diff options
| author |   Juergen Gross <jgross@suse.com> | 2021-01-20 14:55:46 +0100 |
|---|---|---|
| committer |   Borislav Petkov <bp@suse.de> | 2021-02-10 12:36:45 +0100 |
| commit | ab234a260b1f625b26cbefa93ca365b0ae66df33 (patch) | |
| tree | 3308ecacbf6f66119fb14707eb506de1ab43e027 /arch/x86/include/asm/irqflags.h | |
| parent | x86/xen: Drop USERGS_SYSRET64 paravirt call (diff) | |
| download | linux-dev-ab234a260b1f625b26cbefa93ca365b0ae66df33.tar.xz linux-dev-ab234a260b1f625b26cbefa93ca365b0ae66df33.zip | |
x86/pv: Rework arch_local_irq_restore() to not use popf
POPF is a rather expensive operation, so don't use it for restoring
irq flags. Instead, test whether interrupts are enabled in the flags
parameter and enable interrupts via STI in that case.
This results in the restore_fl paravirt op to be no longer needed.
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210120135555.32594-7-jgross@suse.com
Diffstat (limited to 'arch/x86/include/asm/irqflags.h')
| -rw-r--r-- | arch/x86/include/asm/irqflags.h | 20 |
1 files changed, 6 insertions, 14 deletions
diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h index e585a4705b8d..144d70ea4393 100644 --- a/arch/x86/include/asm/irqflags.h +++ b/arch/x86/include/asm/irqflags.h @@ -35,15 +35,6 @@ extern __always_inline unsigned long native_save_fl(void) return flags; } -extern inline void native_restore_fl(unsigned long flags); -extern inline void native_restore_fl(unsigned long flags) -{ - asm volatile("push %0 ; popf" - : /* no output */ - :"g" (flags) - :"memory", "cc"); -} - static __always_inline void native_irq_disable(void) { asm volatile("cli": : :"memory"); @@ -79,11 +70,6 @@ static __always_inline unsigned long arch_local_save_flags(void) return native_save_fl(); } -static __always_inline void arch_local_irq_restore(unsigned long flags) -{ - native_restore_fl(flags); -} - static __always_inline void arch_local_irq_disable(void) { native_irq_disable(); @@ -152,6 +138,12 @@ static __always_inline int arch_irqs_disabled(void) return arch_irqs_disabled_flags(flags); } + +static __always_inline void arch_local_irq_restore(unsigned long flags) +{ + if (!arch_irqs_disabled_flags(flags)) + arch_local_irq_enable(); +} #else #ifdef CONFIG_X86_64 #ifdef CONFIG_XEN_PV |