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author | Paul Mundt <lethal@linux-sh.org> | 2008-11-10 20:00:45 +0900 |
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committer | Paul Mundt <lethal@linux-sh.org> | 2008-11-10 20:00:45 +0900 |
commit | acca4f4d9bd657e8bc7e1665ba5077465138f133 (patch) | |
tree | 39b107c67d9dc59e6064e528457ca97ba4396ba2 /arch/sh | |
parent | f7160c7573615ec82c691e294cf80d920b5d588d (diff) | |
download | linux-3.10-acca4f4d9bd657e8bc7e1665ba5077465138f133.tar.gz linux-3.10-acca4f4d9bd657e8bc7e1665ba5077465138f133.tar.bz2 linux-3.10-acca4f4d9bd657e8bc7e1665ba5077465138f133.zip |
sh: Handle fixmap TLB eviction more coherently.
There was a race in the kmap_coherent() implementation. While we
guarded against preemption, there was nothing preventing eviction of
the pre-faulted fixmap entry from the UTLB. Under certain workloads
this would result in the fixmap entries used for cache colouring being
evicted from the UTLB in the midst of a copy_page().
In addition to pre-faulting, we also make sure to preserve the PTEs
in the kernel page table and introduce a cached PTE for kmap_coherent()
usage. This follows a similar change on MIPS ("[MIPS] Fix aliasing bug
in copy_to_user_page / copy_from_user_page").
Reported-by: Hideo Saito <saito@densan.co.jp>
Reported-by: CHIKAMA Masaki <masaki.chikama@gmail.com>
Tested-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh')
-rw-r--r-- | arch/sh/include/asm/pgtable.h | 6 | ||||
-rw-r--r-- | arch/sh/mm/init.c | 12 | ||||
-rw-r--r-- | arch/sh/mm/pg-sh4.c | 17 |
3 files changed, 32 insertions, 3 deletions
diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h index 52220d70a09..b517ae08b9c 100644 --- a/arch/sh/include/asm/pgtable.h +++ b/arch/sh/include/asm/pgtable.h @@ -148,6 +148,12 @@ extern void paging_init(void); extern void page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd); +#if !defined(CONFIG_CACHE_OFF) && defined(CONFIG_CPU_SH4) && defined(CONFIG_MMU) +extern void kmap_coherent_init(void); +#else +#define kmap_coherent_init() do { } while (0) +#endif + #include <asm-generic/pgtable.h> #endif /* __ASM_SH_PGTABLE_H */ diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c index 4abf00031da..6cbef8caeb5 100644 --- a/arch/sh/mm/init.c +++ b/arch/sh/mm/init.c @@ -137,6 +137,7 @@ void __init page_table_range_init(unsigned long start, unsigned long end, void __init paging_init(void) { unsigned long max_zone_pfns[MAX_NR_ZONES]; + unsigned long vaddr; int nid; /* We don't need to map the kernel through the TLB, as @@ -148,10 +149,15 @@ void __init paging_init(void) * check for a null value. */ set_TTB(swapper_pg_dir); - /* Populate the relevant portions of swapper_pg_dir so that + /* + * Populate the relevant portions of swapper_pg_dir so that * we can use the fixmap entries without calling kmalloc. - * pte's will be filled in by __set_fixmap(). */ - page_table_range_init(FIXADDR_START, FIXADDR_TOP, swapper_pg_dir); + * pte's will be filled in by __set_fixmap(). + */ + vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; + page_table_range_init(vaddr, 0, swapper_pg_dir); + + kmap_coherent_init(); memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); diff --git a/arch/sh/mm/pg-sh4.c b/arch/sh/mm/pg-sh4.c index 38870e0fc18..2fe14da1f83 100644 --- a/arch/sh/mm/pg-sh4.c +++ b/arch/sh/mm/pg-sh4.c @@ -7,6 +7,7 @@ * Released under the terms of the GNU GPL v2.0. */ #include <linux/mm.h> +#include <linux/init.h> #include <linux/mutex.h> #include <linux/fs.h> #include <linux/highmem.h> @@ -16,6 +17,20 @@ #define CACHE_ALIAS (current_cpu_data.dcache.alias_mask) +#define kmap_get_fixmap_pte(vaddr) \ + pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr)) + +static pte_t *kmap_coherent_pte; + +void __init kmap_coherent_init(void) +{ + unsigned long vaddr; + + /* cache the first coherent kmap pte */ + vaddr = __fix_to_virt(FIX_CMAP_BEGIN); + kmap_coherent_pte = kmap_get_fixmap_pte(vaddr); +} + static inline void *kmap_coherent(struct page *page, unsigned long addr) { enum fixed_addresses idx; @@ -34,6 +49,8 @@ static inline void *kmap_coherent(struct page *page, unsigned long addr) update_mmu_cache(NULL, vaddr, pte); + set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte); + return (void *)vaddr; } |