powerpc/lib/sstep: Add cmpb instruction emulation

PATCH In review Matt Brown 4 participants 13 messages Jul 31, 2017 – Aug 11, 2017 PowerPC

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Matt Brown

author

2017-07-31 00:58 UTC #0 lore raw

PATCH v4 1/5 powerpc/lib/sstep: Add cmpb instruction emulation

This patch adds emulation of the cmpb instruction, enabling xmon to emulate this instruction.
Tested for correctness against the cmpb asm instruction on ppc64le.

Signed-off-by Matt Brown <[email protected]>

---
v2:
- fixed opcode
- fixed mask typecasting

---
 arch/powerpc/lib/sstep.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

arch/powerpc/lib/sstep.c +20 -0

index 33117f8..87d277f 100644
@@ -596,6 +596,22 @@ static nokprobe_inline void do_cmp_unsigned(struct pt_regs *regs, unsigned long
 	regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
 }
 
+static nokprobe_inline void do_cmpb(struct pt_regs *regs, unsigned long v1,
+				unsigned long v2, int rd)
+{
+	unsigned long long out_val, mask;
+	int i;
+
+	out_val = 0;
+	for (i = 0; i < 8; i++) {
+		mask = 0xffUL << (i * 8);
+		if ((v1 & mask) == (v2 & mask))
+			out_val |= mask;
+	}
+
+	regs->gpr[rd] = out_val;
+}
+
 static nokprobe_inline int trap_compare(long v1, long v2)
 {
 	int ret = 0;

@@ -1049,6 +1065,10 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 			do_cmp_unsigned(regs, val, val2, rd >> 2);
 			goto instr_done;
 
+		case 508: /* cmpb */
+			do_cmpb(regs, regs->gpr[rd], regs->gpr[rb], ra);
+			goto instr_done;
+
 /*
  * Arithmetic instructions
  */

Signature · 1 line

2.9.3

Matt Brown

author

2017-07-31 00:58 UTC #1 lore raw

PATCH v4 2/5 powerpc/lib/sstep: Add popcnt instruction emulation

This adds emulations for the popcntb, popcntw, and popcntd instructions. Tested for correctness against the popcnt{b,w,d} instructions on ppc64le.

Signed-off-by Matt Brown <[email protected]>

---
v4:
- change ifdef macro from __powerpc64__ to CONFIG_PPC64
- slight optimisations
(now identical to the popcntb implementation in kernel/traps.c)
v3:
- optimised using the Giles-Miller method of side-ways addition
v2:
- fixed opcodes
- fixed typecasting
- fixed bitshifting error for both 32 and 64bit arch

---
 arch/powerpc/lib/sstep.c | 42 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

arch/powerpc/lib/sstep.c +41 -1

index 87d277f..2fd7377 100644
@@ -612,6 +612,34 @@ static nokprobe_inline void do_cmpb(struct pt_regs *regs, unsigned long v1,
 	regs->gpr[rd] = out_val;
 }
 
+/*
+ * The size parameter is used to adjust the equivalent popcnt instruction.
+ * popcntb = 8, popcntw = 32, popcntd = 64
+ */
+static nokprobe_inline void do_popcnt(struct pt_regs *regs, unsigned long v1,
+				int size, int ra)
+{
+	unsigned long long out = v1;
+
+	out -= (out >> 1) & 0x5555555555555555;
+	out = (0x3333333333333333 & out) + (0x3333333333333333 & (out >> 2));
+	out = (out + (out >> 4)) & 0x0f0f0f0f0f0f0f0f;
+
+	if (size == 8) {	/* popcntb */
+		regs->gpr[ra] = out;
+		return;
+	}
+	out += out >> 8;
+	out += out >> 16;
+	if (size == 32) {	/* popcntw */
+		regs->gpr[ra] = out & 0x0000003f0000003f;
+		return;
+	}
+
+	out = (out + (out >> 32)) & 0x7f;
+	regs->gpr[ra] = out;	/* popcntd */
+}
+
 static nokprobe_inline int trap_compare(long v1, long v2)
 {
 	int ret = 0;

