From: Kumar Gala <galak@kernel.crashing.org>
To: linuxppc-dev@ozlabs.org
Cc: paulus@samba.org
Subject: [PATCH v4] [POWERPC] 40x/Book-E: Save/restore volatile exception registers
Date: Tue, 20 May 2008 00:02:47 -0500 [thread overview]
Message-ID: <1211259767-4796-3-git-send-email-galak@kernel.crashing.org> (raw)
In-Reply-To: <1211259767-4796-2-git-send-email-galak@kernel.crashing.org>
On machines with more than one exception level any system register that
might be modified by the "normal" exception level needs to be saved and
restored on taking a higher level exception. We already are saving
and restoring ESR and DEAR.
For critical level add SRR0/1.
For debug level add CSRR0/1 and SRR0/1.
For machine check level add DSRR0/1, CSRR0/1, and SRR0/1.
On FSL Book-E parts we always save/restore the MAS registers for critical,
debug, and machine check level exceptions. On 44x we always save/restore
the MMUCR.
Additionally, we save and restore the ksp_limit since we have to adjust it
for each exception level.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
* Fixed mismerge in asm-offsets.c pointed out by Stephen
* Fixed 40x handling. The critical return path was restoring state as
if it was in real mode.(again, Josh helped debug and fix this).
arch/powerpc/kernel/asm-offsets.c | 23 +++++++
arch/powerpc/kernel/entry_32.S | 125 ++++++++++++++++++++++++++++++++++++-
arch/powerpc/kernel/head_40x.S | 6 ++
arch/powerpc/kernel/head_booke.h | 23 +++++++-
4 files changed, 174 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index ec9228d..8655c76 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -52,6 +52,10 @@
#include <asm/iseries/alpaca.h>
#endif
+#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#include "head_booke.h"
+#endif
+
int main(void)
{
DEFINE(THREAD, offsetof(struct task_struct, thread));
@@ -242,6 +246,25 @@ int main(void)
DEFINE(_SRR1, STACK_FRAME_OVERHEAD+sizeof(struct pt_regs)+8);
#endif /* CONFIG_PPC64 */
+#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+ DEFINE(EXC_LVL_SIZE, STACK_EXC_LVL_FRAME_SIZE);
+ DEFINE(MAS0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas0));
+ /* we overload MMUCR for 44x on MAS0 since they are mutually exclusive */
+ DEFINE(MMUCR, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas0));
+ DEFINE(MAS1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas1));
+ DEFINE(MAS2, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas2));
+ DEFINE(MAS3, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas3));
+ DEFINE(MAS6, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas6));
+ DEFINE(MAS7, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas7));
+ DEFINE(_SRR0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, srr0));
+ DEFINE(_SRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, srr1));
+ DEFINE(_CSRR0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, csrr0));
+ DEFINE(_CSRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, csrr1));
+ DEFINE(_DSRR0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, dsrr0));
