From 20151169f1de4b170368fdb574024027620d0d49 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 18 Dec 2013 09:29:57 +1100 Subject: [PATCH] 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 Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/lib/copyuser_64.S | 53 ++++++++++++++++++++++++---------- 1 file changed, 38 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/lib/copyuser_64.S b/arch/powerpc/lib/copyuser_64.S index d73a59014900..596a285c0755 100644 --- a/arch/powerpc/lib/copyuser_64.S +++ b/arch/powerpc/lib/copyuser_64.S @@ -9,6 +9,14 @@ #include #include +#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 -- GitLab