xref: /linux/arch/m68k/mm/kmap.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
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.
103  */
104 /* Rewritten by Andreas Schwab to remove all races. */
105 
106 void __iomem *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
107 {
108 	struct vm_struct *area;
109 	unsigned long virtaddr, retaddr;
110 	long offset;
111 	pgd_t *pgd_dir;
112 	pmd_t *pmd_dir;
113 	pte_t *pte_dir;
114 
115 	/*
116 	 * Don't allow mappings that wrap..
117 	 */
118 	if (!size || physaddr > (unsigned long)(-size))
119 		return NULL;
120 
121 #ifdef CONFIG_AMIGA
122 	if (MACH_IS_AMIGA) {
123 		if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
124 		    && (cacheflag == IOMAP_NOCACHE_SER))
125 			return (void __iomem *)physaddr;
126 	}
127 #endif
128 
129 #ifdef DEBUG
130 	printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
131 #endif
132 	/*
133 	 * Mappings have to be aligned
134 	 */
135 	offset = physaddr & (IO_SIZE - 1);
136 	physaddr &= -IO_SIZE;
137 	size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
138 
139 	/*
140 	 * Ok, go for it..
141 	 */
142 	area = get_io_area(size);
143 	if (!area)
144 		return NULL;
145 
146 	virtaddr = (unsigned long)area->addr;
147 	retaddr = virtaddr + offset;
148 #ifdef DEBUG
149 	printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
150 #endif
151 
152 	/*
153 	 * add cache and table flags to physical address
154 	 */
155 	if (CPU_IS_040_OR_060) {
156 		physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
157 			     _PAGE_ACCESSED | _PAGE_DIRTY);
158 		switch (cacheflag) {
159 		case IOMAP_FULL_CACHING:
160 			physaddr |= _PAGE_CACHE040;
161 			break;
162 		case IOMAP_NOCACHE_SER:
163 		default:
164 			physaddr |= _PAGE_NOCACHE_S;
165 			break;
166 		case IOMAP_NOCACHE_NONSER:
167 			physaddr |= _PAGE_NOCACHE;
168 			break;
169 		case IOMAP_WRITETHROUGH:
170 			physaddr |= _PAGE_CACHE040W;
171 			break;
172 		}
173 	} else {
174 		physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
175 		switch (cacheflag) {
176 		case IOMAP_NOCACHE_SER:
177 		case IOMAP_NOCACHE_NONSER:
178 		default:
179 			physaddr |= _PAGE_NOCACHE030;
180 			break;
181 		case IOMAP_FULL_CACHING:
182 		case IOMAP_WRITETHROUGH:
183 			break;
184 		}
185 	}
186 
187 	while ((long)size > 0) {
188 #ifdef DEBUG
189 		if (!(virtaddr & (PTRTREESIZE-1)))
190 			printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
191 #endif
192 		pgd_dir = pgd_offset_k(virtaddr);
193 		pmd_dir = pmd_alloc(&init_mm, pgd_dir, virtaddr);
194 		if (!pmd_dir) {
195 			printk("ioremap: no mem for pmd_dir\n");
196 			return NULL;
197 		}
198 
199 		if (CPU_IS_020_OR_030) {
200 			pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
201 			physaddr += PTRTREESIZE;
202 			virtaddr += PTRTREESIZE;
203 			size -= PTRTREESIZE;
204 		} else {
205 			pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
206 			if (!pte_dir) {
207 				printk("ioremap: no mem for pte_dir\n");
208 				return NULL;
209 			}
210 
211 			pte_val(*pte_dir) = physaddr;
212 			virtaddr += PAGE_SIZE;
213 			physaddr += PAGE_SIZE;
214 			size -= PAGE_SIZE;
215 		}
216 	}
217 #ifdef DEBUG
218 	printk("\n");
219 #endif
220 	flush_tlb_all();
221 
222 	return (void __iomem *)retaddr;
223 }
224 EXPORT_SYMBOL(__ioremap);
225 
226 /*
227  * Unmap a ioremap()ed region again
228  */
229 void iounmap(void __iomem *addr)
230 {
231 #ifdef CONFIG_AMIGA
232 	if ((!MACH_IS_AMIGA) ||
233 	    (((unsigned long)addr < 0x40000000) ||
234 	     ((unsigned long)addr > 0x60000000)))
235 			free_io_area((__force void *)addr);
236 #else
237 	free_io_area((__force void *)addr);
238 #endif
239 }
240 EXPORT_SYMBOL(iounmap);
241 
242 /*
243  * __iounmap unmaps nearly everything, so be careful
244  * it doesn't free currently pointer/page tables anymore but it
245  * wans't used anyway and might be added later.
