powerpc: Move branch instruction from ACCOUNT_CPU_USER_ENTRY to caller

[PATCH 1/6] powerpc: Move branch instruction from ACCOUNT_CPU_USER_ENTRY to caller

The first instruction in ACCOUNT_CPU_USER_ENTRY is 'beq' which checks for
exceptions coming from kernel mode. PPR value will be saved immediately after
ACCOUNT_CPU_USER_ENTRY and is also for user level exceptions. So moved this
branch instruction in the caller code.

Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index b1edd80..49b7faf 100644 (file)
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -224,8 +224,9 @@ do_kvm_##n:                                                         \
        std     r10,0(r1);              /* make stack chain pointer     */ \
        std     r0,GPR0(r1);            /* save r0 in stackframe        */ \
        std     r10,GPR1(r1);           /* save r1 in stackframe        */ \
+       beq     4f;                     /* if from kernel mode          */ \
        ACCOUNT_CPU_USER_ENTRY(r9, r10);                                   \
-       std     r2,GPR2(r1);            /* save r2 in stackframe        */ \
+4:     std     r2,GPR2(r1);            /* save r2 in stackframe        */ \
        SAVE_4GPRS(3, r1);              /* save r3 - r6 in stackframe   */ \
        SAVE_2GPRS(7, r1);              /* save r7, r8 in stackframe    */ \
        ld      r9,area+EX_R9(r13);     /* move r9, r10 to stackframe   */ \

diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index ea2a86e..376e36d 100644 (file)
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -30,7 +30,6 @@
 #define ACCOUNT_STOLEN_TIME
 #else
 #define ACCOUNT_CPU_USER_ENTRY(ra, rb)                                 \
-       beq     2f;                     /* if from kernel mode */       \
        MFTB(ra);                       /* get timebase */              \
        ld      rb,PACA_STARTTIME_USER(r13);                            \
        std     ra,PACA_STARTTIME(r13);                                 \
@@ -38,7 +37,6 @@
        ld      ra,PACA_USER_TIME(r13);                                 \
        add     ra,ra,rb;               /* add on to user time */       \
        std     ra,PACA_USER_TIME(r13);                                 \
-2:
 
 #define ACCOUNT_CPU_USER_EXIT(ra, rb)                                  \
        MFTB(ra);                       /* get timebase */              \

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 73c1f08..7a70d0a 100644 (file)
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -62,8 +62,9 @@ system_call_common:
        std     r12,_MSR(r1)
        std     r0,GPR0(r1)
        std     r10,GPR1(r1)
+       beq     2f                      /* if from kernel mode */
        ACCOUNT_CPU_USER_ENTRY(r10, r11)
-       std     r2,GPR2(r1)
+2:     std     r2,GPR2(r1)
        std     r3,GPR3(r1)
        mfcr    r2
        std     r4,GPR4(r1)

diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 4684e33..ae54553 100644 (file)
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -159,8 +159,9 @@ exc_##n##_common:                                                       \
        std     r9,GPR9(r1);            /* save r9 in stackframe */         \
        std     r10,_NIP(r1);           /* save SRR0 to stackframe */       \
        std     r11,_MSR(r1);           /* save SRR1 to stackframe */       \
+       beq     2f;                     /* if from kernel mode */           \
        ACCOUNT_CPU_USER_ENTRY(r10,r11);/* accounting (uses cr0+eq) */      \
-       ld      r3,excf+EX_R10(r13);    /* get back r10 */                  \
+2:     ld      r3,excf+EX_R10(r13);    /* get back r10 */                  \
        ld      r4,excf+EX_R11(r13);    /* get back r11 */                  \
        mfspr   r5,SPRN_SPRG_GEN_SCRATCH;/* get back r13 */                 \
        std     r12,GPR12(r1);          /* save r12 in stackframe */        \