55fdcb2d56
Execution of break instruction, trap instructions, emulation of unaligned loads or floating point instructions - anything that tries to read the instruction's opcode from userspace - needs read access to a page. RIXI (Read Inhibit / Execute Inhibit) support however allows the creation of pags that are executable but not readable. On such a mapping the attempted load of the opcode by the kernel is going to cause an endless loop of page faults. The quick workaround for this is to disable the combinations that the kernel currently isn't able to handle which are executable mappings. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
241 lines
7 KiB
C
241 lines
7 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1994 - 2003, 06, 07 by Ralf Baechle (ralf@linux-mips.org)
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* Copyright (C) 2007 MIPS Technologies, Inc.
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*/
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#include <linux/fs.h>
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#include <linux/fcntl.h>
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#include <linux/kernel.h>
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#include <linux/linkage.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/syscalls.h>
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#include <linux/mm.h>
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#include <asm/cacheflush.h>
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#include <asm/processor.h>
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#include <asm/cpu.h>
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#include <asm/cpu-features.h>
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/* Cache operations. */
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void (*flush_cache_all)(void);
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void (*__flush_cache_all)(void);
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void (*flush_cache_mm)(struct mm_struct *mm);
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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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void (*flush_cache_page)(struct vm_area_struct *vma, unsigned long page,
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unsigned long pfn);
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void (*flush_icache_range)(unsigned long start, unsigned long end);
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EXPORT_SYMBOL_GPL(flush_icache_range);
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void (*local_flush_icache_range)(unsigned long start, unsigned long end);
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EXPORT_SYMBOL_GPL(local_flush_icache_range);
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void (*__flush_cache_vmap)(void);
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void (*__flush_cache_vunmap)(void);
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void (*__flush_kernel_vmap_range)(unsigned long vaddr, int size);
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EXPORT_SYMBOL_GPL(__flush_kernel_vmap_range);
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void (*__invalidate_kernel_vmap_range)(unsigned long vaddr, int size);
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/* MIPS specific cache operations */
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void (*flush_cache_sigtramp)(unsigned long addr);
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void (*local_flush_data_cache_page)(void * addr);
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void (*flush_data_cache_page)(unsigned long addr);
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void (*flush_icache_all)(void);
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EXPORT_SYMBOL_GPL(local_flush_data_cache_page);
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EXPORT_SYMBOL(flush_data_cache_page);
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EXPORT_SYMBOL(flush_icache_all);
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#if defined(CONFIG_DMA_NONCOHERENT) || defined(CONFIG_DMA_MAYBE_COHERENT)
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/* DMA cache operations. */
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void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
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void (*_dma_cache_wback)(unsigned long start, unsigned long size);
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void (*_dma_cache_inv)(unsigned long start, unsigned long size);
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EXPORT_SYMBOL(_dma_cache_wback_inv);
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#endif /* CONFIG_DMA_NONCOHERENT || CONFIG_DMA_MAYBE_COHERENT */
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/*
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* We could optimize the case where the cache argument is not BCACHE but
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* that seems very atypical use ...
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*/
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SYSCALL_DEFINE3(cacheflush, unsigned long, addr, unsigned long, bytes,
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unsigned int, cache)
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{
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if (bytes == 0)
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return 0;
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if (!access_ok(VERIFY_WRITE, (void __user *) addr, bytes))
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return -EFAULT;
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flush_icache_range(addr, addr + bytes);
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return 0;
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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 = page_mapping(page);
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unsigned long addr;
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if (PageHighMem(page))
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return;
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if (mapping && !mapping_mapped(mapping)) {
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SetPageDcacheDirty(page);
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return;
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}
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/*
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* We could delay the flush for the !page_mapping case too. But that
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* case is for exec env/arg pages and those are %99 certainly going to
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* get faulted into the tlb (and thus flushed) anyways.
