned int irq)
+{
+ disable_irq_nosync(irq);
+}
+
void __enable_irq(struct irq_desc *desc)
{
switch (desc->depth) {
@@ -668,6 +738,20 @@
}
EXPORT_SYMBOL(enable_irq);
+/**
+ * enable_nmi - enable handling of an nmi
+ * @irq: Interrupt to enable
+ *
+ * The interrupt to enable must have been requested through request_nmi.
+ * Undoes the effect of one call to disable_nmi(). If this
+ * matches the last disable, processing of interrupts on this
+ * IRQ line is re-enabled.
+ */
+void enable_nmi(unsigned int irq)
+{
+ enable_irq(irq);
+}
+
static int set_irq_wake_real(unsigned int irq, unsigned int on)
{
struct irq_desc *desc = irq_to_desc(irq);
@@ -693,6 +777,13 @@
*
* Wakeup mode lets this IRQ wake the system from sleep
* states like "suspend to RAM".
+ *
+ * Note: irq enable/disable state is completely orthogonal
+ * to the enable/disable state of irq wake. An irq can be
+ * disabled with disable_irq() and still wake the system as
+ * long as the irq has wake enabled. If this does not hold,
+ * then the underlying irq chip and the related driver need
+ * to be investigated.
*/
int irq_set_irq_wake(unsigned int irq, unsigned int on)
{
@@ -702,6 +793,12 @@
if (!desc)
return -EINVAL;
+
+ /* Don't use NMIs as wake up interrupts please */
+ if (desc->istate & IRQS_NMI) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
/* wakeup-capable irqs can be shared between drivers that
* don't need to have the same sleep mode behaviors.
@@ -725,6 +822,8 @@
irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
}
}
+
+out_unlock:
irq_put_desc_busunlock(desc, flags);
return ret;
}
@@ -785,6 +884,7 @@
case IRQ_SET_MASK_OK_DONE:
irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
irqd_set(&desc->irq_data, flags);
+ fallthrough;
case IRQ_SET_MASK_OK_NOCOPY:
flags = irqd_get_trigger_type(&desc->irq_data);
@@ -799,7 +899,7 @@
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 (%pS)\n",
flags, irq_desc_get_irq(desc), chip->irq_set_type);
}
if (unmask)
@@ -977,7 +1077,7 @@
#endif
/*
- * Interrupts which are not explicitely requested as threaded
+ * Interrupts which are not explicitly 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.
@@ -988,14 +1088,14 @@
irqreturn_t ret;
local_bh_disable();
- if (!IS_ENABLED(CONFIG_PREEMPT_RT_BASE))
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT))
local_irq_disable();
ret = action->thread_fn(action->irq, action->dev_id);
if (ret == IRQ_HANDLED)
atomic_inc(&desc->threads_handled);
irq_finalize_oneshot(desc, action);
- if (!IS_ENABLED(CONFIG_PREEMPT_RT_BASE))
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT))
local_irq_enable();
local_bh_enable();
return ret;
@@ -1065,6 +1165,31 @@
}
/*
+ * Internal function to notify that a interrupt thread is ready.
+ */
+static void irq_thread_set_ready(struct irq_desc *desc,
+ struct irqaction *action)
+{
+ set_bit(IRQTF_READY, &action->thread_flags);
+ wake_up(&desc->wait_for_threads);
+}
+
+/*
+ * Internal function to wake up a interrupt thread and wait until it is
+ * ready.
