Commit e26a4331 authored by Catalin Marinas's avatar Catalin Marinas

Merge branch 'irq/generic-nmi' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms

* 'irq/generic-nmi' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms:
  irqdesc: Add domain handler for NMIs
  genirq: Provide NMI handlers
  genirq: Provide NMI management for percpu_devid interrupts
  genirq: Provide basic NMI management for interrupt lines
parents 8aa67d18 6e4933a0
......@@ -156,6 +156,10 @@ __request_percpu_irq(unsigned int irq, irq_handler_t handler,
unsigned long flags, const char *devname,
void __percpu *percpu_dev_id);
extern int __must_check
request_nmi(unsigned int irq, irq_handler_t handler, unsigned long flags,
const char *name, void *dev);
static inline int __must_check
request_percpu_irq(unsigned int irq, irq_handler_t handler,
const char *devname, void __percpu *percpu_dev_id)
......@@ -164,9 +168,16 @@ request_percpu_irq(unsigned int irq, irq_handler_t handler,
devname, percpu_dev_id);
}
extern int __must_check
request_percpu_nmi(unsigned int irq, irq_handler_t handler,
const char *devname, void __percpu *dev);
extern const void *free_irq(unsigned int, void *);
extern void free_percpu_irq(unsigned int, void __percpu *);
extern const void *free_nmi(unsigned int irq, void *dev_id);
extern void free_percpu_nmi(unsigned int irq, void __percpu *percpu_dev_id);
struct device;
extern int __must_check
......@@ -217,6 +228,13 @@ extern void enable_percpu_irq(unsigned int irq, unsigned int type);
extern bool irq_percpu_is_enabled(unsigned int irq);
extern void irq_wake_thread(unsigned int irq, void *dev_id);
extern void disable_nmi_nosync(unsigned int irq);
extern void disable_percpu_nmi(unsigned int irq);
extern void enable_nmi(unsigned int irq);
extern void enable_percpu_nmi(unsigned int irq, unsigned int type);
extern int prepare_percpu_nmi(unsigned int irq);
extern void teardown_percpu_nmi(unsigned int irq);
/* The following three functions are for the core kernel use only. */
extern void suspend_device_irqs(void);
extern void resume_device_irqs(void);
......
......@@ -442,6 +442,8 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
* @irq_set_vcpu_affinity: optional to target a vCPU in a virtual machine
* @ipi_send_single: send a single IPI to destination cpus
* @ipi_send_mask: send an IPI to destination cpus in cpumask
* @irq_nmi_setup: function called from core code before enabling an NMI
* @irq_nmi_teardown: function called from core code after disabling an NMI
* @flags: chip specific flags
*/
struct irq_chip {
......@@ -490,6 +492,9 @@ struct irq_chip {
void (*ipi_send_single)(struct irq_data *data, unsigned int cpu);
void (*ipi_send_mask)(struct irq_data *data, const struct cpumask *dest);
int (*irq_nmi_setup)(struct irq_data *data);
void (*irq_nmi_teardown)(struct irq_data *data);
unsigned long flags;
};
......@@ -505,6 +510,7 @@ struct irq_chip {
* IRQCHIP_ONESHOT_SAFE: One shot does not require mask/unmask
* IRQCHIP_EOI_THREADED: Chip requires eoi() on unmask in threaded mode
* IRQCHIP_SUPPORTS_LEVEL_MSI Chip can provide two doorbells for Level MSIs
* IRQCHIP_SUPPORTS_NMI: Chip can deliver NMIs, only for root irqchips
*/
enum {
IRQCHIP_SET_TYPE_MASKED = (1 << 0),
......@@ -515,6 +521,7 @@ enum {
IRQCHIP_ONESHOT_SAFE = (1 << 5),
IRQCHIP_EOI_THREADED = (1 << 6),
IRQCHIP_SUPPORTS_LEVEL_MSI = (1 << 7),
IRQCHIP_SUPPORTS_NMI = (1 << 8),
};
#include <linux/irqdesc.h>
......@@ -594,6 +601,9 @@ extern void handle_percpu_devid_irq(struct irq_desc *desc);
extern void handle_bad_irq(struct irq_desc *desc);
extern void handle_nested_irq(unsigned int irq);
extern void handle_fasteoi_nmi(struct irq_desc *desc);
extern void handle_percpu_devid_fasteoi_nmi(struct irq_desc *desc);
extern int irq_chip_compose_msi_msg(struct irq_data *data, struct msi_msg *msg);
extern int irq_chip_pm_get(struct irq_data *data);
extern int irq_chip_pm_put(struct irq_data *data);
......