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*/
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addr = (unsigned long) page_address(page);
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flush_data_cache_page(addr);
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}
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EXPORT_SYMBOL(__flush_dcache_page);
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void __flush_anon_page(struct page *page, unsigned long vmaddr)
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{
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unsigned long addr = (unsigned long) page_address(page);
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if (pages_do_alias(addr, vmaddr)) {
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if (page_mapped(page) && !Page_dcache_dirty(page)) {
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void *kaddr;
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kaddr = kmap_coherent(page, vmaddr);
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flush_data_cache_page((unsigned long)kaddr);
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kunmap_coherent();
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} else
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flush_data_cache_page(addr);
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}
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}
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EXPORT_SYMBOL(__flush_anon_page);
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void __flush_icache_page(struct vm_area_struct *vma, struct page *page)
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{
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unsigned long addr;
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if (PageHighMem(page))
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return;
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addr = (unsigned long) page_address(page);
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flush_data_cache_page(addr);
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}
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EXPORT_SYMBOL_GPL(__flush_icache_page);
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void __update_cache(struct vm_area_struct *vma, unsigned long address,
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pte_t pte)
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{
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struct page *page;
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unsigned long pfn, addr;
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int exec = (vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc;
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pfn = pte_pfn(pte);
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if (unlikely(!pfn_valid(pfn)))
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return;
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page = pfn_to_page(pfn);
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if (page_mapping(page) && Page_dcache_dirty(page)) {
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addr = (unsigned long) page_address(page);
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if (exec || pages_do_alias(addr, address & PAGE_MASK))
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flush_data_cache_page(addr);
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ClearPageDcacheDirty(page);
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}
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}
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unsigned long _page_cachable_default;
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EXPORT_SYMBOL(_page_cachable_default);
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static inline void setup_protection_map(void)
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{
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if (cpu_has_rixi) {
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protection_map[0] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
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protection_map[1] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
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protection_map[2] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
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protection_map[3] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
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protection_map[4] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
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protection_map[5] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
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protection_map[6] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
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protection_map[7] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
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protection_map[8] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
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protection_map[9] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
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protection_map[10] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | _PAGE_NO_READ);
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protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE);
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protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
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protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
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protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE);
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protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE);
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} else {
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protection_map[0] = PAGE_NONE;
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protection_map[1] = PAGE_READONLY;
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protection_map[2] = PAGE_COPY;
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protection_map[3] = PAGE_COPY;
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protection_map[4] = PAGE_READONLY;
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protection_map[5] = PAGE_READONLY;
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protection_map[6] = PAGE_COPY;
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protection_map[7] = PAGE_COPY;
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protection_map[8] = PAGE_NONE;
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protection_map[9] = PAGE_READONLY;
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protection_map[10] = PAGE_SHARED;
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protection_map[11] = PAGE_SHARED;
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protection_map[12] = PAGE_READONLY;
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protection_map[13] = PAGE_READONLY;
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protection_map[14] = PAGE_SHARED;
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protection_map[15] = PAGE_SHARED;
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}
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}
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void cpu_cache_init(void)
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{
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if (cpu_has_3k_cache) {
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extern void __weak r3k_cache_init(void);
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r3k_cache_init();
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}
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if (cpu_has_6k_cache) {
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extern void __weak r6k_cache_init(void);
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r6k_cache_init();
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}
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if (cpu_has_4k_cache) {
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extern void __weak r4k_cache_init(void);
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r4k_cache_init();
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}
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if (cpu_has_8k_cache) {
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extern void __weak r8k_cache_init(void);
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r8k_cache_init();
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}
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if (cpu_has_tx39_cache) {
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extern void __weak tx39_cache_init(void);
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tx39_cache_init();
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}
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if (cpu_has_octeon_cache) {
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extern void __weak octeon_cache_init(void);
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octeon_cache_init();
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}
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setup_protection_map();
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}
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int __weak __uncached_access(struct file *file, unsigned long addr)
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{
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if (file->f_flags & O_DSYNC)
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return 1;
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return addr >= __pa(high_memory);
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}
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