diff options
| author | Anton Blanchard <anton@samba.org> | 2013-09-23 04:04:50 +0200 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-10-11 07:48:38 +0200 |
| commit | 52055d07ce0a465949552c9c5d65d2b8b37672c5 (patch) | |
| tree | 7421607319a385d64810626693993853a16cc54a /arch/powerpc/kernel/align.c | |
| parent | powerpc: Add little endian support to alignment handler (diff) | |
| download | linux-52055d07ce0a465949552c9c5d65d2b8b37672c5.tar.xz linux-52055d07ce0a465949552c9c5d65d2b8b37672c5.zip | |
powerpc: Handle VSX alignment faults in little endian mode
Things are complicated by the fact that VSX elements are big
endian ordered even in little endian mode. 8 byte loads and
stores also write to the top 8 bytes of the register.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/align.c')
| -rw-r--r-- | arch/powerpc/kernel/align.c | 41 |
1 files changed, 33 insertions, 8 deletions
diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c index cce82b1e0374..59f70adcbcd9 100644 --- a/arch/powerpc/kernel/align.c +++ b/arch/powerpc/kernel/align.c @@ -630,7 +630,7 @@ static int emulate_spe(struct pt_regs *regs, unsigned int reg, } #endif /* CONFIG_SPE */ -#if defined(CONFIG_VSX) && defined(__BIG_ENDIAN__) +#ifdef CONFIG_VSX /* * Emulate VSX instructions... */ @@ -658,8 +658,25 @@ static int emulate_vsx(unsigned char __user *addr, unsigned int reg, lptr = (unsigned long *) ptr; +#ifdef __LITTLE_ENDIAN__ + if (flags & SW) { + elsize = length; + sw = length-1; + } else { + /* + * The elements are BE ordered, even in LE mode, so process + * them in reverse order. + */ + addr += length - elsize; + + /* 8 byte memory accesses go in the top 8 bytes of the VR */ + if (length == 8) + ptr += 8; + } +#else if (flags & SW) sw = elsize-1; +#endif for (j = 0; j < length; j += elsize) { for (i = 0; i < elsize; ++i) { @@ -669,19 +686,31 @@ static int emulate_vsx(unsigned char __user *addr, unsigned int reg, ret |= __get_user(ptr[i^sw], addr + i); } ptr += elsize; +#ifdef __LITTLE_ENDIAN__ + addr -= elsize; +#else addr += elsize; +#endif } +#ifdef __BIG_ENDIAN__ +#define VSX_HI 0 +#define VSX_LO 1 +#else +#define VSX_HI 1 +#define VSX_LO 0 +#endif + if (!ret) { if (flags & U) regs->gpr[areg] = regs->dar; /* Splat load copies the same data to top and bottom 8 bytes */ if (flags & SPLT) - lptr[1] = lptr[0]; - /* For 8 byte loads, zero the top 8 bytes */ + lptr[VSX_LO] = lptr[VSX_HI]; + /* For 8 byte loads, zero the low 8 bytes */ else if (!(flags & ST) && (8 == length)) - lptr[1] = 0; + lptr[VSX_LO] = 0; } else return -EFAULT; @@ -805,7 +834,6 @@ int fix_alignment(struct pt_regs *regs) /* DAR has the operand effective address */ addr = (unsigned char __user *)regs->dar; -#ifdef __BIG_ENDIAN__ #ifdef CONFIG_VSX if ((instruction & 0xfc00003e) == 0x7c000018) { unsigned int elsize; @@ -840,9 +868,6 @@ int fix_alignment(struct pt_regs *regs) return emulate_vsx(addr, reg, areg, regs, flags, nb, elsize); } #endif -#else - return -EFAULT; -#endif /* A size of 0 indicates an instruction we don't support, with * the exception of DCBZ which is handled as a special case here */ |