1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/arch/m68k/mm/kmap.c
4 *
5 * Copyright (C) 1997 Roman Hodek
6 *
7 * 10/01/99 cleaned up the code and changing to the same interface
8 * used by other architectures /Roman Zippel
9 */
10
11 #include <linux/module.h>
12 #include <linux/mm.h>
13 #include <linux/kernel.h>
14 #include <linux/string.h>
15 #include <linux/types.h>
16 #include <linux/slab.h>
17 #include <linux/vmalloc.h>
18
19 #include <asm/setup.h>
20 #include <asm/segment.h>
21 #include <asm/page.h>
22 #include <asm/pgalloc.h>
23 #include <asm/io.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 descriptors and we
32 * can't mix this with normal page descriptors, so we have to copy that code
33 * (mm/vmalloc.c) and return appropriately aligned addresses.
34 */
35
36 #ifdef CPU_M68040_OR_M68060_ONLY
37
38 #define IO_SIZE PAGE_SIZE
39
get_io_area(unsigned long size)40 static inline struct vm_struct *get_io_area(unsigned long size)
41 {
42 return get_vm_area(size, VM_IOREMAP);
43 }
44
45
free_io_area(void * addr)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
get_io_area(unsigned long size)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
free_io_area(void * addr)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 /* remove gap added in get_io_area() */
93 __iounmap(tmp->addr, tmp->size - IO_SIZE);
94 kfree(tmp);
95 return;
96 }
97 }
98 }
99
100 #endif
101
102 /*
103 * Map some physical address range into the kernel address space.
104 */
105 /* Rewritten by Andreas Schwab to remove all races. */
106
__ioremap(unsigned long physaddr,unsigned long size,int cacheflag)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 |
176 _PAGE_DIRTY | _PAGE_READWRITE);
177 switch (cacheflag) {
178 case IOMAP_NOCACHE_SER:
179 case IOMAP_NOCACHE_NONSER:
180 default:
181 physaddr |= _PAGE_NOCACHE030;
182 break;
183 case IOMAP_FULL_CACHING:
184 case IOMAP_WRITETHROUGH:
185 break;
186 }
187 }
188
189 while ((long)size > 0) {
190 #ifdef DEBUG
191 if (!(virtaddr & (PTRTREESIZE-1)))
192 printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
193 #endif
194 pgd_dir = pgd_offset_k(virtaddr);
195 pmd_dir = pmd_alloc(&init_mm, pgd_dir, virtaddr);
196 if (!pmd_dir) {
197 printk("ioremap: no mem for pmd_dir\n");
198 return NULL;
199 }
200
201 if (CPU_IS_020_OR_030) {
202 pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
203 physaddr += PTRTREESIZE;
204 virtaddr += PTRTREESIZE;
205 size -= PTRTREESIZE;
206 } else {
207 pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
208 if (!pte_dir) {
209 printk("ioremap: no mem for pte_dir\n");
210 return NULL;
211 }
212
213 pte_val(*pte_dir) = physaddr;
214 virtaddr += PAGE_SIZE;
215 physaddr += PAGE_SIZE;
216 size -= PAGE_SIZE;
217 }
218 }
219 #ifdef DEBUG
220 printk("\n");
221 #endif
222 flush_tlb_all();
223
224 return (void __iomem *)retaddr;
225 }
226 EXPORT_SYMBOL(__ioremap);
227
228 /*
229 * Unmap an ioremap()ed region again
230 */
iounmap(void __iomem * addr)231 void iounmap(void __iomem *addr)
232 {
233 #ifdef CONFIG_AMIGA
234 if ((!MACH_IS_AMIGA) ||
235 (((unsigned long)addr < 0x40000000) ||
236 ((unsigned long)addr > 0x60000000)))
237 free_io_area((__force void *)addr);
238 #else
239 free_io_area((__force void *)addr);
240 #endif
241 }
242 EXPORT_SYMBOL(iounmap);
243
244 /*
245 * __iounmap unmaps nearly everything, so be careful
246 * Currently it doesn't free pointer/page tables anymore but this
247 * wasn't used anyway and might be added later.
