1/*
2 * Copyright (C) 2004-2006 Atmel Corporation
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8#include <linux/vmalloc.h>
9#include <linux/mm.h>
10#include <linux/module.h>
11#include <linux/io.h>
12#include <linux/slab.h>
13
14#include <asm/pgtable.h>
15#include <asm/addrspace.h>
16
17/*
18 * Re-map an arbitrary physical address space into the kernel virtual
19 * address space. Needed when the kernel wants to access physical
20 * memory directly.
21 */
22void __iomem *__ioremap(unsigned long phys_addr, size_t size,
23			unsigned long flags)
24{
25	unsigned long addr;
26	struct vm_struct *area;
27	unsigned long offset, last_addr;
28	pgprot_t prot;
29
30	/*
31	 * Check if we can simply use the P4 segment. This area is
32	 * uncacheable, so if caching/buffering is requested, we can't
33	 * use it.
34	 */
35	if ((phys_addr >= P4SEG) && (flags == 0))
36		return (void __iomem *)phys_addr;
37
38	/* Don't allow wraparound or zero size */
39	last_addr = phys_addr + size - 1;
40	if (!size || last_addr < phys_addr)
41		return NULL;
42
43	/*
44	 * XXX: When mapping regular RAM, we'd better make damn sure
45	 * it's never used for anything else.  But this is really the
46	 * caller's responsibility...
47	 */
48	if (PHYSADDR(P2SEGADDR(phys_addr)) == phys_addr)
49		return (void __iomem *)P2SEGADDR(phys_addr);
50
51	/* Mappings have to be page-aligned */
52	offset = phys_addr & ~PAGE_MASK;
53	phys_addr &= PAGE_MASK;
54	size = PAGE_ALIGN(last_addr + 1) - phys_addr;
55
56	prot = __pgprot(_PAGE_PRESENT | _PAGE_GLOBAL | _PAGE_RW | _PAGE_DIRTY
57			| _PAGE_ACCESSED | _PAGE_TYPE_SMALL | flags);
58
59	/*
60	 * Ok, go for it..
61	 */
62	area = get_vm_area(size, VM_IOREMAP);
63	if (!area)
64		return NULL;
65	area->phys_addr = phys_addr;
66	addr = (unsigned long )area->addr;
67	if (ioremap_page_range(addr, addr + size, phys_addr, prot)) {
68		vunmap((void *)addr);
69		return NULL;
70	}
71
72	return (void __iomem *)(offset + (char *)addr);
73}
74EXPORT_SYMBOL(__ioremap);
75
76void __iounmap(void __iomem *addr)
77{
78	struct vm_struct *p;
79
80	if ((unsigned long)addr >= P4SEG)
81		return;
82	if (PXSEG(addr) == P2SEG)
83		return;
84
85	p = remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr));
86	if (unlikely(!p)) {
87		printk (KERN_ERR "iounmap: bad address %p\n", addr);
88		return;
89	}
90
91	kfree (p);
92}
93EXPORT_SYMBOL(__iounmap);
94