File: /usr/src/linux/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/config.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 return 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 = NULL;
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 = (struct vm_struct *)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 return NULL;
71 addr = tmp->size + (unsigned long)tmp->addr;
72 }
73 area->addr = (void *)addr;
74 area->size = size + IO_SIZE;
75 area->next = *p;
76 *p = area;
77 return area;
78 }
79
80 static inline void free_io_area(void *addr)
81 {
82 struct vm_struct **p, *tmp;
83
84 if (!addr)
85 return;
86 addr = (void *)((unsigned long)addr & -IO_SIZE);
87 for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
88 if (tmp->addr == addr) {
89 *p = tmp->next;
90 __iounmap(tmp->addr, tmp->size);
91 kfree(tmp);
92 return;
93 }
94 }
95 }
96
97 #endif
98
99 /*
100 * Map some physical address range into the kernel address space. The
101 * code is copied and adapted from map_chunk().
102 */
103 /* Rewritten by Andreas Schwab to remove all races. */
104
105 void *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
106 {
107 struct vm_struct *area;
108 unsigned long virtaddr, retaddr;
109 long offset;
110 pgd_t *pgd_dir;
111 pmd_t *pmd_dir;
112 pte_t *pte_dir;
113
114 /*
115 * Don't allow mappings that wrap..
116 */
117 if (!size || size > physaddr + size)
118 return NULL;
119
120 #ifdef CONFIG_AMIGA
121 if (MACH_IS_AMIGA) {
122 if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
123 && (cacheflag == IOMAP_NOCACHE_SER))
124 return (void *)physaddr;
125 }
126 #endif
127
128 #ifdef DEBUG
129 printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
130 #endif
131 /*
132 * Mappings have to be aligned
133 */
134 offset = physaddr & (IO_SIZE - 1);
135 physaddr &= -IO_SIZE;
136 size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
137
138 /*
139 * Ok, go for it..
140 */
141 area = get_io_area(size);
142 if (!area)
143 return NULL;
144
145 virtaddr = (unsigned long)area->addr;
146 retaddr = virtaddr + offset;
147 #ifdef DEBUG
148 printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
149 #endif
150
151 /*
152 * add cache and table flags to physical address
153 */
154 if (CPU_IS_040_OR_060) {
155 physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
156 _PAGE_ACCESSED | _PAGE_DIRTY);
157 switch (cacheflag) {
158 case IOMAP_FULL_CACHING:
159 physaddr |= _PAGE_CACHE040;
160 break;
161 case IOMAP_NOCACHE_SER:
162 default:
163 physaddr |= _PAGE_NOCACHE_S;
164 break;
165 case IOMAP_NOCACHE_NONSER:
166 physaddr |= _PAGE_NOCACHE;
167 break;
168 case IOMAP_WRITETHROUGH:
169 physaddr |= _PAGE_CACHE040W;
170 break;
171 }
172 } else {
173 physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
174 switch (cacheflag) {
175 case IOMAP_NOCACHE_SER:
176 case IOMAP_NOCACHE_NONSER:
177 default:
178 physaddr |= _PAGE_NOCACHE030;
179 break;
180 case IOMAP_FULL_CACHING:
181 case IOMAP_WRITETHROUGH:
182 break;
183 }
184 }
185
186 while ((long)size > 0) {
187 #ifdef DEBUG
188 if (!(virtaddr & (PTRTREESIZE-1)))
189 printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
190 #endif
191 pgd_dir = pgd_offset_k(virtaddr);
192 pmd_dir = pmd_alloc_kernel(pgd_dir, virtaddr);
193 if (!pmd_dir) {
194 printk("ioremap: no mem for pmd_dir\n");
195 return NULL;
196 }
197
198 if (CPU_IS_020_OR_030) {
199 pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
200 physaddr += PTRTREESIZE;
201 virtaddr += PTRTREESIZE;
202 size -= PTRTREESIZE;
203 } else {
204 pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
205 if (!pte_dir) {
206 printk("ioremap: no mem for pte_dir\n");
207 return NULL;
208 }
209
210 pte_val(*pte_dir) = physaddr;
211 virtaddr += PAGE_SIZE;
212 physaddr += PAGE_SIZE;
213 size -= PAGE_SIZE;
214 }
215 }
216 #ifdef DEBUG
217 printk("\n");
218 #endif
219 flush_tlb_all();
220
221 return (void *)retaddr;
222 }
223
224 /*
225 * Unmap a ioremap()ed region again
226 */
227 void iounmap(void *addr)
228 {
229 #ifdef CONFIG_AMIGA
230 if ((!MACH_IS_AMIGA) ||
231 (((unsigned long)addr < 0x40000000) ||
232 ((unsigned long)addr > 0x60000000)))
233 free_io_area(addr);
234 #else
235 free_io_area(addr);
236 #endif
237 }
238
239 /*
240 * __iounmap unmaps nearly everything, so be careful
241 * it doesn't free currently pointer/page tables anymore but it
242 * wans't used anyway and might be added later.
