[PATCH 1/3] powerpc: Add MSR_64BIT

[PATCH 1/3] powerpc: Add MSR_64BIT

[Michael Ellerman]

The MSR bit which indicates 64-bit-ness is different between server and
booke, so add a #define which gives you the right mask regardless.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---
 arch/powerpc/include/asm/reg.h       |   10 ++++++++--
 arch/powerpc/include/asm/reg_booke.h |    6 ++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 7e4abeb..fdaafd0 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -99,17 +99,23 @@
 #define MSR_LE		__MASK(MSR_LE_LG)	/* Little Endian */
 
 #if defined(CONFIG_PPC_BOOK3S_64)
+#define MSR_64BIT	MSR_SF
+
 /* Server variant */
 #define MSR_		MSR_ME | MSR_RI | MSR_IR | MSR_DR | MSR_ISF |MSR_HV
-#define MSR_KERNEL      MSR_ | MSR_SF
+#define MSR_KERNEL	MSR_ | MSR_64BIT
 #define MSR_USER32	MSR_ | MSR_PR | MSR_EE
-#define MSR_USER64	MSR_USER32 | MSR_SF
+#define MSR_USER64	MSR_USER32 | MSR_64BIT
 #elif defined(CONFIG_PPC_BOOK3S_32) || defined(CONFIG_8xx)
 /* Default MSR for kernel mode. */
 #define MSR_KERNEL	(MSR_ME|MSR_RI|MSR_IR|MSR_DR)
 #define MSR_USER	(MSR_KERNEL|MSR_PR|MSR_EE)
 #endif
 
+#ifndef MSR_64BIT
+#define MSR_64BIT	0
+#endif
+
 /* Floating Point Status and Control Register (FPSCR) Fields */
 #define FPSCR_FX	0x80000000	/* FPU exception summary */
 #define FPSCR_FEX	0x40000000	/* FPU enabled exception summary */
diff --git a/arch/powerpc/include/asm/reg_booke.h b/arch/powerpc/include/asm/reg_booke.h
index 3b1a9b7..36d7dbd 100644
--- a/arch/powerpc/include/asm/reg_booke.h
+++ b/arch/powerpc/include/asm/reg_booke.h
@@ -27,10 +27,12 @@
 #define MSR_CM		(1<<31) /* Computation Mode (0=32-bit, 1=64-bit) */
 
 #if defined(CONFIG_PPC_BOOK3E_64)
+#define MSR_64BIT	MSR_CM
+
 #define MSR_		MSR_ME | MSR_CE
-#define MSR_KERNEL      MSR_ | MSR_CM
+#define MSR_KERNEL	MSR_ | MSR_64BIT
 #define MSR_USER32	MSR_ | MSR_PR | MSR_EE | MSR_DE
-#define MSR_USER64	MSR_USER32 | MSR_CM | MSR_DE
+#define MSR_USER64	MSR_USER32 | MSR_64BIT
 #elif defined (CONFIG_40x)
 #define MSR_KERNEL	(MSR_ME|MSR_RI|MSR_IR|MSR_DR|MSR_CE)
 #define MSR_USER	(MSR_KERNEL|MSR_PR|MSR_EE)
-- 
1.7.1

[PATCH 2/3] powerpc: Use MSR_64BIT in places

[Michael Ellerman]

Use the new MSR_64BIT in a few places. Some of these are already ifdef'ed
for BOOKE vs BOOKS, but it's still clearer, MSR_SF does not immediately
parse as "MSR bit for 64bit".

