diff options
Diffstat (limited to 'arch/x86/include/asm/gsseg.h')
| -rw-r--r-- | arch/x86/include/asm/gsseg.h | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/arch/x86/include/asm/gsseg.h b/arch/x86/include/asm/gsseg.h index d15577c39e8d..ab6a595cea70 100644 --- a/arch/x86/include/asm/gsseg.h +++ b/arch/x86/include/asm/gsseg.h @@ -14,17 +14,42 @@ extern asmlinkage void asm_load_gs_index(u16 selector); +/* Replace with "lkgs %di" once binutils support LKGS instruction */ +#define LKGS_DI _ASM_BYTES(0xf2,0x0f,0x00,0xf7) + +static inline void native_lkgs(unsigned int selector) +{ + u16 sel = selector; + asm_inline volatile("1: " LKGS_DI + _ASM_EXTABLE_TYPE_REG(1b, 1b, EX_TYPE_ZERO_REG, %k[sel]) + : [sel] "+D" (sel)); +} + static inline void native_load_gs_index(unsigned int selector) { - unsigned long flags; + if (cpu_feature_enabled(X86_FEATURE_LKGS)) { + native_lkgs(selector); + } else { + unsigned long flags; - local_irq_save(flags); - asm_load_gs_index(selector); - local_irq_restore(flags); + local_irq_save(flags); + asm_load_gs_index(selector); + local_irq_restore(flags); + } } #endif /* CONFIG_X86_64 */ +static inline void __init lkgs_init(void) +{ +#ifdef CONFIG_PARAVIRT_XXL +#ifdef CONFIG_X86_64 + if (cpu_feature_enabled(X86_FEATURE_LKGS)) + pv_ops.cpu.load_gs_index = native_lkgs; +#endif +#endif +} + #ifndef CONFIG_PARAVIRT_XXL static inline void load_gs_index(unsigned int selector) |