ee6a7fce8e
The flush_cache_range() function (similarly for flush_cache_page()) is called when the kernel is changing an existing VA->PA mapping range to either a new PA or to different attributes. Since ARMv8 has PIPT-like D-caches, this function does not need to perform any D-cache maintenance. The I-cache maintenance is already handled via set_pte_at() and flush_cache_range() cannot anyway guarantee that there are no cache lines left after invalidation due to the speculative loads. This patch makes flush_cache_range() a no-op. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
88 lines
2.4 KiB
C
88 lines
2.4 KiB
C
/*
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* Based on arch/arm/mm/flush.c
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*
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* Copyright (C) 1995-2002 Russell King
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* Copyright (C) 2012 ARM Ltd.
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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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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/export.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <asm/cacheflush.h>
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#include <asm/cachetype.h>
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#include <asm/tlbflush.h>
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void sync_icache_aliases(void *kaddr, unsigned long len)
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{
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unsigned long addr = (unsigned long)kaddr;
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if (icache_is_aliasing()) {
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__clean_dcache_area_pou(kaddr, len);
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__flush_icache_all();
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} else {
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flush_icache_range(addr, addr + len);
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}
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}
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static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
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unsigned long uaddr, void *kaddr,
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unsigned long len)
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{
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if (vma->vm_flags & VM_EXEC)
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sync_icache_aliases(kaddr, len);
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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 processes
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* address space. Really, we want to allow our "user space" model to handle
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* this.
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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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memcpy(dst, src, len);
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flush_ptrace_access(vma, page, uaddr, dst, len);
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}
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void __sync_icache_dcache(pte_t pte, unsigned long addr)
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{
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struct page *page = pte_page(pte);
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if (!test_and_set_bit(PG_dcache_clean, &page->flags))
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sync_icache_aliases(page_address(page),
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PAGE_SIZE << compound_order(page));
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else if (icache_is_aivivt())
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__flush_icache_all();
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}
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/*
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* This function is called when a page has been modified by the kernel. Mark
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* it as dirty for later flushing when mapped in user space (if executable,
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* see __sync_icache_dcache).
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*/
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void flush_dcache_page(struct page *page)
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{
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if (test_bit(PG_dcache_clean, &page->flags))
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clear_bit(PG_dcache_clean, &page->flags);
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}
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EXPORT_SYMBOL(flush_dcache_page);
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/*
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* Additional functions defined in assembly.
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*/
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EXPORT_SYMBOL(flush_icache_range);
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