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---
 arch/powerpc/kernel/head_64.S   |    2 +-
 arch/powerpc/kernel/signal_64.c |    4 ++--
 arch/powerpc/kernel/traps.c     |    2 +-
 arch/powerpc/xmon/xmon.c        |   14 +++++++-------
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 271140b..e7e03f8 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -645,7 +645,7 @@ _GLOBAL(enable_64b_mode)
 	oris	r11,r11,0x8000		/* CM bit set, we'll set ICM later */
 	mtmsr	r11
 #else /* CONFIG_PPC_BOOK3E */
-	li	r12,(MSR_SF | MSR_ISF)@highest
+	li	r12,(MSR_64BIT | MSR_ISF)@highest
 	sldi	r12,r12,48
 	or	r11,r11,r12
 	mtmsrd	r11
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 27c4a45..da989ff 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -381,7 +381,7 @@ badframe:
 	       regs, uc, &uc->uc_mcontext);
 #endif
 	if (show_unhandled_signals && printk_ratelimit())
-		printk(regs->msr & MSR_SF ? fmt64 : fmt32,
+		printk(regs->msr & MSR_64BIT ? fmt64 : fmt32,
 			current->comm, current->pid, "rt_sigreturn",
 			(long)uc, regs->nip, regs->link);
 
@@ -469,7 +469,7 @@ badframe:
 	       regs, frame, newsp);
 #endif
 	if (show_unhandled_signals && printk_ratelimit())
-		printk(regs->msr & MSR_SF ? fmt64 : fmt32,
+		printk(regs->msr & MSR_64BIT ? fmt64 : fmt32,
 			current->comm, current->pid, "setup_rt_frame",
 			(long)frame, regs->nip, regs->link);
 
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index bd74fac..443353a 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -199,7 +199,7 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
 	} else if (show_unhandled_signals &&
 		    unhandled_signal(current, signr) &&
 		    printk_ratelimit()) {
-			printk(regs->msr & MSR_SF ? fmt64 : fmt32,
+			printk(regs->msr & MSR_64BIT ? fmt64 : fmt32,
 				current->comm, current->pid, signr,
 				addr, regs->nip, regs->link, code);
 		}
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 33794c1..ef9756e 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -399,7 +399,7 @@ static int xmon_core(struct pt_regs *regs, int fromipi)
 	cpu_set(cpu, cpus_in_xmon);
 
 	bp = NULL;
-	if ((regs->msr & (MSR_IR|MSR_PR|MSR_SF)) == (MSR_IR|MSR_SF))
+	if ((regs->msr & (MSR_IR|MSR_PR|MSR_64BIT)) == (MSR_IR|MSR_64BIT))
 		bp = at_breakpoint(regs->nip);
 	if (bp || unrecoverable_excp(regs))
 		fromipi = 0;
@@ -529,7 +529,7 @@ static int xmon_core(struct pt_regs *regs, int fromipi)
 		}
 	}
 #else
-	if ((regs->msr & (MSR_IR|MSR_PR|MSR_SF)) == (MSR_IR|MSR_SF)) {
+	if ((regs->msr & (MSR_IR|MSR_PR|MSR_64BIT)) == (MSR_IR|MSR_64BIT)) {
 		bp = at_breakpoint(regs->nip);
 		if (bp != NULL) {
 			int stepped = emulate_step(regs, bp->instr[0]);
@@ -578,7 +578,7 @@ static int xmon_bpt(struct pt_regs *regs)
 	struct bpt *bp;
 	unsigned long offset;
 
-	if ((regs->msr & (MSR_IR|MSR_PR|MSR_SF)) != (MSR_IR|MSR_SF))
+	if ((regs->msr & (MSR_IR|MSR_PR|MSR_64BIT)) != (MSR_IR|MSR_64BIT))
 		return 0;
 
 	/* Are we at the trap at bp->instr[1] for some bp? */
@@ -609,7 +609,7 @@ static int xmon_sstep(struct pt_regs *regs)
 
 static int xmon_dabr_match(struct pt_regs *regs)
 {
-	if ((regs->msr & (MSR_IR|MSR_PR|MSR_SF)) != (MSR_IR|MSR_SF))
+	if ((regs->msr & (MSR_IR|MSR_PR|MSR_64BIT)) != (MSR_IR|MSR_64BIT))
 		return 0;
 	if (dabr.enabled == 0)
 		return 0;
@@ -619,7 +619,7 @@ static int xmon_dabr_match(struct pt_regs *regs)
 
 static int xmon_iabr_match(struct pt_regs *regs)
 {
-	if ((regs->msr & (MSR_IR|MSR_PR|MSR_SF)) != (MSR_IR|MSR_SF))
+	if ((regs->msr & (MSR_IR|MSR_PR|MSR_64BIT)) != (MSR_IR|MSR_64BIT))
 		return 0;
 	if (iabr == NULL)
 		return 0;
@@ -644,7 +644,7 @@ static int xmon_fault_handler(struct pt_regs *regs)
 	if (in_xmon && catch_memory_errors)
 		handle_fault(regs);	/* doesn't return */
 
