powerpc/lib/sstep: Add prty instruction emulation

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.dev@gmail.com>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 09dc05446717be4b4afc3587ef9a6e4cd2263464..a2ded89db73e7a7a42481842062f6b0f7d62971c 100644 (file)
--- 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)
 {
@@ -1262,6 +1280,14 @@ 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);