text: /*
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file "COPYING" in the main directory of this archive
   * for more details.
   *
   * Copyright (C) 1994 - 2003, 06, 07 by Ralf Baechle (ralf@linux-mips.org)
   * Copyright (C) 2007 MIPS Technologies, Inc.
   */
  #include <linux/fs.h>
  #include <linux/fcntl.h>
  #include <linux/kernel.h>
  #include <linux/linkage.h>
  #include <linux/export.h>
  #include <linux/sched.h>
  #include <linux/syscalls.h>
  #include <linux/mm.h>
  
  #include <asm/cacheflush.h>
  #include <asm/highmem.h>
  #include <asm/processor.h>
  #include <asm/cpu.h>
  #include <asm/cpu-features.h>
  #include <asm/setup.h>
  
  /* Cache operations. */
  void (*flush_cache_all)(void);
  void (*__flush_cache_all)(void);
  EXPORT_SYMBOL_GPL(__flush_cache_all);
  void (*flush_cache_mm)(struct mm_struct *mm);
  void (*flush_cache_range)(struct vm_area_struct *vma, unsigned long start,
  	unsigned long end);
  void (*flush_cache_page)(struct vm_area_struct *vma, unsigned long page,
  	unsigned long pfn);
  void (*flush_icache_range)(unsigned long start, unsigned long end);
  EXPORT_SYMBOL_GPL(flush_icache_range);
  void (*local_flush_icache_range)(unsigned long start, unsigned long end);
  EXPORT_SYMBOL_GPL(local_flush_icache_range);
  void (*__flush_icache_user_range)(unsigned long start, unsigned long end);
  EXPORT_SYMBOL_GPL(__flush_icache_user_range);
  void (*__local_flush_icache_user_range)(unsigned long start, unsigned long end);
  EXPORT_SYMBOL_GPL(__local_flush_icache_user_range);
  
  void (*__flush_cache_vmap)(void);
  void (*__flush_cache_vunmap)(void);
  
  void (*__flush_kernel_vmap_range)(unsigned long vaddr, int size);
  EXPORT_SYMBOL_GPL(__flush_kernel_vmap_range);
  
  /* MIPS specific cache operations */
  void (*flush_cache_sigtramp)(unsigned long addr);
  void (*local_flush_data_cache_page)(void * addr);
  void (*flush_data_cache_page)(unsigned long addr);
  void (*flush_icache_all)(void);
  
  EXPORT_SYMBOL_GPL(local_flush_data_cache_page);
  EXPORT_SYMBOL(flush_data_cache_page);
  EXPORT_SYMBOL(flush_icache_all);
  
  #if defined(CONFIG_DMA_NONCOHERENT) || defined(CONFIG_DMA_MAYBE_COHERENT)
  
  /* DMA cache operations. */
  void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
  void (*_dma_cache_wback)(unsigned long start, unsigned long size);
  void (*_dma_cache_inv)(unsigned long start, unsigned long size);
  
  EXPORT_SYMBOL(_dma_cache_wback_inv);
  
  #endif /* CONFIG_DMA_NONCOHERENT || CONFIG_DMA_MAYBE_COHERENT */
  
  /*
   * We could optimize the case where the cache argument is not BCACHE but
   * that seems very atypical use ...
   */
  SYSCALL_DEFINE3(cacheflush, unsigned long, addr, unsigned long, bytes,
  	unsigned int, cache)
  {
  	if (bytes == 0)
  		return 0;
  	if (!access_ok(VERIFY_WRITE, (void __user *) addr, bytes))
  		return -EFAULT;
  
  	__flush_icache_user_range(addr, addr + bytes);
  
  	return 0;
  }
  
  void __flush_dcache_page(struct page *page)
  {
  	struct address_space *mapping = page_mapping(page);
  	unsigned long addr;
  
  	if (mapping && !mapping_mapped(mapping)) {
  		SetPageDcacheDirty(page);
  		return;
  	}
  