+ DEFINE(_DSRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, dsrr1));
+ DEFINE(SAVED_KSP_LIMIT, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, saved_ksp_limit));
+#endif
+
DEFINE(CLONE_VM, CLONE_VM);
DEFINE(CLONE_UNTRACED, CLONE_UNTRACED);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index c94aba5..fe21674 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -46,14 +46,52 @@
#ifdef CONFIG_BOOKE
.globl mcheck_transfer_to_handler
mcheck_transfer_to_handler:
- b transfer_to_handler_full
+ mfspr r0,SPRN_DSRR0
+ stw r0,_DSRR0(r11)
+ mfspr r0,SPRN_DSRR1
+ stw r0,_DSRR1(r11)
+ /* fall through */
.globl debug_transfer_to_handler
debug_transfer_to_handler:
- b transfer_to_handler_full
+ mfspr r0,SPRN_CSRR0
+ stw r0,_CSRR0(r11)
+ mfspr r0,SPRN_CSRR1
+ stw r0,_CSRR1(r11)
+ /* fall through */
.globl crit_transfer_to_handler
crit_transfer_to_handler:
+#ifdef CONFIG_FSL_BOOKE
+ mfspr r0,SPRN_MAS0
+ stw r0,MAS0(r11)
+ mfspr r0,SPRN_MAS1
+ stw r0,MAS1(r11)
+ mfspr r0,SPRN_MAS2
+ stw r0,MAS2(r11)
+ mfspr r0,SPRN_MAS3
+ stw r0,MAS3(r11)
+ mfspr r0,SPRN_MAS6
+ stw r0,MAS6(r11)
+#ifdef CONFIG_PHYS_64BIT
+ mfspr r0,SPRN_MAS7
+ stw r0,MAS7(r11)
+#endif /* CONFIG_PHYS_64BIT */
+#endif /* CONFIG_FSL_BOOKE */
+#ifdef CONFIG_44x
+ mfspr r0,SPRN_MMUCR
+ stw r0,MMUCR(r11)
+#endif
+ mfspr r0,SPRN_SRR0
+ stw r0,_SRR0(r11)
+ mfspr r0,SPRN_SRR1
+ stw r0,_SRR1(r11)
+
+ mfspr r8,SPRN_SPRG3
+ lwz r0,KSP_LIMIT(r8)
+ stw r0,SAVED_KSP_LIMIT(r11)
+ rlwimi r0,r1,0,0,(31-THREAD_SHIFT)
+ stw r0,KSP_LIMIT(r8)
/* fall through */
#endif
@@ -64,6 +102,16 @@ crit_transfer_to_handler:
stw r0,GPR10(r11)
lwz r0,crit_r11@l(0)
stw r0,GPR11(r11)
+ mfspr r0,SPRN_SRR0
+ stw r0,crit_srr0@l(0)
+ mfspr r0,SPRN_SRR1
+ stw r0,crit_srr1@l(0)
+
+ mfspr r8,SPRN_SPRG3
+ lwz r0,KSP_LIMIT(r8)
+ stw r0,saved_ksp_limit@l(0)
+ rlwimi r0,r1,0,0,(31-THREAD_SHIFT)
+ stw r0,KSP_LIMIT(r8)
/* fall through */
#endif
@@ -854,17 +902,90 @@ exc_exit_restart_end:
exc_lvl_rfi; \
b .; /* prevent prefetch past exc_lvl_rfi */
+#define RESTORE_xSRR(exc_lvl_srr0, exc_lvl_srr1) \
+ lwz r9,_##exc_lvl_srr0(r1); \
+ lwz r10,_##exc_lvl_srr1(r1); \
+ mtspr SPRN_##exc_lvl_srr0,r9; \
+ mtspr SPRN_##exc_lvl_srr1,r10;
+
+#if defined(CONFIG_FSL_BOOKE)
+#ifdef CONFIG_PHYS_64BIT
+#define RESTORE_MAS7 \
+ lwz r11,MAS7(r1); \
+ mtspr SPRN_MAS7,r11;
+#else
+#define RESTORE_MAS7
+#endif /* CONFIG_PHYS_64BIT */
+#define RESTORE_MMU_REGS \
+ lwz r9,MAS0(r1); \
+ lwz r10,MAS1(r1); \
+ lwz r11,MAS2(r1); \
+ mtspr SPRN_MAS0,r9; \
+ lwz r9,MAS3(r1); \
+ mtspr SPRN_MAS1,r10; \
+ lwz r10,MAS6(r1); \
+ mtspr SPRN_MAS2,r11; \
+ mtspr SPRN_MAS3,r9; \
+ mtspr SPRN_MAS6,r10; \
+ RESTORE_MAS7;
+#elif defined(CONFIG_44x)
+#define RESTORE_MMU_REGS \
+ lwz r9,MMUCR(r1); \
+ mtspr SPRN_MMUCR,r9;
+#else
+#define RESTORE_MMU_REGS
+#endif
+
+#ifdef CONFIG_40x
.globl ret_from_crit_exc
ret_from_crit_exc:
+ mfspr r9,SPRN_SPRG3
+ lis r10,saved_ksp_limit@ha;
+ lwz r10,saved_ksp_limit@l(r10);
+ tovirt(r9,r9);
+ stw r10,KSP_LIMIT(r9)
+ lis r9,crit_srr0@ha;
+ lwz r9,crit_srr0@l(r9);
+ lis r10,crit_srr1@ha;
+ lwz r10,crit_srr1@l(r10);
