powerpc/8xx: No need to save r10 and r3 when not calling FixupDAR

r10 and r3 are only used inside FixupDAR function. So lets save them inside
that function only.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 899c70174db4351b38b67dc4c54eed4c5cc413df..6f544eab983eebd5f41d65c83bca2f6e9bc58e5b 100644 (file)
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -485,20 +485,12 @@ InstructionTLBError:
  */
        . = 0x1400
 DataTLBError:
-#ifdef CONFIG_8xx_CPU6
-       stw     r3, 8(r0)
-#endif
        EXCEPTION_PROLOG_0
-       mtspr   SPRN_SPRG_SCRATCH2, r10
 
-       mfspr   r10, SPRN_DAR
-       cmpwi   cr0, r10, 0x00f0
+       mfspr   r11, SPRN_DAR
+       cmpwi   cr0, r11, 0x00f0
        beq-    FixupDAR        /* must be a buggy dcbX, icbi insn. */
 DARFixed:/* Return from dcbx instruction bug workaround */
-#ifdef CONFIG_8xx_CPU6
-       lwz     r3, 8(r0)
-#endif
-       mfspr   r10,SPRN_SPRG_SCRATCH2
        EXCEPTION_EPILOG_0
        b       DataAccess
 
@@ -528,6 +520,10 @@ DARFixed:/* Return from dcbx instruction bug workaround */
  /* define if you don't want to use self modifying code */
 #define NO_SELF_MODIFYING_CODE
 FixupDAR:/* Entry point for dcbx workaround. */
+#ifdef CONFIG_8xx_CPU6
+       stw     r3, 8(r0)
+#endif
+       mtspr   SPRN_SPRG_SCRATCH2, r10
        /* fetch instruction from memory. */
        mfspr   r10, SPRN_SRR0
        andis.  r11, r10, 0x8000        /* Address >= 0x80000000 */
@@ -543,6 +539,9 @@ FixupDAR:/* Entry point for dcbx workaround. */
        mtspr   SPRN_MD_TWC, r11        /* Load pte table base address */
        mfspr   r11, SPRN_MD_TWC        /* ....and get the pte address */
        lwz     r11, 0(r11)     /* Get the pte */
+#ifdef CONFIG_8xx_CPU6
+       lwz     r3, 8(r0)       /* restore r3 from memory */
+#endif
        /* concat physical page address(r11) and page offset(r10) */
        rlwimi  r11, r10, 0, 20, 31
        lwz     r11,0(r11)
@@ -563,15 +562,13 @@ FixupDAR:/* Entry point for dcbx workaround. */
        beq+    142f
        cmpwi   cr0, r10, 1964  /* Is icbi? */
        beq+    142f
-141:   b       DARFixed        /* Nope, go back to normal TLB processing */
+141:   mfspr   r10,SPRN_SPRG_SCRATCH2
+       b       DARFixed        /* Nope, go back to normal TLB processing */
 
 144:   mfspr   r10, SPRN_DSISR
        rlwinm  r10, r10,0,7,5  /* Clear store bit for buggy dcbst insn */
        mtspr   SPRN_DSISR, r10
 142:   /* continue, it was a dcbx, dcbi instruction. */
-#ifdef CONFIG_8xx_CPU6
-       lwz     r3, 8(r0)       /* restore r3 from memory */
-#endif
 #ifndef NO_SELF_MODIFYING_CODE
        andis.  r10,r11,0x1f    /* test if reg RA is r0 */
        li      r10,modified_instr@l
@@ -590,6 +587,7 @@ modified_instr:
        bne+    143f
        subf    r10,r0,r10      /* r10=r10-r0, only if reg RA is r0 */
 143:   mtdar   r10             /* store faulting EA in DAR */
+       mfspr   r10,SPRN_SPRG_SCRATCH2
        b       DARFixed        /* Go back to normal TLB handling */
 #else
        mfctr   r10
@@ -643,6 +641,7 @@ modified_instr:
        mfdar   r11
        mtctr   r11                     /* restore ctr reg from DAR */
        mtdar   r10                     /* save fault EA to DAR */
+       mfspr   r10,SPRN_SPRG_SCRATCH2
        b       DARFixed                /* Go back to normal TLB handling */
 
        /* special handling for r10,r11 since these are modified already */