diff options
Diffstat (limited to 'arch/arm64/include/asm/tlb.h')
| -rw-r--r-- | arch/arm64/include/asm/tlb.h | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h new file mode 100644 index 00000000000..654f0968030 --- /dev/null +++ b/arch/arm64/include/asm/tlb.h @@ -0,0 +1,190 @@ +/* + * Based on arch/arm/include/asm/tlb.h + * + * Copyright (C) 2002 Russell King + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#ifndef __ASM_TLB_H +#define __ASM_TLB_H + +#include <linux/pagemap.h> +#include <linux/swap.h> + +#include <asm/pgalloc.h> +#include <asm/tlbflush.h> + +#define MMU_GATHER_BUNDLE 8 + +/* + * TLB handling. This allows us to remove pages from the page + * tables, and efficiently handle the TLB issues. + */ +struct mmu_gather { + struct mm_struct *mm; + unsigned int fullmm; + struct vm_area_struct *vma; + unsigned long range_start; + unsigned long range_end; + unsigned int nr; + unsigned int max; + struct page **pages; + struct page *local[MMU_GATHER_BUNDLE]; +}; + +/* + * This is unnecessarily complex. There's three ways the TLB shootdown + * code is used: + * 1. Unmapping a range of vmas. See zap_page_range(), unmap_region(). + * tlb->fullmm = 0, and tlb_start_vma/tlb_end_vma will be called. + * tlb->vma will be non-NULL. + * 2. Unmapping all vmas. See exit_mmap(). + * tlb->fullmm = 1, and tlb_start_vma/tlb_end_vma will be called. + * tlb->vma will be non-NULL. Additionally, page tables will be freed. + * 3. Unmapping argument pages. See shift_arg_pages(). + * tlb->fullmm = 0, but tlb_start_vma/tlb_end_vma will not be called. + * tlb->vma will be NULL. + */ +static inline void tlb_flush(struct mmu_gather *tlb) +{ + if (tlb->fullmm || !tlb->vma) + flush_tlb_mm(tlb->mm); + else if (tlb->range_end > 0) { + flush_tlb_range(tlb->vma, tlb->range_start, tlb->range_end); + tlb->range_start = TASK_SIZE; + tlb->range_end = 0; + } +} + +static inline void tlb_add_flush(struct mmu_gather *tlb, unsigned long addr) +{ + if (!tlb->fullmm) { + if (addr < tlb->range_start) + tlb->range_start = addr; + if (addr + PAGE_SIZE > tlb->range_end) + tlb->range_end = addr + PAGE_SIZE; + } +} + +static inline void __tlb_alloc_page(struct mmu_gather *tlb) +{ + unsigned long addr = __get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0); + + if (addr) { + tlb->pages = (void *)addr; + tlb->max = PAGE_SIZE / sizeof(struct page *); + } +} + +static inline void tlb_flush_mmu(struct mmu_gather *tlb) +{ + tlb_flush(tlb); + free_pages_and_swap_cache(tlb->pages, tlb->nr); + tlb->nr = 0; + if (tlb->pages == tlb->local) + __tlb_alloc_page(tlb); +} + +static inline void +tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned int fullmm) +{ + tlb->mm = mm; + tlb->fullmm = fullmm; + tlb->vma = NULL; + tlb->max = ARRAY_SIZE(tlb->local); + tlb->pages = tlb->local; + tlb->nr = 0; + __tlb_alloc_page(tlb); +} + +static inline void +tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) +{ + tlb_flush_mmu(tlb); + + /* keep the page table cache within bounds */ + check_pgt_cache(); + + if (tlb->pages != tlb->local) + free_pages((unsigned long)tlb->pages, 0); +} + +/* + * Memorize the range for the TLB flush. + */ +static inline void +tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, unsigned long addr) +{ + tlb_add_flush(tlb, addr); +} + +/* + * In the case of tlb vma handling, we can optimise these away in the + * case where we're doing a full MM flush. When we're doing a munmap, + * the vmas are adjusted to only cover the region to be torn down. + */ +static inline void +tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ + if (!tlb->fullmm) { + tlb->vma = vma; + tlb->range_start = TASK_SIZE; + tlb->range_end = 0; + } +} + +static inline void +tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ + if (!tlb->fullmm) + tlb_flush(tlb); +} + +static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) +{ + tlb->pages[tlb->nr++] = page; + VM_BUG_ON(tlb->nr > tlb->max); + return tlb->max - tlb->nr; +} + +static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) +{ + if (!__tlb_remove_page(tlb, page)) + tlb_flush_mmu(tlb); +} + +static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, + unsigned long addr) +{ + pgtable_page_dtor(pte); + tlb_add_flush(tlb, addr); + tlb_remove_page(tlb, pte); +} + +#ifndef CONFIG_ARM64_64K_PAGES +static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, + unsigned long addr) +{ + tlb_add_flush(tlb, addr); + tlb_remove_page(tlb, virt_to_page(pmdp)); +} +#endif + +#define pte_free_tlb(tlb, ptep, addr) __pte_free_tlb(tlb, ptep, addr) +#define pmd_free_tlb(tlb, pmdp, addr) __pmd_free_tlb(tlb, pmdp, addr) +#define pud_free_tlb(tlb, pudp, addr) pud_free((tlb)->mm, pudp) + +#define tlb_migrate_finish(mm) do { } while (0) + +#endif |