![Kirill A. Shutemov](/assets/img/avatar_default.png)
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
418 lines
10 KiB
C
418 lines
10 KiB
C
/*
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* linux/arch/arm/mm/flush.c
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*
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* Copyright (C) 1995-2002 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <linux/highmem.h>
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#include <asm/cacheflush.h>
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#include <asm/cachetype.h>
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#include <asm/highmem.h>
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#include <asm/smp_plat.h>
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#include <asm/tlbflush.h>
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#include <linux/hugetlb.h>
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#include "mm.h"
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#ifdef CONFIG_ARM_HEAVY_MB
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void (*soc_mb)(void);
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void arm_heavy_mb(void)
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{
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#ifdef CONFIG_OUTER_CACHE_SYNC
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if (outer_cache.sync)
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outer_cache.sync();
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#endif
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if (soc_mb)
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soc_mb();
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}
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EXPORT_SYMBOL(arm_heavy_mb);
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#endif
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#ifdef CONFIG_CPU_CACHE_VIPT
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static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr)
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{
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unsigned long to = FLUSH_ALIAS_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
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const int zero = 0;
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set_top_pte(to, pfn_pte(pfn, PAGE_KERNEL));
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asm( "mcrr p15, 0, %1, %0, c14\n"
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" mcr p15, 0, %2, c7, c10, 4"
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:
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: "r" (to), "r" (to + PAGE_SIZE - 1), "r" (zero)
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: "cc");
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}
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static void flush_icache_alias(unsigned long pfn, unsigned long vaddr, unsigned long len)
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{
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unsigned long va = FLUSH_ALIAS_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
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unsigned long offset = vaddr & (PAGE_SIZE - 1);
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unsigned long to;
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set_top_pte(va, pfn_pte(pfn, PAGE_KERNEL));
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to = va + offset;
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flush_icache_range(to, to + len);
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}
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void flush_cache_mm(struct mm_struct *mm)
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{
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if (cache_is_vivt()) {
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vivt_flush_cache_mm(mm);
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return;
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}
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if (cache_is_vipt_aliasing()) {
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asm( "mcr p15, 0, %0, c7, c14, 0\n"
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" mcr p15, 0, %0, c7, c10, 4"
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:
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: "r" (0)
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: "cc");
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}
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}
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void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
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{
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if (cache_is_vivt()) {
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vivt_flush_cache_range(vma, start, end);
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return;
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}
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if (cache_is_vipt_aliasing()) {
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asm( "mcr p15, 0, %0, c7, c14, 0\n"
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" mcr p15, 0, %0, c7, c10, 4"
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:
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: "r" (0)
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: "cc");
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}
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if (vma->vm_flags & VM_EXEC)
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__flush_icache_all();
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}
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void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn)
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{
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if (cache_is_vivt()) {
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vivt_flush_cache_page(vma, user_addr, pfn);
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return;
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}
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if (cache_is_vipt_aliasing()) {
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flush_pfn_alias(pfn, user_addr);
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__flush_icache_all();
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}
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if (vma->vm_flags & VM_EXEC && icache_is_vivt_asid_tagged())
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__flush_icache_all();
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}
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#else
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#define flush_pfn_alias(pfn,vaddr) do { } while (0)
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#define flush_icache_alias(pfn,vaddr,len) do { } while (0)
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#endif
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#define FLAG_PA_IS_EXEC 1
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#define FLAG_PA_CORE_IN_MM 2
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static void flush_ptrace_access_other(void *args)
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{
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__flush_icache_all();
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}
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static inline
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void __flush_ptrace_access(struct page *page, unsigned long uaddr, void *kaddr,
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unsigned long len, unsigned int flags)
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{
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if (cache_is_vivt()) {
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if (flags & FLAG_PA_CORE_IN_MM) {
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unsigned long addr = (unsigned long)kaddr;
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__cpuc_coherent_kern_range(addr, addr + len);
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}
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return;
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}
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if (cache_is_vipt_aliasing()) {
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flush_pfn_alias(page_to_pfn(page), uaddr);
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__flush_icache_all();
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return;
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}
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/* VIPT non-aliasing D-cache */
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if (flags & FLAG_PA_IS_EXEC) {
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unsigned long addr = (unsigned long)kaddr;
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if (icache_is_vipt_aliasing())
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flush_icache_alias(page_to_pfn(page), uaddr, len);
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else
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__cpuc_coherent_kern_range(addr, addr + len);
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if (cache_ops_need_broadcast())
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smp_call_function(flush_ptrace_access_other,
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NULL, 1);
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}
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}
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static
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void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
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unsigned long uaddr, void *kaddr, unsigned long len)
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{
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unsigned int flags = 0;
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if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(vma->vm_mm)))
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flags |= FLAG_PA_CORE_IN_MM;
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if (vma->vm_flags & VM_EXEC)
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flags |= FLAG_PA_IS_EXEC;
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__flush_ptrace_access(page, uaddr, kaddr, len, flags);
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}
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void flush_uprobe_xol_access(struct page *page, unsigned long uaddr,
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void *kaddr, unsigned long len)
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{
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unsigned int flags = FLAG_PA_CORE_IN_MM|FLAG_PA_IS_EXEC;
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__flush_ptrace_access(page, uaddr, kaddr, len, flags);
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}
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/*
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* Copy user data from/to a page which is mapped into a different
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* processes address space. Really, we want to allow our "user
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* space" model to handle this.
