Commit df087e45 authored by LEROY Christophe's avatar LEROY Christophe Committed by Scott Wood
Browse files

Partially revert "powerpc: Remove duplicate cacheable_memcpy/memzero functions" 



This partially reverts
commit 'powerpc: Remove duplicate cacheable_memcpy/memzero functions
("b05ae4ee")'

Functions cacheable_memcpy/memzero are more efficient than
memcpy/memset as they use the dcbz instruction which avoids refill
of the cacheline with the data that we will overwrite.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
parent 934628c7

arch/powerpc/lib/copy_32.S

+127 −0
Original line number Diff line number Diff line
@@ -69,6 +69,54 @@ CACHELINE_BYTES = L1_CACHE_BYTES 
LG_CACHELINE_BYTES = L1_CACHE_SHIFT

CACHELINE_MASK = (L1_CACHE_BYTES-1)



/*

 * Use dcbz on the complete cache lines in the destination

 * to set them to zero.  This requires that the destination

 * area is cacheable.  -- paulus

 */

_GLOBAL(cacheable_memzero)

	mr	r5,r4

	li	r4,0

	addi	r6,r3,-4

	cmplwi	0,r5,4

	blt	7f

	stwu	r4,4(r6)

	beqlr

	andi.	r0,r6,3

	add	r5,r0,r5

	subf	r6,r0,r6

	clrlwi	r7,r6,32-LG_CACHELINE_BYTES

	add	r8,r7,r5

	srwi	r9,r8,LG_CACHELINE_BYTES

	addic.	r9,r9,-1	/* total number of complete cachelines */

	ble	2f

	xori	r0,r7,CACHELINE_MASK & ~3

	srwi.	r0,r0,2

	beq	3f

	mtctr	r0

4:	stwu	r4,4(r6)

	bdnz	4b

3:	mtctr	r9

	li	r7,4

10:	dcbz	r7,r6

	addi	r6,r6,CACHELINE_BYTES

	bdnz	10b

	clrlwi	r5,r8,32-LG_CACHELINE_BYTES

	addi	r5,r5,4

2:	srwi	r0,r5,2

	mtctr	r0

	bdz	6f

1:	stwu	r4,4(r6)

	bdnz	1b

6:	andi.	r5,r5,3

7:	cmpwi	0,r5,0

	beqlr

	mtctr	r5

	addi	r6,r6,3

8:	stbu	r4,1(r6)

	bdnz	8b

	blr



_GLOBAL(memset)

	rlwimi	r4,r4,8,16,23

	rlwimi	r4,r4,16,0,15
@@ -94,6 +142,85 @@ _GLOBAL(memset) 
	bdnz	8b

	blr



/*

 * This version uses dcbz on the complete cache lines in the

 * destination area to reduce memory traffic.  This requires that

 * the destination area is cacheable.

 * We only use this version if the source and dest don't overlap.

 * -- paulus.

 */

_GLOBAL(cacheable_memcpy)

	add	r7,r3,r5		/* test if the src & dst overlap */

	add	r8,r4,r5

	cmplw	0,r4,r7

	cmplw	1,r3,r8

	crand	0,0,4			/* cr0.lt &= cr1.lt */

	blt	memcpy			/* if regions overlap */



	addi	r4,r4,-4

	addi	r6,r3,-4

	neg	r0,r3

	andi.	r0,r0,CACHELINE_MASK	/* # bytes to start of cache line */

	beq	58f



	cmplw	0,r5,r0			/* is this more than total to do? */

	blt	63f			/* if not much to do */

	andi.	r8,r0,3			/* get it word-aligned first */

	subf	r5,r0,r5

	mtctr	r8

	beq+	61f

70:	lbz	r9,4(r4)		/* do some bytes */

	stb	r9,4(r6)

	addi	r4,r4,1

	addi	r6,r6,1

	bdnz	70b

61:	srwi.	r0,r0,2

	mtctr	r0

	beq	58f

72:	lwzu	r9,4(r4)		/* do some words */

	stwu	r9,4(r6)

	bdnz	72b



58:	srwi.	r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */

	clrlwi	r5,r5,32-LG_CACHELINE_BYTES

	li	r11,4

	mtctr	r0

	beq	63f

53:

	dcbz	r11,r6

	COPY_16_BYTES

#if L1_CACHE_BYTES >= 32

	COPY_16_BYTES

#if L1_CACHE_BYTES >= 64

	COPY_16_BYTES

	COPY_16_BYTES

#if L1_CACHE_BYTES >= 128

	COPY_16_BYTES

	COPY_16_BYTES

	COPY_16_BYTES

	COPY_16_BYTES

#endif

#endif

#endif

	bdnz	53b



63:	srwi.	r0,r5,2

	mtctr	r0

	beq	64f

30:	lwzu	r0,4(r4)

	stwu	r0,4(r6)

	bdnz	30b



64:	andi.	r0,r5,3

	mtctr	r0

	beq+	65f

40:	lbz	r0,4(r4)

	stb	r0,4(r6)

	addi	r4,r4,1

	addi	r6,r6,1

	bdnz	40b

65:	blr



_GLOBAL(memmove)

	cmplw	0,r3,r4

	bgt	backwards_memcpy

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