-	if ((regs->msr & (MSR_IR|MSR_PR|MSR_SF)) == (MSR_IR|MSR_SF)) {
+	if ((regs->msr & (MSR_IR|MSR_PR|MSR_64BIT)) == (MSR_IR|MSR_64BIT)) {
 		bp = in_breakpoint_table(regs->nip, &offset);
 		if (bp != NULL) {
 			regs->nip = bp->address + offset;
@@ -929,7 +929,7 @@ static int do_step(struct pt_regs *regs)
 	int stepped;
 
 	/* check we are in 64-bit kernel mode, translation enabled */
-	if ((regs->msr & (MSR_SF|MSR_PR|MSR_IR)) == (MSR_SF|MSR_IR)) {
+	if ((regs->msr & (MSR_64BIT|MSR_PR|MSR_IR)) == (MSR_64BIT|MSR_IR)) {
 		if (mread(regs->nip, &instr, 4) == 4) {
 			stepped = emulate_step(regs, instr);
 			if (stepped < 0) {
-- 
1.7.1

[PATCH 3/3] powerpc: Use MSR_64BIT in sstep.c, fix kprobes on BOOK3E

[Michael Ellerman]

We check MSR_SF a lot in sstep.c, to decide if we need to emulate the
truncation of values when running in 32-bit mode. Factor out that code
into a helper, and convert it and the other uses to use MSR_64BIT.

This fixes a bug on BOOK3E where kprobes would end up returning to a
32-bit address, because regs->nip was truncated, because (msr & MSR_SF)
was false.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---
 arch/powerpc/lib/sstep.c |   61 ++++++++++++++++++++-------------------------
 1 files changed, 27 insertions(+), 34 deletions(-)

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index ae5189a..0e5e540 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -45,6 +45,18 @@ extern int do_stxvd2x(int rn, unsigned long ea);
 #endif
 
 /*
+ * Emulate the truncation of 64 bit values in 32-bit mode.
+ */
+static unsigned long truncate_if_32bit(unsigned long msr, unsigned long val)
+{
+#ifdef __powerpc64__
+	if ((msr & MSR_64BIT) == 0)
+		val &= 0xffffffffUL;
+#endif
+	return val;
+}
+
+/*
  * Determine whether a conditional branch instruction would branch.
  */
 static int __kprobes branch_taken(unsigned int instr, struct pt_regs *regs)
@@ -90,11 +102,8 @@ static unsigned long __kprobes dform_ea(unsigned int instr, struct pt_regs *regs
 		if (instr & 0x04000000)		/* update forms */
 			regs->gpr[ra] = ea;
 	}
-#ifdef __powerpc64__
-	if (!(regs->msr & MSR_SF))
-		ea &= 0xffffffffUL;
-#endif
-	return ea;
+
+	return truncate_if_32bit(regs->msr, ea);
 }
 
 #ifdef __powerpc64__
@@ -113,9 +122,8 @@ static unsigned long __kprobes dsform_ea(unsigned int instr, struct pt_regs *reg
 		if ((instr & 3) == 1)		/* update forms */
 			regs->gpr[ra] = ea;
 	}
-	if (!(regs->msr & MSR_SF))
-		ea &= 0xffffffffUL;
-	return ea;
+
+	return truncate_if_32bit(regs->msr, ea);
 }
 #endif /* __powerpc64 */
 
@@ -136,11 +144,8 @@ static unsigned long __kprobes xform_ea(unsigned int instr, struct pt_regs *regs
 		if (do_update)		/* update forms */
 			regs->gpr[ra] = ea;
 	}
-#ifdef __powerpc64__
-	if (!(regs->msr & MSR_SF))
-		ea &= 0xffffffffUL;
-#endif
-	return ea;
+
+	return truncate_if_32bit(regs->msr, ea);
 }
 
