The patch titled
powerpc: 8xx: fix swap
has been removed from the -mm tree. Its filename was
powerpc-8xx-fix-swap.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: powerpc: 8xx: fix swap
From: Vitaly Bordug <vitb@xxxxxxxxxxxxxxxxxxx>
This makes swap routines operate correctly on the ppc_8xx based machines.
Code has been revalidated on mpc885ads (8M sdram) with recent kernel. Based
on patch from Yuri Tikhonov <yur@xxxxxxxxxxx> to do the same on arch/ppc
instance.
Recent kernel's size makes swap feature very important on low-memory
platforms, those are actually non-operable without it.
Signed-off-by: Yuri Tikhonov <yur@xxxxxxxxxxx>
Signed-off-by: Vitaly Bordug <vitb@xxxxxxxxxxxxxxxxxxx>
Cc: Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx>
Cc: Scott Wood <scottwood@xxxxxxxxxxxxx>
Cc: Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/head_8xx.S | 30 +++++++++++++++++++++++++-
include/asm-powerpc/pgtable-ppc32.h | 8 ------
2 files changed, 29 insertions(+), 9 deletions(-)
diff -puN arch/powerpc/kernel/head_8xx.S~powerpc-8xx-fix-swap arch/powerpc/kernel/head_8xx.S
--- a/arch/powerpc/kernel/head_8xx.S~powerpc-8xx-fix-swap
+++ a/arch/powerpc/kernel/head_8xx.S
@@ -332,8 +332,18 @@ InstructionTLBMiss:
mfspr r11, SPRN_MD_TWC /* ....and get the pte address */
lwz r10, 0(r11) /* Get the pte */
+#ifdef CONFIG_SWAP
+ /* do not set the _PAGE_ACCESSED bit of a non-present page */
+ andi. r11, r10, _PAGE_PRESENT
+ beq 4f
+ ori r10, r10, _PAGE_ACCESSED
+ mfspr r11, SPRN_MD_TWC /* get the pte address again */
+ stw r10, 0(r11)
+4:
+#else
ori r10, r10, _PAGE_ACCESSED
stw r10, 0(r11)
+#endif
/* The Linux PTE won't go exactly into the MMU TLB.
* Software indicator bits 21, 22 and 28 must be clear.
@@ -398,8 +408,17 @@ DataStoreTLBMiss:
DO_8xx_CPU6(0x3b80, r3)
mtspr SPRN_MD_TWC, r11
- mfspr r11, SPRN_MD_TWC /* get the pte address again */
+#ifdef CONFIG_SWAP
+ /* do not set the _PAGE_ACCESSED bit of a non-present page */
+ andi. r11, r10, _PAGE_PRESENT
+ beq 4f
ori r10, r10, _PAGE_ACCESSED
+4:
+ /* and update pte in table */
+#else
+ ori r10, r10, _PAGE_ACCESSED
+#endif
+ mfspr r11, SPRN_MD_TWC /* get the pte address again */
stw r10, 0(r11)
/* The Linux PTE won't go exactly into the MMU TLB.
@@ -507,7 +526,16 @@ DataTLBError:
/* Update 'changed', among others.
*/
+#ifdef CONFIG_SWAP
+ ori r10, r10, _PAGE_DIRTY|_PAGE_HWWRITE
+ /* do not set the _PAGE_ACCESSED bit of a non-present page */
+ andi. r11, r10, _PAGE_PRESENT
+ beq 4f
+ ori r10, r10, _PAGE_ACCESSED
+4:
+#else
ori r10, r10, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE
+#endif
mfspr r11, SPRN_MD_TWC /* Get pte address again */
stw r10, 0(r11) /* and update pte in table */
diff -puN include/asm-powerpc/pgtable-ppc32.h~powerpc-8xx-fix-swap include/asm-powerpc/pgtable-ppc32.h
--- a/include/asm-powerpc/pgtable-ppc32.h~powerpc-8xx-fix-swap
+++ a/include/asm-powerpc/pgtable-ppc32.h
@@ -339,14 +339,6 @@ extern int icache_44x_need_flush;
#define _PMD_PAGE_MASK 0x000c
#define _PMD_PAGE_8M 0x000c
-/*
- * The 8xx TLB miss handler allegedly sets _PAGE_ACCESSED in the PTE
- * for an address even if _PAGE_PRESENT is not set, as a performance
- * optimization. This is a bug if you ever want to use swap unless
- * _PAGE_ACCESSED is 2, which it isn't, or unless you have 8xx-specific
- * definitions for __swp_entry etc. below, which would be gross.
- * -- paulus
- */
#define _PTE_NONE_MASK _PAGE_ACCESSED
#else /* CONFIG_6xx */
_
Patches currently in -mm which might be from vitb@xxxxxxxxxxxxxxxxxxx are
origin.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
