m68k: Allow ioremapping top of memory
[linux-2.6.git] / arch / m68k / mm / kmap.c
1 /*
2  *  linux/arch/m68k/mm/kmap.c
3  *
4  *  Copyright (C) 1997 Roman Hodek
5  *
6  *  10/01/99 cleaned up the code and changing to the same interface
7  *           used by other architectures                /Roman Zippel
8  */
9
10 #include <linux/module.h>
11 #include <linux/mm.h>
12 #include <linux/kernel.h>
13 #include <linux/string.h>
14 #include <linux/types.h>
15 #include <linux/slab.h>
16 #include <linux/vmalloc.h>
17
18 #include <asm/setup.h>
19 #include <asm/segment.h>
20 #include <asm/page.h>
21 #include <asm/pgalloc.h>
22 #include <asm/io.h>
23 #include <asm/system.h>
24
25 #undef DEBUG
26
27 #define PTRTREESIZE     (256*1024)
28
29 /*
30  * For 040/060 we can use the virtual memory area like other architectures,
31  * but for 020/030 we want to use early termination page descriptor and we
32  * can't mix this with normal page descriptors, so we have to copy that code
33  * (mm/vmalloc.c) and return appriorate aligned addresses.
34  */
35
36 #ifdef CPU_M68040_OR_M68060_ONLY
37
38 #define IO_SIZE         PAGE_SIZE
39
40 static inline struct vm_struct *get_io_area(unsigned long size)
41 {
42         return get_vm_area(size, VM_IOREMAP);
43 }
44
45
46 static inline void free_io_area(void *addr)
47 {
48         vfree((void *)(PAGE_MASK & (unsigned long)addr));
49 }
50
51 #else
52
53 #define IO_SIZE         (256*1024)
54
55 static struct vm_struct *iolist;
56
57 static struct vm_struct *get_io_area(unsigned long size)
58 {
59         unsigned long addr;
60         struct vm_struct **p, *tmp, *area;
61
62         area = kmalloc(sizeof(*area), GFP_KERNEL);
63         if (!area)
64                 return NULL;
65         addr = KMAP_START;
66         for (p = &iolist; (tmp = *p) ; p = &tmp->next) {
67                 if (size + addr < (unsigned long)tmp->addr)
68                         break;
69                 if (addr > KMAP_END-size) {
70                         kfree(area);
71                         return NULL;
72                 }
73                 addr = tmp->size + (unsigned long)tmp->addr;
74         }
75         area->addr = (void *)addr;
76         area->size = size + IO_SIZE;
77         area->next = *p;
78         *p = area;
79         return area;
80 }
81
82 static inline void free_io_area(void *addr)
83 {
84         struct vm_struct **p, *tmp;
85
86         if (!addr)
87                 return;
88         addr = (void *)((unsigned long)addr & -IO_SIZE);
89         for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
90                 if (tmp->addr == addr) {
91                         *p = tmp->next;
92                         __iounmap(tmp->addr, tmp->size);
93                         kfree(tmp);
94                         return;
95                 }
96         }
97 }
98
99 #endif
100
101 /*
102  * Map some physical address range into the kernel address space. The
103  * code is copied and adapted from map_chunk().
104  */
105 /* Rewritten by Andreas Schwab to remove all races. */
106
107 void __iomem *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
108 {
109         struct vm_struct *area;
110         unsigned long virtaddr, retaddr;
111         long offset;
112         pgd_t *pgd_dir;
113         pmd_t *pmd_dir;
114         pte_t *pte_dir;
115
116         /*
117          * Don't allow mappings that wrap..
118          */
119         if (!size || physaddr > (unsigned long)(-size))
120                 return NULL;
121
122 #ifdef CONFIG_AMIGA
123         if (MACH_IS_AMIGA) {
124                 if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
125                     && (cacheflag == IOMAP_NOCACHE_SER))
126                         return (void __iomem *)physaddr;
127         }
128 #endif
129
130 #ifdef DEBUG
131         printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
132 #endif
133         /*
134          * Mappings have to be aligned
135          */
136         offset = physaddr & (IO_SIZE - 1);
137         physaddr &= -IO_SIZE;
138         size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
139
140         /*
141          * Ok, go for it..