 /*
@@ -466,7 +471,7 @@ static void __kprobes set_cr0(struct pt_regs *regs, int rd)
 
 	regs->ccr = (regs->ccr & 0x0fffffff) | ((regs->xer >> 3) & 0x10000000);
 #ifdef __powerpc64__
-	if (!(regs->msr & MSR_SF))
+	if (!(regs->msr & MSR_64BIT))
 		val = (int) val;
 #endif
 	if (val < 0)
@@ -487,7 +492,7 @@ static void __kprobes add_with_carry(struct pt_regs *regs, int rd,
 		++val;
 	regs->gpr[rd] = val;
 #ifdef __powerpc64__
-	if (!(regs->msr & MSR_SF)) {
+	if (!(regs->msr & MSR_64BIT)) {
 		val = (unsigned int) val;
 		val1 = (unsigned int) val1;
 	}
@@ -570,8 +575,7 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
 		if ((instr & 2) == 0)
 			imm += regs->nip;
 		regs->nip += 4;
-		if ((regs->msr & MSR_SF) == 0)
-			regs->nip &= 0xffffffffUL;
+		regs->nip = truncate_if_32bit(regs->msr, regs->nip);
 		if (instr & 1)
 			regs->link = regs->nip;
 		if (branch_taken(instr, regs))
@@ -604,13 +608,9 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
 			imm -= 0x04000000;
 		if ((instr & 2) == 0)
 			imm += regs->nip;
-		if (instr & 1) {
-			regs->link = regs->nip + 4;
-			if ((regs->msr & MSR_SF) == 0)
-				regs->link &= 0xffffffffUL;
-		}
-		if ((regs->msr & MSR_SF) == 0)
-			imm &= 0xffffffffUL;
+		if (instr & 1)
+			regs->link = truncate_if_32bit(regs->msr, regs->nip + 4);
+		imm = truncate_if_32bit(regs->msr, imm);
 		regs->nip = imm;
 		return 1;
 	case 19:
@@ -618,11 +618,8 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
 		case 16:	/* bclr */
 		case 528:	/* bcctr */
 			imm = (instr & 0x400)? regs->ctr: regs->link;
-			regs->nip += 4;
-			if ((regs->msr & MSR_SF) == 0) {
-				regs->nip &= 0xffffffffUL;
-				imm &= 0xffffffffUL;
-			}
+			regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
+			imm = truncate_if_32bit(regs->msr, imm);
 			if (instr & 1)
 				regs->link = regs->nip;
 			if (branch_taken(instr, regs))
@@ -1616,11 +1613,7 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
 		return 0;	/* invoke DSI if -EFAULT? */
 	}
  instr_done:
-	regs->nip += 4;
-#ifdef __powerpc64__
-	if ((regs->msr & MSR_SF) == 0)
-		regs->nip &= 0xffffffffUL;
-#endif
+	regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
 	return 1;
 
  logical_done:
-- 
1.7.1

Re: [PATCH 2/3] powerpc: Use MSR_64BIT in places

[Kumar Gala]

On Apr 8, 2011, at 2:56 AM, Michael Ellerman wrote:

> Use the new MSR_64BIT in a few places. Some of these are already ifdef'ed
> for BOOKE vs BOOKS, but it's still clearer, MSR_SF does not immediately
> parse as "MSR bit for 64bit".
> 
> Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
> ---
> arch/powerpc/kernel/head_64.S   |    2 +-
> arch/powerpc/kernel/signal_64.c |    4 ++--
> arch/powerpc/kernel/traps.c     |    2 +-
> arch/powerpc/xmon/xmon.c        |   14 +++++++-------
> 4 files changed, 11 insertions(+), 11 deletions(-)

However MSR_ISF does ;)

- k

Re: [PATCH 2/3] powerpc: Use MSR_64BIT in places

[Benjamin Herrenschmidt]