248 */
__iounmap(void * addr,unsigned long size)249 void __iounmap(void *addr, unsigned long size)
250 {
251 unsigned long virtaddr = (unsigned long)addr;
252 pgd_t *pgd_dir;
253 pmd_t *pmd_dir;
254 pte_t *pte_dir;
255
256 while ((long)size > 0) {
257 pgd_dir = pgd_offset_k(virtaddr);
258 if (pgd_bad(*pgd_dir)) {
259 printk("iounmap: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
260 pgd_clear(pgd_dir);
261 return;
262 }
263 pmd_dir = pmd_offset(pgd_dir, virtaddr);
264
265 if (CPU_IS_020_OR_030) {
266 int pmd_off = (virtaddr/PTRTREESIZE) & 15;
267 int pmd_type = pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK;
268
269 if (pmd_type == _PAGE_PRESENT) {
270 pmd_dir->pmd[pmd_off] = 0;
271 virtaddr += PTRTREESIZE;
272 size -= PTRTREESIZE;
273 continue;
274 } else if (pmd_type == 0)
275 continue;
276 }
277
278 if (pmd_bad(*pmd_dir)) {
279 printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
280 pmd_clear(pmd_dir);
281 return;
282 }
283 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
284
285 pte_val(*pte_dir) = 0;
286 virtaddr += PAGE_SIZE;
287 size -= PAGE_SIZE;
288 }
289
290 flush_tlb_all();
291 }
292
293 /*
294 * Set new cache mode for some kernel address space.
295 * The caller must push data for that range itself, if such data may already
296 * be in the cache.
297 */
kernel_set_cachemode(void * addr,unsigned long size,int cmode)298 void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
299 {
300 unsigned long virtaddr = (unsigned long)addr;
301 pgd_t *pgd_dir;
302 pmd_t *pmd_dir;
303 pte_t *pte_dir;
304
305 if (CPU_IS_040_OR_060) {
306 switch (cmode) {
307 case IOMAP_FULL_CACHING:
308 cmode = _PAGE_CACHE040;
309 break;
310 case IOMAP_NOCACHE_SER:
311 default:
312 cmode = _PAGE_NOCACHE_S;
313 break;
314 case IOMAP_NOCACHE_NONSER:
315 cmode = _PAGE_NOCACHE;
316 break;
317 case IOMAP_WRITETHROUGH:
318 cmode = _PAGE_CACHE040W;
319 break;
320 }
321 } else {
322 switch (cmode) {
323 case IOMAP_NOCACHE_SER:
324 case IOMAP_NOCACHE_NONSER:
325 default:
326 cmode = _PAGE_NOCACHE030;
327 break;
328 case IOMAP_FULL_CACHING:
329 case IOMAP_WRITETHROUGH:
330 cmode = 0;
331 }
332 }
333
334 while ((long)size > 0) {
335 pgd_dir = pgd_offset_k(virtaddr);
336 if (pgd_bad(*pgd_dir)) {
337 printk("iocachemode: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
338 pgd_clear(pgd_dir);
339 return;
340 }
341 pmd_dir = pmd_offset(pgd_dir, virtaddr);
342
343 if (CPU_IS_020_OR_030) {
344 int pmd_off = (virtaddr/PTRTREESIZE) & 15;
345
346 if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
347 pmd_dir->pmd[pmd_off] = (pmd_dir->pmd[pmd_off] &
348 _CACHEMASK040) | cmode;
349 virtaddr += PTRTREESIZE;
350 size -= PTRTREESIZE;
351 continue;
352 }
353 }
354
355 if (pmd_bad(*pmd_dir)) {
356 printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
357 pmd_clear(pmd_dir);
358 return;
359 }
360 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
361
362 pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
363 virtaddr += PAGE_SIZE;
364 size -= PAGE_SIZE;
365 }
366
367 flush_tlb_all();
368 }
369 EXPORT_SYMBOL(kernel_set_cachemode);
370