[PATCH 4/5] powerpc/lib/sstep: Add prty instruction emulation

[Matt Brown]

This add emulation for the prtyw and prtyd instructions.

Signed-off-by: Matt Brown <matthew.brown.dev at gmail.com>
---
 arch/powerpc/lib/sstep.c | 58 +++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 52 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 603654d..3228783 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -652,6 +652,42 @@ static nokprobe_inline void do_bpermd(struct pt_regs *regs, unsigned long v1,
 	regs->gpr[ra] = 0 | perm;
 }
 
+static nokprobe_inline void do_prtyw(struct pt_regs *regs, unsigned long v,
+				int ra)
+{
+	unsigned long low, high, out;
+	unsigned int i;
+
+	high = 0;
+	low = 0;
+	out = 0;
+
+	for (i = 0; i < 8; i++) {
+		if (v & (1 << (i * 8)))
+			(i < 4) ? (low++) : (high++);
+	}
+
+	if (low % 2)
+		out |= low;
+	if (high % 2)
+		out |= (high << 32);
+
+	regs->gpr[ra] = out;
+}
+
+static nokprobe_inline void do_prtyd(struct pt_regs *regs, unsigned long v,
+				int ra)
+{
+	unsigned int count, i;
+
+	count = 0;
+	for (i = 0; i < 8; i++) {
+		if (v & (1 << (i * 8)))
+			count++;
+	}
+	regs->gpr[ra] = count % 2;
+}
+
 static nokprobe_inline int trap_compare(long v1, long v2)
 {
 	int ret = 0;
@@ -1278,16 +1314,15 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 			do_popcnt(regs, val, 8, ra);
 			goto logical_done;
 
-		case 17076744:	/* popcntw */
+		case 2101768:	/* prtyw */
 			val = regs->gpr[rd];
-			do_popcnt(regs, val, 32, ra);
+			do_prtyw(regs, val, ra);
 			goto logical_done;
-#ifdef __powerpc64__
-		case 19173896:	/* popcntd */
+
+		case 2134536:	/* prtyd */
 			val = regs->gpr[rd];
-			do_popcnt(regs, val, 64, ra);
+			do_prtyd(regs, val, ra);
 			goto logical_done;
-#endif
 
 #ifdef __powerpc64__
 		case 2396736:	/* bpermd */
@@ -1297,6 +1332,17 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 			goto logical_done;
 #endif
 
+		case 17076744:	/* popcntw */
+			val = regs->gpr[rd];
+			do_popcnt(regs, val, 32, ra);
+			goto logical_done;
+#ifdef __powerpc64__
+		case 19173896:	/* popcntd */
+			val = regs->gpr[rd];
+			do_popcnt(regs, val, 64, ra);
+			goto logical_done;
+#endif
+
 /*
  * Shift instructions
  */
-- 
2.9.3