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*
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* Note that this code needs to run on the current CPU.
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*/
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void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
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unsigned long uaddr, void *dst, const void *src,
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unsigned long len)
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{
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#ifdef CONFIG_SMP
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preempt_disable();
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#endif
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memcpy(dst, src, len);
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flush_ptrace_access(vma, page, uaddr, dst, len);
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#ifdef CONFIG_SMP
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preempt_enable();
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#endif
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}
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void __flush_dcache_page(struct address_space *mapping, struct page *page)
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{
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/*
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* Writeback any data associated with the kernel mapping of this
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* page. This ensures that data in the physical page is mutually
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* coherent with the kernels mapping.
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*/
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if (!PageHighMem(page)) {
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size_t page_size = PAGE_SIZE << compound_order(page);
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__cpuc_flush_dcache_area(page_address(page), page_size);
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} else {
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unsigned long i;
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if (cache_is_vipt_nonaliasing()) {
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for (i = 0; i < (1 << compound_order(page)); i++) {
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void *addr = kmap_atomic(page + i);
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__cpuc_flush_dcache_area(addr, PAGE_SIZE);
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kunmap_atomic(addr);
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}
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} else {
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for (i = 0; i < (1 << compound_order(page)); i++) {
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void *addr = kmap_high_get(page + i);
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if (addr) {
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__cpuc_flush_dcache_area(addr, PAGE_SIZE);
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kunmap_high(page + i);
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}
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}
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}
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}
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/*
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* If this is a page cache page, and we have an aliasing VIPT cache,
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* we only need to do one flush - which would be at the relevant
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* userspace colour, which is congruent with page->index.
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*/
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if (mapping && cache_is_vipt_aliasing())
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flush_pfn_alias(page_to_pfn(page),
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page->index << PAGE_SHIFT);
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}
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static void __flush_dcache_aliases(struct address_space *mapping, struct page *page)
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{
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struct mm_struct *mm = current->active_mm;
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struct vm_area_struct *mpnt;
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pgoff_t pgoff;
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/*
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* There are possible user space mappings of this page:
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* - VIVT cache: we need to also write back and invalidate all user
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* data in the current VM view associated with this page.
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* - aliasing VIPT: we only need to find one mapping of this page.
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*/
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pgoff = page->index;
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flush_dcache_mmap_lock(mapping);
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vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
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unsigned long offset;
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/*
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* If this VMA is not in our MM, we can ignore it.
