/* * linux/arch/arm/mm/flush.c * * Copyright (C) 1995-2002 Russell King * * 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. */ #include #include #include #include #include #include #include "mm.h" #ifdef CONFIG_CPU_CACHE_VIPT #define ALIAS_FLUSH_START 0xffff4000 static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr) { unsigned long to = ALIAS_FLUSH_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT); const int zero = 0; set_pte_ext(TOP_PTE(to), pfn_pte(pfn, PAGE_KERNEL), 0); flush_tlb_kernel_page(to); asm( "mcrr p15, 0, %1, %0, c14\n" " mcr p15, 0, %2, c7, c10, 4\n" " mcr p15, 0, %2, c7, c5, 0\n" : : "r" (to), "r" (to + PAGE_SIZE - L1_CACHE_BYTES), "r" (zero) : "cc"); } void flush_cache_mm(struct mm_struct *mm) { if (cache_is_vivt()) { if (cpu_isset(smp_processor_id(), mm->cpu_vm_mask)) __cpuc_flush_user_all(); return; } if (cache_is_vipt_aliasing()) { asm( "mcr p15, 0, %0, c7, c14, 0\n" " mcr p15, 0, %0, c7, c5, 0\n" " mcr p15, 0, %0, c7, c10, 4" : : "r" (0) : "cc"); } } void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) { if (cache_is_vivt()) { if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask)) __cpuc_flush_user_range(start & PAGE_MASK, PAGE_ALIGN(end), vma->vm_flags); return; } if (cache_is_vipt_aliasing()) { asm( "mcr p15, 0, %0, c7, c14, 0\n" " mcr p15, 0, %0, c7, c5, 0\n" " mcr p15, 0, %0, c7, c10, 4" : : "r" (0) : "cc"); } } void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn) { if (cache_is_vivt()) { if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask)) { unsigned long addr = user_addr & PAGE_MASK; __cpuc_flush_user_range(addr, addr + PAGE_SIZE, vma->vm_flags); } return; } if (cache_is_vipt_aliasing()) flush_pfn_alias(pfn, user_addr); } void flush_ptrace_access(struct vm_area_struct *vma, struct page *page, unsigned long uaddr, void *kaddr, unsigned long len, int write) { if (cache_is_vivt()) { if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask)) { unsigned long addr = (unsigned long)kaddr; __cpuc_coherent_kern_range(addr, addr + len); } return; } if (cache_is_vipt_aliasing()) { flush_pfn_alias(page_to_pfn(page), uaddr); return; } /* VIPT non-aliasing cache */ if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask) && vma->vm_flags & VM_EXEC) { unsigned long addr = (unsigned long)kaddr; /* only flushing the kernel mapping on non-aliasing VIPT */ __cpuc_coherent_kern_range(addr, addr + len); } } #else #define flush_pfn_alias(pfn,vaddr) do { } while (0) #endif void __flush_dcache_page(struct address_space *mapping, struct page *page) { /* * Writeback any data associated with the kernel mapping of this * page. This ensures that data in the physical page is mutually * coherent with the kernels mapping. */ __cpuc_flush_dcache_page(page_address(page)); /* * If this is a page cache page, and we have an aliasing VIPT cache, * we only need to do one flush - which would be at the relevant * userspace colour, which is congruent with page->index. */ if (mapping && cache_is_vipt_aliasing()) flush_pfn_alias(page_to_pfn(page), page->index << PAGE_CACHE_SHIFT); } static void __flush_dcache_aliases(struct address_space *mapping, struct page *page) { struct mm_struct *mm = current->active_mm; struct vm_area_struct *mpnt; struct prio_tree_iter iter; pgoff_t pgoff; /* * There are possible user space mappings of this page: * - VIVT cache: we need to also write back and invalidate all user * data in the current VM view associated with this page. * - aliasing VIPT: we only need to find one mapping of this page. */ pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); flush_dcache_mmap_lock(mapping); vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) { unsigned long offset; /* * If this VMA is not in our MM, we can ignore it. */ if (mpnt->vm_mm != mm) continue; if (!(mpnt->vm_flags & VM_MAYSHARE)) continue; offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT; flush_cache_page(mpnt, mpnt->vm_start + offset, page_to_pfn(page)); } flush_dcache_mmap_unlock(mapping); } /* * Ensure cache coherency between kernel mapping and userspace mapping * of this page. * * We have three cases to consider: * - VIPT non-aliasing cache: fully coherent so nothing required. * - VIVT: fully aliasing, so we need to handle every alias in our * current VM view. * - VIPT aliasing: need to handle one alias in our current VM view. * * If we need to handle aliasing: * If the page only exists in the page cache and there are no user * space mappings, we can be lazy and remember that we may have dirty * kernel cache lines for later. Otherwise, we assume we have * aliasing mappings. * * Note that we disable the lazy flush for SMP. */ void flush_dcache_page(struct page *page) { struct address_space *mapping = page_mapping(page); #ifndef CONFIG_SMP if (mapping && !mapping_mapped(mapping)) set_bit(PG_dcache_dirty, &page->flags); else #endif { __flush_dcache_page(mapping, page); if (mapping && cache_is_vivt()) __flush_dcache_aliases(mapping, page); else if (mapping) __flush_icache_all(); } } EXPORT_SYMBOL(flush_dcache_page); /* * Flush an anonymous page so that users of get_user_pages() * can safely access the data. The expected sequence is: * * get_user_pages() * -> flush_anon_page * memcpy() to/from page * if written to page, flush_dcache_page() */ void __flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr) { unsigned long pfn; /* VIPT non-aliasing caches need do nothing */ if (cache_is_vipt_nonaliasing()) return; /* * Write back and invalidate userspace mapping. */ pfn = page_to_pfn(page); if (cache_is_vivt()) { flush_cache_page(vma, vmaddr, pfn); } else { /* * For aliasing VIPT, we can flush an alias of the * userspace address only. */ flush_pfn_alias(pfn, vmaddr); } /* * Invalidate kernel mapping. No data should be contained * in this mapping of the page. FIXME: this is overkill * since we actually ask for a write-back and invalidate. */ __cpuc_flush_dcache_page(page_address(page)); }