linux_dsm_epyc7002/arch/x86/include/asm/irq_regs.h
Peter Zijlstra 602447f954 x86/percpu, x86/irq: Relax {set,get}_irq_regs()
Nadav reported that since the this_cpu_*() ops got asm-volatile
constraints on, code generation suffered for do_IRQ(), but since this
is all with IRQs disabled we can use __this_cpu_*().

  smp_x86_platform_ipi                                      234        222   -12,+0
  smp_kvm_posted_intr_ipi                                    74         66   -8,+0
  smp_kvm_posted_intr_wakeup_ipi                             86         78   -8,+0
  smp_apic_timer_interrupt                                  292        284   -8,+0
  smp_kvm_posted_intr_nested_ipi                             74         66   -8,+0
  do_IRQ                                                    195        187   -8,+0

Reported-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-17 12:43:42 +02:00

33 lines
683 B
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Per-cpu current frame pointer - the location of the last exception frame on
* the stack, stored in the per-cpu area.
*
* Jeremy Fitzhardinge <jeremy@goop.org>
*/
#ifndef _ASM_X86_IRQ_REGS_H
#define _ASM_X86_IRQ_REGS_H
#include <asm/percpu.h>
#define ARCH_HAS_OWN_IRQ_REGS
DECLARE_PER_CPU(struct pt_regs *, irq_regs);
static inline struct pt_regs *get_irq_regs(void)
{
return __this_cpu_read(irq_regs);
}
static inline struct pt_regs *set_irq_regs(struct pt_regs *new_regs)
{
struct pt_regs *old_regs;
old_regs = get_irq_regs();
__this_cpu_write(irq_regs, new_regs);
return old_regs;
}
#endif /* _ASM_X86_IRQ_REGS_32_H */