[PATCH v2] powerpc/mm: Add mask of always present MMU features
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STALE2202d
From: Christophe Leroy <hidden>
Date: 2020-10-12 15:41:46
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
On the same principle as commit 773edeadf672 ("powerpc/mm: Add mask
of possible MMU features"), add mask for MMU features that are
always there in order to optimise out dead branches.
Signed-off-by: Christophe Leroy <redacted>
---
v2: Features must be anded with MMU_FTRS_POSSIBLE instead of ~0, otherwise
MMU_FTRS_ALWAYS is ~0 when no #ifdef matches.
---
arch/powerpc/include/asm/mmu.h | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index 255a1837e9f7..64e7e7f7cda9 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h@@ -201,8 +201,30 @@ enum { 0, }; +enum { + MMU_FTRS_ALWAYS = +#ifdef CONFIG_PPC_8xx + MMU_FTR_TYPE_8xx & +#endif +#ifdef CONFIG_40x + MMU_FTR_TYPE_40x & +#endif +#ifdef CONFIG_PPC_47x + MMU_FTR_TYPE_47x & +#elif defined(CONFIG_44x) + MMU_FTR_TYPE_44x & +#endif +#if defined(CONFIG_E200) || defined(CONFIG_E500) + MMU_FTR_TYPE_FSL_E & +#endif + MMU_FTRS_POSSIBLE, +}; + static inline bool early_mmu_has_feature(unsigned long feature) { + if (MMU_FTRS_ALWAYS & feature) + return true; + return !!(MMU_FTRS_POSSIBLE & cur_cpu_spec->mmu_features & feature); }
@@ -231,6 +253,9 @@ static __always_inline bool mmu_has_feature(unsigned long feature) } #endif + if (MMU_FTRS_ALWAYS & feature) + return true; + if (!(MMU_FTRS_POSSIBLE & feature)) return false;
--
2.25.0