From 58d0ba578bc3b7c044d4ef570307bcb03862cb66 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Mon, 5 Mar 2012 11:49:28 +0000 Subject: arm64: TLB maintenance functionality This patch adds the TLB maintenance functions. There is no distinction made between the I and D TLBs. TLB maintenance operations are automatically broadcast between CPUs in hardware. The inner-shareable operations are always present, even on UP systems. NOTE: Large part of this patch to be dropped once Peter Z's generic mmu_gather patches are merged. Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Acked-by: Tony Lindgren Acked-by: Nicolas Pitre Acked-by: Olof Johansson Acked-by: Santosh Shilimkar Acked-by: Arnd Bergmann --- arch/arm64/include/asm/tlb.h | 190 ++++++++++++++++++++++++++++++++++++++ arch/arm64/include/asm/tlbflush.h | 122 ++++++++++++++++++++++++ arch/arm64/mm/tlb.S | 71 ++++++++++++++ 3 files changed, 383 insertions(+) create mode 100644 arch/arm64/include/asm/tlb.h create mode 100644 arch/arm64/include/asm/tlbflush.h create mode 100644 arch/arm64/mm/tlb.S diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h new file mode 100644 index 0000000..654f096 --- /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 . + */ +#ifndef __ASM_TLB_H +#define __ASM_TLB_H + +#include +#include + +#include +#include + +#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 diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h new file mode 100644 index 0000000..122d632 --- /dev/null +++ b/arch/arm64/include/asm/tlbflush.h @@ -0,0 +1,122 @@ +/* + * Based on arch/arm/include/asm/tlbflush.h + * + * Copyright (C) 1999-2003 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 . + */ +#ifndef __ASM_TLBFLUSH_H +#define __ASM_TLBFLUSH_H + +#ifndef __ASSEMBLY__ + +#include +#include + +extern void __cpu_flush_user_tlb_range(unsigned long, unsigned long, struct vm_area_struct *); +extern void __cpu_flush_kern_tlb_range(unsigned long, unsigned long); + +extern struct cpu_tlb_fns cpu_tlb; + +/* + * TLB Management + * ============== + * + * The arch/arm64/mm/tlb.S files implement these methods. + * + * The TLB specific code is expected to perform whatever tests it needs + * to determine if it should invalidate the TLB for each call. Start + * addresses are inclusive and end addresses are exclusive; it is safe to + * round these addresses down. + * + * flush_tlb_all() + * + * Invalidate the entire TLB. + * + * flush_tlb_mm(mm) + * + * Invalidate all TLB entries in a particular address space. + * - mm - mm_struct describing address space + * + * flush_tlb_range(mm,start,end) + * + * Invalidate a range of TLB entries in the specified address + * space. + * - mm - mm_struct describing address space + * - start - start address (may not be aligned) + * - end - end address (exclusive, may not be aligned) + * + * flush_tlb_page(vaddr,vma) + * + * Invalidate the specified page in the specified address range. + * - vaddr - virtual address (may not be aligned) + * - vma - vma_struct describing address range + * + * flush_kern_tlb_page(kaddr) + * + * Invalidate the TLB entry for the specified page. The address + * will be in the kernels virtual memory space. Current uses + * only require the D-TLB to be invalidated. + * - kaddr - Kernel virtual memory address + */ +static inline void flush_tlb_all(void) +{ + dsb(); + asm("tlbi vmalle1is"); + dsb(); + isb(); +} + +static inline void flush_tlb_mm(struct mm_struct *mm) +{ + unsigned long asid = (unsigned long)ASID(mm) << 48; + + dsb(); + asm("tlbi aside1is, %0" : : "r" (asid)); + dsb(); +} + +static inline void flush_tlb_page(struct vm_area_struct *vma, + unsigned long uaddr) +{ + unsigned long addr = uaddr >> 12 | + ((unsigned long)ASID(vma->vm_mm) << 48); + + dsb(); + asm("tlbi vae1is, %0" : : "r" (addr)); + dsb(); +} + +/* + * Convert calls to our calling convention. + */ +#define flush_tlb_range(vma,start,end) __cpu_flush_user_tlb_range(start,end,vma) +#define flush_tlb_kernel_range(s,e) __cpu_flush_kern_tlb_range(s,e) + +/* + * On AArch64, the cache coherency is handled via the set_pte_at() function. + */ +static inline void update_mmu_cache(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) +{ + /* + * set_pte() does not have a DSB, so make sure that the page table + * write is visible. + */ + dsb(); +} + +#endif + +#endif diff --git a/arch/arm64/mm/tlb.S b/arch/arm64/mm/tlb.S new file mode 100644 index 0000000..8ae80a1 --- /dev/null +++ b/arch/arm64/mm/tlb.S @@ -0,0 +1,71 @@ +/* + * Based on arch/arm/mm/tlb.S + * + * Copyright (C) 1997-2002 Russell King + * Copyright (C) 2012 ARM Ltd. + * Written by Catalin Marinas + * + * 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 . + */ +#include +#include +#include +#include +#include +#include "proc-macros.S" + +/* + * __cpu_flush_user_tlb_range(start, end, vma) + * + * Invalidate a range of TLB entries in the specified address space. + * + * - start - start address (may not be aligned) + * - end - end address (exclusive, may not be aligned) + * - vma - vma_struct describing address range + */ +ENTRY(__cpu_flush_user_tlb_range) + vma_vm_mm x3, x2 // get vma->vm_mm + mmid x3, x3 // get vm_mm->context.id + dsb sy + lsr x0, x0, #12 // align address + lsr x1, x1, #12 + bfi x0, x3, #48, #16 // start VA and ASID + bfi x1, x3, #48, #16 // end VA and ASID +1: tlbi vae1is, x0 // TLB invalidate by address and ASID + add x0, x0, #1 + cmp x0, x1 + b.lo 1b + dsb sy + ret +ENDPROC(__cpu_flush_user_tlb_range) + +/* + * __cpu_flush_kern_tlb_range(start,end) + * + * Invalidate a range of kernel TLB entries. + * + * - start - start address (may not be aligned) + * - end - end address (exclusive, may not be aligned) + */ +ENTRY(__cpu_flush_kern_tlb_range) + dsb sy + lsr x0, x0, #12 // align address + lsr x1, x1, #12 +1: tlbi vaae1is, x0 // TLB invalidate by address + add x0, x0, #1 + cmp x0, x1 + b.lo 1b + dsb sy + isb + ret +ENDPROC(__cpu_flush_kern_tlb_range) -- cgit v1.1