@@ -1194,6 +1222,10 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 			regs->gpr[ra] = regs->gpr[rd] & ~regs->gpr[rb];
 			goto logical_done;
 
+		case 122:	/* popcntb */
+			do_popcnt(regs, regs->gpr[rd], 8, ra);
+			goto logical_done;
+
 		case 124:	/* nor */
 			regs->gpr[ra] = ~(regs->gpr[rd] | regs->gpr[rb]);
 			goto logical_done;

@@ -1206,6 +1238,10 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 			regs->gpr[ra] = regs->gpr[rd] ^ regs->gpr[rb];
 			goto logical_done;
 
+		case 378:	/* popcntw */
+			do_popcnt(regs, regs->gpr[rd], 32, ra);
+			goto logical_done;
+
 		case 412:	/* orc */
 			regs->gpr[ra] = regs->gpr[rd] | ~regs->gpr[rb];
 			goto logical_done;

@@ -1217,7 +1253,11 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 		case 476:	/* nand */
 			regs->gpr[ra] = ~(regs->gpr[rd] & regs->gpr[rb]);
 			goto logical_done;
-
+#ifdef CONFIG_PPC64
+		case 506:	/* popcntd */
+			do_popcnt(regs, regs->gpr[rd], 64, ra);
+			goto logical_done;
+#endif
 		case 922:	/* extsh */
 			regs->gpr[ra] = (signed short) regs->gpr[rd];
 			goto logical_done;

Signature · 1 line

2.9.3

Matt Brown

author

2017-07-31 00:59 UTC #3 lore raw

PATCH v4 3/5 powerpc/lib/sstep: Add bpermd instruction emulation

In reply to Matt Brown

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

Signed-off-by Matt Brown <[email protected]>

---
v4:
- change ifdef macro from __powerpc64__ to CONFIG_PPC64
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(-)

arch/powerpc/lib/sstep.c +23 -1

index 2fd7377..c9fd613 100644
@@ -640,6 +640,24 @@ static nokprobe_inline void do_popcnt(struct pt_regs *regs, unsigned long v1,
 	regs->gpr[ra] = out;	/* popcntd */
 }
 
+#ifdef CONFIG_PPC64
+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 /* CONFIG_PPC64 */
+
 static nokprobe_inline int trap_compare(long v1, long v2)
 {
 	int ret = 0;

@@ -1229,7 +1247,11 @@ 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 CONFIG_PPC64
+		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;

Signature · 1 line

2.9.3

Matt Brown

author

2017-07-31 00:59 UTC #5 lore raw

PATCH v4 4/5 powerpc/lib/sstep: Add prty instruction emulation

In reply to Matt Brown

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 <[email protected]>

---
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(+)

arch/powerpc/lib/sstep.c +26 -0

index c9fd613..af4eef9 100644
@@ -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);

Signature · 1 line

2.9.3

Matt Brown

author

2017-07-31 00:59 UTC #7 lore raw

PATCH v4 5/5 powerpc/lib/sstep: Add isel instruction emulation

In reply to Matt Brown

This adds emulation for the isel instruction.
Tested for correctness against the isel instruction and its extended mnemonics (lt, gt, eq) on ppc64le.

