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/page.h>
21 #include <asm/io.h>
22 #include <asm/tlbflush.h>
23
24 #undef DEBUG
25
26 /*
27 * For 040/060 we can use the virtual memory area like other architectures,
28 * but for 020/030 we want to use early termination page descriptors and we
29 * can't mix this with normal page descriptors, so we have to copy that code
30 * (mm/vmalloc.c) and return appropriately aligned addresses.
31 */
32
33 #ifdef CPU_M68040_OR_M68060_ONLY
34
35 #define IO_SIZE PAGE_SIZE
36
get_io_area(unsigned long size)37 static inline struct vm_struct *get_io_area(unsigned long size)
38 {
39 return get_vm_area(size, VM_IOREMAP);
40 }
41
42
free_io_area(void * addr)43 static inline void free_io_area(void *addr)
44 {
45 vfree((void *)(PAGE_MASK & (unsigned long)addr));
46 }
47
48 #else
49
50 #define IO_SIZE PMD_SIZE
51
52 static struct vm_struct *iolist;
53
54 /*
55 * __free_io_area unmaps nearly everything, so be careful
56 * Currently it doesn't free pointer/page tables anymore but this
57 * wasn't used anyway and might be added later.
58 */
__free_io_area(void * addr,unsigned long size)59 static void __free_io_area(void *addr, unsigned long size)
60 {
61 unsigned long virtaddr = (unsigned long)addr;
62 pgd_t *pgd_dir;
63 p4d_t *p4d_dir;
64 pud_t *pud_dir;
65 pmd_t *pmd_dir;
66 pte_t *pte_dir;
67
68 while ((long)size > 0) {
69 pgd_dir = pgd_offset_k(virtaddr);
70 p4d_dir = p4d_offset(pgd_dir, virtaddr);
71 pud_dir = pud_offset(p4d_dir, virtaddr);
72 if (pud_bad(*pud_dir)) {
73 printk("iounmap: bad pud(%08lx)\n", pud_val(*pud_dir));
74 pud_clear(pud_dir);
75 return;
76 }
77 pmd_dir = pmd_offset(pud_dir, virtaddr);
78
79 #if CONFIG_PGTABLE_LEVELS == 3
80 if (CPU_IS_020_OR_030) {
81 int pmd_type = pmd_val(*pmd_dir) & _DESCTYPE_MASK;
82
83 if (pmd_type == _PAGE_PRESENT) {
84 pmd_clear(pmd_dir);
85 virtaddr += PMD_SIZE;
86 size -= PMD_SIZE;
87
88 } else if (pmd_type == 0)
89 continue;
90 }
91 #endif
92
93 if (pmd_bad(*pmd_dir)) {
94 printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
95 pmd_clear(pmd_dir);
96 return;
97 }
98 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
99
100 pte_val(*pte_dir) = 0;
101 virtaddr += PAGE_SIZE;
102 size -= PAGE_SIZE;
103 }
104
105 flush_tlb_all();
106 }
107
get_io_area(unsigned long size)108 static struct vm_struct *get_io_area(unsigned long size)
109 {
110 unsigned long addr;
111 struct vm_struct **p, *tmp, *area;
112
113 area = kmalloc(sizeof(*area), GFP_KERNEL);
114 if (!area)
115 return NULL;
116 addr = KMAP_START;
117 for (p = &iolist; (tmp = *p) ; p = &tmp->next) {
118 if (size + addr < (unsigned long)tmp->addr)
119 break;
120 if (addr > KMAP_END-size) {
121 kfree(area);
122 return NULL;
123 }
124 addr = tmp->size + (unsigned long)tmp->addr;
125 }
126 area->addr = (void *)addr;
127 area->size = size + IO_SIZE;
128 area->next = *p;
129 *p = area;
130 return area;
131 }
132
free_io_area(void * addr)133 static inline void free_io_area(void *addr)
134 {
135 struct vm_struct **p, *tmp;
136
137 if (!addr)
138 return;
139 addr = (void *)((unsigned long)addr & -IO_SIZE);
140 for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
141 if (tmp->addr == addr) {
142 *p = tmp->next;
143 /* remove gap added in get_io_area() */
144 __free_io_area(tmp->addr, tmp->size - IO_SIZE);
145 kfree(tmp);
146 return;
147 }
148 }
149 }
150
151 #endif
152
153 /*
154 * Map some physical address range into the kernel address space.