+ mtspr SPRN_SRR0,r9;
+ mtspr SPRN_SRR1,r10;
RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, RFCI)
+#endif /* CONFIG_40x */
#ifdef CONFIG_BOOKE
+ .globl ret_from_crit_exc
+ret_from_crit_exc:
+ mfspr r9,SPRN_SPRG3
+ lwz r10,SAVED_KSP_LIMIT(r1)
+ stw r10,KSP_LIMIT(r9)
+ RESTORE_xSRR(SRR0,SRR1);
+ RESTORE_MMU_REGS;
+ RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, RFCI)
+
.globl ret_from_debug_exc
ret_from_debug_exc:
+ mfspr r9,SPRN_SPRG3
+ lwz r10,SAVED_KSP_LIMIT(r1)
+ stw r10,KSP_LIMIT(r9)
+ lwz r9,THREAD_INFO-THREAD(r9)
+ rlwinm r10,r1,0,0,(31-THREAD_SHIFT)
+ lwz r10,TI_PREEMPT(r10)
+ stw r10,TI_PREEMPT(r9)
+ RESTORE_xSRR(SRR0,SRR1);
+ RESTORE_xSRR(CSRR0,CSRR1);
+ RESTORE_MMU_REGS;
RET_FROM_EXC_LEVEL(SPRN_DSRR0, SPRN_DSRR1, RFDI)
.globl ret_from_mcheck_exc
ret_from_mcheck_exc:
+ mfspr r9,SPRN_SPRG3
+ lwz r10,SAVED_KSP_LIMIT(r1)
+ stw r10,KSP_LIMIT(r9)
+ RESTORE_xSRR(SRR0,SRR1);
+ RESTORE_xSRR(CSRR0,CSRR1);
+ RESTORE_xSRR(DSRR0,DSRR1);
+ RESTORE_MMU_REGS;
RET_FROM_EXC_LEVEL(SPRN_MCSRR0, SPRN_MCSRR1, RFMCI)
#endif /* CONFIG_BOOKE */
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 8ef77e3..75fd226 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -93,6 +93,12 @@ _ENTRY(crit_r10)
.space 4
_ENTRY(crit_r11)
.space 4
+_ENTRY(crit_srr0)
+ .space 4
+_ENTRY(crit_srr1)
+ .space 4
+_ENTRY(saved_ksp_limit)
+ .space 4
/*
* Exception vector entry code. This code runs with address translation
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index b0874d2..f277fad 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -72,7 +72,7 @@
#define DEBUG_STACK_BASE dbgirq_ctx
#define DEBUG_SPRG SPRN_SPRG6W
-#define EXC_LVL_FRAME_OVERHEAD (THREAD_SIZE - INT_FRAME_SIZE)
+#define EXC_LVL_FRAME_OVERHEAD (THREAD_SIZE - INT_FRAME_SIZE - EXC_LVL_SIZE)
#ifdef CONFIG_SMP
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
@@ -376,4 +376,25 @@ label:
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
+#ifndef __ASSEMBLY__
+struct exception_regs {
+ unsigned long mas0;
+ unsigned long mas1;
+ unsigned long mas2;
+ unsigned long mas3;
+ unsigned long mas6;
+ unsigned long mas7;
+ unsigned long srr0;
+ unsigned long srr1;
+ unsigned long csrr0;
+ unsigned long csrr1;
+ unsigned long dsrr0;
+ unsigned long dsrr1;
+ unsigned long saved_ksp_limit;
+};
+
+/* ensure this structure is always sized to a multiple of the stack alignment */
+#define STACK_EXC_LVL_FRAME_SIZE _ALIGN_UP(sizeof (struct exception_regs), 16)
+
+#endif /* __ASSEMBLY__ */
#endif /* __HEAD_BOOKE_H__ */
--
1.5.4.5
next prev parent reply other threads:[~2008-05-20 5:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-20 5:02 [PATCH v4] [POWERPC] Move to runtime allocated exception stacks Kumar Gala
2008-05-20 5:02 ` [PATCH v4] [POWERPC] Rework EXC_LEVEL_EXCEPTION_PROLOG code Kumar Gala
2008-05-20 5:02 ` Kumar Gala [this message]
2008-05-29 20:34 ` [PATCH v4] [POWERPC] Move to runtime allocated exception stacks Josh Boyer
2008-05-31 5:04 ` Paul Mackerras
2008-05-31 6:05 ` Kumar Gala
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