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Commit 20151169 authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Benjamin Herrenschmidt
Browse files

powerpc: Make 64-bit non-VMX __copy_tofrom_user bi-endian 



The powerpc 64-bit __copy_tofrom_user() function uses shifts to handle
unaligned invocations.  However, these shifts were designed for
big-endian systems: On little-endian systems, they must shift in the
opposite direction.

This commit relies on the C preprocessor to insert the correct shifts
into the assembly code.

[ This is a rare but nasty LE issue. Most of the time we use the POWER7
optimised __copy_tofrom_user_power7 loop, but when it hits an exception
we fall back to the base __copy_tofrom_user loop. - Anton ]

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent e8a00ad5

arch/powerpc/lib/copyuser_64.S

+38 −15
Original line number Original line Diff line number Diff line
@@ -9,6 +9,14 @@ 
#include <asm/processor.h>

#include <asm/processor.h>

#include <asm/ppc_asm.h>

#include <asm/ppc_asm.h>





#ifdef __BIG_ENDIAN__

#define sLd sld		/* Shift towards low-numbered address. */

#define sHd srd		/* Shift towards high-numbered address. */

#else

#define sLd srd		/* Shift towards low-numbered address. */

#define sHd sld		/* Shift towards high-numbered address. */

#endif



	.align	7

	.align	7

_GLOBAL(__copy_tofrom_user)

_GLOBAL(__copy_tofrom_user)

BEGIN_FTR_SECTION

BEGIN_FTR_SECTION
@@ -118,10 +126,10 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) 




24:	ld	r9,0(r4)	/* 3+2n loads, 2+2n stores */

24:	ld	r9,0(r4)	/* 3+2n loads, 2+2n stores */

25:	ld	r0,8(r4)

25:	ld	r0,8(r4)

	sld	r6,r9,r10

	sLd	r6,r9,r10

26:	ldu	r9,16(r4)

26:	ldu	r9,16(r4)

	srd	r7,r0,r11

	sHd	r7,r0,r11

	sld	r8,r0,r10

	sLd	r8,r0,r10

	or	r7,r7,r6

	or	r7,r7,r6

	blt	cr6,79f

	blt	cr6,79f

27:	ld	r0,8(r4)

27:	ld	r0,8(r4)
@@ -129,35 +137,35 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) 




28:	ld	r0,0(r4)	/* 4+2n loads, 3+2n stores */

28:	ld	r0,0(r4)	/* 4+2n loads, 3+2n stores */

29:	ldu	r9,8(r4)

29:	ldu	r9,8(r4)

	sld	r8,r0,r10

	sLd	r8,r0,r10

	addi	r3,r3,-8

	addi	r3,r3,-8

	blt	cr6,5f

	blt	cr6,5f

30:	ld	r0,8(r4)

30:	ld	r0,8(r4)

	srd	r12,r9,r11

	sHd	r12,r9,r11

	sld	r6,r9,r10

	sLd	r6,r9,r10

31:	ldu	r9,16(r4)

31:	ldu	r9,16(r4)

	or	r12,r8,r12

	or	r12,r8,r12

	srd	r7,r0,r11

	sHd	r7,r0,r11

	sld	r8,r0,r10

	sLd	r8,r0,r10

	addi	r3,r3,16

	addi	r3,r3,16

	beq	cr6,78f

	beq	cr6,78f





1:	or	r7,r7,r6

1:	or	r7,r7,r6

32:	ld	r0,8(r4)

32:	ld	r0,8(r4)

76:	std	r12,8(r3)

76:	std	r12,8(r3)

2:	srd	r12,r9,r11

2:	sHd	r12,r9,r11

	sld	r6,r9,r10

	sLd	r6,r9,r10

33:	ldu	r9,16(r4)

33:	ldu	r9,16(r4)

	or	r12,r8,r12

	or	r12,r8,r12

77:	stdu	r7,16(r3)

77:	stdu	r7,16(r3)

	srd	r7,r0,r11

	sHd	r7,r0,r11

	sld	r8,r0,r10

	sLd	r8,r0,r10

	bdnz	1b

	bdnz	1b





78:	std	r12,8(r3)

78:	std	r12,8(r3)

	or	r7,r7,r6

	or	r7,r7,r6

79:	std	r7,16(r3)

79:	std	r7,16(r3)

5:	srd	r12,r9,r11

5:	sHd	r12,r9,r11

	or	r12,r8,r12

	or	r12,r8,r12

80:	std	r12,24(r3)

80:	std	r12,24(r3)

	bne	6f

	bne	6f
@@ -165,23 +173,38 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) 
	blr

	blr

6:	cmpwi	cr1,r5,8

6:	cmpwi	cr1,r5,8

	addi	r3,r3,32

	addi	r3,r3,32

	sld	r9,r9,r10

	sLd	r9,r9,r10

	ble	cr1,7f

	ble	cr1,7f

34:	ld	r0,8(r4)

34:	ld	r0,8(r4)

	srd	r7,r0,r11

	sHd	r7,r0,r11

	or	r9,r7,r9

	or	r9,r7,r9

7:

7:

	bf	cr7*4+1,1f

	bf	cr7*4+1,1f

#ifdef __BIG_ENDIAN__

	rotldi	r9,r9,32

	rotldi	r9,r9,32

#endif

94:	stw	r9,0(r3)

94:	stw	r9,0(r3)

#ifdef __LITTLE_ENDIAN__

	rotrdi	r9,r9,32

#endif

	addi	r3,r3,4

	addi	r3,r3,4

1:	bf	cr7*4+2,2f

1:	bf	cr7*4+2,2f

#ifdef __BIG_ENDIAN__

	rotldi	r9,r9,16

	rotldi	r9,r9,16

#endif

95:	sth	r9,0(r3)

95:	sth	r9,0(r3)

#ifdef __LITTLE_ENDIAN__

	rotrdi	r9,r9,16

#endif

	addi	r3,r3,2

	addi	r3,r3,2

2:	bf	cr7*4+3,3f

2:	bf	cr7*4+3,3f

#ifdef __BIG_ENDIAN__

	rotldi	r9,r9,8

	rotldi	r9,r9,8

#endif

96:	stb	r9,0(r3)

96:	stb	r9,0(r3)

#ifdef __LITTLE_ENDIAN__

	rotrdi	r9,r9,8

#endif

3:	li	r3,0

3:	li	r3,0

	blr

	blr