/*
   * arch/parisc/mm/ioremap.c
   *

   * (C) Copyright 1995 1996 Linus Torvalds

   * (C) Copyright 2001-2006 Helge Deller <deller@gmx.de>

   * (C) Copyright 2005 Kyle McMartin <kyle@parisc-linux.org>

   */
  
  #include <linux/vmalloc.h>
  #include <linux/errno.h>
  #include <linux/module.h>

  #include <linux/io.h>

  #include <asm/pgalloc.h>

  /*
   * Generic mapping function (not visible outside):
   */
  
  /*
   * Remap an arbitrary physical address space into the kernel virtual

   * address space.

   *
   * NOTE! We need to allow non-page-aligned mappings too: we will obviously
   * have to convert them into an offset in a page-aligned mapping, but the
   * caller shouldn't need to know that small detail.
   */
  void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
  {

  	void __iomem *addr;

  	struct vm_struct *area;
  	unsigned long offset, last_addr;

  	pgprot_t pgprot;

  #ifdef CONFIG_EISA

  	unsigned long end = phys_addr + size - 1;
  	/* Support EISA addresses */

  	if ((phys_addr >= 0x00080000 && end < 0x000fffff) ||
  	    (phys_addr >= 0x00500000 && end < 0x03bfffff)) {
  		phys_addr |= F_EXTEND(0xfc000000);

  		flags |= _PAGE_NO_CACHE;

  	}

  #endif

  	/* Don't allow wraparound or zero size */
  	last_addr = phys_addr + size - 1;
  	if (!size || last_addr < phys_addr)
  		return NULL;
  
  	/*
  	 * Don't allow anybody to remap normal RAM that we're using..
  	 */
  	if (phys_addr < virt_to_phys(high_memory)) {
  		char *t_addr, *t_end;
  		struct page *page;
  
  		t_addr = __va(phys_addr);
  		t_end = t_addr + (size - 1);
  	   

  		for (page = virt_to_page(t_addr); 
  		     page <= virt_to_page(t_end); page++) {

  			if(!PageReserved(page))
  				return NULL;

  		}

  	}

  	pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY |
  			  _PAGE_ACCESSED | flags);

  	/*
  	 * Mappings have to be page-aligned
  	 */
  	offset = phys_addr & ~PAGE_MASK;
  	phys_addr &= PAGE_MASK;

  	size = PAGE_ALIGN(last_addr + 1) - phys_addr;

  
  	/*
  	 * Ok, go for it..
  	 */
  	area = get_vm_area(size, VM_IOREMAP);
  	if (!area)
  		return NULL;

  	addr = (void __iomem *) area->addr;

  	if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
  			       phys_addr, pgprot)) {

  		vfree(addr);
  		return NULL;
  	}

  	return (void __iomem *) (offset + (char __iomem *)addr);

  }

  EXPORT_SYMBOL(__ioremap);

  void iounmap(const volatile void __iomem *addr)

  {

  	if (addr > high_memory)
  		return vfree((void *) (PAGE_MASK & (unsigned long __force) addr));

  }

  EXPORT_SYMBOL(iounmap);