......@@ -171,6 +171,11 @@ static inline int handle_domain_irq(struct irq_domain *domain,
{
return __handle_domain_irq(domain, hwirq, true, regs);
}
#ifdef CONFIG_IRQ_DOMAIN
int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
struct pt_regs *regs);
#endif
#endif
/* Test to see if a driver has successfully requested an irq */
......
......@@ -729,6 +729,37 @@ void handle_fasteoi_irq(struct irq_desc *desc)
}
EXPORT_SYMBOL_GPL(handle_fasteoi_irq);
/**
* handle_fasteoi_nmi - irq handler for NMI interrupt lines
* @desc: the interrupt description structure for this irq
*
* A simple NMI-safe handler, considering the restrictions
* from request_nmi.
*
* Only a single callback will be issued to the chip: an ->eoi()
* call when the interrupt has been serviced. This enables support
* for modern forms of interrupt handlers, which handle the flow
* details in hardware, transparently.
*/
void handle_fasteoi_nmi(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct irqaction *action = desc->action;
unsigned int irq = irq_desc_get_irq(desc);
irqreturn_t res;
trace_irq_handler_entry(irq, action);
/*
* NMIs cannot be shared, there is only one action.
*/
res = action->handler(irq, action->dev_id);
trace_irq_handler_exit(irq, action, res);
if (chip->irq_eoi)
chip->irq_eoi(&desc->irq_data);
}
EXPORT_SYMBOL_GPL(handle_fasteoi_nmi);
/**
* handle_edge_irq - edge type IRQ handler
* @desc: the interrupt description structure for this irq
......@@ -908,6 +939,29 @@ void handle_percpu_devid_irq(struct irq_desc *desc)
chip->irq_eoi(&desc->irq_data);
}
/**
* handle_percpu_devid_fasteoi_nmi - Per CPU local NMI handler with per cpu
* dev ids
* @desc: the interrupt description structure for this irq
*
* Similar to handle_fasteoi_nmi, but handling the dev_id cookie
* as a percpu pointer.
*/
void handle_percpu_devid_fasteoi_nmi(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct irqaction *action = desc->action;
unsigned int irq = irq_desc_get_irq(desc);
irqreturn_t res;
trace_irq_handler_entry(irq, action);
res = action->handler(irq, raw_cpu_ptr(action->percpu_dev_id));
trace_irq_handler_exit(irq, action, res);
if (chip->irq_eoi)
chip->irq_eoi(&desc->irq_data);
}
static void
__irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle,
int is_chained, const char *name)
......