+ */
+static void wake_up_and_wait_for_irq_thread_ready(struct irq_desc *desc,
+ struct irqaction *action)
+{
+ if (!action || !action->thread)
+ return;
+
+ wake_up_process(action->thread);
+ wait_event(desc->wait_for_threads,
+ test_bit(IRQTF_READY, &action->thread_flags));
+}
+
+/*
* Interrupt handler thread
*/
static int irq_thread(void *data)
@@ -1075,6 +1200,10 @@
irqreturn_t (*handler_fn)(struct irq_desc *desc,
struct irqaction *action);
+ irq_thread_set_ready(desc, action);
+
+ sched_set_fifo(current);
+
if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
&action->thread_flags))
handler_fn = irq_forced_thread_fn;
@@ -1082,7 +1211,7 @@
handler_fn = irq_thread_fn;
init_task_work(&on_exit_work, irq_thread_dtor);
- task_work_add(current, &on_exit_work, false);
+ task_work_add(current, &on_exit_work, TWA_NONE);
irq_thread_check_affinity(desc, action);
@@ -1191,13 +1320,43 @@
c->irq_release_resources(d);
}
+static bool irq_supports_nmi(struct irq_desc *desc)
+{
+ struct irq_data *d = irq_desc_get_irq_data(desc);
+
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+ /* Only IRQs directly managed by the root irqchip can be set as NMI */
+ if (d->parent_data)
+ return false;
+#endif
+ /* Don't support NMIs for chips behind a slow bus */
+ if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
+ return false;
+
+ return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
+}
+
+static int irq_nmi_setup(struct irq_desc *desc)
+{
+ struct irq_data *d = irq_desc_get_irq_data(desc);
+ struct irq_chip *c = d->chip;
+
+ return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
+}
+
+static void irq_nmi_teardown(struct irq_desc *desc)
+{
+ struct irq_data *d = irq_desc_get_irq_data(desc);
+ struct irq_chip *c = d->chip;
+
+ if (c->irq_nmi_teardown)
+ c->irq_nmi_teardown(d);
+}
+
static int
setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
{
struct task_struct *t;
- struct sched_param param = {
- .sched_priority = MAX_USER_RT_PRIO/2,
- };
if (!secondary) {
t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
@@ -1205,21 +1364,17 @@
} else {
t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
new->name);
- param.sched_priority -= 1;
}
if (IS_ERR(t))
return PTR_ERR(t);
-
- sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
/*
* We keep the reference to the task struct even if
* the thread dies to avoid that the interrupt code
* references an already freed task_struct.
*/
- get_task_struct(t);
- new->thread = t;
+ new->thread = get_task_struct(t);
/*
* Tell the thread to set its affinity. This is
* important for shared interrupt handlers as we do
@@ -1365,8 +1520,16 @@
* fields must have IRQF_SHARED set and the bits which
* set the trigger type must match. Also all must
* agree on ONESHOT.
+ * Interrupt lines used for NMIs cannot be shared.
*/
unsigned int oldtype;
+
+ if (desc->istate & IRQS_NMI) {
+ pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
+ new->name, irq, desc->irq_data.chip->name);
+ ret = -EINVAL;
+ goto out_unlock;
+ }
/*
* If nobody did set the configuration before, inherit
@@ -1456,15 +1619,13 @@
* 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);
+ pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
+ new->name, irq);
ret = -EINVAL;
goto out_unlock;
}
if (!shared) {
- init_waitqueue_head(&desc->wait_for_threads);
-
/* Setup the type (level, edge polarity) if configured: */
if (new->flags & IRQF_TRIGGER_MASK) {
ret = __irq_set_trigger(desc,
@@ -1554,14 +1715,8 @@
irq_setup_timings(desc, new);
- /*
- * Strictly no need to wake it up, but hung_task complains
- * when no hard interrupt wakes the thread up.
- */
- if (new->thread)
- wake_up_process(new->thread);
- if (new->secondary)
- wake_up_process(new->secondary->thread);
+ wake_up_and_wait_for_irq_thread_ready(desc, new);
+ wake_up_and_wait_for_irq_thread_ready(desc, new->secondary);
register_irq_proc(irq, desc);
new->dir = NULL;
@@ -1606,34 +1761,6 @@
module_put(desc->owner);
return ret;
}
-
-/**
- * setup_irq - setup an interrupt
- * @irq: Interrupt line to setup
- * @act: irqaction for the interrupt
- *
- * Used to statically setup interrupts in the early boot process.
