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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2013-12-18 09:29:57 +1100 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-12-30 14:02:30 +1100 |
| commit | 20151169f1de4b170368fdb574024027620d0d49 (patch) | |
| tree | 4606638e96a390c82d602fd5df00cd193890bf20 | |
| parent | e8a00ad5e238421ded856ea39f692b94c2d324eb (diff) | |
| download | linux-xtensa-20151169f1de4b170368fdb574024027620d0d49.tar.gz | |
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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| -rw-r--r-- | arch/powerpc/lib/copyuser_64.S | 53 |
1 files changed, 38 insertions, 15 deletions
diff --git a/arch/powerpc/lib/copyuser_64.S b/arch/powerpc/lib/copyuser_64.S index d73a5901490018..596a285c07554d 100644 --- a/arch/powerpc/lib/copyuser_64.S +++ b/arch/powerpc/lib/copyuser_64.S @@ -9,6 +9,14 @@ #include <asm/processor.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 _GLOBAL(__copy_tofrom_user) 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 */ 25: ld r0,8(r4) - sld r6,r9,r10 + sLd r6,r9,r10 26: ldu r9,16(r4) - srd r7,r0,r11 - sld r8,r0,r10 + sHd r7,r0,r11 + sLd r8,r0,r10 or r7,r7,r6 blt cr6,79f 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 */ 29: ldu r9,8(r4) - sld r8,r0,r10 + sLd r8,r0,r10 addi r3,r3,-8 blt cr6,5f 30: ld r0,8(r4) - srd r12,r9,r11 - sld r6,r9,r10 + sHd r12,r9,r11 + sLd r6,r9,r10 31: ldu r9,16(r4) or r12,r8,r12 - srd r7,r0,r11 - sld r8,r0,r10 + sHd r7,r0,r11 + sLd r8,r0,r10 addi r3,r3,16 beq cr6,78f 1: or r7,r7,r6 32: ld r0,8(r4) 76: std r12,8(r3) -2: srd r12,r9,r11 - sld r6,r9,r10 +2: sHd r12,r9,r11 + sLd r6,r9,r10 33: ldu r9,16(r4) or r12,r8,r12 77: stdu r7,16(r3) - srd r7,r0,r11 - sld r8,r0,r10 + sHd r7,r0,r11 + sLd r8,r0,r10 bdnz 1b 78: std r12,8(r3) or r7,r7,r6 79: std r7,16(r3) -5: srd r12,r9,r11 +5: sHd r12,r9,r11 or r12,r8,r12 80: std r12,24(r3) bne 6f @@ -165,23 +173,38 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) blr 6: cmpwi cr1,r5,8 addi r3,r3,32 - sld r9,r9,r10 + sLd r9,r9,r10 ble cr1,7f 34: ld r0,8(r4) - srd r7,r0,r11 + sHd r7,r0,r11 or r9,r7,r9 7: bf cr7*4+1,1f +#ifdef __BIG_ENDIAN__ rotldi r9,r9,32 +#endif 94: stw r9,0(r3) +#ifdef __LITTLE_ENDIAN__ + rotrdi r9,r9,32 +#endif addi r3,r3,4 1: bf cr7*4+2,2f +#ifdef __BIG_ENDIAN__ rotldi r9,r9,16 +#endif 95: sth r9,0(r3) +#ifdef __LITTLE_ENDIAN__ + rotrdi r9,r9,16 +#endif addi r3,r3,2 2: bf cr7*4+3,3f +#ifdef __BIG_ENDIAN__ rotldi r9,r9,8 +#endif 96: stb r9,0(r3) +#ifdef __LITTLE_ENDIAN__ + rotrdi r9,r9,8 +#endif 3: li r3,0 blr |