155 */
156 /* Rewritten by Andreas Schwab to remove all races. */
157
__ioremap(unsigned long physaddr,unsigned long size,int cacheflag)158 void __iomem *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
159 {
160 struct vm_struct *area;
161 unsigned long virtaddr, retaddr;
162 long offset;
163 pgd_t *pgd_dir;
164 p4d_t *p4d_dir;
165 pud_t *pud_dir;
166 pmd_t *pmd_dir;
167 pte_t *pte_dir;
168
169 /*
170 * Don't allow mappings that wrap..
171 */
172 if (!size || physaddr > (unsigned long)(-size))
173 return NULL;
174
175 #ifdef CONFIG_AMIGA
176 if (MACH_IS_AMIGA) {
177 if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
178 && (cacheflag == IOMAP_NOCACHE_SER))
179 return (void __iomem *)physaddr;
180 }
181 #endif
182 #ifdef CONFIG_COLDFIRE
183 if (__cf_internalio(physaddr))
184 return (void __iomem *) physaddr;
185 #endif
186
187 #ifdef DEBUG
188 printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
189 #endif
190 /*
191 * Mappings have to be aligned
192 */
193 offset = physaddr & (IO_SIZE - 1);
194 physaddr &= -IO_SIZE;
195 size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
196
197 /*
198 * Ok, go for it..
199 */
200 area = get_io_area(size);
201 if (!area)
202 return NULL;
203
204 virtaddr = (unsigned long)area->addr;
205 retaddr = virtaddr + offset;
206 #ifdef DEBUG
207 printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
208 #endif
209
210 /*
211 * add cache and table flags to physical address
212 */
213 if (CPU_IS_040_OR_060) {
214 physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
215 _PAGE_ACCESSED | _PAGE_DIRTY);
216 switch (cacheflag) {
217 case IOMAP_FULL_CACHING:
218 physaddr |= _PAGE_CACHE040;
219 break;
220 case IOMAP_NOCACHE_SER:
221 default:
222 physaddr |= _PAGE_NOCACHE_S;
223 break;
224 case IOMAP_NOCACHE_NONSER:
225 physaddr |= _PAGE_NOCACHE;
226 break;
227 case IOMAP_WRITETHROUGH:
228 physaddr |= _PAGE_CACHE040W;
229 break;
230 }
231 } else {
232 physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED |
233 _PAGE_DIRTY | _PAGE_READWRITE);
234 switch (cacheflag) {
235 case IOMAP_NOCACHE_SER:
236 case IOMAP_NOCACHE_NONSER:
237 default:
238 physaddr |= _PAGE_NOCACHE030;
239 break;
240 case IOMAP_FULL_CACHING:
241 case IOMAP_WRITETHROUGH:
242 break;
243 }
244 }
245
246 while ((long)size > 0) {
247 #ifdef DEBUG
248 if (!(virtaddr & (PMD_SIZE-1)))
249 printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
250 #endif
251 pgd_dir = pgd_offset_k(virtaddr);
252 p4d_dir = p4d_offset(pgd_dir, virtaddr);
253 pud_dir = pud_offset(p4d_dir, virtaddr);
254 pmd_dir = pmd_alloc(&init_mm, pud_dir, virtaddr);
255 if (!pmd_dir) {
256 printk("ioremap: no mem for pmd_dir\n");
257 return NULL;
258 }
259
260 #if CONFIG_PGTABLE_LEVELS == 3
261 if (CPU_IS_020_OR_030) {
262 pmd_val(*pmd_dir) = physaddr;
263 physaddr += PMD_SIZE;
264 virtaddr += PMD_SIZE;
265 size -= PMD_SIZE;
266 } else
267 #endif
268 {
269 pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
