Thread (2 messages) 2 messages, 2 authors, 2015-01-05

Re: [PATCH 04/11] powerpc/8xx: Take benefit of aligned PGDIR

From: Joakim Tjernlund <hidden>
Date: 2015-01-05 18:19:17
Also in: lkml

On Tue, 2014-12-16 at 16:03 +0100, Christophe Leroy wrote:
L1 base address is now aligned so we can insert L1 index into r11 directl=
y and
then preserve r10
=20
Signed-off-by: Christophe Leroy <redacted>
Acked-by: Joakim Tjernlund <redacted>
quoted hunk ↗ jump to hunk
=20
---
 arch/powerpc/kernel/head_8xx.S | 34 +++++++++++++++-------------------
 1 file changed, 15 insertions(+), 19 deletions(-)
=20
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8x=
x.S
quoted hunk ↗ jump to hunk
index 2c329f1..ae05f28 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
quoted hunk ↗ jump to hunk
+       lwz     r11, 0(r11)/* Get the level 1 entry */
=20
        /* 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 */
=20
 #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
quoted hunk ↗ jump to hunk
+       lwz     r11, 0(r11)/* Get the level 1 entry */
=20
        /* 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 */
@@ -515,16 +513,14 @@ 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. */=
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