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10c9c10c31
This patch implements consistent device DMA handling of memory management. DMA device operations are also here. Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
99 lines
2.4 KiB
C
99 lines
2.4 KiB
C
/*
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* linux/arch/unicore32/mm/flush.c
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*
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* Code specific to PKUnity SoC and UniCore ISA
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*
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* Copyright (C) 2001-2010 GUAN Xue-tao
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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 <asm/cacheflush.h>
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#include <asm/system.h>
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#include <asm/tlbflush.h>
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void flush_cache_mm(struct mm_struct *mm)
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{
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}
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void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
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unsigned long end)
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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,
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unsigned long pfn)
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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, unsigned long len)
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{
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/* VIPT non-aliasing D-cache */
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if (vma->vm_flags & VM_EXEC) {
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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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}
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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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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 __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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__cpuc_flush_kern_dcache_area(page_address(page), PAGE_SIZE);
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}
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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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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 (mapping && !mapping_mapped(mapping))
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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)
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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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