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 <matthew.brown....@gmail.com>
---
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);
--
2.9.3
