[POWERPC] 40x/Book-E: Save/restore volatile exception registers
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>
Acked-by: Paul Mackerras <paulus@samba.org>
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 @@
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_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 */