/*
   * Copyright (C) 2004-2006 Atmel Corporation
   *
   * 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 <linux/highmem.h>
  #include <linux/unistd.h>
  
  #include <asm/cacheflush.h>
  #include <asm/cachectl.h>
  #include <asm/processor.h>
  #include <asm/uaccess.h>

  #include <asm/syscalls.h>

  
  /*
   * If you attempt to flush anything more than this, you need superuser
   * privileges.  The value is completely arbitrary.
   */
  #define CACHEFLUSH_MAX_LEN	1024
  
  void invalidate_dcache_region(void *start, size_t size)
  {

  	unsigned long v, begin, end, linesz, mask;

  
  	linesz = boot_cpu_data.dcache.linesz;

  	mask = linesz - 1;

  	/* when first and/or last cachelines are shared, flush them
  	 * instead of invalidating ... never discard valid data!
  	 */
  	begin = (unsigned long)start;

  	end = begin + size;

  	if (begin & mask) {
  		flush_dcache_line(start);
  		begin += linesz;

  	}

  	if (end & mask) {

  		flush_dcache_line((void *)end);

  		end &= ~mask;

  	}

  	/* remaining cachelines only need invalidation */

  	for (v = begin; v < end; v += linesz)

  		invalidate_dcache_line((void *)v);

  	flush_write_buffer();

  }
  
  void clean_dcache_region(void *start, size_t size)
  {
  	unsigned long v, begin, end, linesz;
  
  	linesz = boot_cpu_data.dcache.linesz;
  	begin = (unsigned long)start & ~(linesz - 1);
  	end = ((unsigned long)start + size + linesz - 1) & ~(linesz - 1);
  
  	for (v = begin; v < end; v += linesz)
  		clean_dcache_line((void *)v);
  	flush_write_buffer();
  }
  
  void flush_dcache_region(void *start, size_t size)
  {
  	unsigned long v, begin, end, linesz;
  
  	linesz = boot_cpu_data.dcache.linesz;
  	begin = (unsigned long)start & ~(linesz - 1);
  	end = ((unsigned long)start + size + linesz - 1) & ~(linesz - 1);
  
  	for (v = begin; v < end; v += linesz)
  		flush_dcache_line((void *)v);
  	flush_write_buffer();
  }
  
  void invalidate_icache_region(void *start, size_t size)
  {
  	unsigned long v, begin, end, linesz;
  
  	linesz = boot_cpu_data.icache.linesz;
  	begin = (unsigned long)start & ~(linesz - 1);
  	end = ((unsigned long)start + size + linesz - 1) & ~(linesz - 1);
  
  	for (v = begin; v < end; v += linesz)
  		invalidate_icache_line((void *)v);
  }
  
  static inline void __flush_icache_range(unsigned long start, unsigned long end)
  {
  	unsigned long v, linesz;
  
  	linesz = boot_cpu_data.dcache.linesz;
  	for (v = start; v < end; v += linesz) {
  		clean_dcache_line((void *)v);
  		invalidate_icache_line((void *)v);
  	}
  
  	flush_write_buffer();
  }
  
  /*
   * This one is called after a module has been loaded.
   */
  void flush_icache_range(unsigned long start, unsigned long end)
  {
  	unsigned long linesz;
  
  	linesz = boot_cpu_data.dcache.linesz;
  	__flush_icache_range(start & ~(linesz - 1),
  			     (end + linesz - 1) & ~(linesz - 1));
  }
  
  /*

   * This one is called from __do_fault() and do_swap_page().

   */
  void flush_icache_page(struct vm_area_struct *vma, struct page *page)
  {
  	if (vma->vm_flags & VM_EXEC) {

  		void *v = page_address(page);

  		__flush_icache_range((unsigned long)v, (unsigned long)v + PAGE_SIZE);

  	}
  }

  asmlinkage int sys_cacheflush(int operation, void __user *addr, size_t len)
  {
  	int ret;
  
  	if (len > CACHEFLUSH_MAX_LEN) {
  		ret = -EPERM;
  		if (!capable(CAP_SYS_ADMIN))
  			goto out;
  	}
  
  	ret = -EFAULT;
  	if (!access_ok(VERIFY_WRITE, addr, len))
  		goto out;
  
  	switch (operation) {
  	case CACHE_IFLUSH:
  		flush_icache_range((unsigned long)addr,
  				   (unsigned long)addr + len);
  		ret = 0;
  		break;
  	default:
  		ret = -EINVAL;
  	}
  
  out:
  	return ret;
  }

  
  void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
  		unsigned long vaddr, void *dst, const void *src,
  		unsigned long len)
  {
  	memcpy(dst, src, len);
  	if (vma->vm_flags & VM_EXEC)
  		flush_icache_range((unsigned long)dst,
  				(unsigned long)dst + len);
  }