1 // SPDX-License-Identifier: GPL-2.0
2 /* arch/sparc64/mm/tlb.c
4 * Copyright (C) 2004 David S. Miller <davem@redhat.com>
7 #include <linux/kernel.h>
8 #include <linux/percpu.h>
10 #include <linux/swap.h>
11 #include <linux/preempt.h>
12 #include <linux/pagemap.h>
14 #include <asm/tlbflush.h>
15 #include <asm/cacheflush.h>
16 #include <asm/mmu_context.h>
19 /* Heavily inspired by the ppc64 code. */
21 static DEFINE_PER_CPU(struct tlb_batch, tlb_batch);
23 void flush_tlb_pending(void)
25 struct tlb_batch *tb = &get_cpu_var(tlb_batch);
26 struct mm_struct *mm = tb->mm;
33 if (CTX_VALID(mm->context)) {
34 if (tb->tlb_nr == 1) {
35 global_flush_tlb_page(mm, tb->vaddrs[0]);
38 smp_flush_tlb_pending(tb->mm, tb->tlb_nr,
41 __flush_tlb_pending(CTX_HWBITS(tb->mm->context),
42 tb->tlb_nr, &tb->vaddrs[0]);
50 put_cpu_var(tlb_batch);
53 void arch_enter_lazy_mmu_mode(void)
55 struct tlb_batch *tb = this_cpu_ptr(&tlb_batch);
60 void arch_leave_lazy_mmu_mode(void)
62 struct tlb_batch *tb = this_cpu_ptr(&tlb_batch);
69 static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr,
70 bool exec, unsigned int hugepage_shift)
72 struct tlb_batch *tb = &get_cpu_var(tlb_batch);
81 if (unlikely(nr != 0 && mm != tb->mm)) {
87 flush_tsb_user_page(mm, vaddr, hugepage_shift);
88 global_flush_tlb_page(mm, vaddr);
94 tb->hugepage_shift = hugepage_shift;
97 if (tb->hugepage_shift != hugepage_shift) {
99 tb->hugepage_shift = hugepage_shift;
103 tb->vaddrs[nr] = vaddr;
105 if (nr >= TLB_BATCH_NR)
109 put_cpu_var(tlb_batch);
112 void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
113 pte_t *ptep, pte_t orig, int fullmm,
114 unsigned int hugepage_shift)
116 if (tlb_type != hypervisor &&
118 unsigned long paddr, pfn = pte_pfn(orig);
119 struct address_space *mapping;
126 page = pfn_to_page(pfn);
127 if (PageReserved(page))
130 /* A real file page? */
131 folio = page_folio(page);
132 mapping = folio_flush_mapping(folio);
136 paddr = (unsigned long) page_address(page);
137 if ((paddr ^ vaddr) & (1 << 13))
138 flush_dcache_folio_all(mm, folio);
143 tlb_batch_add_one(mm, vaddr, pte_exec(orig), hugepage_shift);
146 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
147 static void tlb_batch_pmd_scan(struct mm_struct *mm, unsigned long vaddr,
153 pte = pte_offset_map(&pmd, vaddr);
156 end = vaddr + HPAGE_SIZE;
157 while (vaddr < end) {
158 if (pte_val(*pte) & _PAGE_VALID) {
159 bool exec = pte_exec(*pte);
161 tlb_batch_add_one(mm, vaddr, exec, PAGE_SHIFT);
170 static void __set_pmd_acct(struct mm_struct *mm, unsigned long addr,
171 pmd_t orig, pmd_t pmd)
176 if ((pmd_val(pmd) ^ pmd_val(orig)) & _PAGE_PMD_HUGE) {
178 * Note that this routine only sets pmds for THP pages.
179 * Hugetlb pages are handled elsewhere. We need to check
180 * for huge zero page. Huge zero pages are like hugetlb
181 * pages in that there is no RSS, but there is the need
182 * for TSB entries. So, huge zero page counts go into
185 if (pmd_val(pmd) & _PAGE_PMD_HUGE) {
186 if (is_huge_zero_page(pmd_page(pmd)))
187 mm->context.hugetlb_pte_count++;
189 mm->context.thp_pte_count++;
191 if (is_huge_zero_page(pmd_page(orig)))
192 mm->context.hugetlb_pte_count--;
194 mm->context.thp_pte_count--;
197 /* Do not try to allocate the TSB hash table if we
198 * don't have one already. We have various locks held
199 * and thus we'll end up doing a GFP_KERNEL allocation
200 * in an atomic context.
202 * Instead, we let the first TLB miss on a hugepage
207 if (!pmd_none(orig)) {
209 if (pmd_trans_huge(orig)) {
210 pte_t orig_pte = __pte(pmd_val(orig));
211 bool exec = pte_exec(orig_pte);
213 tlb_batch_add_one(mm, addr, exec, REAL_HPAGE_SHIFT);
214 tlb_batch_add_one(mm, addr + REAL_HPAGE_SIZE, exec,
217 tlb_batch_pmd_scan(mm, addr, orig);
222 void set_pmd_at(struct mm_struct *mm, unsigned long addr,
223 pmd_t *pmdp, pmd_t pmd)
228 __set_pmd_acct(mm, addr, orig, pmd);
231 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
232 unsigned long address, pmd_t *pmdp, pmd_t pmd)
238 } while (cmpxchg64(&pmdp->pmd, old.pmd, pmd.pmd) != old.pmd);
239 __set_pmd_acct(vma->vm_mm, address, old, pmd);
245 * This routine is only called when splitting a THP
247 pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
252 entry = __pmd(pmd_val(*pmdp) & ~_PAGE_VALID);
253 old = pmdp_establish(vma, address, pmdp, entry);
254 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
257 * set_pmd_at() will not be called in a way to decrement
258 * thp_pte_count when splitting a THP, so do it now.
259 * Sanity check pmd before doing the actual decrement.
261 if ((pmd_val(entry) & _PAGE_PMD_HUGE) &&
262 !is_huge_zero_page(pmd_page(entry)))
263 (vma->vm_mm)->context.thp_pte_count--;
268 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
271 struct list_head *lh = (struct list_head *) pgtable;
273 assert_spin_locked(&mm->page_table_lock);
276 if (!pmd_huge_pte(mm, pmdp))
279 list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
280 pmd_huge_pte(mm, pmdp) = pgtable;
283 pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
285 struct list_head *lh;
288 assert_spin_locked(&mm->page_table_lock);
291 pgtable = pmd_huge_pte(mm, pmdp);
292 lh = (struct list_head *) pgtable;
294 pmd_huge_pte(mm, pmdp) = NULL;
296 pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
299 pte_val(pgtable[0]) = 0;
300 pte_val(pgtable[1]) = 0;
304 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */