Re: [PATCH v4 4/5] powerpc/lib/sstep: Add prty instruction emulation
From: Cyril Bur <hidden>
Date: 2017-07-31 03:55:49
On Mon, 2017-07-31 at 10:58 +1000, Matt Brown wrote:
This adds emulation for the prtyw and prtyd instructions. Tested for logical correctness against the prtyw and prtyd instructions on ppc64le. Signed-off-by: Matt Brown <redacted>
Reviewed-by: Cyril Bur <redacted>
quoted hunk ↗ jump to hunk
--- v4: - use simpler xor method v3: - optimised using the Giles-Miller method of side-ways addition v2: - fixed opcodes - fixed bitshifting and typecast errors - merged do_prtyw and do_prtyd into single function --- arch/powerpc/lib/sstep.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index c9fd613..af4eef9 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c@@ -657,6 +657,24 @@ static nokprobe_inline void do_bpermd(struct pt_regs *regs, unsigned long v1, regs->gpr[ra] = perm; } #endif /* CONFIG_PPC64 */ +/* + * The size parameter adjusts the equivalent prty instruction. + * prtyw = 32, prtyd = 64 + */ +static nokprobe_inline void do_prty(struct pt_regs *regs, unsigned long v, + int size, int ra) +{ + unsigned long long res = v ^ (v >> 8); + + res ^= res >> 16; + if (size == 32) { /* prtyw */ + regs->gpr[ra] = res & 0x0000000100000001; + return; + } + + res ^= res >> 32; + regs->gpr[ra] = res & 1; /*prtyd */ +} static nokprobe_inline int trap_compare(long v1, long v2) {@@ -1247,6 +1265,14 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, case 124: /* nor */ regs->gpr[ra] = ~(regs->gpr[rd] | regs->gpr[rb]); goto logical_done; + + case 154: /* prtyw */ + do_prty(regs, regs->gpr[rd], 32, ra); + goto logical_done; + + case 186: /* prtyd */ + do_prty(regs, regs->gpr[rd], 64, ra); + goto logical_done; #ifdef CONFIG_PPC64 case 252: /* bpermd */ do_bpermd(regs, regs->gpr[rd], regs->gpr[rb], ra);