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[ARM] Feroceon: speed up flushing of the entire cache

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Flushing the L1 D cache with a test/clean/invalidate loop is very
easy in software, but it is not the quickest way of doing it, as
there is a lot of overhead involved in re-scanning the cache from
the beginning every time we hit a dirty line.

This patch makes proc-feroceon.S use "clean+invalidate by set/way"
loops according to possible cache configuration of Feroceon CPUs
(either direct-mapped or 4-way set associative).

Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
This commit is contained in:
Nicolas Pitre 2008-04-24 02:04:54 +02:00 committed by Lennert Buytenhek
parent 79e90dd5aa
commit 6c386e58aa
1 changed files with 48 additions and 11 deletions
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59
arch/arm/mm/proc-feroceon.S
View file

@ -44,11 +44,31 @@
*/
#define CACHE_DLINESIZE 32
.bss
.align 3
__cache_params_loc:
.space 8
.text
__cache_params:
.word __cache_params_loc
/*
* cpu_feroceon_proc_init()
*/
ENTRY(cpu_feroceon_proc_init)
mrc p15, 0, r0, c0, c0, 1 @ read cache type register
ldr r1, __cache_params
mov r2, #(16 << 5)
tst r0, #(1 << 16) @ get way
mov r0, r0, lsr #18 @ get cache size order
movne r3, #((4 - 1) << 30) @ 4-way
and r0, r0, #0xf
moveq r3, #0 @ 1-way
mov r2, r2, lsl r0 @ actual cache size
movne r2, r2, lsr #2 @ turned into # of sets
sub r2, r2, #(1 << 5)
stmia r1, {r2, r3}
mov pc, lr
/*
@ -117,11 +137,19 @@ ENTRY(feroceon_flush_user_cache_all)
*/
ENTRY(feroceon_flush_kern_cache_all)
mov r2, #VM_EXEC
mov ip, #0
__flush_whole_cache:
1: mrc p15, 0, r15, c7, c14, 3 @ test,clean,invalidate
bne 1b
ldr r1, __cache_params
ldmia r1, {r1, r3}
1: orr ip, r1, r3
2: mcr p15, 0, ip, c7, c14, 2 @ clean + invalidate D set/way
subs ip, ip, #(1 << 30) @ next way
bcs 2b
subs r1, r1, #(1 << 5) @ next set
bcs 1b
tst r2, #VM_EXEC
mov ip, #0
mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
mcrne p15, 0, ip, c7, c10, 4 @ drain WB
mov pc, lr
@ -138,7 +166,6 @@ __flush_whole_cache:
*/
.align 5
ENTRY(feroceon_flush_user_cache_range)
mov ip, #0
sub r3, r1, r0 @ calculate total size
cmp r3, #CACHE_DLIMIT
bgt __flush_whole_cache
@ -152,6 +179,7 @@ ENTRY(feroceon_flush_user_cache_range)
cmp r0, r1
blo 1b
tst r2, #VM_EXEC
mov ip, #0
mcrne p15, 0, ip, c7, c10, 4 @ drain WB
mov pc, lr
@ -306,16 +334,25 @@ ENTRY(cpu_feroceon_dcache_clean_area)
.align 5
ENTRY(cpu_feroceon_switch_mm)
#ifdef CONFIG_MMU
mov ip, #0
@ && 'Clean & Invalidate whole DCache'
1: mrc p15, 0, r15, c7, c14, 3 @ test,clean,invalidate
bne 1b
mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
mcr p15, 0, ip, c7, c10, 4 @ drain WB
/*
* Note: we wish to call __flush_whole_cache but we need to preserve
* lr to do so. The only way without touching main memory is to
* use r2 which is normally used to test the VM_EXEC flag, and
* compensate locally for the skipped ops if it is not set.
*/
mov r2, lr @ abuse r2 to preserve lr
bl __flush_whole_cache
@ if r2 contains the VM_EXEC bit then the next 2 ops are done already
tst r2, #VM_EXEC
mcreq p15, 0, ip, c7, c5, 0 @ invalidate I cache
mcreq p15, 0, ip, c7, c10, 4 @ drain WB
mcr p15, 0, r0, c2, c0, 0 @ load page table pointer
mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
#endif
mov pc, r2
#else
mov pc, lr
#endif
/*
* cpu_feroceon_set_pte_ext(ptep, pte, ext)