1/*
2 * Based on arch/arm/mm/ioremap.c
3 *
4 * (C) Copyright 1995 1996 Linus Torvalds
5 * Hacked for ARM by Phil Blundell <philb@gnu.org>
6 * Hacked to allow all architectures to build, and various cleanups
7 * by Russell King
8 * Copyright (C) 2012 ARM Ltd.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
21 */
22
23#include <linux/export.h>
24#include <linux/mm.h>
25#include <linux/vmalloc.h>
26#include <linux/io.h>
27
28#include <asm/fixmap.h>
29#include <asm/tlbflush.h>
30#include <asm/pgalloc.h>
31
32static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
33				      pgprot_t prot, void *caller)
34{
35	unsigned long last_addr;
36	unsigned long offset = phys_addr & ~PAGE_MASK;
37	int err;
38	unsigned long addr;
39	struct vm_struct *area;
40
41	/*
42	 * Page align the mapping address and size, taking account of any
43	 * offset.
44	 */
45	phys_addr &= PAGE_MASK;
46	size = PAGE_ALIGN(size + offset);
47
48	/*
49	 * Don't allow wraparound, zero size or outside PHYS_MASK.
50	 */
51	last_addr = phys_addr + size - 1;
52	if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK))
53		return NULL;
54
55	/*
56	 * Don't allow RAM to be mapped.
57	 */
58	if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr))))
59		return NULL;
60
61	area = get_vm_area_caller(size, VM_IOREMAP, caller);
62	if (!area)
63		return NULL;
64	addr = (unsigned long)area->addr;
65	area->phys_addr = phys_addr;
66
67	err = ioremap_page_range(addr, addr + size, phys_addr, prot);
68	if (err) {
69		vunmap((void *)addr);
70		return NULL;
71	}
72
73	return (void __iomem *)(offset + addr);
74}
75
76void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot)
77{
78	return __ioremap_caller(phys_addr, size, prot,
79				__builtin_return_address(0));
80}
81EXPORT_SYMBOL(__ioremap);
82
83void __iounmap(volatile void __iomem *io_addr)
84{
85	unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
86
87	/*
88	 * We could get an address outside vmalloc range in case
89	 * of ioremap_cache() reusing a RAM mapping.
90	 */
91	if (VMALLOC_START <= addr && addr < VMALLOC_END)
92		vunmap((void *)addr);
93}
94EXPORT_SYMBOL(__iounmap);
95
96void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size)
97{
98	/* For normal memory we already have a cacheable mapping. */
99	if (pfn_valid(__phys_to_pfn(phys_addr)))
100		return (void __iomem *)__phys_to_virt(phys_addr);
101
102	return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL),
103				__builtin_return_address(0));
104}
105EXPORT_SYMBOL(ioremap_cache);
106
107/*
108 * Must be called after early_fixmap_init
109 */
110void __init early_ioremap_init(void)
111{
112	early_ioremap_setup();
113}
114