  	/*
  	 * We could delay the flush for the !page_mapping case too.  But that
  	 * case is for exec env/arg pages and those are %99 certainly going to
  	 * get faulted into the tlb (and thus flushed) anyways.
  	 */
  	if (PageHighMem(page))
  		addr = (unsigned long)kmap_atomic(page);
  	else
  		addr = (unsigned long)page_address(page);
  
  	flush_data_cache_page(addr);
  
  	if (PageHighMem(page))
  		__kunmap_atomic((void *)addr);
  }
  
  EXPORT_SYMBOL(__flush_dcache_page);
  
  void __flush_anon_page(struct page *page, unsigned long vmaddr)
  {
  	unsigned long addr = (unsigned long) page_address(page);
  
  	if (pages_do_alias(addr, vmaddr)) {
  		if (page_mapcount(page) && !Page_dcache_dirty(page)) {
  			void *kaddr;
  
  			kaddr = kmap_coherent(page, vmaddr);
  			flush_data_cache_page((unsigned long)kaddr);
  			kunmap_coherent();
  		} else
  			flush_data_cache_page(addr);
  	}
  }
  
  EXPORT_SYMBOL(__flush_anon_page);
  
  void __update_cache(unsigned long address, pte_t pte)
  {
  	struct page *page;
  	unsigned long pfn, addr;
  	int exec = !pte_no_exec(pte) && !cpu_has_ic_fills_f_dc;
  
  	pfn = pte_pfn(pte);
  	if (unlikely(!pfn_valid(pfn)))
  		return;
  	page = pfn_to_page(pfn);
  	if (Page_dcache_dirty(page)) {
  		if (PageHighMem(page))
  			addr = (unsigned long)kmap_atomic(page);
  		else
  			addr = (unsigned long)page_address(page);
  
  		if (exec || pages_do_alias(addr, address & PAGE_MASK))
  			flush_data_cache_page(addr);
  
  		if (PageHighMem(page))
  			__kunmap_atomic((void *)addr);
  
  		ClearPageDcacheDirty(page);
  	}
  }
  
  unsigned long _page_cachable_default;
  EXPORT_SYMBOL(_page_cachable_default);
  
  static inline void setup_protection_map(void)
  {
  	if (cpu_has_rixi) {
  		protection_map[0]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
  		protection_map[1]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
  		protection_map[2]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
  		protection_map[3]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
  		protection_map[4]  = __pgprot(_page_cachable_default | _PAGE_PRESENT);
  		protection_map[5]  = __pgprot(_page_cachable_default | _PAGE_PRESENT);
  		protection_map[6]  = __pgprot(_page_cachable_default | _PAGE_PRESENT);
  		protection_map[7]  = __pgprot(_page_cachable_default | _PAGE_PRESENT);
  
  		protection_map[8]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
  		protection_map[9]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
  		protection_map[10] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | _PAGE_NO_READ);
  		protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE);
  		protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
  		protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
  		protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE);
  		protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE);
  
  	} else {
  		protection_map[0] = PAGE_NONE;
  		protection_map[1] = PAGE_READONLY;
  		protection_map[2] = PAGE_COPY;
  		protection_map[3] = PAGE_COPY;
  		protection_map[4] = PAGE_READONLY;
  		protection_map[5] = PAGE_READONLY;
  		protection_map[6] = PAGE_COPY;
  		protection_map[7] = PAGE_COPY;
  		protection_map[8] = PAGE_NONE;
  		protection_map[9] = PAGE_READONLY;
  		protection_map[10] = PAGE_SHARED;
  		protection_map[11] = PAGE_SHARED;
  		protection_map[12] = PAGE_READONLY;
  		protection_map[13] = PAGE_READONLY;
  		protection_map[14] = PAGE_SHARED;
  		protection_map[15] = PAGE_SHARED;
  	}
  }
  
  void cpu_cache_init(void)
  {
  	if (cpu_has_3k_cache) {
  		extern void __weak r3k_cache_init(void);
  
  		r3k_cache_init();
  	}
  	if (cpu_has_6k_cache) {
  		extern void __weak r6k_cache_init(void);
  
  		r6k_cache_init();
  	}
  	if (cpu_has_4k_cache) {
  		extern void __weak r4k_cache_init(void);
  
  		r4k_cache_init();
  	}
  	if (cpu_has_8k_cache) {
  		extern void __weak r8k_cache_init(void);
  
  		r8k_cache_init();
  	}
  	if (cpu_has_tx39_cache) {
  		extern void __weak tx39_cache_init(void);
  
  		tx39_cache_init();
  	}
  
  	if (cpu_has_octeon_cache) {
  		extern void __weak octeon_cache_init(void);
  
  		octeon_cache_init();
  	}
  
  	setup_protection_map();
  }
  
  int __weak __uncached_access(struct file *file, unsigned long addr)
  {
  	if (file->f_flags & O_DSYNC)
  		return 1;
  
  	return addr >= __pa(high_memory);
  }
  