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

From: Christophe Leroy
Date: Tue Dec 16 2014 - 10:06:01 EST


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@xxxxxx>

---
arch/powerpc/kernel/head_8xx.S | 34 +++++++++++++++-------------------
1 file changed, 15 insertions(+), 19 deletions(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
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
+ 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 */
@@ -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. */
--
2.1.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/