xref: /openbmc/linux/arch/m68k/mm/kmap.c (revision f3539c12)
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 
24 #undef DEBUG
25 
26 #define PTRTREESIZE	(256*1024)
27 
28 /*
29  * For 040/060 we can use the virtual memory area like other architectures,
30  * but for 020/030 we want to use early termination page descriptors and we
31  * can't mix this with normal page descriptors, so we have to copy that code
32  * (mm/vmalloc.c) and return appropriately aligned addresses.
33  */
34 
35 #ifdef CPU_M68040_OR_M68060_ONLY
36 
37 #define IO_SIZE		PAGE_SIZE
38 
39 static inline struct vm_struct *get_io_area(unsigned long size)
40 {
41 	return get_vm_area(size, VM_IOREMAP);
42 }
43 
44 
45 static inline void free_io_area(void *addr)
46 {
47 	vfree((void *)(PAGE_MASK & (unsigned long)addr));
48 }
49 
50 #else
51 
52 #define IO_SIZE		(256*1024)
53 
54 static struct vm_struct *iolist;
55 
56 static struct vm_struct *get_io_area(unsigned long size)
57 {
58 	unsigned long addr;
59 	struct vm_struct **p, *tmp, *area;
60 
61 	area = kmalloc(sizeof(*area), GFP_KERNEL);
62 	if (!area)
63 		return NULL;
64 	addr = KMAP_START;
65 	for (p = &iolist; (tmp = *p) ; p = &tmp->next) {
66 		if (size + addr < (unsigned long)tmp->addr)
67 			break;
68 		if (addr > KMAP_END-size) {
69 			kfree(area);
70 			return NULL;
71 		}
72 		addr = tmp->size + (unsigned long)tmp->addr;
73 	}
74 	area->addr = (void *)addr;
75 	area->size = size + IO_SIZE;
76 	area->next = *p;
77 	*p = area;
78 	return area;
79 }
80 
81 static inline void free_io_area(void *addr)
82 {
83 	struct vm_struct **p, *tmp;
84 
85 	if (!addr)
86 		return;
87 	addr = (void *)((unsigned long)addr & -IO_SIZE);
88 	for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
89 		if (tmp->addr == addr) {
90 			*p = tmp->next;
91 			__iounmap(tmp->addr, tmp->size);
92 			kfree(tmp);
93 			return;
94 		}
95 	}
96 }
97 
98 #endif
99 
100 /*
101  * Map some physical address range into the kernel address space.
102  */
103 /* Rewritten by Andreas Schwab to remove all races. */
104 
105 void __iomem *__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 || physaddr > (unsigned long)(-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 __iomem *)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 |
174 			     _PAGE_DIRTY | _PAGE_READWRITE);
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 an 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  * Currently it doesn't free pointer/page tables anymore but this
245  * wasn'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