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| author | David S. Miller <davem@davemloft.net> | 2005-07-28 01:08:44 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2005-07-28 01:08:44 +0200 |
| commit | 48b0e5487fcdcb3421bda67666277348b2bd2661 (patch) | |
| tree | 37822b91e0ded470f4728aa7511e8d3f72d977e5 /arch/sparc64 | |
| parent | [SPARC]: Add inotify syscall entries. (diff) | |
| download | linux-48b0e5487fcdcb3421bda67666277348b2bd2661.tar.xz linux-48b0e5487fcdcb3421bda67666277348b2bd2661.zip | |
[SPARC64]: Fix ugly dependency on NR_CPUS being a power-of-2.
The page->flags D-cache dirty state tracking depended upon
NR_CPUS being a power-of-2 via it's "NR_CPUS - 1" masking.
Fix that to use a fixed (256 - 1) mask as that is the limit
imposed by thread_info->cpu which is a "u8".
Finally, add a compile time check that NR_CPUS is not greater
than 256.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc64')
| -rw-r--r-- | arch/sparc64/mm/init.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c index 8fc413cb6acd..3fbaf342a452 100644 --- a/arch/sparc64/mm/init.c +++ b/arch/sparc64/mm/init.c @@ -121,15 +121,24 @@ __inline__ void flush_dcache_page_impl(struct page *page) } #define PG_dcache_dirty PG_arch_1 +#define PG_dcache_cpu_shift 24 +#define PG_dcache_cpu_mask (256 - 1) + +#if NR_CPUS > 256 +#error D-cache dirty tracking and thread_info->cpu need fixing for > 256 cpus +#endif #define dcache_dirty_cpu(page) \ - (((page)->flags >> 24) & (NR_CPUS - 1UL)) + (((page)->flags >> PG_dcache_cpu_shift) & PG_dcache_cpu_mask) static __inline__ void set_dcache_dirty(struct page *page, int this_cpu) { unsigned long mask = this_cpu; - unsigned long non_cpu_bits = ~((NR_CPUS - 1UL) << 24UL); - mask = (mask << 24) | (1UL << PG_dcache_dirty); + unsigned long non_cpu_bits; + + non_cpu_bits = ~(PG_dcache_cpu_mask << PG_dcache_cpu_shift); + mask = (mask << PG_dcache_cpu_shift) | (1UL << PG_dcache_dirty); + __asm__ __volatile__("1:\n\t" "ldx [%2], %%g7\n\t" "and %%g7, %1, %%g1\n\t" @@ -151,7 +160,7 @@ static __inline__ void clear_dcache_dirty_cpu(struct page *page, unsigned long c __asm__ __volatile__("! test_and_clear_dcache_dirty\n" "1:\n\t" "ldx [%2], %%g7\n\t" - "srlx %%g7, 24, %%g1\n\t" + "srlx %%g7, %4, %%g1\n\t" "and %%g1, %3, %%g1\n\t" "cmp %%g1, %0\n\t" "bne,pn %%icc, 2f\n\t" @@ -164,7 +173,8 @@ static __inline__ void clear_dcache_dirty_cpu(struct page *page, unsigned long c "2:" : /* no outputs */ : "r" (cpu), "r" (mask), "r" (&page->flags), - "i" (NR_CPUS - 1UL) + "i" (PG_dcache_cpu_mask), + "i" (PG_dcache_cpu_shift) : "g1", "g7"); } @@ -180,7 +190,8 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t p if (pfn_valid(pfn) && (page = pfn_to_page(pfn), page_mapping(page)) && ((pg_flags = page->flags) & (1UL << PG_dcache_dirty))) { - int cpu = ((pg_flags >> 24) & (NR_CPUS - 1UL)); + int cpu = ((pg_flags >> PG_dcache_cpu_shift) & + PG_dcache_cpu_mask); int this_cpu = get_cpu(); /* This is just to optimize away some function calls |