Signed-off-by Matt Brown <[email protected]>

---
v4:
- simplify if statement to ternary op
(same as isel emulation in kernel/traps.c)
v2:
- fixed opcode
- fixed definition to include the 'if RA=0, a=0' clause
- fixed ccr bitshifting error

---
 arch/powerpc/lib/sstep.c | 8 ++++++++
 1 file changed, 8 insertions(+)

arch/powerpc/lib/sstep.c +8 -0

index af4eef9..473bab5 100644
@@ -1240,6 +1240,14 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 /*
  * Logical instructions
  */
+		case 15:	/* isel */
+			mb = (instr >> 6) & 0x1f; /* bc */
+			val = (regs->ccr >> (31 - mb)) & 1;
+			val2 = (ra) ? regs->gpr[ra] : 0;
+
+			regs->gpr[rd] = (val) ? val2 : regs->gpr[rb];
+			goto logical_done;
+
 		case 26:	/* cntlzw */
 			asm("cntlzw %0,%1" : "=r" (regs->gpr[ra]) :
 			    "r" (regs->gpr[rd]));

Signature · 1 line

2.9.3

Cyril Bur

Reviewed-by on v4 1/5

2017-07-31 01:42 UTC #9 lore raw

In reply to Matt Brown

Quoted 5 lines · Matt Brown

This patch adds emulation of the cmpb instruction, enabling xmon to emulate this instruction.
Tested for correctness against the cmpb asm instruction on ppc64le.
Signed-off-by Matt Brown <[email protected]>

Reviewed-by Cyril Bur <[email protected]>

Quoted 46 lines

---
v2:
- fixed opcode
- fixed mask typecasting

---
 arch/powerpc/lib/sstep.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

arch/powerpc/lib/sstep.c +20 -0

index 33117f8..87d277f 100644
@@ -596,6 +596,22 @@ static nokprobe_inline void do_cmp_unsigned(struct pt_regs *regs, unsigned long
 	regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
 }
 
+static nokprobe_inline void do_cmpb(struct pt_regs *regs, unsigned long v1,
+				unsigned long v2, int rd)
+{
+	unsigned long long out_val, mask;
+	int i;
+
+	out_val = 0;
+	for (i = 0; i < 8; i++) {
+		mask = 0xffUL << (i * 8);
+		if ((v1 & mask) == (v2 & mask))
+			out_val |= mask;
+	}
+
+	regs->gpr[rd] = out_val;
+}
+
 static nokprobe_inline int trap_compare(long v1, long v2)
 {
 	int ret = 0;

@@ -1049,6 +1065,10 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 			do_cmp_unsigned(regs, val, val2, rd >> 2);
 			goto instr_done;
 
+		case 508: /* cmpb */
+			do_cmpb(regs, regs->gpr[rd], regs->gpr[rb], ra);
+			goto instr_done;
+
 /*
  * Arithmetic instructions
  */

Cyril Bur

Reviewed-by on v4 3/5

2017-07-31 03:42 UTC #4 lore raw

Re: [PATCH v4 3/5] powerpc/lib/sstep: Add bpermd instruction emulation

In reply to Matt Brown

Quoted 4 lines · Matt Brown

This adds emulation for the bpermd instruction.
Tested for correctness against the bpermd instruction on ppc64le.
Signed-off-by Matt Brown <[email protected]>

Reviewed-by Cyril Bur <[email protected]>

Quoted 53 lines

---
v4:
- change ifdef macro from __powerpc64__ to CONFIG_PPC64
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(-)

arch/powerpc/lib/sstep.c +23 -1

index 2fd7377..c9fd613 100644
@@ -640,6 +640,24 @@ static nokprobe_inline void do_popcnt(struct pt_regs *regs, unsigned long v1,
 	regs->gpr[ra] = out;	/* popcntd */
 }
 
+#ifdef CONFIG_PPC64
+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 /* CONFIG_PPC64 */
+
 static nokprobe_inline int trap_compare(long v1, long v2)
 {
 	int ret = 0;

@@ -1229,7 +1247,11 @@ 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 CONFIG_PPC64
+		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;

