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| author | Matt Brown <matthew.brown.dev@gmail.com> | 2017-07-31 03:58:22 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-08-10 15:30:26 +0300 |
| commit | 02c0f62a60b67d6c9bfe9429cbe3aa034b6c6676 (patch) | |
| tree | 7272ef26038662808e496080338d5813ddb3c7dd | |
| parent | 93fc5ca9a0048c17b47582051940bfdcb516f9f2 (diff) | |
| download | linux-02c0f62a60b67d6c9bfe9429cbe3aa034b6c6676.tar.xz | |
powerpc/lib/sstep: Add cmpb instruction emulation
This patch adds emulation of the cmpb instruction, enabling xmon to
emulate this instruction.
Tested for correctness against the cmpb asm instruction on ppc64le.
Signed-off-by: Matt Brown <matthew.brown.dev@gmail.com>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/lib/sstep.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index ee33327686ae..cc6327b8f589 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -596,6 +596,22 @@ static nokprobe_inline void do_cmp_unsigned(struct pt_regs *regs, unsigned long regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift); } +static nokprobe_inline void do_cmpb(struct pt_regs *regs, unsigned long v1, + unsigned long v2, int rd) +{ + unsigned long long out_val, mask; + int i; + + out_val = 0; + for (i = 0; i < 8; i++) { + mask = 0xffUL << (i * 8); + if ((v1 & mask) == (v2 & mask)) + out_val |= mask; + } + + regs->gpr[rd] = out_val; +} + static nokprobe_inline int trap_compare(long v1, long v2) { int ret = 0; @@ -1064,6 +1080,10 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, do_cmp_unsigned(regs, val, val2, rd >> 2); goto instr_done; + case 508: /* cmpb */ + do_cmpb(regs, regs->gpr[rd], regs->gpr[rb], ra); + goto instr_done; + /* * Arithmetic instructions */ |