142          */
143         area = get_io_area(size);
144         if (!area)
145                 return NULL;
146
147         virtaddr = (unsigned long)area->addr;
148         retaddr = virtaddr + offset;
149 #ifdef DEBUG
150         printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
151 #endif
152
153         /*
154          * add cache and table flags to physical address
155          */
156         if (CPU_IS_040_OR_060) {
157                 physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
158                              _PAGE_ACCESSED | _PAGE_DIRTY);
159                 switch (cacheflag) {
160                 case IOMAP_FULL_CACHING:
161                         physaddr |= _PAGE_CACHE040;
162                         break;
163                 case IOMAP_NOCACHE_SER:
164                 default:
165                         physaddr |= _PAGE_NOCACHE_S;
166                         break;
167                 case IOMAP_NOCACHE_NONSER:
168                         physaddr |= _PAGE_NOCACHE;
169                         break;
170                 case IOMAP_WRITETHROUGH:
171                         physaddr |= _PAGE_CACHE040W;
172                         break;
173                 }
174         } else {
175                 physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
176                 switch (cacheflag) {
177                 case IOMAP_NOCACHE_SER:
178                 case IOMAP_NOCACHE_NONSER:
179                 default:
180                         physaddr |= _PAGE_NOCACHE030;
181                         break;
182                 case IOMAP_FULL_CACHING:
183                 case IOMAP_WRITETHROUGH:
184                         break;
185                 }
186         }
187
188         while ((long)size > 0) {
189 #ifdef DEBUG
190                 if (!(virtaddr & (PTRTREESIZE-1)))
191                         printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
192 #endif
193                 pgd_dir = pgd_offset_k(virtaddr);
194                 pmd_dir = pmd_alloc(&init_mm, pgd_dir, virtaddr);
195                 if (!pmd_dir) {
196                         printk("ioremap: no mem for pmd_dir\n");
197                         return NULL;
198                 }
199
200                 if (CPU_IS_020_OR_030) {
201                         pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
202                         physaddr += PTRTREESIZE;
203                         virtaddr += PTRTREESIZE;
204                         size -= PTRTREESIZE;
205                 } else {
206                         pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
207                         if (!pte_dir) {
208                                 printk("ioremap: no mem for pte_dir\n");
209                                 return NULL;
210                         }
211
212                         pte_val(*pte_dir) = physaddr;
213                         virtaddr += PAGE_SIZE;
214                         physaddr += PAGE_SIZE;
215                         size -= PAGE_SIZE;
216                 }
217         }
218 #ifdef DEBUG
219         printk("\n");
220 #endif
221         flush_tlb_all();
222
223         return (void __iomem *)retaddr;
224 }
225 EXPORT_SYMBOL(__ioremap);
226
227 /*
228  * Unmap a ioremap()ed region again
229  */
230 void iounmap(void __iomem *addr)
231 {
232 #ifdef CONFIG_AMIGA
233         if ((!MACH_IS_AMIGA) ||
234             (((unsigned long)addr < 0x40000000) ||
235              ((unsigned long)addr > 0x60000000)))
236                         free_io_area((__force void *)addr);
237 #else
238         free_io_area((__force void *)addr);
239 #endif
240 }
241 EXPORT_SYMBOL(iounmap);
242
243 /*
244  * __iounmap unmaps nearly everything, so be careful
245  * it doesn't free currently pointer/page tables anymore but it
246  * wans't used anyway and might be added later.
247  */
248 void __iounmap(void *addr, unsigned long size)
249 {
250         unsigned long virtaddr = (unsigned long)addr;
251         pgd_t *pgd_dir;
252         pmd_t *pmd_dir;
253         pte_t *pte_dir;
254
255         while ((long)size > 0) {
256                 pgd_dir = pgd_offset_k(virtaddr);
257                 if (pgd_bad(*pgd_dir)) {
258                         printk("iounmap: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
259                         pgd_clear(pgd_dir);
260                         return;
261                 }
262                 pmd_dir = pmd_offset(pgd_dir, virtaddr);
263
264                 if (CPU_IS_020_OR_030) {
265                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
266                         int pmd_type = pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK;
267
268                         if (pmd_type == _PAGE_PRESENT) {
269                                 pmd_dir->pmd[pmd_off] = 0;
270                                 virtaddr += PTRTREESIZE;
271                                 size -= PTRTREESIZE;
272                                 continue;
273                         } else if (pmd_type == 0)
274                                 continue;
275                 }
276
277                 if (pmd_bad(*pmd_dir)) {
278                         printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
279                         pmd_clear(pmd_dir);
280                         return;
281                 }
282                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
283
284                 pte_val(*pte_dir) = 0;
285                 virtaddr += PAGE_SIZE;
286                 size -= PAGE_SIZE;
287         }
288
289         flush_tlb_all();
290 }
291
292 /*
293  * Set new cache mode for some kernel address space.
294  * The caller must push data for that range itself, if such data may already
295  * be in the cache.
296  */
297 void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
298 {
299         unsigned long virtaddr = (unsigned long)addr;
300         pgd_t *pgd_dir;
301         pmd_t *pmd_dir;
302         pte_t *pte_dir;
303
304         if (CPU_IS_040_OR_060) {
305                 switch (cmode) {
306                 case IOMAP_FULL_CACHING:
307                         cmode = _PAGE_CACHE040;
308                         break;
309                 case IOMAP_NOCACHE_SER:
310                 default:
311                         cmode = _PAGE_NOCACHE_S;
312                         break;
313                 case IOMAP_NOCACHE_NONSER:
314                         cmode = _PAGE_NOCACHE;
315                         break;
316                 case IOMAP_WRITETHROUGH:
317                         cmode = _PAGE_CACHE040W;
318                         break;
319                 }
320         } else {
321                 switch (cmode) {
322                 case IOMAP_NOCACHE_SER:
323                 case IOMAP_NOCACHE_NONSER:
324                 default:
325                         cmode = _PAGE_NOCACHE030;
326                         break;
327                 case IOMAP_FULL_CACHING:
328                 case IOMAP_WRITETHROUGH:
329                         cmode = 0;
330                 }
331         }
332
333         while ((long)size > 0) {
334                 pgd_dir = pgd_offset_k(virtaddr);
335                 if (pgd_bad(*pgd_dir)) {
336                         printk("iocachemode: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
337                         pgd_clear(pgd_dir);
338                         return;
339                 }
340                 pmd_dir = pmd_offset(pgd_dir, virtaddr);
341
342                 if (CPU_IS_020_OR_030) {
343                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
344
345                         if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
346                                 pmd_dir->pmd[pmd_off] = (pmd_dir->pmd[pmd_off] &
347                                                          _CACHEMASK040) | cmode;
348                                 virtaddr += PTRTREESIZE;
349                                 size -= PTRTREESIZE;
350                                 continue;
351                         }
352                 }
353
354                 if (pmd_bad(*pmd_dir)) {
355                         printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
356                         pmd_clear(pmd_dir);
357                         return;
358                 }
359                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
360
361                 pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
362                 virtaddr += PAGE_SIZE;
363                 size -= PAGE_SIZE;
364         }
365
366         flush_tlb_all();
367 }
368 EXPORT_SYMBOL(kernel_set_cachemode);