Cyril Bur

Reviewed-by on v4 4/5

2017-07-31 03:55 UTC #6 lore raw

Re: [PATCH v4 4/5] powerpc/lib/sstep: Add prty instruction emulation

In reply to Matt Brown

Quoted 5 lines · Matt Brown

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 <[email protected]>

Reviewed-by Cyril Bur <[email protected]>

Quoted 57 lines

---
 arch/powerpc/lib/sstep.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

arch/powerpc/lib/sstep.c +26 -0

index c9fd613..af4eef9 100644
@@ -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);

Cyril Bur

Reviewed-by on v4 5/5

2017-07-31 04:11 UTC #8 lore raw

Re: [PATCH v4 5/5] powerpc/lib/sstep: Add isel instruction emulation

In reply to Matt Brown

Quoted 5 lines · Matt Brown

This adds emulation for the isel instruction.
Tested for correctness against the isel instruction and its extended mnemonics (lt, gt, eq) on ppc64le.
Signed-off-by Matt Brown <[email protected]>

Reviewed-by Cyril Bur <[email protected]>

Quoted 31 lines

---
v4:
- simplify if statement to ternary op
(same as isel emulation in kernel/traps.c)
v2:
- fixed opcode
- fixed definition to include the 'if RA=0, a=0' clause
- fixed ccr bitshifting error

---
 arch/powerpc/lib/sstep.c | 8 ++++++++
 1 file changed, 8 insertions(+)

arch/powerpc/lib/sstep.c +8 -0

index af4eef9..473bab5 100644
@@ -1240,6 +1240,14 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 /*
  * Logical instructions
  */
+		case 15:	/* isel */
+			mb = (instr >> 6) & 0x1f; /* bc */
+			val = (regs->ccr >> (31 - mb)) & 1;
+			val2 = (ra) ? regs->gpr[ra] : 0;
+
+			regs->gpr[rd] = (val) ? val2 : regs->gpr[rb];
+			goto logical_done;
+
 		case 26:	/* cntlzw */
 			asm("cntlzw %0,%1" : "=r" (regs->gpr[ra]) :
 			    "r" (regs->gpr[rd]));

Cyril Bur

Reviewed-by on v4 2/5

2017-07-31 04:15 UTC #2 lore raw

Re: [PATCH v4 2/5] powerpc/lib/sstep: Add popcnt instruction emulation

In reply to Matt Brown

Quoted 4 lines · Matt Brown

This adds emulations for the popcntb, popcntw, and popcntd instructions. Tested for correctness against the popcnt{b,w,d} instructions on ppc64le.
Signed-off-by Matt Brown <[email protected]>

Unlike the rest of this series, it isn't immediately clear that it is correct, we're definitely on the other side of the optimisation vs readability line. It looks like it is, perhaps some comments to clarify.

Otherwise,

Reviewed-by Cyril Bur <[email protected]>

Quoted 89 lines

---
 arch/powerpc/lib/sstep.c | 42 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

arch/powerpc/lib/sstep.c +41 -1

index 87d277f..2fd7377 100644
@@ -612,6 +612,34 @@ static nokprobe_inline void do_cmpb(struct pt_regs *regs, unsigned long v1,
 	regs->gpr[rd] = out_val;
 }
 
+/*
+ * The size parameter is used to adjust the equivalent popcnt instruction.
+ * popcntb = 8, popcntw = 32, popcntd = 64
+ */
+static nokprobe_inline void do_popcnt(struct pt_regs *regs, unsigned long v1,
+				int size, int ra)
+{
+	unsigned long long out = v1;
+
+	out -= (out >> 1) & 0x5555555555555555;
+	out = (0x3333333333333333 & out) + (0x3333333333333333 & (out >> 2));
+	out = (out + (out >> 4)) & 0x0f0f0f0f0f0f0f0f;
+
+	if (size == 8) {	/* popcntb */
+		regs->gpr[ra] = out;
+		return;
+	}
+	out += out >> 8;
+	out += out >> 16;
+	if (size == 32) {	/* popcntw */
+		regs->gpr[ra] = out & 0x0000003f0000003f;
+		return;
+	}
+
+	out = (out + (out >> 32)) & 0x7f;
+	regs->gpr[ra] = out;	/* popcntd */
+}
+
 static nokprobe_inline int trap_compare(long v1, long v2)
 {
 	int ret = 0;

