blob: cea7d0ea36e44c42b30d1a4b36bf7c461f7b4b66 [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>
12
13#include <linux/vmalloc.h>
14#include <asm/cacheflush.h>
15#include <asm/io.h>
16#include <asm/tlbflush.h>
17
18static inline void remap_area_pte(pte_t * pte, unsigned long address,
19 phys_t size, phys_t phys_addr, unsigned long flags)
20{
21 phys_t end;
22 unsigned long pfn;
23 pgprot_t pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | __READABLE
24 | __WRITEABLE | flags);
25
26 address &= ~PMD_MASK;
27 end = address + size;
28 if (end > PMD_SIZE)
29 end = PMD_SIZE;
30 if (address >= end)
31 BUG();
32 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;
55 if (address >= end)
56 BUG();
57 do {
Hugh Dickins872fec12005-10-29 18:16:21 -070058 pte_t * pte = pte_alloc_kernel(pmd, address);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 if (!pte)
60 return -ENOMEM;
61 remap_area_pte(pte, address, end - address, address + phys_addr, flags);
62 address = (address + PMD_SIZE) & PMD_MASK;
63 pmd++;
64 } while (address && (address < end));
65 return 0;
66}
67
68static int remap_area_pages(unsigned long address, phys_t phys_addr,
69 phys_t size, unsigned long flags)
70{
71 int error;
72 pgd_t * dir;
73 unsigned long end = address + size;
74
75 phys_addr -= address;
76 dir = pgd_offset(&init_mm, address);
77 flush_cache_all();
78 if (address >= end)
79 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 do {
Ralf Baechlec6e8b582005-02-10 12:19:59 +000081 pud_t *pud;
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 pmd_t *pmd;
Ralf Baechlec6e8b582005-02-10 12:19:59 +000083
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 error = -ENOMEM;
Ralf Baechlec6e8b582005-02-10 12:19:59 +000085 pud = pud_alloc(&init_mm, dir, address);
86 if (!pud)
87 break;
88 pmd = pmd_alloc(&init_mm, pud, address);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 if (!pmd)
90 break;
91 if (remap_area_pmd(pmd, address, end - address,
92 phys_addr + address, flags))
93 break;
94 error = 0;
95 address = (address + PGDIR_SIZE) & PGDIR_MASK;
96 dir++;
97 } while (address && (address < end));
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 flush_tlb_all();
99 return error;
100}
101
102/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 * Generic mapping function (not visible outside):
104 */
105
106/*
107 * Remap an arbitrary physical address space into the kernel virtual
108 * address space. Needed when the kernel wants to access high addresses
109 * directly.
110 *
111 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
112 * have to convert them into an offset in a page-aligned mapping, but the
113 * caller shouldn't need to know that small detail.
114 */
115
116#define IS_LOW512(addr) (!((phys_t)(addr) & (phys_t) ~0x1fffffffULL))
117
Maciej W. Rozyckic3455b02005-06-30 10:48:40 +0000118void __iomem * __ioremap(phys_t phys_addr, phys_t size, unsigned long flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119{
120 struct vm_struct * area;
121 unsigned long offset;
122 phys_t last_addr;
123 void * addr;
124
125 phys_addr = fixup_bigphys_addr(phys_addr, size);
126
127 /* Don't allow wraparound or zero size */
128 last_addr = phys_addr + size - 1;
129 if (!size || last_addr < phys_addr)
130 return NULL;
131
132 /*
133 * Map uncached objects in the low 512mb of address space using KSEG1,
134 * otherwise map using page tables.
135 */
136 if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) &&
137 flags == _CACHE_UNCACHED)
Maciej W. Rozyckic3455b02005-06-30 10:48:40 +0000138 return (void __iomem *) CKSEG1ADDR(phys_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
140 /*
141 * Don't allow anybody to remap normal RAM that we're using..
142 */
143 if (phys_addr < virt_to_phys(high_memory)) {
144 char *t_addr, *t_end;
145 struct page *page;
146
147 t_addr = __va(phys_addr);
148 t_end = t_addr + (size - 1);
149
150 for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++)
151 if(!PageReserved(page))
152 return NULL;
153 }
154
155 /*
156 * Mappings have to be page-aligned
157 */
158 offset = phys_addr & ~PAGE_MASK;
159 phys_addr &= PAGE_MASK;
160 size = PAGE_ALIGN(last_addr + 1) - phys_addr;
161
162 /*
163 * Ok, go for it..
164 */
165 area = get_vm_area(size, VM_IOREMAP);
166 if (!area)
167 return NULL;
168 addr = area->addr;
169 if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
170 vunmap(addr);
171 return NULL;
172 }
173
Maciej W. Rozyckic3455b02005-06-30 10:48:40 +0000174 return (void __iomem *) (offset + (char *)addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175}
176
Ralf Baechlec6e8b582005-02-10 12:19:59 +0000177#define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178
Ralf Baechled89e36d2006-10-19 14:21:47 +0100179void __iounmap(const volatile void __iomem *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180{
181 struct vm_struct *p;
182
183 if (IS_KSEG1(addr))
184 return;
185
186 p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr));
Ralf Baechlec6e8b582005-02-10 12:19:59 +0000187 if (!p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 printk(KERN_ERR "iounmap: bad address %p\n", addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
190 kfree(p);
191}
192
193EXPORT_SYMBOL(__ioremap);
194EXPORT_SYMBOL(__iounmap);