/* highmem.c: arch-specific highmem stuff
   *
   * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   * Written by David Howells (dhowells@redhat.com)
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version
   * 2 of the License, or (at your option) any later version.
   */
  #include <linux/highmem.h>

  #include <linux/module.h>

  
  void *kmap(struct page *page)
  {
  	might_sleep();
  	if (!PageHighMem(page))
  		return page_address(page);
  	return kmap_high(page);
  }

  EXPORT_SYMBOL(kmap);

  void kunmap(struct page *page)
  {
  	if (in_interrupt())
  		BUG();
  	if (!PageHighMem(page))
  		return;
  	kunmap_high(page);
  }

  EXPORT_SYMBOL(kunmap);

  struct page *kmap_atomic_to_page(void *ptr)
  {
  	return virt_to_page(ptr);
  }

  void *kmap_atomic(struct page *page)

  {
  	unsigned long paddr;
  	int type;
  
  	pagefault_disable();
  	type = kmap_atomic_idx_push();
  	paddr = page_to_phys(page);
  
  	switch (type) {
  	/*
  	 * The first 4 primary maps are reserved for architecture code
  	 */

  	case 0:		return __kmap_atomic_primary(0, paddr, 6);
  	case 1:		return __kmap_atomic_primary(0, paddr, 7);
  	case 2:		return __kmap_atomic_primary(0, paddr, 8);
  	case 3:		return __kmap_atomic_primary(0, paddr, 9);
  	case 4:		return __kmap_atomic_primary(0, paddr, 10);

  
  	case 5 ... 5 + NR_TLB_LINES - 1:
  		return __kmap_atomic_secondary(type - 5, paddr);
  
  	default:
  		BUG();
  		return NULL;
  	}
  }

  EXPORT_SYMBOL(kmap_atomic);

  
  void __kunmap_atomic(void *kvaddr)
  {

  	int type = kmap_atomic_idx();

  	switch (type) {

  	case 0:		__kunmap_atomic_primary(0, 6);	break;
  	case 1:		__kunmap_atomic_primary(0, 7);	break;
  	case 2:		__kunmap_atomic_primary(0, 8);	break;
  	case 3:		__kunmap_atomic_primary(0, 9);	break;
  	case 4:		__kunmap_atomic_primary(0, 10);	break;

  
  	case 5 ... 5 + NR_TLB_LINES - 1:
  		__kunmap_atomic_secondary(type - 5, kvaddr);
  		break;
  
  	default:
  		BUG();
  	}

  	kmap_atomic_idx_pop();

  	pagefault_enable();
  }
  EXPORT_SYMBOL(__kunmap_atomic);