korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-15 08:14:15 +08:00
Code Issues Packages Projects Releases Wiki Activity

ARM: cache-v7: shift CLIDR to extract appropriate field before masking

Browse Source 
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>
This commit is contained in:
Russell King 2015-04-03 11:15:53 +01:00
parent 5aca370826
commit 47b8484ea6
1 changed files with 6 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
arch/arm/mm/cache-v7.S
View File

@ -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: