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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-04-03 11:25:39 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2015-04-14 22:26:52 +0100
commitd3cd451dfb579367b4c5968256b3d8342dd0b0e8 (patch)
treefa411df2beabfe0378906882f026c03560ea1b97 /arch/arm
parentcd8b24d9e852b53e68c69a086358c81423dfb8d1 (diff)
ARM: cache-v7: optimise branches in v7_flush_cache_louis
Optimise the branches such that for the majority of unaffected devices, we avoid needing to execute the errata work-around code path by branching to start_flush_levels early. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/mm/cache-v7.S19
1 files changed, 10 insertions, 9 deletions
diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
index 5b5d0c00bca7..793d061b4dce 100644
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -93,17 +93,18 @@ ENTRY(v7_flush_dcache_louis)
ALT_SMP(mov r3, r0, lsr #20) @ move LoUIS into position
ALT_UP( mov r3, r0, lsr #26) @ move LoUU into position
ands r3, r3, #7 << 1 @ extract LoU*2 field from clidr
+ bne start_flush_levels @ LoU != 0, start flushing
#ifdef CONFIG_ARM_ERRATA_643719
- ALT_SMP(mrceq p15, 0, r2, c0, c0, 0) @ read main ID register
- ALT_UP(reteq lr) @ LoUU is zero, so nothing to do
- movweq r1, #:lower16:0x410fc090 @ ID of ARM Cortex A9 r0p?
- movteq r1, #:upper16:0x410fc090
- biceq r2, r2, #0x0000000f @ clear minor revision number
- teqeq r2, r1 @ test for errata affected core and if so...
- moveqs r3, #1 << 1 @ fix LoUIS value (and set flags state to 'ne')
+ALT_SMP(mrc p15, 0, r2, c0, c0, 0) @ read main ID register
+ALT_UP( ret lr) @ LoUU is zero, so nothing to do
+ movw r1, #:lower16:0x410fc090 @ ID of ARM Cortex A9 r0p?
+ movt r1, #:upper16:0x410fc090
+ bic r2, r2, #0x0000000f @ clear minor revision number
+ teq r2, r1 @ test for errata affected core and if so...
+ moveq r3, #1 << 1 @ fix LoUIS value
+ beq start_flush_levels @ start flushing cache levels
#endif
- reteq lr @ return if level == 0
- b start_flush_levels @ start flushing cache levels
+ ret lr
ENDPROC(v7_flush_dcache_louis)
/*