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| author | Rex Feany <RFeany@mrv.com> | 2009-09-23 14:45:52 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-09-24 15:56:30 +1000 |
| commit | e0908085fc2391c85b85fb814ae1df377c8e0dcb (patch) | |
| tree | 46560ab77e41c84ff15c05b5753d7512f8850ba8 /arch/powerpc | |
| parent | daf8f40391b2a1978ea2071c20959d91fade6b1a (diff) | |
| download | linux-e0908085fc2391c85b85fb814ae1df377c8e0dcb.tar.gz linux-e0908085fc2391c85b85fb814ae1df377c8e0dcb.tar.bz2 linux-e0908085fc2391c85b85fb814ae1df377c8e0dcb.zip | |
powerpc/8xx: Fix regression introduced by cache coherency rewrite
After upgrading to the latest kernel on my mpc875 userspace started
running incredibly slow (hours to get to a shell, even!).
I tracked it down to commit 8d30c14cab30d405a05f2aaceda1e9ad57800f36,
that patch removed a work-around for the 8xx. Adding it
back makes my problem go away.
Signed-off-by: Rex Feany <rfeany@mrv.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/mm/pgtable.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c index 83f1551ec2c9..53040931de32 100644 --- a/arch/powerpc/mm/pgtable.c +++ b/arch/powerpc/mm/pgtable.c @@ -30,6 +30,8 @@ #include <asm/tlbflush.h> #include <asm/tlb.h> +#include "mmu_decl.h" + DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); #ifdef CONFIG_SMP @@ -166,7 +168,7 @@ struct page * maybe_pte_to_page(pte_t pte) * support falls into the same category. */ -static pte_t set_pte_filter(pte_t pte) +static pte_t set_pte_filter(pte_t pte, unsigned long addr) { pte = __pte(pte_val(pte) & ~_PAGE_HPTEFLAGS); if (pte_looks_normal(pte) && !(cpu_has_feature(CPU_FTR_COHERENT_ICACHE) || @@ -175,6 +177,17 @@ static pte_t set_pte_filter(pte_t pte) if (!pg) return pte; if (!test_bit(PG_arch_1, &pg->flags)) { +#ifdef CONFIG_8xx + /* On 8xx, cache control instructions (particularly + * "dcbst" from flush_dcache_icache) fault as write + * operation if there is an unpopulated TLB entry + * for the address in question. To workaround that, + * we invalidate the TLB here, thus avoiding dcbst + * misbehaviour. + */ + /* 8xx doesn't care about PID, size or ind args */ + _tlbil_va(addr, 0, 0, 0); +#endif /* CONFIG_8xx */ flush_dcache_icache_page(pg); set_bit(PG_arch_1, &pg->flags); } @@ -194,7 +207,7 @@ static pte_t set_access_flags_filter(pte_t pte, struct vm_area_struct *vma, * as we don't have two bits to spare for _PAGE_EXEC and _PAGE_HWEXEC so * instead we "filter out" the exec permission for non clean pages. */ -static pte_t set_pte_filter(pte_t pte) +static pte_t set_pte_filter(pte_t pte, unsigned long addr) { struct page *pg; @@ -276,7 +289,7 @@ void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, * this context might not have been activated yet when this * is called. */ - pte = set_pte_filter(pte); + pte = set_pte_filter(pte, addr); /* Perform the setting of the PTE */ __set_pte_at(mm, addr, ptep, pte, 0); |