......@@ -56,6 +56,7 @@ static const struct irq_bit_descr irqchip_flags[] = {
BIT_MASK_DESCR(IRQCHIP_ONESHOT_SAFE),
BIT_MASK_DESCR(IRQCHIP_EOI_THREADED),
BIT_MASK_DESCR(IRQCHIP_SUPPORTS_LEVEL_MSI),
BIT_MASK_DESCR(IRQCHIP_SUPPORTS_NMI),
};
static void
......@@ -140,6 +141,7 @@ static const struct irq_bit_descr irqdesc_istates[] = {
BIT_MASK_DESCR(IRQS_WAITING),
BIT_MASK_DESCR(IRQS_PENDING),
BIT_MASK_DESCR(IRQS_SUSPENDED),
BIT_MASK_DESCR(IRQS_NMI),
};
......@@ -203,8 +205,8 @@ static ssize_t irq_debug_write(struct file *file, const char __user *user_buf,
chip_bus_lock(desc);
raw_spin_lock_irqsave(&desc->lock, flags);
if (irq_settings_is_level(desc)) {
/* Can't do level, sorry */
if (irq_settings_is_level(desc) || desc->istate & IRQS_NMI) {
/* Can't do level nor NMIs, sorry */
err = -EINVAL;
} else {
desc->istate |= IRQS_PENDING;
......
......@@ -49,6 +49,7 @@ enum {
* IRQS_WAITING - irq is waiting
* IRQS_PENDING - irq is pending and replayed later
* IRQS_SUSPENDED - irq is suspended
* IRQS_NMI - irq line is used to deliver NMIs
*/
enum {
IRQS_AUTODETECT = 0x00000001,
......@@ -60,6 +61,7 @@ enum {
IRQS_PENDING = 0x00000200,
IRQS_SUSPENDED = 0x00000800,
IRQS_TIMINGS = 0x00001000,
IRQS_NMI = 0x00002000,
};
#include "debug.h"
......
......@@ -669,6 +669,41 @@ int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
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
*
* 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_enter();
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;
nmi_exit();
set_irq_regs(old_regs);
return ret;
}
#endif
#endif
/* Dynamic interrupt handling */
......
......@@ -341,7 +341,7 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
/* The release function is promised process context */
might_sleep();
if (!desc)
if (!desc || desc->istate & IRQS_NMI)
return -EINVAL;
/* Complete initialisation of *notify */
......@@ -550,6 +550,21 @@ bool disable_hardirq(unsigned int irq)
}
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) {
......@@ -606,6 +621,20 @@ void enable_irq(unsigned int irq)
}
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);
......@@ -641,6 +670,12 @@ int irq_set_irq_wake(unsigned int irq, unsigned int on)
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.
*/
......@@ -663,6 +698,8 @@ int irq_set_irq_wake(unsigned int irq, unsigned int on)
irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
}
}
out_unlock:
irq_put_desc_busunlock(desc, flags);
return ret;
}
......@@ -1125,6 +1162,39 @@ static void irq_release_resources(struct irq_desc *desc)
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)
{
......@@ -1299,9 +1369,17 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
* 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
* the one provided by the requester.
......@@ -1753,6 +1831,59 @@ const void *free_irq(unsigned int irq, void *dev_id)
}
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(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
* @irq: Interrupt line to allocate
......@@ -1922,6 +2053,101 @@ int request_any_context_irq(unsigned int irq, irq_handler_t handler,
}
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();
......@@ -1956,6 +2182,11 @@ void enable_percpu_irq(unsigned int irq, unsigned int type)
}
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
* @irq: Linux irq number to check for
......@@ -1995,6 +2226,11 @@ void disable_percpu_irq(unsigned int irq)
}
EXPORT_SYMBOL_GPL(disable_percpu_irq);
void disable_percpu_nmi(unsigned int irq)
{
disable_percpu_irq(irq);
}
/*
* Internal function to unregister a percpu irqaction.
*/
......@@ -2026,6 +2262,8 @@ static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_
/* Found it - now remove it from the list of entries: */
desc->action = NULL;
desc->istate &= ~IRQS_NMI;
raw_spin_unlock_irqrestore(&desc->lock, flags);
unregister_handler_proc(irq, action);
......@@ -2079,6 +2317,19 @@ void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
}
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
* @irq: Interrupt line to setup
......@@ -2168,6 +2419,158 @@ int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
}
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 ready_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);
}
/**
* irq_get_irqchip_state - returns the irqchip state of a interrupt.
* @irq: Interrupt line that is forwarded to a VM
......
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