On Fri, 2011-04-08 at 04:24 -0500, Kumar Gala wrote:
> On Apr 8, 2011, at 2:56 AM, Michael Ellerman wrote:
> 
> > Use the new MSR_64BIT in a few places. Some of these are already ifdef'ed
> > for BOOKE vs BOOKS, but it's still clearer, MSR_SF does not immediately
> > parse as "MSR bit for 64bit".
> > 
> > Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
> > ---
> > arch/powerpc/kernel/head_64.S   |    2 +-
> > arch/powerpc/kernel/signal_64.c |    4 ++--
> > arch/powerpc/kernel/traps.c     |    2 +-
> > arch/powerpc/xmon/xmon.c        |   14 +++++++-------
> > 4 files changed, 11 insertions(+), 11 deletions(-)
> 
> However MSR_ISF does ;)

I'm not sure I parse that one :-) Any ways ISF is "interrupt SF" and has
no equivalent in the MSR for BookE (it's elsewhere, EPCR no ?).

Cheers,
Ben.

Re: [PATCH 2/3] powerpc: Use MSR_64BIT in places

[Kumar Gala]

On Apr 9, 2011, at 5:04 PM, Benjamin Herrenschmidt wrote:

> On Fri, 2011-04-08 at 04:24 -0500, Kumar Gala wrote:
>> On Apr 8, 2011, at 2:56 AM, Michael Ellerman wrote:
>>=20
>>> Use the new MSR_64BIT in a few places. Some of these are already =
ifdef'ed
>>> for BOOKE vs BOOKS, but it's still clearer, MSR_SF does not =
immediately
>>> parse as "MSR bit for 64bit".
>>>=20
>>> Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
>>> ---
>>> arch/powerpc/kernel/head_64.S   |    2 +-
>>> arch/powerpc/kernel/signal_64.c |    4 ++--
>>> arch/powerpc/kernel/traps.c     |    2 +-
>>> arch/powerpc/xmon/xmon.c        |   14 +++++++-------
>>> 4 files changed, 11 insertions(+), 11 deletions(-)
>>=20
>> However MSR_ISF does ;)
>=20
> I'm not sure I parse that one :-) Any ways ISF is "interrupt SF" and =
has
> no equivalent in the MSR for BookE (it's elsewhere, EPCR no ?).

I was just saying that if _SF doesn't parse as 64-bit mode, ISF doesn't =
parse as interrupt into 64-bit mode :)

- k=

Re: [PATCH 2/3] powerpc: Use MSR_64BIT in places

[Benjamin Herrenschmidt]

On Sun, 2011-04-10 at 12:29 -0500, Kumar Gala wrote:
> On Apr 9, 2011, at 5:04 PM, Benjamin Herrenschmidt wrote:
> 
> > On Fri, 2011-04-08 at 04:24 -0500, Kumar Gala wrote:
> >> On Apr 8, 2011, at 2:56 AM, Michael Ellerman wrote:
> >> 
> >>> Use the new MSR_64BIT in a few places. Some of these are already ifdef'ed
> >>> for BOOKE vs BOOKS, but it's still clearer, MSR_SF does not immediately
> >>> parse as "MSR bit for 64bit".
> >>> 
> >>> Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
> >>> ---
> >>> arch/powerpc/kernel/head_64.S   |    2 +-
> >>> arch/powerpc/kernel/signal_64.c |    4 ++--
> >>> arch/powerpc/kernel/traps.c     |    2 +-
> >>> arch/powerpc/xmon/xmon.c        |   14 +++++++-------
> >>> 4 files changed, 11 insertions(+), 11 deletions(-)
> >> 
> >> However MSR_ISF does ;)
> > 
> > I'm not sure I parse that one :-) Any ways ISF is "interrupt SF" and has
> > no equivalent in the MSR for BookE (it's elsewhere, EPCR no ?).
> 
> I was just saying that if _SF doesn't parse as 64-bit mode, ISF doesn't parse as interrupt into 64-bit mode :)

Ah right :-) But it's not used nearly as much and has no equivalent on
BookE so I wouldn't bother. The deal here is really more about getting
a single definition for both subarchs.

Cheers,
Ben.