@@ -1194,6 +1222,10 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 			regs->gpr[ra] = regs->gpr[rd] & ~regs->gpr[rb];
 			goto logical_done;
 
+		case 122:	/* popcntb */
+			do_popcnt(regs, regs->gpr[rd], 8, ra);
+			goto logical_done;
+
 		case 124:	/* nor */
 			regs->gpr[ra] = ~(regs->gpr[rd] | regs->gpr[rb]);
 			goto logical_done;

@@ -1206,6 +1238,10 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 			regs->gpr[ra] = regs->gpr[rd] ^ regs->gpr[rb];
 			goto logical_done;
 
+		case 378:	/* popcntw */
+			do_popcnt(regs, regs->gpr[rd], 32, ra);
+			goto logical_done;
+
 		case 412:	/* orc */
 			regs->gpr[ra] = regs->gpr[rd] | ~regs->gpr[rb];
 			goto logical_done;

@@ -1217,7 +1253,11 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 		case 476:	/* nand */
 			regs->gpr[ra] = ~(regs->gpr[rd] & regs->gpr[rb]);
 			goto logical_done;
-
+#ifdef CONFIG_PPC64
+		case 506:	/* popcntd */
+			do_popcnt(regs, regs->gpr[rd], 64, ra);
+			goto logical_done;
+#endif
 		case 922:	/* extsh */
 			regs->gpr[ra] = (signed short) regs->gpr[rd];
 			goto logical_done;

Segher Boessenkool

2017-08-01 12:44 UTC #10 lore raw

In reply to Matt Brown

Hi!

arch/powerpc/lib/sstep.c int analyse_instr(struct instruction_op *op, struct pt_regs *regs, · line 1070

Quoted 7 lines · Matt Brown

arch/powerpc/lib/sstep.c +3 -0

@@ -1049,6 +1065,10 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 			do_cmp_unsigned(regs, val, val2, rd >> 2);
 			goto instr_done;
 
+		case 508: /* cmpb */
+			do_cmpb(regs, regs->gpr[rd], regs->gpr[rb], ra);
+			goto instr_done;

Should this then be under an ifdef for 64-bit?

Segher

Matt Brown

author

2017-08-02 01:23 UTC #11 lore raw

Quoted 7 lines · Segher Boessenkool

Hi!

Quoted 4 lines · Matt Brown

arch/powerpc/lib/sstep.c +0 -0

@@ -1049,6 +1065,10 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
                      do_cmp_unsigned(regs, val, val2, rd >> 2);
                      goto instr_done;

Quoted 5 lines

arch/powerpc/lib/sstep.c int analyse_instr(struct instruction_op *op, struct pt_regs *regs, · line 1070
Quoted 3 lines
arch/powerpc/lib/sstep.c +3 -0
+             case 508: /* cmpb */
+                     do_cmpb(regs, regs->gpr[rd], regs->gpr[rb], ra);
+                     goto instr_done;
Should this then be under an ifdef for 64-bit?

I don't think so, the cmpb instruction should be 32 and 64-bit. It isn't listed under the '64-bit Fixed-point Logical Instructions' section in the ISA either.

Thanks,
Matt

Quoted 3 lines

Segher

Michael Ellerman

2017-08-11 12:19 UTC #12 lore raw

In reply to Matt Brown

Quoted 6 lines · Matt Brown

This patch adds emulation of the cmpb instruction, enabling xmon to emulate this instruction.
Tested for correctness against the cmpb asm instruction on ppc64le.
Signed-off-by Matt Brown <[email protected]>
Reviewed-by Cyril Bur <[email protected]>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/02c0f62a60b67d6c9bfe9429cbe3aa

cheers