270 if (!pte_dir) {
271 printk("ioremap: no mem for pte_dir\n");
272 return NULL;
273 }
274
275 pte_val(*pte_dir) = physaddr;
276 virtaddr += PAGE_SIZE;
277 physaddr += PAGE_SIZE;
278 size -= PAGE_SIZE;
279 }
280 }
281 #ifdef DEBUG
282 printk("\n");
283 #endif
284 flush_tlb_all();
285
286 return (void __iomem *)retaddr;
287 }
288 EXPORT_SYMBOL(__ioremap);
289
290 /*
291 * Unmap an ioremap()ed region again
292 */
iounmap(void __iomem * addr)293 void iounmap(void __iomem *addr)
294 {
295 #ifdef CONFIG_AMIGA
296 if ((!MACH_IS_AMIGA) ||
297 (((unsigned long)addr < 0x40000000) ||
298 ((unsigned long)addr > 0x60000000)))
299 free_io_area((__force void *)addr);
300 #else
301 #ifdef CONFIG_COLDFIRE
302 if (cf_internalio(addr))
303 return;
304 #endif
305 free_io_area((__force void *)addr);
306 #endif
307 }
308 EXPORT_SYMBOL(iounmap);
309
310 /*
311 * Set new cache mode for some kernel address space.
312 * The caller must push data for that range itself, if such data may already
313 * be in the cache.
314 */
kernel_set_cachemode(void * addr,unsigned long size,int cmode)315 void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
316 {
317 unsigned long virtaddr = (unsigned long)addr;
318 pgd_t *pgd_dir;
319 p4d_t *p4d_dir;
320 pud_t *pud_dir;
321 pmd_t *pmd_dir;
322 pte_t *pte_dir;
323
324 if (CPU_IS_040_OR_060) {
325 switch (cmode) {
326 case IOMAP_FULL_CACHING:
327 cmode = _PAGE_CACHE040;
328 break;
329 case IOMAP_NOCACHE_SER:
330 default:
331 cmode = _PAGE_NOCACHE_S;
332 break;
333 case IOMAP_NOCACHE_NONSER:
334 cmode = _PAGE_NOCACHE;
335 break;
336 case IOMAP_WRITETHROUGH:
337 cmode = _PAGE_CACHE040W;
338 break;
339 }
340 } else {
341 switch (cmode) {
342 case IOMAP_NOCACHE_SER:
343 case IOMAP_NOCACHE_NONSER:
344 default:
345 cmode = _PAGE_NOCACHE030;
346 break;
347 case IOMAP_FULL_CACHING:
348 case IOMAP_WRITETHROUGH:
349 cmode = 0;
350 }
351 }
352
353 while ((long)size > 0) {
354 pgd_dir = pgd_offset_k(virtaddr);
355 p4d_dir = p4d_offset(pgd_dir, virtaddr);
356 pud_dir = pud_offset(p4d_dir, virtaddr);
357 if (pud_bad(*pud_dir)) {
358 printk("iocachemode: bad pud(%08lx)\n", pud_val(*pud_dir));
359 pud_clear(pud_dir);
360 return;
361 }
362 pmd_dir = pmd_offset(pud_dir, virtaddr);
363
364 #if CONFIG_PGTABLE_LEVELS == 3
365 if (CPU_IS_020_OR_030) {
366 unsigned long pmd = pmd_val(*pmd_dir);
367
368 if ((pmd & _DESCTYPE_MASK) == _PAGE_PRESENT) {
369 *pmd_dir = __pmd((pmd & _CACHEMASK040) | cmode);
370 virtaddr += PMD_SIZE;
371 size -= PMD_SIZE;
372 continue;
373 }
374 }
375 #endif
376
377 if (pmd_bad(*pmd_dir)) {
378 printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
379 pmd_clear(pmd_dir);
380 return;
381 }
382 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
383
384 pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
385 virtaddr += PAGE_SIZE;
386 size -= PAGE_SIZE;
387 }
388
389 flush_tlb_all();
390 }
391 EXPORT_SYMBOL(kernel_set_cachemode);
392