Commit 47b8484e authored by Russell King's avatar Russell King
Browse files

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: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 5aca3708

arch/arm/mm/cache-v7.S

+6 −7
Original line number Diff line number Diff line
@@ -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:

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