246  */
247 void __iounmap(void *addr, unsigned long size)
248 {
249 	unsigned long virtaddr = (unsigned long)addr;
250 	pgd_t *pgd_dir;
251 	pmd_t *pmd_dir;
252 	pte_t *pte_dir;
253 
254 	while ((long)size > 0) {
255 		pgd_dir = pgd_offset_k(virtaddr);
256 		if (pgd_bad(*pgd_dir)) {
257 			printk("iounmap: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
258 			pgd_clear(pgd_dir);
259 			return;
260 		}
261 		pmd_dir = pmd_offset(pgd_dir, virtaddr);
262 
263 		if (CPU_IS_020_OR_030) {
264 			int pmd_off = (virtaddr/PTRTREESIZE) & 15;
265 			int pmd_type = pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK;
266 
267 			if (pmd_type == _PAGE_PRESENT) {
268 				pmd_dir->pmd[pmd_off] = 0;
269 				virtaddr += PTRTREESIZE;
270 				size -= PTRTREESIZE;
271 				continue;
272 			} else if (pmd_type == 0)
273 				continue;
274 		}
275 
276 		if (pmd_bad(*pmd_dir)) {
277 			printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
278 			pmd_clear(pmd_dir);
279 			return;
280 		}
281 		pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
282 
283 		pte_val(*pte_dir) = 0;
284 		virtaddr += PAGE_SIZE;
285 		size -= PAGE_SIZE;
286 	}
287 
288 	flush_tlb_all();
289 }
290 
291 /*
292  * Set new cache mode for some kernel address space.
293  * The caller must push data for that range itself, if such data may already
294  * be in the cache.
295  */
296 void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
297 {
298 	unsigned long virtaddr = (unsigned long)addr;
299 	pgd_t *pgd_dir;
300 	pmd_t *pmd_dir;
301 	pte_t *pte_dir;
302 
303 	if (CPU_IS_040_OR_060) {
304 		switch (cmode) {
305 		case IOMAP_FULL_CACHING:
306 			cmode = _PAGE_CACHE040;
307 			break;
308 		case IOMAP_NOCACHE_SER:
309 		default:
310 			cmode = _PAGE_NOCACHE_S;
311 			break;
312 		case IOMAP_NOCACHE_NONSER:
313 			cmode = _PAGE_NOCACHE;
314 			break;
315 		case IOMAP_WRITETHROUGH:
316 			cmode = _PAGE_CACHE040W;
317 			break;
318 		}
319 	} else {
320 		switch (cmode) {
321 		case IOMAP_NOCACHE_SER:
322 		case IOMAP_NOCACHE_NONSER:
323 		default:
324 			cmode = _PAGE_NOCACHE030;
325 			break;
326 		case IOMAP_FULL_CACHING:
327 		case IOMAP_WRITETHROUGH:
328 			cmode = 0;
329 		}
330 	}
331 
332 	while ((long)size > 0) {
333 		pgd_dir = pgd_offset_k(virtaddr);
334 		if (pgd_bad(*pgd_dir)) {
335 			printk("iocachemode: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
336 			pgd_clear(pgd_dir);
337 			return;
338 		}
339 		pmd_dir = pmd_offset(pgd_dir, virtaddr);
340 
341 		if (CPU_IS_020_OR_030) {
342 			int pmd_off = (virtaddr/PTRTREESIZE) & 15;
343 
344 			if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
345 				pmd_dir->pmd[pmd_off] = (pmd_dir->pmd[pmd_off] &
346 							 _CACHEMASK040) | cmode;
347 				virtaddr += PTRTREESIZE;
348 				size -= PTRTREESIZE;
349 				continue;
350 			}
351 		}
352 
353 		if (pmd_bad(*pmd_dir)) {
354 			printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
355 			pmd_clear(pmd_dir);
356 			return;
357 		}
358 		pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
359 
360 		pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
361 		virtaddr += PAGE_SIZE;
362 		size -= PAGE_SIZE;
363 	}
364 
365 	flush_tlb_all();
366 }
367 EXPORT_SYMBOL(kernel_set_cachemode);
368