[PATCH v2 05/12] powerpc/32s: Simplify calculation of segment register content
flat view
STALE1952d
LANDED
From: Christophe Leroy <hidden>
Date: 2021-06-03 08:41:50
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Landed in mainline as 882136fb2f52 on 2021-06-16.
segment register has VSID on bits 8-31. Bits 4-7 are reserved, there is no requirement to set them to 0. VSIDs are calculated from VSID of SR0 by adding 0x111. Even with highest possible VSID which would be 0xFFFFF0, adding 16 times 0x111 results in 0x1001100. So, the reserved bits are never overflowed, no need to clear the reserved bits after each calculation. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/include/asm/book3s/32/mmu-hash.h | 42 ++++++++++--------- 1 file changed, 23 insertions(+), 19 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index 583388399b1b..f5be185cbdf8 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h@@ -115,28 +115,32 @@ extern s32 patch__flush_hash_B; #include <asm/reg.h> #include <asm/task_size_32.h> -#define UPDATE_TWO_USER_SEGMENTS(n) do { \ - if (TASK_SIZE > ((n) << 28)) \ - mtsr(val1, (n) << 28); \ - if (TASK_SIZE > (((n) + 1) << 28)) \ - mtsr(val2, ((n) + 1) << 28); \ - val1 = (val1 + 0x222) & 0xf0ffffff; \ - val2 = (val2 + 0x222) & 0xf0ffffff; \ -} while (0) +static __always_inline void update_user_segment(u32 n, u32 val) +{ + if (n << 28 < TASK_SIZE) + mtsr(val + n * 0x111, n << 28); +} static __always_inline void update_user_segments(u32 val) { - int val1 = val; - int val2 = (val + 0x111) & 0xf0ffffff; - - UPDATE_TWO_USER_SEGMENTS(0); - UPDATE_TWO_USER_SEGMENTS(2); - UPDATE_TWO_USER_SEGMENTS(4); - UPDATE_TWO_USER_SEGMENTS(6); - UPDATE_TWO_USER_SEGMENTS(8); - UPDATE_TWO_USER_SEGMENTS(10); - UPDATE_TWO_USER_SEGMENTS(12); - UPDATE_TWO_USER_SEGMENTS(14); + val &= 0xf0ffffff; + + update_user_segment(0, val); + update_user_segment(1, val); + update_user_segment(2, val); + update_user_segment(3, val); + update_user_segment(4, val); + update_user_segment(5, val); + update_user_segment(6, val); + update_user_segment(7, val); + update_user_segment(8, val); + update_user_segment(9, val); + update_user_segment(10, val); + update_user_segment(11, val); + update_user_segment(12, val); + update_user_segment(13, val); + update_user_segment(14, val); + update_user_segment(15, val); } #endif /* !__ASSEMBLY__ */
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2.25.0