powerpc/8xx: Take benefit of aligned PGDIR

L1 base address is now aligned so we can insert L1 index into r11 directly and
then preserve r10

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

1 files changed, 15 insertions, 19 deletions

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 32cc9e55b772..0ab16b66d712 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -326,16 +326,15 @@ InstructionTLBMiss:
         ori     r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
 3:
 #endif
-        /* Extract level 1 index */
-        rlwinm  r10, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
-        lwzx    r11, r10, r11   /* Get the level 1 entry */
-        rlwinm  r10, r11,0,0,19 /* Extract page descriptor page address */
+        /* Insert level 1 index */
+        rlwimi  r11, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
+        lwz     r11, 0(r11)     /* Get the level 1 entry */
 
         /* Load the MI_TWC with the attributes for this "segment." */
         MTSPR_CPU6(SPRN_MI_TWC, r11, r3)        /* Set segment attributes */
-        mfspr   r11, SPRN_SRR0  /* Get effective address of fault */
+        rlwinm  r11, r11,0,0,19 /* Extract page descriptor page address */
         /* Extract level 2 index */
-        rlwinm  r11, r11, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
+        rlwinm  r10, r10, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
         lwzx    r10, r10, r11   /* Get the pte */
 
 #ifdef CONFIG_SWAP
@@ -380,13 +379,12 @@ DataStoreTLBMiss:
         lis     r11, (swapper_pg_dir-PAGE_OFFSET)@h
         ori     r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
 3:
-        /* Extract level 1 index */
-        rlwinm  r10, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
-        lwzx    r11, r10, r11   /* Get the level 1 entry */
+        /* Insert level 1 index */
+        rlwimi  r11, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
+        lwz     r11, 0(r11)     /* Get the level 1 entry */
 
         /* We have a pte table, so load fetch the pte from the table.
          */
-        mfspr   r10, SPRN_MD_EPN        /* Get address of fault */
         /* Extract level 2 index */
         rlwinm  r10, r10, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
         rlwimi  r10, r11, 0, 0, 32 - PAGE_SHIFT - 1     /* Add level 2 base */
@@ -512,16 +510,14 @@ FixupDAR:/* Entry point for dcbx workaround. */
         beq-    3f              /* Branch if user space */
         lis     r11, (swapper_pg_dir-PAGE_OFFSET)@h
         ori     r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
-        /* Extract level 1 index */
-3:      rlwinm  r10, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
-        lwzx    r11, r10, r11   /* Get the level 1 entry */
-        rlwinm  r10, r11,0,0,19 /* Extract page descriptor page address */
-        mfspr   r11, SPRN_SRR0  /* Get effective address of fault */
-        /* Extract level 2 index */
-        rlwinm  r11, r11, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
-        lwzx    r11, r10, r11   /* Get the pte */
+        /* Insert level 1 index */
+3:      rlwimi  r11, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
+        lwz     r11, 0(r11)     /* Get the level 1 entry */
+        rlwinm  r11, r11,0,0,19 /* Extract page descriptor page address */
+        /* Insert level 2 index */
+        rlwimi  r11, r10, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
+        lwz     r11, 0(r11)     /* Get the pte */
         /* concat physical page address(r11) and page offset(r10) */
-        mfspr   r10, SPRN_SRR0
         rlwimi  r11, r10, 0, 32 - PAGE_SHIFT, 31
         lwz     r11,0(r11)
 /* Check if it really is a dcbx instruction. */