0287721441918da5d9aedebd072c37f862e1245f
[linux-2.6.git] / arch / parisc / mm / ioremap.c
1 /*
2  * arch/parisc/mm/ioremap.c
3  *
4  * (C) Copyright 1995 1996 Linus Torvalds
5  * (C) Copyright 2001 Helge Deller <deller@gmx.de>
6  * (C) Copyright 2005 Kyle McMartin <kyle@parisc-linux.org>
7  */
8
9 #include <linux/vmalloc.h>
10 #include <linux/errno.h>
11 #include <linux/module.h>
12 #include <asm/io.h>
13 #include <asm/pgalloc.h>
14 #include <asm/tlbflush.h>
15 #include <asm/cacheflush.h>
16
17 static inline void 
18 remap_area_pte(pte_t *pte, unsigned long address, unsigned long size,
19                unsigned long phys_addr, unsigned long flags)
20 {
21         unsigned long end, pfn;
22         pgprot_t pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY |
23                                    _PAGE_ACCESSED | flags);
24
25         address &= ~PMD_MASK;
26
27         end = address + size;
28         if (end > PMD_SIZE)
29                 end = PMD_SIZE;
30
31         BUG_ON(address >= end);
32
33         pfn = phys_addr >> PAGE_SHIFT;
34         do {
35                 BUG_ON(!pte_none(*pte));
36
37                 set_pte(pte, pfn_pte(pfn, pgprot));
38
39                 address += PAGE_SIZE;
40                 pfn++;
41                 pte++;
42         } while (address && (address < end));
43 }
44
45 static inline int 
46 remap_area_pmd(pmd_t *pmd, unsigned long address, unsigned long size,
47                unsigned long phys_addr, unsigned long flags)
48 {
49         unsigned long end;
50
51         address &= ~PGDIR_MASK;
52
53         end = address + size;
54         if (end > PGDIR_SIZE)
55                 end = PGDIR_SIZE;
56
57         BUG_ON(address >= end);
58
59         phys_addr -= address;
60         do {
61                 pte_t *pte = pte_alloc_kernel(pmd, address);
62                 if (!pte)
63                         return -ENOMEM;
64
65                 remap_area_pte(pte, address, end - address, 
66                                address + phys_addr, flags);
67
68                 address = (address + PMD_SIZE) & PMD_MASK;
69                 pmd++;
70         } while (address && (address < end));
71
72         return 0;
73 }
74
75 #ifdef CONFIG_HPPA_IOREMAP
76 static int 
77 remap_area_pages(unsigned long address, unsigned long phys_addr,
78                  unsigned long size, unsigned long flags)
79 {
80         pgd_t *dir;
81         int error = 0;
82         unsigned long end = address + size;
83
84         BUG_ON(address >= end);
85
86         phys_addr -= address;
87         dir = pgd_offset_k(address);
88
89         flush_cache_all();
90
91         do {
92                 pud_t *pud;
93                 pmd_t *pmd;
94
95                 error = -ENOMEM;
96                 pud = pud_alloc(&init_mm, dir, address);
97                 if (!pud)
98                         break;
99
100                 pmd = pmd_alloc(&init_mm, pud, address);
101                 if (!pmd)
102                         break;
103
104                 if (remap_area_pmd(pmd, address, end - address,
105                                    phys_addr + address, flags))
106                         break;
107
108                 error = 0;
109                 address = (address + PGDIR_SIZE) & PGDIR_MASK;
110                 dir++;
111         } while (address && (address < end));
112
113         flush_tlb_all();
114
115         return error;
116 }
117 #endif /* CONFIG_HPPA_IOREMAP */
118
119 #ifdef CONFIG_DEBUG_IOREMAP
120 static unsigned long last = 0;
121
122 void gsc_bad_addr(unsigned long addr)
123 {
124         if (time_after(jiffies, last + HZ*10)) {
125                 printk("gsc_foo() called with bad address 0x%lx\n", addr);
126                 dump_stack();
127                 last = jiffies;
128         }
129 }
130 EXPORT_SYMBOL(gsc_bad_addr);
131
132 void __raw_bad_addr(const volatile void __iomem *addr)
133 {
134         if (time_after(jiffies, last + HZ*10)) {
135                 printk("__raw_foo() called with bad address 0x%p\n", addr);
136                 dump_stack();
137                 last = jiffies;
138         }
139 }
140 EXPORT_SYMBOL(__raw_bad_addr);
141 #endif
142
143 /*
144  * Generic mapping function (not visible outside):
145  */
146
147 /*
148  * Remap an arbitrary physical address space into the kernel virtual
149  * address space.
150  *
151  * NOTE! We need to allow non-page-aligned mappings too: we will obviously
152  * have to convert them into an offset in a page-aligned mapping, but the
153  * caller shouldn't need to know that small detail.
154  */
155 void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
156 {
157 #if !defined(CONFIG_HPPA_IOREMAP)
158         unsigned long end = phys_addr + size - 1;
159         /* Support EISA addresses */
160         if ((phys_addr >= 0x00080000 && end < 0x000fffff)
161                         || (phys_addr >= 0x00500000 && end < 0x03bfffff)) {
162                 phys_addr |= 0xfc000000;
163         }
164
165 #ifdef CONFIG_DEBUG_IOREMAP
166         return (void __iomem *)(phys_addr - (0x1UL << NYBBLE_SHIFT));
167 #else
168         return (void __iomem *)phys_addr;
169 #endif
170
171 #else
172         void *addr;
173         struct vm_struct *area;
174         unsigned long offset, last_addr;
175
176         /* Don't allow wraparound or zero size */
177         last_addr = phys_addr + size - 1;
178         if (!size || last_addr < phys_addr)
179                 return NULL;
180
181         /*
182          * Don't allow anybody to remap normal RAM that we're using..
183          */
184         if (phys_addr < virt_to_phys(high_memory)) {
185                 char *t_addr, *t_end;
186                 struct page *page;
187
188                 t_addr = __va(phys_addr);
189                 t_end = t_addr + (size - 1);
190            
191                 for (page = virt_to_page(t_addr); 
192                      page <= virt_to_page(t_end); page++) {
193                         if(!PageReserved(page))
194                                 return NULL;
195                 }
196         }
197
198         /*
199          * Mappings have to be page-aligned
200          */
201         offset = phys_addr & ~PAGE_MASK;
202         phys_addr &= PAGE_MASK;
203         size = PAGE_ALIGN(last_addr) - phys_addr;
204
205         /*
206          * Ok, go for it..
207          */
208         area = get_vm_area(size, VM_IOREMAP);
209         if (!area)
210                 return NULL;
211
212         addr = area->addr;
213         if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
214                 vfree(addr);
215                 return NULL;
216         }
217
218         return (void __iomem *) (offset + (char *)addr);
219 #endif
220 }
221
222 void iounmap(void __iomem *addr)
223 {
224 #ifdef CONFIG_HPPA_IOREMAP
225         if (addr > high_memory)
226                 return vfree((void *) (PAGE_MASK & (unsigned long __force) addr));
227 #else
228         return;
229 #endif
230 }