mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-26 19:36:41 +00:00
0fe1ac48be
Anton Blanchard found that large POWER systems would occasionally crash in the exception exit path when profiling with perf_events. The symptom was that an interrupt would occur late in the exit path when the MSR[RI] (recoverable interrupt) bit was clear. Interrupts should be hard-disabled at this point but they were enabled. Because the interrupt was not recoverable the system panicked. The reason is that the exception exit path was calling perf_event_do_pending after hard-disabling interrupts, and perf_event_do_pending will re-enable interrupts. The simplest and cleanest fix for this is to use the same mechanism that 32-bit powerpc does, namely to cause a self-IPI by setting the decrementer to 1. This means we can remove the tests in the exception exit path and raw_local_irq_restore. This also makes sure that the call to perf_event_do_pending from timer_interrupt() happens within irq_enter/irq_exit. (Note that calling perf_event_do_pending from timer_interrupt does not mean that there is a possible 1/HZ latency; setting the decrementer to 1 ensures that the timer interrupt will happen immediately, i.e. within one timebase tick, which is a few nanoseconds or 10s of nanoseconds.) Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: stable@kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
135 lines
3.1 KiB
C
135 lines
3.1 KiB
C
/*
|
|
* Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
|
|
*/
|
|
#ifndef _ASM_POWERPC_HW_IRQ_H
|
|
#define _ASM_POWERPC_HW_IRQ_H
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
#include <linux/errno.h>
|
|
#include <linux/compiler.h>
|
|
#include <asm/ptrace.h>
|
|
#include <asm/processor.h>
|
|
|
|
extern void timer_interrupt(struct pt_regs *);
|
|
|
|
#ifdef CONFIG_PPC64
|
|
#include <asm/paca.h>
|
|
|
|
static inline unsigned long local_get_flags(void)
|
|
{
|
|
unsigned long flags;
|
|
|
|
__asm__ __volatile__("lbz %0,%1(13)"
|
|
: "=r" (flags)
|
|
: "i" (offsetof(struct paca_struct, soft_enabled)));
|
|
|
|
return flags;
|
|
}
|
|
|
|
static inline unsigned long raw_local_irq_disable(void)
|
|
{
|
|
unsigned long flags, zero;
|
|
|
|
__asm__ __volatile__("li %1,0; lbz %0,%2(13); stb %1,%2(13)"
|
|
: "=r" (flags), "=&r" (zero)
|
|
: "i" (offsetof(struct paca_struct, soft_enabled))
|
|
: "memory");
|
|
|
|
return flags;
|
|
}
|
|
|
|
extern void raw_local_irq_restore(unsigned long);
|
|
extern void iseries_handle_interrupts(void);
|
|
|
|
#define raw_local_irq_enable() raw_local_irq_restore(1)
|
|
#define raw_local_save_flags(flags) ((flags) = local_get_flags())
|
|
#define raw_local_irq_save(flags) ((flags) = raw_local_irq_disable())
|
|
|
|
#define raw_irqs_disabled() (local_get_flags() == 0)
|
|
#define raw_irqs_disabled_flags(flags) ((flags) == 0)
|
|
|
|
#ifdef CONFIG_PPC_BOOK3E
|
|
#define __hard_irq_enable() __asm__ __volatile__("wrteei 1": : :"memory");
|
|
#define __hard_irq_disable() __asm__ __volatile__("wrteei 0": : :"memory");
|
|
#else
|
|
#define __hard_irq_enable() __mtmsrd(mfmsr() | MSR_EE, 1)
|
|
#define __hard_irq_disable() __mtmsrd(mfmsr() & ~MSR_EE, 1)
|
|
#endif
|
|
|
|
#define hard_irq_disable() \
|
|
do { \
|
|
__hard_irq_disable(); \
|
|
get_paca()->soft_enabled = 0; \
|
|
get_paca()->hard_enabled = 0; \
|
|
} while(0)
|
|
|
|
#else
|
|
|
|
#if defined(CONFIG_BOOKE)
|
|
#define SET_MSR_EE(x) mtmsr(x)
|
|
#define raw_local_irq_restore(flags) __asm__ __volatile__("wrtee %0" : : "r" (flags) : "memory")
|
|
#else
|
|
#define SET_MSR_EE(x) mtmsr(x)
|
|
#define raw_local_irq_restore(flags) mtmsr(flags)
|
|
#endif
|
|
|
|
static inline void raw_local_irq_disable(void)
|
|
{
|
|
#ifdef CONFIG_BOOKE
|
|
__asm__ __volatile__("wrteei 0": : :"memory");
|
|
#else
|
|
unsigned long msr;
|
|
|
|
msr = mfmsr();
|
|
SET_MSR_EE(msr & ~MSR_EE);
|
|
#endif
|
|
}
|
|
|
|
static inline void raw_local_irq_enable(void)
|
|
{
|
|
#ifdef CONFIG_BOOKE
|
|
__asm__ __volatile__("wrteei 1": : :"memory");
|
|
#else
|
|
unsigned long msr;
|
|
|
|
msr = mfmsr();
|
|
SET_MSR_EE(msr | MSR_EE);
|
|
#endif
|
|
}
|
|
|
|
static inline void raw_local_irq_save_ptr(unsigned long *flags)
|
|
{
|
|
unsigned long msr;
|
|
msr = mfmsr();
|
|
*flags = msr;
|
|
#ifdef CONFIG_BOOKE
|
|
__asm__ __volatile__("wrteei 0": : :"memory");
|
|
#else
|
|
SET_MSR_EE(msr & ~MSR_EE);
|
|
#endif
|
|
}
|
|
|
|
#define raw_local_save_flags(flags) ((flags) = mfmsr())
|
|
#define raw_local_irq_save(flags) raw_local_irq_save_ptr(&flags)
|
|
#define raw_irqs_disabled() ((mfmsr() & MSR_EE) == 0)
|
|
#define raw_irqs_disabled_flags(flags) (((flags) & MSR_EE) == 0)
|
|
|
|
#define hard_irq_disable() raw_local_irq_disable()
|
|
|
|
static inline int irqs_disabled_flags(unsigned long flags)
|
|
{
|
|
return (flags & MSR_EE) == 0;
|
|
}
|
|
|
|
#endif /* CONFIG_PPC64 */
|
|
|
|
/*
|
|
* interrupt-retrigger: should we handle this via lost interrupts and IPIs
|
|
* or should we not care like we do now ? --BenH.
|
|
*/
|
|
struct irq_chip;
|
|
|
|
#endif /* __KERNEL__ */
|
|
#endif /* _ASM_POWERPC_HW_IRQ_H */
|