[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/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 888a364043a83ad0d1dea405e2d6a84442ebbb2f..c94aba54b5dd75f64aadbb4056e529807b7d7f14 100644 (file)
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -44,29 +44,16 @@
 #endif
 
 #ifdef CONFIG_BOOKE
-#include "head_booke.h"
-#define TRANSFER_TO_HANDLER_EXC_LEVEL(exc_level)       \
-       mtspr   exc_level##_SPRG,r8;                    \
-       BOOKE_LOAD_EXC_LEVEL_STACK(exc_level);          \
-       lwz     r0,GPR10-INT_FRAME_SIZE(r8);            \
-       stw     r0,GPR10(r11);                          \
-       lwz     r0,GPR11-INT_FRAME_SIZE(r8);            \
-       stw     r0,GPR11(r11);                          \
-       mfspr   r8,exc_level##_SPRG
-
        .globl  mcheck_transfer_to_handler
 mcheck_transfer_to_handler:
-       TRANSFER_TO_HANDLER_EXC_LEVEL(MCHECK)
        b       transfer_to_handler_full
 
        .globl  debug_transfer_to_handler
 debug_transfer_to_handler:
-       TRANSFER_TO_HANDLER_EXC_LEVEL(DEBUG)
        b       transfer_to_handler_full
 
        .globl  crit_transfer_to_handler
 crit_transfer_to_handler:
-       TRANSFER_TO_HANDLER_EXC_LEVEL(CRIT)
        /* fall through */
 #endif
 

diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 9eacf4ca442a3106684159eeba845506fcc6dddf..b0874d228eaf99edf15c6349d48bb66c55bfb854 100644 (file)
--- 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 @@ label:
        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 @@ label:
        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;                                                                 \