diff options
| author | Yuri Tikhonov <yur@emcraft.com> | 2008-02-02 10:47:31 +0300 |
|---|---|---|
| committer | Kumar Gala <galak@kernel.crashing.org> | 2008-03-07 16:56:54 -0600 |
| commit | 1757f2d12dce775982aaa006bce1cf4f7ce90111 (patch) | |
| tree | 068d45767a864ad383ece702fbcbcf3cd2e2752e | |
| parent | 3e0d65bf6d5b464949b749a8da7977f6b197d301 (diff) | |
[PPC] 8xx: swap bug-fix
This makes swap routines operate correctly on the ppc_8xx based machines.
Recent kernel's size makes swap feature very important on low-memory platfor
those are actually non-operable without it.
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
| -rw-r--r-- | arch/ppc/kernel/head_8xx.S | 30 | ||||
| -rw-r--r-- | include/asm-ppc/pgtable.h | 8 |
2 files changed, 29 insertions, 9 deletions
diff --git a/arch/ppc/kernel/head_8xx.S b/arch/ppc/kernel/head_8xx.S index eb8d26f87362..321bda2de2cb 100644 --- a/arch/ppc/kernel/head_8xx.S +++ b/arch/ppc/kernel/head_8xx.S @@ -329,8 +329,18 @@ 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. @@ -395,8 +405,17 @@ 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. @@ -575,7 +594,16 @@ 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 --git a/include/asm-ppc/pgtable.h b/include/asm-ppc/pgtable.h index 69347bdbb401..70435d32129a 100644 --- a/include/asm-ppc/pgtable.h +++ b/include/asm-ppc/pgtable.h @@ -299,14 +299,6 @@ extern unsigned long ioremap_bot, ioremap_base; #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 */ |