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ARM: 6528/1: Use CTR for the I-cache line size on ARMv7

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The current implementation of the v7_coherent_*_range function assumes
that the D and I cache lines have the same size, which is incorrect
architecturally. This patch adds the icache_line_size macro which reads
the CTR register. The main loop in v7_coherent_*_range is split in two
independent loops or the D and I caches. This also has the performance
advantage that the DSB is moved outside the main loop.

Reported-by: Kevin Sapp <ksapp@quicinc.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Catalin Marinas 2010-12-07 16:56:29 +01:00 committed by Russell King
parent f91e2c3bd4
commit da30e0ac0f
2 changed files with 28 additions and 11 deletions
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29
arch/arm/mm/cache-v7.S
View File

@ -173,15 +173,22 @@ ENTRY(v7_coherent_user_range)
UNWIND(.fnstart )
dcache_line_size r2, r3
sub r3, r2, #1
bic r0, r0, r3
bic r12, r0, r3
1:
USER( mcr p15, 0, r0, c7, c11, 1 ) @ clean D line to the point of unification
dsb
USER( mcr p15, 0, r0, c7, c5, 1 ) @ invalidate I line
add r0, r0, r2
2:
cmp r0, r1
USER( mcr p15, 0, r12, c7, c11, 1 ) @ clean D line to the point of unification
add r12, r12, r2
cmp r12, r1
blo 1b
dsb
icache_line_size r2, r3
sub r3, r2, #1
bic r12, r0, r3
2:
USER( mcr p15, 0, r12, c7, c5, 1 ) @ invalidate I line
add r12, r12, r2
cmp r12, r1
blo 2b
3:
mov r0, #0
ALT_SMP(mcr p15, 0, r0, c7, c1, 6) @ invalidate BTB Inner Shareable
ALT_UP(mcr p15, 0, r0, c7, c5, 6) @ invalidate BTB
@ -194,10 +201,10 @@ ENTRY(v7_coherent_user_range)
* isn't mapped, just try the next page.
*/
9001:
mov r0, r0, lsr #12
mov r0, r0, lsl #12
add r0, r0, #4096
b 2b
mov r12, r12, lsr #12
mov r12, r12, lsl #12
add r12, r12, #4096
b 3b
UNWIND(.fnend )
ENDPROC(v7_coherent_kern_range)
ENDPROC(v7_coherent_user_range)

10
arch/arm/mm/proc-macros.S
View File

@ -72,6 +72,16 @@
mov \reg, \reg, lsl \tmp @ actual cache line size
.endm
/*
* icache_line_size - get the minimum I-cache line size from the CTR register
* on ARMv7.
*/
.macro icache_line_size, reg, tmp
mrc p15, 0, \tmp, c0, c0, 1 @ read ctr
and \tmp, \tmp, #0xf @ cache line size encoding
mov \reg, #4 @ bytes per word
mov \reg, \reg, lsl \tmp @ actual cache line size
.endm
/*
* Sanity check the PTE configuration for the code below - which makes