- */
-int setup_irq(unsigned int irq, struct irqaction *act)
-{
- int retval;
- struct irq_desc *desc = irq_to_desc(irq);
-
- if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
- return -EINVAL;
-
- retval = irq_chip_pm_get(&desc->irq_data);
- if (retval < 0)
- return retval;
-
- retval = __setup_irq(irq, desc, act);
-
- if (retval)
- irq_chip_pm_put(&desc->irq_data);
-
- return retval;
-}
-EXPORT_SYMBOL_GPL(setup_irq);
/*
* Internal function to unregister an irqaction - used to free
@@ -1776,22 +1903,6 @@
}
/**
- * remove_irq - free an interrupt
- * @irq: Interrupt line to free
- * @act: irqaction for the interrupt
- *
- * Used to remove interrupts statically setup by the early boot process.
- */
-void remove_irq(unsigned int irq, struct irqaction *act)
-{
- struct irq_desc *desc = irq_to_desc(irq);
-
- if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
- __free_irq(desc, act->dev_id);
-}
-EXPORT_SYMBOL_GPL(remove_irq);
-
-/**
* free_irq - free an interrupt allocated with request_irq
* @irq: Interrupt line to free
* @dev_id: Device identity to free
@@ -1831,6 +1942,59 @@
return devname;
}
EXPORT_SYMBOL(free_irq);
+
+/* This function must be called with desc->lock held */
+static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
+{
+ const char *devname = NULL;
+
+ desc->istate &= ~IRQS_NMI;
+
+ if (!WARN_ON(desc->action == NULL)) {
+ irq_pm_remove_action(desc, desc->action);
+ devname = desc->action->name;
+ unregister_handler_proc(irq, desc->action);
+
+ kfree(desc->action);
+ desc->action = NULL;
+ }
+
+ irq_settings_clr_disable_unlazy(desc);
+ irq_shutdown_and_deactivate(desc);
+
+ irq_release_resources(desc);
+
+ irq_chip_pm_put(&desc->irq_data);
+ module_put(desc->owner);
+
+ return devname;
+}
+
+const void *free_nmi(unsigned int irq, void *dev_id)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ unsigned long flags;
+ const void *devname;
+
+ if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
+ return NULL;
+
+ if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
+ return NULL;
+
+ /* NMI still enabled */
+ if (WARN_ON(desc->depth == 0))
+ disable_nmi_nosync(irq);
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+
+ irq_nmi_teardown(desc);
+ devname = __cleanup_nmi(irq, desc);
+
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+
+ return devname;
+}
/**
* request_threaded_irq - allocate an interrupt line
@@ -2001,6 +2165,101 @@
}
EXPORT_SYMBOL_GPL(request_any_context_irq);
+/**
+ * request_nmi - allocate an interrupt line for NMI delivery
+ * @irq: Interrupt line to allocate
+ * @handler: Function to be called when the IRQ occurs.
+ * Threaded handler for threaded interrupts.
+ * @irqflags: Interrupt type flags
+ * @name: An ascii name for the claiming device
+ * @dev_id: A cookie passed back to the handler function
+ *
+ * This call allocates interrupt resources and enables the
+ * interrupt line and IRQ handling. It sets up the IRQ line
+ * to be handled as an NMI.
+ *
+ * An interrupt line delivering NMIs cannot be shared and IRQ handling
+ * cannot be threaded.
+ *
+ * Interrupt lines requested for NMI delivering must produce per cpu
+ * interrupts and have auto enabling setting disabled.
+ *
+ * Dev_id must be globally unique. Normally the address of the
+ * device data structure is used as the cookie. Since the handler
+ * receives this value it makes sense to use it.
+ *
+ * If the interrupt line cannot be used to deliver NMIs, function
+ * will fail and return a negative value.
