diff options
| author | Neil Campbell <neilc@linux.vnet.ibm.com> | 2009-12-14 04:08:57 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-12-18 14:55:43 +1100 |
| commit | bb7f20b1c639606def3b91f4e4aca6daeee5d80a (patch) | |
| tree | 9ccfe5acbbb9750ac5aae7048fd86b26cdf90c53 /arch | |
| parent | f04b10cddb0fbceadbad7af38c31543298948d8f (diff) | |
| download | linux-bb7f20b1c639606def3b91f4e4aca6daeee5d80a.tar.bz2 | |
powerpc: Handle VSX alignment faults correctly in little-endian mode
This patch fixes the handling of VSX alignment faults in little-endian
mode (the current code assumes the processor is in big-endian mode).
The patch also makes the handlers clear the top 8 bytes of the register
when handling an 8 byte VSX load.
This is based on 2.6.32.
Signed-off-by: Neil Campbell <neilc@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/align.c | 63 |
1 files changed, 46 insertions, 17 deletions
diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c index 3839839f83c7..b876e989220b 100644 --- a/arch/powerpc/kernel/align.c +++ b/arch/powerpc/kernel/align.c @@ -642,10 +642,14 @@ static int emulate_spe(struct pt_regs *regs, unsigned int reg, */ static int emulate_vsx(unsigned char __user *addr, unsigned int reg, unsigned int areg, struct pt_regs *regs, - unsigned int flags, unsigned int length) + unsigned int flags, unsigned int length, + unsigned int elsize) { char *ptr; + unsigned long *lptr; int ret = 0; + int sw = 0; + int i, j; flush_vsx_to_thread(current); @@ -654,19 +658,35 @@ static int emulate_vsx(unsigned char __user *addr, unsigned int reg, else ptr = (char *) ¤t->thread.vr[reg - 32]; - if (flags & ST) - ret = __copy_to_user(addr, ptr, length); - else { - if (flags & SPLT){ - ret = __copy_from_user(ptr, addr, length); - ptr += length; + lptr = (unsigned long *) ptr; + + if (flags & SW) + sw = elsize-1; + + for (j = 0; j < length; j += elsize) { + for (i = 0; i < elsize; ++i) { + if (flags & ST) + ret |= __put_user(ptr[i^sw], addr + i); + else + ret |= __get_user(ptr[i^sw], addr + i); } - ret |= __copy_from_user(ptr, addr, length); + ptr += elsize; + addr += elsize; } - if (flags & U) - regs->gpr[areg] = regs->dar; - if (ret) + + 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 */ + else if (!(flags & ST) && (8 == length)) + lptr[1] = 0; + } else return -EFAULT; + return 1; } #endif @@ -767,16 +787,25 @@ int fix_alignment(struct pt_regs *regs) #ifdef CONFIG_VSX if ((instruction & 0xfc00003e) == 0x7c000018) { - /* Additional register addressing bit (64 VSX vs 32 FPR/GPR */ + unsigned int elsize; + + /* Additional register addressing bit (64 VSX vs 32 FPR/GPR) */ reg |= (instruction & 0x1) << 5; /* Simple inline decoder instead of a table */ + /* VSX has only 8 and 16 byte memory accesses */ + nb = 8; if (instruction & 0x200) nb = 16; - else if (instruction & 0x080) - nb = 8; - else - nb = 4; + + /* Vector stores in little-endian mode swap individual + elements, so process them separately */ + elsize = 4; + if (instruction & 0x80) + elsize = 8; + flags = 0; + if (regs->msr & MSR_LE) + flags |= SW; if (instruction & 0x100) flags |= ST; if (instruction & 0x040) @@ -787,7 +816,7 @@ int fix_alignment(struct pt_regs *regs) nb = 8; } PPC_WARN_ALIGNMENT(vsx, regs); - return emulate_vsx(addr, reg, areg, regs, flags, nb); + return emulate_vsx(addr, reg, areg, regs, flags, nb, elsize); } #endif /* A size of 0 indicates an instruction we don't support, with |