| // SPDX-License-Identifier: GPL-2.0 |
| /* arch/sparc64/mm/tlb.c |
| * |
| * Copyright (C) 2004 David S. Miller <davem@redhat.com> |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/percpu.h> |
| #include <linux/mm.h> |
| #include <linux/swap.h> |
| #include <linux/preempt.h> |
| #include <linux/pagemap.h> |
| |
| #include <asm/tlbflush.h> |
| #include <asm/cacheflush.h> |
| #include <asm/mmu_context.h> |
| #include <asm/tlb.h> |
| |
| /* Heavily inspired by the ppc64 code. */ |
| |
| static DEFINE_PER_CPU(struct tlb_batch, tlb_batch); |
| |
| void flush_tlb_pending(void) |
| { |
| struct tlb_batch *tb = &get_cpu_var(tlb_batch); |
| struct mm_struct *mm = tb->mm; |
| |
| if (!tb->tlb_nr) |
| goto out; |
| |
| flush_tsb_user(tb); |
| |
| if (CTX_VALID(mm->context)) { |
| if (tb->tlb_nr == 1) { |
| global_flush_tlb_page(mm, tb->vaddrs[0]); |
| } else { |
| #ifdef CONFIG_SMP |
| smp_flush_tlb_pending(tb->mm, tb->tlb_nr, |
| &tb->vaddrs[0]); |
| #else |
| __flush_tlb_pending(CTX_HWBITS(tb->mm->context), |
| tb->tlb_nr, &tb->vaddrs[0]); |
| #endif |
| } |
| } |
| |
| tb->tlb_nr = 0; |
| |
| out: |
| put_cpu_var(tlb_batch); |
| } |
| |
| void arch_enter_lazy_mmu_mode(void) |
| { |
| struct tlb_batch *tb = this_cpu_ptr(&tlb_batch); |
| |
| tb->active = 1; |
| } |
| |
| void arch_leave_lazy_mmu_mode(void) |
| { |
| struct tlb_batch *tb = this_cpu_ptr(&tlb_batch); |
| |
| if (tb->tlb_nr) |
| flush_tlb_pending(); |
| tb->active = 0; |
| } |
| |
| static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr, |
| bool exec, unsigned int hugepage_shift) |
| { |
| struct tlb_batch *tb = &get_cpu_var(tlb_batch); |
| unsigned long nr; |
| |
| vaddr &= PAGE_MASK; |
| if (exec) |
| vaddr |= 0x1UL; |
| |
| nr = tb->tlb_nr; |
| |
| if (unlikely(nr != 0 && mm != tb->mm)) { |
| flush_tlb_pending(); |
| nr = 0; |
| } |
| |
| if (!tb->active) { |
| flush_tsb_user_page(mm, vaddr, hugepage_shift); |
| global_flush_tlb_page(mm, vaddr); |
| goto out; |
| } |
| |
| if (nr == 0) { |
| tb->mm = mm; |
| tb->hugepage_shift = hugepage_shift; |
| } |
| |
| if (tb->hugepage_shift != hugepage_shift) { |
| flush_tlb_pending(); |
| tb->hugepage_shift = hugepage_shift; |
| nr = 0; |
| } |
| |
| tb->vaddrs[nr] = vaddr; |
| tb->tlb_nr = ++nr; |
| if (nr >= TLB_BATCH_NR) |
| flush_tlb_pending(); |
| |
| out: |
| put_cpu_var(tlb_batch); |
| } |
| |
| void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr, |
| pte_t *ptep, pte_t orig, int fullmm, |
| unsigned int hugepage_shift) |
| { |
| if (tlb_type != hypervisor && |
| pte_dirty(orig)) { |
| unsigned long paddr, pfn = pte_pfn(orig); |
| struct address_space *mapping; |
| struct page *page; |
| struct folio *folio; |
| |
| if (!pfn_valid(pfn)) |
| goto no_cache_flush; |
| |
| page = pfn_to_page(pfn); |
| if (PageReserved(page)) |
| goto no_cache_flush; |
| |
| /* A real file page? */ |
| folio = page_folio(page); |
| mapping = folio_flush_mapping(folio); |
| if (!mapping) |
| goto no_cache_flush; |
| |
| paddr = (unsigned long) page_address(page); |
| if ((paddr ^ vaddr) & (1 << 13)) |
| flush_dcache_folio_all(mm, folio); |
| } |
| |
| no_cache_flush: |
| if (!fullmm) |
| tlb_batch_add_one(mm, vaddr, pte_exec(orig), hugepage_shift); |
| } |
| |
| #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
| static void tlb_batch_pmd_scan(struct mm_struct *mm, unsigned long vaddr, |
| pmd_t pmd) |
| { |
| unsigned long end; |
| pte_t *pte; |
| |
| pte = pte_offset_map(&pmd, vaddr); |
| if (!pte) |
| return; |
| end = vaddr + HPAGE_SIZE; |
| while (vaddr < end) { |
| if (pte_val(*pte) & _PAGE_VALID) { |
| bool exec = pte_exec(*pte); |
| |
| tlb_batch_add_one(mm, vaddr, exec, PAGE_SHIFT); |
| } |
| pte++; |
| vaddr += PAGE_SIZE; |
| } |