243 */
244 void __iounmap(void *addr, unsigned long size)
245 {
246 unsigned long virtaddr = (unsigned long)addr;
247 pgd_t *pgd_dir;
248 pmd_t *pmd_dir;
249 pte_t *pte_dir;
250
251 while ((long)size > 0) {
252 pgd_dir = pgd_offset_k(virtaddr);
253 if (pgd_bad(*pgd_dir)) {
254 printk("iounmap: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
255 pgd_clear(pgd_dir);
256 return;
257 }
258 pmd_dir = pmd_offset(pgd_dir, virtaddr);
259
260 if (CPU_IS_020_OR_030) {
261 int pmd_off = (virtaddr/PTRTREESIZE) & 15;
262
263 if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
264 pmd_dir->pmd[pmd_off] = 0;
265 virtaddr += PTRTREESIZE;
266 size -= PTRTREESIZE;
267 continue;
268 }
269 }
270
271 if (pmd_bad(*pmd_dir)) {
272 printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
273 pmd_clear(pmd_dir);
274 return;
275 }
276 pte_dir = pte_offset(pmd_dir, virtaddr);
277
278 pte_val(*pte_dir) = 0;
279 virtaddr += PAGE_SIZE;
280 size -= PAGE_SIZE;
281 }
282
283 flush_tlb_all();
284 }
285
286 /*
287 * Set new cache mode for some kernel address space.
288 * The caller must push data for that range itself, if such data may already
289 * be in the cache.
290 */
291 void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
292 {
293 unsigned long virtaddr = (unsigned long)addr;
294 pgd_t *pgd_dir;
295 pmd_t *pmd_dir;
296 pte_t *pte_dir;
297
298 if (CPU_IS_040_OR_060) {
299 switch (cmode) {
300 case IOMAP_FULL_CACHING:
301 cmode = _PAGE_CACHE040;
302 break;
303 case IOMAP_NOCACHE_SER:
304 default:
305 cmode = _PAGE_NOCACHE_S;
306 break;
307 case IOMAP_NOCACHE_NONSER:
308 cmode = _PAGE_NOCACHE;
309 break;
310 case IOMAP_WRITETHROUGH:
311 cmode = _PAGE_CACHE040W;
312 break;
313 }
314 } else {
315 switch (cmode) {
316 case IOMAP_NOCACHE_SER:
317 case IOMAP_NOCACHE_NONSER:
318 default:
319 cmode = _PAGE_NOCACHE030;
320 break;
321 case IOMAP_FULL_CACHING:
322 case IOMAP_WRITETHROUGH:
323 cmode = 0;
324 }
325 }
326
327 while ((long)size > 0) {
328 pgd_dir = pgd_offset_k(virtaddr);
329 if (pgd_bad(*pgd_dir)) {
330 printk("iocachemode: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
331 pgd_clear(pgd_dir);
332 return;
333 }
334 pmd_dir = pmd_offset(pgd_dir, virtaddr);
335
336 if (CPU_IS_020_OR_030) {
337 int pmd_off = (virtaddr/PTRTREESIZE) & 15;
338
339 if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
340 pmd_dir->pmd[pmd_off] = (pmd_dir->pmd[pmd_off] &
341 _CACHEMASK040) | cmode;
342 virtaddr += PTRTREESIZE;
343 size -= PTRTREESIZE;
344 continue;
345 }
346 }
347
348 if (pmd_bad(*pmd_dir)) {
349 printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
350 pmd_clear(pmd_dir);
351 return;
352 }
353 pte_dir = pte_offset(pmd_dir, virtaddr);
354
355 pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
356 virtaddr += PAGE_SIZE;
357 size -= PAGE_SIZE;
358 }
359
360 flush_tlb_all();
361 }
362