diff options
Diffstat (limited to 'arch/powerpc/include/asm/book3s/32/kup.h')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/32/kup.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h index 64201125a287..d4b145b279f6 100644 --- a/arch/powerpc/include/asm/book3s/32/kup.h +++ b/arch/powerpc/include/asm/book3s/32/kup.h @@ -4,6 +4,8 @@ #include <asm/bug.h> #include <asm/book3s/32/mmu-hash.h> +#include <asm/mmu.h> +#include <asm/synch.h> #ifndef __ASSEMBLY__ @@ -28,6 +30,15 @@ static inline void kuep_lock(void) return; update_user_segments(mfsr(0) | SR_NX); + /* + * This isync() shouldn't be necessary as the kernel is not excepted to + * run any instruction in userspace soon after the update of segments, + * but hash based cores (at least G3) seem to exhibit a random + * behaviour when the 'isync' is not there. 603 cores don't have this + * behaviour so don't do the 'isync' as it saves several CPU cycles. + */ + if (mmu_has_feature(MMU_FTR_HPTE_TABLE)) + isync(); /* Context sync required after mtsr() */ } static inline void kuep_unlock(void) @@ -36,6 +47,15 @@ static inline void kuep_unlock(void) return; update_user_segments(mfsr(0) & ~SR_NX); + /* + * This isync() shouldn't be necessary as a 'rfi' will soon be executed + * to return to userspace, but hash based cores (at least G3) seem to + * exhibit a random behaviour when the 'isync' is not there. 603 cores + * don't have this behaviour so don't do the 'isync' as it saves several + * CPU cycles. + */ + if (mmu_has_feature(MMU_FTR_HPTE_TABLE)) + isync(); /* Context sync required after mtsr() */ } #ifdef CONFIG_PPC_KUAP |