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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-04-03 11:15:53 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2015-04-14 22:26:51 +0100
commit47b8484ea6569511a3cd915bea29886b4cd08333 (patch)
treec4f80e72ea340c972fcf55cf13b7c27d223bc31b /arch/arm/mm/cache-v7.S
parent5aca370826a2487aaaae5db31f6bb0b906e9755f (diff)
ARM: cache-v7: shift CLIDR to extract appropriate field before masking
Rather than have code which masks and then shifts, such as: mrc p15, 1, r0, c0, c0, 1 ALT_SMP(ands r3, r0, #7 << 21) ALT_UP( ands r3, r0, #7 << 27) ALT_SMP(mov r3, r3, lsr #20) ALT_UP( mov r3, r3, lsr #26) re-arrange this as a shift and then mask. The masking is the same for each field which we want to extract, so this allows the mask to be shared amongst code paths: mrc p15, 1, r0, c0, c0, 1 ALT_SMP(mov r3, r0, lsr #20) ALT_UP( mov r3, r0, lsr #26) ands r3, r3, #7 << 1 Use this method for the LoUIS, LoUU and LoC fields. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/cache-v7.S')
-rw-r--r--arch/arm/mm/cache-v7.S13
1 files changed, 6 insertions, 7 deletions
diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
index 30c81e7d6aaa..d062f8cbb886 100644
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -90,8 +90,9 @@ ENDPROC(v7_flush_icache_all)
ENTRY(v7_flush_dcache_louis)
dmb @ ensure ordering with previous memory accesses
mrc p15, 1, r0, c0, c0, 1 @ read clidr, r0 = clidr
- ALT_SMP(ands r3, r0, #(7 << 21)) @ extract LoUIS from clidr
- ALT_UP(ands r3, r0, #(7 << 27)) @ extract LoUU from clidr
+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
#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
@@ -99,10 +100,8 @@ ENTRY(v7_flush_dcache_louis)
movteq r1, #:upper16:0x410fc090
biceq r2, r2, #0x0000000f @ clear minor revision number
teqeq r2, r1 @ test for errata affected core and if so...
- orreqs r3, #(1 << 21) @ fix LoUIS value (and set flags state to 'ne')
+ moveqs r3, #1 << 1 @ fix LoUIS value (and set flags state to 'ne')
#endif
- ALT_SMP(mov r3, r3, lsr #20) @ r3 = LoUIS * 2
- ALT_UP(mov r3, r3, lsr #26) @ r3 = LoUU * 2
reteq lr @ return if level == 0
mov r10, #0 @ r10 (starting level) = 0
b flush_levels @ start flushing cache levels
@@ -120,8 +119,8 @@ ENDPROC(v7_flush_dcache_louis)
ENTRY(v7_flush_dcache_all)
dmb @ ensure ordering with previous memory accesses
mrc p15, 1, r0, c0, c0, 1 @ read clidr
- ands r3, r0, #0x7000000 @ extract loc from clidr
- mov r3, r3, lsr #23 @ left align loc bit field
+ mov r3, r0, lsr #23 @ move LoC into position
+ ands r3, r3, #7 << 1 @ extract LoC*2 from clidr
beq finished @ if loc is 0, then no need to clean
mov r10, #0 @ start clean at cache level 0
flush_levels: