[POWERPC] Rework EXC_LEVEL_EXCEPTION_PROLOG code
* Cleanup the code a bit my allocating an INT_FRAME on our exception
stack there by make references go from GPR11-INT_FRAME_SIZE(r8) to
just GPR11(r8)
* simplify {lvl}_transfer_to_handler code by moving the copying of the
temp registers we use if we come from user space into the PROLOG
* If the exception came from kernel mode copy thread_info flags,
preempt, and task pointer from the process thread_info.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 9eacf4c..b0874d2 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -72,18 +72,20 @@
#define DEBUG_STACK_BASE dbgirq_ctx
#define DEBUG_SPRG SPRN_SPRG6W
+#define EXC_LVL_FRAME_OVERHEAD (THREAD_SIZE - INT_FRAME_SIZE)
+
#ifdef CONFIG_SMP
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
mfspr r8,SPRN_PIR; \
slwi r8,r8,2; \
addis r8,r8,level##_STACK_BASE@ha; \
lwz r8,level##_STACK_BASE@l(r8); \
- addi r8,r8,THREAD_SIZE;
+ addi r8,r8,EXC_LVL_FRAME_OVERHEAD;
#else
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
lis r8,level##_STACK_BASE@ha; \
lwz r8,level##_STACK_BASE@l(r8); \
- addi r8,r8,THREAD_SIZE;
+ addi r8,r8,EXC_LVL_FRAME_OVERHEAD;
#endif
/*
@@ -97,22 +99,36 @@
#define EXC_LEVEL_EXCEPTION_PROLOG(exc_level, exc_level_srr0, exc_level_srr1) \
mtspr exc_level##_SPRG,r8; \
BOOKE_LOAD_EXC_LEVEL_STACK(exc_level);/* r8 points to the exc_level stack*/ \
- stw r10,GPR10-INT_FRAME_SIZE(r8); \
- stw r11,GPR11-INT_FRAME_SIZE(r8); \
- mfcr r10; /* save CR in r10 for now */\
- mfspr r11,exc_level_srr1; /* check whether user or kernel */\
- andi. r11,r11,MSR_PR; \
- mr r11,r8; \
- mfspr r8,exc_level##_SPRG; \
- beq 1f; \
- /* COMING FROM USER MODE */ \
+ stw r9,GPR9(r8); /* save various registers */\
+ mfcr r9; /* save CR in r9 for now */\
+ stw r10,GPR10(r8); \
+ stw r11,GPR11(r8); \
+ stw r9,_CCR(r8); /* save CR on stack */\
+ mfspr r10,exc_level_srr1; /* check whether user or kernel */\
+ andi. r10,r10,MSR_PR; \
mfspr r11,SPRN_SPRG3; /* if from user, start at top of */\
lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
- addi r11,r11,THREAD_SIZE; \
-1: subi r11,r11,INT_FRAME_SIZE; /* Allocate an exception frame */\
- stw r10,_CCR(r11); /* save various registers */\
- stw r12,GPR12(r11); \
+ addi r11,r11,EXC_LVL_FRAME_OVERHEAD; /* allocate stack frame */\
+ beq 1f; \
+ /* COMING FROM USER MODE */ \
+ stw r9,_CCR(r11); /* save CR */\
+ lwz r10,GPR10(r8); /* copy regs from exception stack */\
+ lwz r9,GPR9(r8); \
+ stw r10,GPR10(r11); \
+ lwz r10,GPR11(r8); \
stw r9,GPR9(r11); \
+ stw r10,GPR11(r11); \
+ b 2f; \
+ /* COMING FROM PRIV MODE */ \
+1: lwz r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r11); \
+ lwz r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r11); \
+ stw r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r8); \
+ stw r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r8); \
+ lwz r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r11); \
+ stw r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r8); \
+ mr r11,r8; \
+2: mfspr r8,exc_level##_SPRG; \
+ stw r12,GPR12(r11); /* save various registers */\
mflr r10; \
stw r10,_LINK(r11); \
mfspr r12,SPRN_DEAR; /* save DEAR and ESR in the frame */\
@@ -255,8 +271,8 @@
lwz r12,GPR12(r11); \
mtspr DEBUG_SPRG,r8; \
BOOKE_LOAD_EXC_LEVEL_STACK(DEBUG); /* r8 points to the debug stack */ \
- lwz r10,GPR10-INT_FRAME_SIZE(r8); \
- lwz r11,GPR11-INT_FRAME_SIZE(r8); \
+ lwz r10,GPR10(r8); \
+ lwz r11,GPR11(r8); \
mfspr r8,DEBUG_SPRG; \
\
RFDI; \
@@ -308,8 +324,8 @@
lwz r12,GPR12(r11); \
mtspr CRIT_SPRG,r8; \
BOOKE_LOAD_EXC_LEVEL_STACK(CRIT); /* r8 points to the debug stack */ \
- lwz r10,GPR10-INT_FRAME_SIZE(r8); \
- lwz r11,GPR11-INT_FRAME_SIZE(r8); \
+ lwz r10,GPR10(r8); \
+ lwz r11,GPR11(r8); \
mfspr r8,CRIT_SPRG; \
\
rfci; \