mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 08:15:19 +07:00
c16816acd0
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
104 lines
2.5 KiB
C
104 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
|
|
* Copyright (C) 2005-2006, Thomas Gleixner
|
|
*
|
|
* This file contains the IRQ-resend code
|
|
*
|
|
* If the interrupt is waiting to be processed, we try to re-run it.
|
|
* We can't directly run it from here since the caller might be in an
|
|
* interrupt-protected region. Not all irq controller chips can
|
|
* retrigger interrupts at the hardware level, so in those cases
|
|
* we allow the resending of IRQs via a tasklet.
|
|
*/
|
|
|
|
#include <linux/irq.h>
|
|
#include <linux/module.h>
|
|
#include <linux/random.h>
|
|
#include <linux/interrupt.h>
|
|
|
|
#include "internals.h"
|
|
|
|
#ifdef CONFIG_HARDIRQS_SW_RESEND
|
|
|
|
/* Bitmap to handle software resend of interrupts: */
|
|
static DECLARE_BITMAP(irqs_resend, IRQ_BITMAP_BITS);
|
|
|
|
/*
|
|
* Run software resends of IRQ's
|
|
*/
|
|
static void resend_irqs(unsigned long arg)
|
|
{
|
|
struct irq_desc *desc;
|
|
int irq;
|
|
|
|
while (!bitmap_empty(irqs_resend, nr_irqs)) {
|
|
irq = find_first_bit(irqs_resend, nr_irqs);
|
|
clear_bit(irq, irqs_resend);
|
|
desc = irq_to_desc(irq);
|
|
if (!desc)
|
|
continue;
|
|
local_irq_disable();
|
|
desc->handle_irq(desc);
|
|
local_irq_enable();
|
|
}
|
|
}
|
|
|
|
/* Tasklet to handle resend: */
|
|
static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
|
|
|
|
#endif
|
|
|
|
/*
|
|
* IRQ resend
|
|
*
|
|
* Is called with interrupts disabled and desc->lock held.
|
|
*/
|
|
void check_irq_resend(struct irq_desc *desc)
|
|
{
|
|
/*
|
|
* We do not resend level type interrupts. Level type
|
|
* interrupts are resent by hardware when they are still
|
|
* active. Clear the pending bit so suspend/resume does not
|
|
* get confused.
|
|
*/
|
|
if (irq_settings_is_level(desc)) {
|
|
desc->istate &= ~IRQS_PENDING;
|
|
return;
|
|
}
|
|
if (desc->istate & IRQS_REPLAY)
|
|
return;
|
|
if (desc->istate & IRQS_PENDING) {
|
|
desc->istate &= ~IRQS_PENDING;
|
|
desc->istate |= IRQS_REPLAY;
|
|
|
|
if ((!desc->irq_data.chip->irq_retrigger ||
|
|
!desc->irq_data.chip->irq_retrigger(&desc->irq_data)) &&
|
|
!handle_enforce_irqctx(&desc->irq_data)) {
|
|
#ifdef CONFIG_HARDIRQS_SW_RESEND
|
|
unsigned int irq = irq_desc_get_irq(desc);
|
|
|
|
/*
|
|
* If the interrupt is running in the thread
|
|
* context of the parent irq we need to be
|
|
* careful, because we cannot trigger it
|
|
* directly.
|
|
*/
|
|
if (irq_settings_is_nested_thread(desc)) {
|
|
/*
|
|
* If the parent_irq is valid, we
|
|
* retrigger the parent, otherwise we
|
|
* do nothing.
|
|
*/
|
|
if (!desc->parent_irq)
|
|
return;
|
|
irq = desc->parent_irq;
|
|
}
|
|
/* Set it pending and activate the softirq: */
|
|
set_bit(irq, irqs_resend);
|
|
tasklet_schedule(&resend_tasklet);
|
|
#endif
|
|
}
|
|
}
|
|
}
|