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 | |
| parent | x86/xen: Drop USERGS_SYSRET64 paravirt call (diff) | |
| download | linux-ab234a260b1f625b26cbefa93ca365b0ae66df33.tar.xz linux-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')
| -rw-r--r-- | arch/x86/include/asm/irqflags.h | 20 | ||||
| -rw-r--r-- | arch/x86/include/asm/paravirt.h | 5 | ||||
| -rw-r--r-- | arch/x86/include/asm/paravirt_types.h | 7 |
3 files changed, 8 insertions, 24 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 diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index dd43b1100a87..4abf110e2243 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -648,11 +648,6 @@ static inline notrace unsigned long arch_local_save_flags(void) return PVOP_CALLEE0(unsigned long, irq.save_fl); } -static inline notrace void arch_local_irq_restore(unsigned long f) -{ - PVOP_VCALLEE1(irq.restore_fl, f); -} - static inline notrace void arch_local_irq_disable(void) { PVOP_VCALLEE0(irq.irq_disable); diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 0169365f1403..de87087d3bde 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -168,16 +168,13 @@ struct pv_cpu_ops { struct pv_irq_ops { #ifdef CONFIG_PARAVIRT_XXL /* - * Get/set interrupt state. save_fl and restore_fl are only - * expected to use X86_EFLAGS_IF; all other bits - * returned from save_fl are undefined, and may be ignored by - * restore_fl. + * Get/set interrupt state. save_fl is expected to use X86_EFLAGS_IF; + * all other bits returned from save_fl are undefined. * * NOTE: These functions callers expect the callee to preserve * more registers than the standard C calling convention. */ struct paravirt_callee_save save_fl; - struct paravirt_callee_save restore_fl; struct paravirt_callee_save irq_disable; struct paravirt_callee_save irq_enable; |