LXR linux/arch/parisc/mm/ioremap.c

   1/*
   2 * arch/parisc/mm/ioremap.c
   3 *
   4 * (C) Copyright 1995 1996 Linus Torvalds
   5 * (C) Copyright 2001-2006 Helge Deller <deller@gmx.de>
   6 * (C) Copyright 2005 Kyle McMartin <kyle@parisc-linux.org>
   7 */
   8
   9#include <linux/vmalloc.h>
  10#include <linux/errno.h>
  11#include <linux/module.h>
  12#include <linux/io.h>
  13#include <asm/pgalloc.h>
  14
  15/*
  16 * Generic mapping function (not visible outside):
  17 */
  18
  19/*
  20 * Remap an arbitrary physical address space into the kernel virtual
  21 * address space.
  22 *
  23 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
  24 * have to convert them into an offset in a page-aligned mapping, but the
  25 * caller shouldn't need to know that small detail.
  26 */
  27void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
  28{
  29        void __iomem *addr;
  30        struct vm_struct *area;
  31        unsigned long offset, last_addr;
  32        pgprot_t pgprot;
  33
  34#ifdef CONFIG_EISA
  35        unsigned long end = phys_addr + size - 1;
  36        /* Support EISA addresses */
  37        if ((phys_addr >= 0x00080000 && end < 0x000fffff) ||
  38            (phys_addr >= 0x00500000 && end < 0x03bfffff)) {
  39                phys_addr |= F_EXTEND(0xfc000000);
  40                flags |= _PAGE_NO_CACHE;
  41        }
  42#endif
  43
  44        /* Don't allow wraparound or zero size */
  45        last_addr = phys_addr + size - 1;
  46        if (!size || last_addr < phys_addr)
  47                return NULL;
  48
  49        /*
  50         * Don't allow anybody to remap normal RAM that we're using..
  51         */
  52        if (phys_addr < virt_to_phys(high_memory)) {
  53                char *t_addr, *t_end;
  54                struct page *page;
  55
  56                t_addr = __va(phys_addr);
  57                t_end = t_addr + (size - 1);
  58           
  59                for (page = virt_to_page(t_addr); 
  60                     page <= virt_to_page(t_end); page++) {
  61                        if(!PageReserved(page))
  62                                return NULL;
  63                }
  64        }
  65
  66        pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY |
  67                          _PAGE_ACCESSED | flags);
  68
  69        /*
  70         * Mappings have to be page-aligned
  71         */
  72        offset = phys_addr & ~PAGE_MASK;
  73        phys_addr &= PAGE_MASK;
  74        size = PAGE_ALIGN(last_addr + 1) - phys_addr;
  75
  76        /*
  77         * Ok, go for it..
  78         */
  79        area = get_vm_area(size, VM_IOREMAP);
  80        if (!area)
  81                return NULL;
  82
  83        addr = (void __iomem *) area->addr;
  84        if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
  85                               phys_addr, pgprot)) {
  86                vfree(addr);
  87                return NULL;
  88        }
  89
  90        return (void __iomem *) (offset + (char __iomem *)addr);
  91}
  92EXPORT_SYMBOL(__ioremap);
  93
  94void iounmap(const volatile void __iomem *addr)
  95{
  96        if (addr > high_memory)
  97                return vfree((void *) (PAGE_MASK & (unsigned long __force) addr));
  98}
  99EXPORT_SYMBOL(iounmap);
 100