1 /* arch/sparc64/mm/tlb.c 2 * 3 * Copyright (C) 2004 David S. Miller <davem@redhat.com> 4 */ 5 6 #include <linux/kernel.h> 7 #include <linux/percpu.h> 8 #include <linux/mm.h> 9 #include <linux/swap.h> 10 #include <linux/preempt.h> 11 12 #include <asm/pgtable.h> 13 #include <asm/pgalloc.h> 14 #include <asm/tlbflush.h> 15 #include <asm/cacheflush.h> 16 #include <asm/mmu_context.h> 17 #include <asm/tlb.h> 18 19 /* Heavily inspired by the ppc64 code. */ 20 21 static DEFINE_PER_CPU(struct tlb_batch, tlb_batch); 22 23 void flush_tlb_pending(void) 24 { 25 struct tlb_batch *tb = &get_cpu_var(tlb_batch); 26 struct mm_struct *mm = tb->mm; 27 28 if (!tb->tlb_nr) 29 goto out; 30 31 flush_tsb_user(tb); 32 33 if (CTX_VALID(mm->context)) { 34 if (tb->tlb_nr == 1) { 35 global_flush_tlb_page(mm, tb->vaddrs[0]); 36 } else { 37 #ifdef CONFIG_SMP 38 smp_flush_tlb_pending(tb->mm, tb->tlb_nr, 39 &tb->vaddrs[0]); 40 #else 41 __flush_tlb_pending(CTX_HWBITS(tb->mm->context), 42 tb->tlb_nr, &tb->vaddrs[0]); 43 #endif 44 } 45 } 46 47 tb->tlb_nr = 0; 48 49 out: 50 put_cpu_var(tlb_batch); 51 } 52 53 void arch_enter_lazy_mmu_mode(void) 54 { 55 struct tlb_batch *tb = &__get_cpu_var(tlb_batch); 56 57 tb->active = 1; 58 } 59 60 void arch_leave_lazy_mmu_mode(void) 61 { 62 struct tlb_batch *tb = &__get_cpu_var(tlb_batch); 63 64 if (tb->tlb_nr) 65 flush_tlb_pending(); 66 tb->active = 0; 67 } 68 69 static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr, 70 bool exec) 71 { 72 struct tlb_batch *tb = &get_cpu_var(tlb_batch); 73 unsigned long nr; 74 75 vaddr &= PAGE_MASK; 76 if (exec) 77 vaddr |= 0x1UL; 78 79 nr = tb->tlb_nr; 80 81 if (unlikely(nr != 0 && mm != tb->mm)) { 82 flush_tlb_pending(); 83 nr = 0; 84 } 85 86 if (!tb->active) { 87 flush_tsb_user_page(mm, vaddr); 88 global_flush_tlb_page(mm, vaddr); 89 goto out; 90 } 91 92 if (nr == 0) 93 tb->mm = mm; 94 95 tb->vaddrs[nr] = vaddr; 96 tb->tlb_nr = ++nr; 97 if (nr >= TLB_BATCH_NR) 98 flush_tlb_pending(); 99 100 out: 101 put_cpu_var(tlb_batch); 102 } 103 104 void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr, 105 pte_t *ptep, pte_t orig, int fullmm) 106 { 107 if (tlb_type != hypervisor && 108 pte_dirty(orig)) { 109 unsigned long paddr, pfn = pte_pfn(orig); 110 struct address_space *mapping; 111 struct page *page; 112 113 if (!pfn_valid(pfn)) 114 goto no_cache_flush; 115 116 page = pfn_to_page(pfn); 117 if (PageReserved(page)) 118 goto no_cache_flush; 119 120 /* A real file page? */ 121 mapping = page_mapping(page); 122 if (!mapping) 123 goto no_cache_flush; 124 125 paddr = (unsigned long) page_address(page); 126 if ((paddr ^ vaddr) & (1 << 13)) 127 flush_dcache_page_all(mm, page); 128 } 129 130 no_cache_flush: 131 if (!fullmm) 132 tlb_batch_add_one(mm, vaddr, pte_exec(orig)); 133 } 134 135 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 136 static void tlb_batch_pmd_scan(struct mm_struct *mm, unsigned long vaddr, 137 pmd_t pmd, bool exec) 138 { 139 unsigned long end; 140 pte_t *pte; 141 142 pte = pte_offset_map(&pmd, vaddr); 143 end = vaddr + HPAGE_SIZE; 144 while (vaddr < end) { 145 if (pte_val(*pte) & _PAGE_VALID) 146 tlb_batch_add_one(mm, vaddr, exec); 147 pte++; 148 vaddr += PAGE_SIZE; 149 } 150 pte_unmap(pte); 151 } 152 153 void set_pmd_at(struct mm_struct *mm, unsigned long addr, 154 pmd_t *pmdp, pmd_t pmd) 155 { 156 pmd_t orig = *pmdp; 157 158 *pmdp = pmd; 159 160 if (mm == &init_mm) 161 return; 162 163 if ((pmd_val(pmd) ^ pmd_val(orig)) & _PAGE_PMD_HUGE) { 164 if (pmd_val(pmd) & _PAGE_PMD_HUGE) 165 mm->context.huge_pte_count++; 166 else 167 mm->context.huge_pte_count--; 168 169 /* Do not try to allocate the TSB hash table if we 170 * don't have one already. We have various locks held 171 * and thus we'll end up doing a GFP_KERNEL allocation 172 * in an atomic context. 173 * 174 * Instead, we let the first TLB miss on a hugepage 175 * take care of this. 176 */ 177 } 178 179 if (!pmd_none(orig)) { 180 pte_t orig_pte = __pte(pmd_val(orig)); 181 bool exec = pte_exec(orig_pte); 182 183 addr &= HPAGE_MASK; 184 if (pmd_trans_huge(orig)) { 185 tlb_batch_add_one(mm, addr, exec); 186 tlb_batch_add_one(mm, addr + REAL_HPAGE_SIZE, exec); 187 } else { 188 tlb_batch_pmd_scan(mm, addr, orig, exec); 189 } 190 } 191 } 192 193 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, 194 pgtable_t pgtable) 195 { 196 struct list_head *lh = (struct list_head *) pgtable; 197 198 assert_spin_locked(&mm->page_table_lock); 199 200 /* FIFO */ 201 if (!pmd_huge_pte(mm, pmdp)) 202 INIT_LIST_HEAD(lh); 203 else 204 list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp)); 205 pmd_huge_pte(mm, pmdp) = pgtable; 206 } 207 208 pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) 209 { 210 struct list_head *lh; 211 pgtable_t pgtable; 212 213 assert_spin_locked(&mm->page_table_lock); 214 215 /* FIFO */ 216 pgtable = pmd_huge_pte(mm, pmdp); 217 lh = (struct list_head *) pgtable; 218 if (list_empty(lh)) 219 pmd_huge_pte(mm, pmdp) = NULL; 220 else { 221 pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next; 222 list_del(lh); 223 } 224 pte_val(pgtable[0]) = 0; 225 pte_val(pgtable[1]) = 0; 226 227 return pgtable; 228 } 229 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 230