+ */
+int request_nmi(unsigned int irq, irq_handler_t handler,
+ unsigned long irqflags, const char *name, void *dev_id)
+{
+ struct irqaction *action;
+ struct irq_desc *desc;
+ unsigned long flags;
+ int retval;
+
+ if (irq == IRQ_NOTCONNECTED)
+ return -ENOTCONN;
+
+ /* NMI cannot be shared, used for Polling */
+ if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
+ return -EINVAL;
+
+ if (!(irqflags & IRQF_PERCPU))
+ return -EINVAL;
+
+ if (!handler)
+ return -EINVAL;
+
+ desc = irq_to_desc(irq);
+
+ if (!desc || irq_settings_can_autoenable(desc) ||
+ !irq_settings_can_request(desc) ||
+ WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
+ !irq_supports_nmi(desc))
+ return -EINVAL;
+
+ action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
+ if (!action)
+ return -ENOMEM;
+
+ action->handler = handler;
+ action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
+ action->name = name;
+ action->dev_id = dev_id;
+
+ retval = irq_chip_pm_get(&desc->irq_data);
+ if (retval < 0)
+ goto err_out;
+
+ retval = __setup_irq(irq, desc, action);
+ if (retval)
+ goto err_irq_setup;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+
+ /* Setup NMI state */
+ desc->istate |= IRQS_NMI;
+ retval = irq_nmi_setup(desc);
+ if (retval) {
+ __cleanup_nmi(irq, desc);
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+ return -EINVAL;
+ }
+
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+
+ return 0;
+
+err_irq_setup:
+ irq_chip_pm_put(&desc->irq_data);
+err_out:
+ kfree(action);
+
+ return retval;
+}
+
void enable_percpu_irq(unsigned int irq, unsigned int type)
{
unsigned int cpu = smp_processor_id();
@@ -2034,6 +2293,11 @@
irq_put_desc_unlock(desc, flags);
}
EXPORT_SYMBOL_GPL(enable_percpu_irq);
+
+void enable_percpu_nmi(unsigned int irq, unsigned int type)
+{
+ enable_percpu_irq(irq, type);
+}
/**
* irq_percpu_is_enabled - Check whether the per cpu irq is enabled
@@ -2074,6 +2338,11 @@
}
EXPORT_SYMBOL_GPL(disable_percpu_irq);
+void disable_percpu_nmi(unsigned int irq)
+{
+ disable_percpu_irq(irq);
+}
+
/*
* Internal function to unregister a percpu irqaction.
*/
@@ -2104,6 +2373,8 @@
/* Found it - now remove it from the list of entries: */
desc->action = NULL;
+
+ desc->istate &= ~IRQS_NMI;
raw_spin_unlock_irqrestore(&desc->lock, flags);
@@ -2157,6 +2428,19 @@
chip_bus_sync_unlock(desc);
}
EXPORT_SYMBOL_GPL(free_percpu_irq);
+
+void free_percpu_nmi(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;
+
+ if (WARN_ON(!(desc->istate & IRQS_NMI)))
+ return;
+
+ kfree(__free_percpu_irq(irq, dev_id));
+}
/**
* setup_percpu_irq - setup a per-cpu interrupt
@@ -2247,6 +2531,158 @@
}
EXPORT_SYMBOL_GPL(__request_percpu_irq);
+/**
+ * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
+ * @irq: Interrupt line to allocate
+ * @handler: Function to be called when the IRQ occurs.
+ * @name: An ascii name for the claiming device
+ * @dev_id: A percpu cookie passed back to the handler function
+ *
+ * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
+ * have to be setup on each CPU by calling prepare_percpu_nmi() before
+ * being enabled on the same CPU by using enable_percpu_nmi().
+ *
+ * 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.
+ *
+ * Interrupt lines requested for NMI delivering should have auto enabling
+ * setting disabled.
+ *
+ * If the interrupt line cannot be used to deliver NMIs, function
+ * will fail returning a negative value.