| pte_unmap(pte); |
| } |
| |
| |
| static void __set_pmd_acct(struct mm_struct *mm, unsigned long addr, |
| pmd_t orig, pmd_t pmd) |
| { |
| if (mm == &init_mm) |
| return; |
| |
| if ((pmd_val(pmd) ^ pmd_val(orig)) & _PAGE_PMD_HUGE) { |
| /* |
| * Note that this routine only sets pmds for THP pages. |
| * Hugetlb pages are handled elsewhere. We need to check |
| * for huge zero page. Huge zero pages are like hugetlb |
| * pages in that there is no RSS, but there is the need |
| * for TSB entries. So, huge zero page counts go into |
| * hugetlb_pte_count. |
| */ |
| if (pmd_val(pmd) & _PAGE_PMD_HUGE) { |
| if (is_huge_zero_page(pmd_page(pmd))) |
| mm->context.hugetlb_pte_count++; |
| else |
| mm->context.thp_pte_count++; |
| } else { |
| if (is_huge_zero_page(pmd_page(orig))) |
| mm->context.hugetlb_pte_count--; |
| else |
| mm->context.thp_pte_count--; |
| } |
| |
| /* Do not try to allocate the TSB hash table if we |
| * don't have one already. We have various locks held |
| * and thus we'll end up doing a GFP_KERNEL allocation |
| * in an atomic context. |
| * |
| * Instead, we let the first TLB miss on a hugepage |
| * take care of this. |
| */ |
| } |
| |
| if (!pmd_none(orig)) { |
| addr &= HPAGE_MASK; |
| if (pmd_trans_huge(orig)) { |
| pte_t orig_pte = __pte(pmd_val(orig)); |
| bool exec = pte_exec(orig_pte); |
| |
| tlb_batch_add_one(mm, addr, exec, REAL_HPAGE_SHIFT); |
| tlb_batch_add_one(mm, addr + REAL_HPAGE_SIZE, exec, |
| REAL_HPAGE_SHIFT); |
| } else { |
| tlb_batch_pmd_scan(mm, addr, orig); |
| } |
| } |
| } |
| |
| void set_pmd_at(struct mm_struct *mm, unsigned long addr, |
| pmd_t *pmdp, pmd_t pmd) |
| { |
| pmd_t orig = *pmdp; |
| |
| *pmdp = pmd; |
| __set_pmd_acct(mm, addr, orig, pmd); |
| } |
| |
| static inline pmd_t pmdp_establish(struct vm_area_struct *vma, |
| unsigned long address, pmd_t *pmdp, pmd_t pmd) |
| { |
| pmd_t old; |
| |
| do { |
| old = *pmdp; |
| } while (cmpxchg64(&pmdp->pmd, old.pmd, pmd.pmd) != old.pmd); |
| __set_pmd_acct(vma->vm_mm, address, old, pmd); |
| |
| return old; |
| } |
| |
| /* |
| * This routine is only called when splitting a THP |
| */ |
| pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, |
| pmd_t *pmdp) |
| { |
| pmd_t old, entry; |
| |
| entry = __pmd(pmd_val(*pmdp) & ~_PAGE_VALID); |
| old = pmdp_establish(vma, address, pmdp, entry); |
| flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); |
| |
| /* |
| * set_pmd_at() will not be called in a way to decrement |
| * thp_pte_count when splitting a THP, so do it now. |
| * Sanity check pmd before doing the actual decrement. |
| */ |
| if ((pmd_val(entry) & _PAGE_PMD_HUGE) && |
| !is_huge_zero_page(pmd_page(entry))) |
| (vma->vm_mm)->context.thp_pte_count--; |
| |
| return old; |
| } |
| |
| void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, |
| pgtable_t pgtable) |
| { |
| struct list_head *lh = (struct list_head *) pgtable; |
| |
| assert_spin_locked(&mm->page_table_lock); |
| |
| /* FIFO */ |
| if (!pmd_huge_pte(mm, pmdp)) |
| INIT_LIST_HEAD(lh); |
| else |
| list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp)); |
| pmd_huge_pte(mm, pmdp) = pgtable; |
| } |
| |
| pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) |
| { |
| struct list_head *lh; |
| pgtable_t pgtable; |
| |
| assert_spin_locked(&mm->page_table_lock); |
| |
| /* FIFO */ |
| pgtable = pmd_huge_pte(mm, pmdp); |
| lh = (struct list_head *) pgtable; |
| if (list_empty(lh)) |
| pmd_huge_pte(mm, pmdp) = NULL; |
| else { |
| pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next; |
| list_del(lh); |
| } |
| pte_val(pgtable[0]) = 0; |
| pte_val(pgtable[1]) = 0; |
| |
| return pgtable; |
| } |
| #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |