Commit 02c0f62a authored by Matt Brown's avatar Matt Brown Committed by Michael Ellerman

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: default avatarMatt Brown <matthew.brown.dev@gmail.com>
Reviewed-by: default avatarCyril Bur <cyrilbur@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 93fc5ca9
...@@ -596,6 +596,22 @@ static nokprobe_inline void do_cmp_unsigned(struct pt_regs *regs, unsigned long ...@@ -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); 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) static nokprobe_inline int trap_compare(long v1, long v2)
{ {
int ret = 0; int ret = 0;
...@@ -1064,6 +1080,10 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, ...@@ -1064,6 +1080,10 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
do_cmp_unsigned(regs, val, val2, rd >> 2); do_cmp_unsigned(regs, val, val2, rd >> 2);
goto instr_done; goto instr_done;
case 508: /* cmpb */
do_cmpb(regs, regs->gpr[rd], regs->gpr[rb], ra);
goto instr_done;
/* /*
* Arithmetic instructions * Arithmetic instructions
*/ */
......
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