+ */
+int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
+ const char *name, void __percpu *dev_id)
+{
+ struct irqaction *action;
+ struct irq_desc *desc;
+ unsigned long flags;
+ int retval;
+
+ if (!handler)
+ return -EINVAL;
+
+ desc = irq_to_desc(irq);
+
+ if (!desc || !irq_settings_can_request(desc) ||
+ !irq_settings_is_per_cpu_devid(desc) ||
+ irq_settings_can_autoenable(desc) ||
+ !irq_supports_nmi(desc))
+ return -EINVAL;
+
+ /* The line cannot already be NMI */
+ if (desc->istate & IRQS_NMI)
+ return -EINVAL;
+
+ action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
+ if (!action)
+ return -ENOMEM;
+
+ action->handler = handler;
+ action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
+ | IRQF_NOBALANCING;
+ action->name = name;
+ action->percpu_dev_id = dev_id;
+
+ retval = irq_chip_pm_get(&desc->irq_data);
+ if (retval < 0)
+ goto err_out;
+
+ retval = __setup_irq(irq, desc, action);
+ if (retval)
+ goto err_irq_setup;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+ desc->istate |= IRQS_NMI;
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+
+ return 0;
+
+err_irq_setup:
+ irq_chip_pm_put(&desc->irq_data);
+err_out:
+ kfree(action);
+
+ return retval;
+}
+
+/**
+ * prepare_percpu_nmi - performs CPU local setup for NMI delivery
+ * @irq: Interrupt line to prepare for NMI delivery
+ *
+ * This call prepares an interrupt line to deliver NMI on the current CPU,
+ * before that interrupt line gets enabled with enable_percpu_nmi().
+ *
+ * As a CPU local operation, this should be called from non-preemptible
+ * context.
+ *
+ * If the interrupt line cannot be used to deliver NMIs, function
+ * will fail returning a negative value.
+ */
+int prepare_percpu_nmi(unsigned int irq)
+{
+ unsigned long flags;
+ struct irq_desc *desc;
+ int ret = 0;
+
+ WARN_ON(preemptible());
+
+ desc = irq_get_desc_lock(irq, &flags,
+ IRQ_GET_DESC_CHECK_PERCPU);
+ if (!desc)
+ return -EINVAL;
+
+ if (WARN(!(desc->istate & IRQS_NMI),
+ KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
+ irq)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = irq_nmi_setup(desc);
+ if (ret) {
+ pr_err("Failed to setup NMI delivery: irq %u\n", irq);
+ goto out;
+ }
+
+out:
+ irq_put_desc_unlock(desc, flags);
+ return ret;
+}
+
+/**
+ * teardown_percpu_nmi - undoes NMI setup of IRQ line
+ * @irq: Interrupt line from which CPU local NMI configuration should be
+ * removed
+ *
+ * This call undoes the setup done by prepare_percpu_nmi().
+ *
+ * IRQ line should not be enabled for the current CPU.
+ *
+ * As a CPU local operation, this should be called from non-preemptible
+ * context.
+ */
+void teardown_percpu_nmi(unsigned int irq)
+{
+ unsigned long flags;
+ struct irq_desc *desc;
+
+ WARN_ON(preemptible());
+
+ desc = irq_get_desc_lock(irq, &flags,
+ IRQ_GET_DESC_CHECK_PERCPU);
+ if (!desc)
+ return;
+
+ if (WARN_ON(!(desc->istate & IRQS_NMI)))
+ goto out;
+
+ irq_nmi_teardown(desc);
+out:
+ irq_put_desc_unlock(desc, flags);
+}
+
int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
bool *state)
{
@@ -2255,6 +2691,8 @@
do {
chip = irq_data_get_irq_chip(data);
+ if (WARN_ON_ONCE(!chip))
+ return -ENODEV;
if (chip->irq_get_irqchip_state)
break;
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
@@ -2312,7 +2750,7 @@
* This call sets the internal irqchip state of an interrupt,
* depending on the value of @which.
*
- * This function should be called with preemption disabled if the
+ * This function should be called with migration disabled if the
* interrupt controller has per-cpu registers.
*/
int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
@@ -2332,6 +2770,10 @@
do {
chip = irq_data_get_irq_chip(data);
+ if (WARN_ON_ONCE(!chip)) {
+ err = -ENODEV;
+ goto out_unlock;
+ }
if (chip->irq_set_irqchip_state)
break;
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
@@ -2344,6 +2786,7 @@
if (data)
err = chip->irq_set_irqchip_state(data, which, val);
+out_unlock:
irq_put_desc_busunlock(desc, flags);
return err;
}
--
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