blob: cacfd31e8ec9d1121c86e81feb35fac4344a9a3b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * (C) Copyright 1995 1996 Linus Torvalds
7 * (C) Copyright 2001, 2002 Ralf Baechle
8 */
9#include <linux/module.h>
10#include <asm/addrspace.h>
11#include <asm/byteorder.h>
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +040012#include <linux/sched.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090013#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/vmalloc.h>
Ralf Baechle5ce704f2007-02-21 09:37:44 +000015#include <asm/cacheflush.h>
16#include <asm/io.h>
17#include <asm/tlbflush.h>
18
19static inline void remap_area_pte(pte_t * pte, unsigned long address,
20 phys_t size, phys_t phys_addr, unsigned long flags)
21{
22 phys_t end;
23 unsigned long pfn;
24 pgprot_t pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | __READABLE
25 | __WRITEABLE | flags);
26
27 address &= ~PMD_MASK;
28 end = address + size;
29 if (end > PMD_SIZE)
30 end = PMD_SIZE;
Ralf Baechleb72b7092009-03-30 14:49:44 +020031 BUG_ON(address >= end);
Ralf Baechle5ce704f2007-02-21 09:37:44 +000032 pfn = phys_addr >> PAGE_SHIFT;
33 do {
34 if (!pte_none(*pte)) {
35 printk("remap_area_pte: page already exists\n");
36 BUG();
37 }
38 set_pte(pte, pfn_pte(pfn, pgprot));
39 address += PAGE_SIZE;
40 pfn++;
41 pte++;
42 } while (address && (address < end));
43}
44
45static inline int remap_area_pmd(pmd_t * pmd, unsigned long address,
46 phys_t size, phys_t phys_addr, unsigned long flags)
47{
48 phys_t end;
49
50 address &= ~PGDIR_MASK;
51 end = address + size;
52 if (end > PGDIR_SIZE)
53 end = PGDIR_SIZE;
54 phys_addr -= address;
Ralf Baechleb72b7092009-03-30 14:49:44 +020055 BUG_ON(address >= end);
Ralf Baechle5ce704f2007-02-21 09:37:44 +000056 do {
57 pte_t * pte = pte_alloc_kernel(pmd, address);
58 if (!pte)
59 return -ENOMEM;
60 remap_area_pte(pte, address, end - address, address + phys_addr, flags);
61 address = (address + PMD_SIZE) & PMD_MASK;
62 pmd++;
63 } while (address && (address < end));
64 return 0;
65}
66
67static int remap_area_pages(unsigned long address, phys_t phys_addr,
68 phys_t size, unsigned long flags)
69{
70 int error;
71 pgd_t * dir;
72 unsigned long end = address + size;
73
74 phys_addr -= address;
75 dir = pgd_offset(&init_mm, address);
76 flush_cache_all();
Ralf Baechleb72b7092009-03-30 14:49:44 +020077 BUG_ON(address >= end);
Ralf Baechle5ce704f2007-02-21 09:37:44 +000078 do {
79 pud_t *pud;
80 pmd_t *pmd;
81
82 error = -ENOMEM;
83 pud = pud_alloc(&init_mm, dir, address);
84 if (!pud)
85 break;
86 pmd = pmd_alloc(&init_mm, pud, address);
87 if (!pmd)
88 break;
89 if (remap_area_pmd(pmd, address, end - address,
90 phys_addr + address, flags))
91 break;
92 error = 0;
93 address = (address + PGDIR_SIZE) & PGDIR_MASK;
94 dir++;
95 } while (address && (address < end));
96 flush_tlb_all();
97 return error;
98}
Linus Torvalds1da177e2005-04-16 15:20:36 -070099
100/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 * Generic mapping function (not visible outside):
102 */
103
104/*
105 * Remap an arbitrary physical address space into the kernel virtual
106 * address space. Needed when the kernel wants to access high addresses
107 * directly.
108 *
109 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
110 * have to convert them into an offset in a page-aligned mapping, but the
111 * caller shouldn't need to know that small detail.
112 */
113
114#define IS_LOW512(addr) (!((phys_t)(addr) & (phys_t) ~0x1fffffffULL))
115
Maciej W. Rozyckic3455b02005-06-30 10:48:40 +0000116void __iomem * __ioremap(phys_t phys_addr, phys_t size, unsigned long flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117{
118 struct vm_struct * area;
119 unsigned long offset;
120 phys_t last_addr;
121 void * addr;
122
123 phys_addr = fixup_bigphys_addr(phys_addr, size);
124
125 /* Don't allow wraparound or zero size */
126 last_addr = phys_addr + size - 1;
127 if (!size || last_addr < phys_addr)
128 return NULL;
129
130 /*
131 * Map uncached objects in the low 512mb of address space using KSEG1,
132 * otherwise map using page tables.
133 */
134 if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) &&
135 flags == _CACHE_UNCACHED)
Maciej W. Rozyckic3455b02005-06-30 10:48:40 +0000136 return (void __iomem *) CKSEG1ADDR(phys_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137
138 /*
139 * Don't allow anybody to remap normal RAM that we're using..
140 */
141 if (phys_addr < virt_to_phys(high_memory)) {
142 char *t_addr, *t_end;
143 struct page *page;
144
145 t_addr = __va(phys_addr);
146 t_end = t_addr + (size - 1);
147
148 for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++)
149 if(!PageReserved(page))
150 return NULL;
151 }
152
153 /*
154 * Mappings have to be page-aligned
155 */
156 offset = phys_addr & ~PAGE_MASK;
157 phys_addr &= PAGE_MASK;
158 size = PAGE_ALIGN(last_addr + 1) - phys_addr;
159
160 /*
161 * Ok, go for it..
162 */
163 area = get_vm_area(size, VM_IOREMAP);
164 if (!area)
165 return NULL;
166 addr = area->addr;
Ralf Baechle5ce704f2007-02-21 09:37:44 +0000167 if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 vunmap(addr);
169 return NULL;
170 }
171
Maciej W. Rozyckic3455b02005-06-30 10:48:40 +0000172 return (void __iomem *) (offset + (char *)addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173}
174
Ralf Baechlec6e8b582005-02-10 12:19:59 +0000175#define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
Ralf Baechled89e36d2006-10-19 14:21:47 +0100177void __iounmap(const volatile void __iomem *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178{
179 struct vm_struct *p;
180
181 if (IS_KSEG1(addr))
182 return;
183
184 p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr));
Ralf Baechlec6e8b582005-02-10 12:19:59 +0000185 if (!p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 printk(KERN_ERR "iounmap: bad address %p\n", addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187
188 kfree(p);
189}
190
191EXPORT_SYMBOL(__ioremap);
192EXPORT_SYMBOL(__iounmap);