[PATCH v3 3/5] powerpc/lib/sstep: Add bpermd instruction emulation

[Matt Brown]

This adds emulation for the bpermd instruction.
Tested for correctness against the bpermd instruction on ppc64le.

Signed-off-by: Matt Brown <matthew.brown....@gmail.com>
---
v2:
        - fixed opcode
        - added ifdef tags to do_bpermd func
        - fixed bitshifting errors
---
 arch/powerpc/lib/sstep.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index c1f9cdb..6a79618 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -638,6 +638,24 @@ static nokprobe_inline void do_popcnt(struct pt_regs 
*regs, unsigned long v1,
        regs->gpr[ra] = out;    /* popcntd */
 }
 
+#ifdef __powerpc64__
+static nokprobe_inline void do_bpermd(struct pt_regs *regs, unsigned long v1,
+                               unsigned long v2, int ra)
+{
+       unsigned char perm, idx;
+       unsigned int i;
+
+       perm = 0;
+       for (i = 0; i < 8; i++) {
+               idx = (v1 >> (i * 8)) & 0xff;
+               if (idx < 64)
+                       if (v2 & PPC_BIT(idx))
+                               perm |= 1 << i;
+       }
+       regs->gpr[ra] = perm;
+}
+#endif /* __powerpc64__ */
+
 static nokprobe_inline int trap_compare(long v1, long v2)
 {
        int ret = 0;
@@ -1227,7 +1245,11 @@ 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;
-
+#ifdef __powerpc64__
+               case 252:       /* bpermd */
+                       do_bpermd(regs, regs->gpr[rd], regs->gpr[rb], ra);
+                       goto logical_done;
+#endif
                case 284:       /* xor */
                        regs->gpr[ra] = ~(regs->gpr[rd] ^ regs->gpr[rb]);
                        goto logical_done;
-- 
2.9.3