include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[linux-2.6.git] / arch / mips / mm / ioremap.c
1 /*
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 #include <linux/sched.h>
13 #include <linux/slab.h>
14 #include <linux/vmalloc.h>
15 #include <asm/cacheflush.h>
16 #include <asm/io.h>
17 #include <asm/tlbflush.h>
18
19 static 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;
31         BUG_ON(address >= end);
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
45 static 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         BUG_ON(address >= end);
56         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
67 static 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();
77         BUG_ON(address >= end);
78         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 }
99
100 /*
101  * 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
116 void __iomem * __ioremap(phys_t phys_addr, phys_t size, unsigned long flags)
117 {
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)
136                 return (void __iomem *) CKSEG1ADDR(phys_addr);
137
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;
167         if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
168                 vunmap(addr);
169                 return NULL;
170         }
171
172         return (void __iomem *) (offset + (char *)addr);
173 }
174
175 #define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
176
177 void __iounmap(const volatile void __iomem *addr)
178 {
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));
185         if (!p)
186                 printk(KERN_ERR "iounmap: bad address %p\n", addr);
187
188         kfree(p);
189 }
190
191 EXPORT_SYMBOL(__ioremap);
192 EXPORT_SYMBOL(__iounmap);