diff options
| -rw-r--r-- | arch/sparc/mm/init_64.c | 81 |
1 files changed, 54 insertions, 27 deletions
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c index d5cebdb37a4b..57154c638e71 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -664,6 +664,53 @@ unsigned long tlb_context_cache = CTX_FIRST_VERSION; DECLARE_BITMAP(mmu_context_bmap, MAX_CTX_NR); DEFINE_PER_CPU(struct mm_struct *, per_cpu_secondary_mm) = {0}; +static void mmu_context_wrap(void) +{ + unsigned long old_ver = tlb_context_cache & CTX_VERSION_MASK; + unsigned long new_ver, new_ctx, old_ctx; + struct mm_struct *mm; + int cpu; + + bitmap_zero(mmu_context_bmap, 1 << CTX_NR_BITS); + + /* Reserve kernel context */ + set_bit(0, mmu_context_bmap); + + new_ver = (tlb_context_cache & CTX_VERSION_MASK) + CTX_FIRST_VERSION; + if (unlikely(new_ver == 0)) + new_ver = CTX_FIRST_VERSION; + tlb_context_cache = new_ver; + + /* + * Make sure that any new mm that are added into per_cpu_secondary_mm, + * are going to go through get_new_mmu_context() path. + */ + mb(); + + /* + * Updated versions to current on those CPUs that had valid secondary + * contexts + */ + for_each_online_cpu(cpu) { + /* + * If a new mm is stored after we took this mm from the array, + * it will go into get_new_mmu_context() path, because we + * already bumped the version in tlb_context_cache. + */ + mm = per_cpu(per_cpu_secondary_mm, cpu); + + if (unlikely(!mm || mm == &init_mm)) + continue; + + old_ctx = mm->context.sparc64_ctx_val; + if (likely((old_ctx & CTX_VERSION_MASK) == old_ver)) { + new_ctx = (old_ctx & ~CTX_VERSION_MASK) | new_ver; + set_bit(new_ctx & CTX_NR_MASK, mmu_context_bmap); + mm->context.sparc64_ctx_val = new_ctx; + } + } +} + /* Caller does TLB context flushing on local CPU if necessary. * The caller also ensures that CTX_VALID(mm->context) is false. * @@ -678,50 +725,30 @@ void get_new_mmu_context(struct mm_struct *mm) { unsigned long ctx, new_ctx; unsigned long orig_pgsz_bits; - int new_version; spin_lock(&ctx_alloc_lock); +retry: + /* wrap might have happened, test again if our context became valid */ + if (unlikely(CTX_VALID(mm->context))) + goto out; orig_pgsz_bits = (mm->context.sparc64_ctx_val & CTX_PGSZ_MASK); ctx = (tlb_context_cache + 1) & CTX_NR_MASK; new_ctx = find_next_zero_bit(mmu_context_bmap, 1 << CTX_NR_BITS, ctx); - new_version = 0; if (new_ctx >= (1 << CTX_NR_BITS)) { new_ctx = find_next_zero_bit(mmu_context_bmap, ctx, 1); if (new_ctx >= ctx) { - int i; - new_ctx = (tlb_context_cache & CTX_VERSION_MASK) + - CTX_FIRST_VERSION + 1; - if (new_ctx == 1) - new_ctx = CTX_FIRST_VERSION + 1; - - /* Don't call memset, for 16 entries that's just - * plain silly... - */ - mmu_context_bmap[0] = 3; - mmu_context_bmap[1] = 0; - mmu_context_bmap[2] = 0; - mmu_context_bmap[3] = 0; - for (i = 4; i < CTX_BMAP_SLOTS; i += 4) { - mmu_context_bmap[i + 0] = 0; - mmu_context_bmap[i + 1] = 0; - mmu_context_bmap[i + 2] = 0; - mmu_context_bmap[i + 3] = 0; - } - new_version = 1; - goto out; + mmu_context_wrap(); + goto retry; } } if (mm->context.sparc64_ctx_val) cpumask_clear(mm_cpumask(mm)); mmu_context_bmap[new_ctx>>6] |= (1UL << (new_ctx & 63)); new_ctx |= (tlb_context_cache & CTX_VERSION_MASK); -out: tlb_context_cache = new_ctx; mm->context.sparc64_ctx_val = new_ctx | orig_pgsz_bits; +out: spin_unlock(&ctx_alloc_lock); - - if (unlikely(new_version)) - smp_new_mmu_context_version(); } static int numa_enabled = 1; |