diff options
| author | Michael Neuling <mikey@neuling.org> | 2008-07-11 16:31:09 +1000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2008-07-15 12:29:25 +1000 |
| commit | cd6f37be7fdc9fea407379745350f6630b9d3cdd (patch) | |
| tree | ca8c813d84c6db6ba6052a42c0fb4e8aff411422 /arch/powerpc | |
| parent | 7c29217096d83f657e6ee70479af09b46f4275f6 (diff) | |
powerpc: Add VSX load/store alignment exception handler
VSX loads and stores will take an alignment exception when the address
is not on a 4 byte boundary.
This add support for these alignment exceptions and will emulate the
requested load or store.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/align.c | 58 |
1 files changed, 57 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c index f22b5d0a4a9..367129789cc 100644 --- a/arch/powerpc/kernel/align.c +++ b/arch/powerpc/kernel/align.c @@ -48,6 +48,7 @@ struct aligninfo { #define HARD 0x80 /* string, stwcx. */ #define E4 0x40 /* SPE endianness is word */ #define E8 0x80 /* SPE endianness is double word */ +#define SPLT 0x80 /* VSX SPLAT load */ /* DSISR bits reported for a DCBZ instruction: */ #define DCBZ 0x5f /* 8xx/82xx dcbz faults when cache not enabled */ @@ -637,6 +638,36 @@ static int emulate_spe(struct pt_regs *regs, unsigned int reg, } #endif /* CONFIG_SPE */ +#ifdef CONFIG_VSX +/* + * Emulate VSX instructions... + */ +static int emulate_vsx(unsigned char __user *addr, unsigned int reg, + unsigned int areg, struct pt_regs *regs, + unsigned int flags, unsigned int length) +{ + char *ptr = (char *) ¤t->thread.TS_FPR(reg); + int ret; + + flush_vsx_to_thread(current); + + if (flags & ST) + ret = __copy_to_user(addr, ptr, length); + else { + if (flags & SPLT){ + ret = __copy_from_user(ptr, addr, length); + ptr += length; + } + ret |= __copy_from_user(ptr, addr, length); + } + if (flags & U) + regs->gpr[areg] = regs->dar; + if (ret) + return -EFAULT; + return 1; +} +#endif + /* * Called on alignment exception. Attempts to fixup * @@ -647,7 +678,7 @@ static int emulate_spe(struct pt_regs *regs, unsigned int reg, int fix_alignment(struct pt_regs *regs) { - unsigned int instr, nb, flags; + unsigned int instr, nb, flags, instruction = 0; unsigned int reg, areg; unsigned int dsisr; unsigned char __user *addr; @@ -689,6 +720,7 @@ int fix_alignment(struct pt_regs *regs) if (cpu_has_feature(CPU_FTR_REAL_LE) && (regs->msr & MSR_LE)) instr = cpu_to_le32(instr); dsisr = make_dsisr(instr); + instruction = instr; } /* extract the operation and registers from the dsisr */ @@ -728,6 +760,30 @@ int fix_alignment(struct pt_regs *regs) /* DAR has the operand effective address */ addr = (unsigned char __user *)regs->dar; +#ifdef CONFIG_VSX + if ((instruction & 0xfc00003e) == 0x7c000018) { + /* Additional register addressing bit (64 VSX vs 32 FPR/GPR */ + reg |= (instruction & 0x1) << 5; + /* Simple inline decoder instead of a table */ + if (instruction & 0x200) + nb = 16; + else if (instruction & 0x080) + nb = 8; + else + nb = 4; + flags = 0; + if (instruction & 0x100) + flags |= ST; + if (instruction & 0x040) + flags |= U; + /* splat load needs a special decoder */ + if ((instruction & 0x400) == 0){ + flags |= SPLT; + nb = 8; + } + return emulate_vsx(addr, reg, areg, regs, flags, nb); + } +#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 */ |