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genirq: Provide NMI management for percpu_devid interrupts

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Add support for percpu_devid interrupts treated as NMIs.

Percpu_devid NMIs need to be setup/torn down on each CPU they target.

The same restrictions as for global NMIs still apply for percpu_devid NMIs.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This commit is contained in:
Julien Thierry 2019-01-31 14:53:59 +00:00 committed by Marc Zyngier
parent b525903c25
commit 4b078c3f1a
2 changed files with 186 additions and 0 deletions
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9
include/linux/interrupt.h
View File

@ -168,10 +168,15 @@ 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;
@ -224,7 +229,11 @@ 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);

177
kernel/irq/manage.c
View File

@ -2182,6 +2182,11 @@ out:
}
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
@ -2221,6 +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.
*/
@ -2252,6 +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);
@ -2305,6 +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
@ -2394,6 +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