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*/
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if (mpnt->vm_mm != mm)
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continue;
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if (!(mpnt->vm_flags & VM_MAYSHARE))
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continue;
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offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
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flush_cache_page(mpnt, mpnt->vm_start + offset, page_to_pfn(page));
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}
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flush_dcache_mmap_unlock(mapping);
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}
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#if __LINUX_ARM_ARCH__ >= 6
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void __sync_icache_dcache(pte_t pteval)
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{
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unsigned long pfn;
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struct page *page;
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struct address_space *mapping;
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if (cache_is_vipt_nonaliasing() && !pte_exec(pteval))
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/* only flush non-aliasing VIPT caches for exec mappings */
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return;
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pfn = pte_pfn(pteval);
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if (!pfn_valid(pfn))
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return;
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page = pfn_to_page(pfn);
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if (cache_is_vipt_aliasing())
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mapping = page_mapping(page);
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else
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mapping = NULL;
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if (!test_and_set_bit(PG_dcache_clean, &page->flags))
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__flush_dcache_page(mapping, page);
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if (pte_exec(pteval))
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__flush_icache_all();
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}
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#endif
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/*
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* Ensure cache coherency between kernel mapping and userspace mapping
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* of this page.
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*
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* We have three cases to consider:
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* - VIPT non-aliasing cache: fully coherent so nothing required.
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* - VIVT: fully aliasing, so we need to handle every alias in our
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* current VM view.
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* - VIPT aliasing: need to handle one alias in our current VM view.
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*
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* If we need to handle aliasing:
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* If the page only exists in the page cache and there are no user
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* space mappings, we can be lazy and remember that we may have dirty
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* kernel cache lines for later. Otherwise, we assume we have
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* aliasing mappings.
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*
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* Note that we disable the lazy flush for SMP configurations where
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* the cache maintenance operations are not automatically broadcasted.
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*/
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void flush_dcache_page(struct page *page)
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{
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struct address_space *mapping;
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/*
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* The zero page is never written to, so never has any dirty
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* cache lines, and therefore never needs to be flushed.
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*/
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if (page == ZERO_PAGE(0))
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return;
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mapping = page_mapping(page);
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if (!cache_ops_need_broadcast() &&
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mapping && !page_mapcount(page))
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clear_bit(PG_dcache_clean, &page->flags);
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else {
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__flush_dcache_page(mapping, page);
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if (mapping && cache_is_vivt())
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__flush_dcache_aliases(mapping, page);
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else if (mapping)
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__flush_icache_all();
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set_bit(PG_dcache_clean, &page->flags);
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}
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}
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EXPORT_SYMBOL(flush_dcache_page);
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/*
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* Ensure cache coherency for the kernel mapping of this page. We can
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* assume that the page is pinned via kmap.
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*
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* If the page only exists in the page cache and there are no user
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* space mappings, this is a no-op since the page was already marked
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* dirty at creation. Otherwise, we need to flush the dirty kernel
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* cache lines directly.
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*/
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void flush_kernel_dcache_page(struct page *page)
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{
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if (cache_is_vivt() || cache_is_vipt_aliasing()) {
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struct address_space *mapping;
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mapping = page_mapping(page);
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if (!mapping || mapping_mapped(mapping)) {
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void *addr;
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addr = page_address(page);
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/*
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* kmap_atomic() doesn't set the page virtual
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* address for highmem pages, and
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* kunmap_atomic() takes care of cache
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* flushing already.
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*/
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if (!IS_ENABLED(CONFIG_HIGHMEM) || addr)
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__cpuc_flush_dcache_area(addr, PAGE_SIZE);
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}
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}
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}
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EXPORT_SYMBOL(flush_kernel_dcache_page);
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/*
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* Flush an anonymous page so that users of get_user_pages()
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* can safely access the data. The expected sequence is:
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*
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* get_user_pages()
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* -> flush_anon_page
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* memcpy() to/from page
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* if written to page, flush_dcache_page()
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*/
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void __flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
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{
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unsigned long pfn;
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/* VIPT non-aliasing caches need do nothing */
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if (cache_is_vipt_nonaliasing())
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return;
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/*
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* Write back and invalidate userspace mapping.
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*/
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pfn = page_to_pfn(page);
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if (cache_is_vivt()) {
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flush_cache_page(vma, vmaddr, pfn);
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} else {
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/*
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* For aliasing VIPT, we can flush an alias of the
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* userspace address only.
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*/
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flush_pfn_alias(pfn, vmaddr);
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__flush_icache_all();
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}
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/*
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* Invalidate kernel mapping. No data should be contained
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* in this mapping of the page. FIXME: this is overkill
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* since we actually ask for a write-back and invalidate.
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*/
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__cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
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}
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