xref: /openbmc/linux/arch/m68k/mm/kmap.c (revision 842ed298)
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/io.h>
23 #include <asm/tlbflush.h>
24 
25 #undef DEBUG
26 
27 /*
28  * For 040/060 we can use the virtual memory area like other architectures,
29  * but for 020/030 we want to use early termination page descriptors and we
30  * can't mix this with normal page descriptors, so we have to copy that code
31  * (mm/vmalloc.c) and return appropriately aligned addresses.
32  */
33 
34 #ifdef CPU_M68040_OR_M68060_ONLY
35 
36 #define IO_SIZE		PAGE_SIZE
37 
38 static inline struct vm_struct *get_io_area(unsigned long size)
39 {
40 	return get_vm_area(size, VM_IOREMAP);
41 }
42 
43 
44 static inline void free_io_area(void *addr)
45 {
46 	vfree((void *)(PAGE_MASK & (unsigned long)addr));
47 }
48 
49 #else
50 
51 #define IO_SIZE		PMD_SIZE
52 
53 static struct vm_struct *iolist;
54 
55 /*
56  * __free_io_area unmaps nearly everything, so be careful
57  * Currently it doesn't free pointer/page tables anymore but this
58  * wasn't used anyway and might be added later.
59  */
60 static void __free_io_area(void *addr, unsigned long size)
61 {
62 	unsigned long virtaddr = (unsigned long)addr;
63 	pgd_t *pgd_dir;
64 	p4d_t *p4d_dir;
65 	pud_t *pud_dir;
66 	pmd_t *pmd_dir;
67 	pte_t *pte_dir;
68 
69 	while ((long)size > 0) {
70 		pgd_dir = pgd_offset_k(virtaddr);
71 		p4d_dir = p4d_offset(pgd_dir, virtaddr);
72 		pud_dir = pud_offset(p4d_dir, virtaddr);
73 		if (pud_bad(*pud_dir)) {
74 			printk("iounmap: bad pud(%08lx)\n", pud_val(*pud_dir));
75 			pud_clear(pud_dir);
76 			return;
77 		}
78 		pmd_dir = pmd_offset(pud_dir, virtaddr);
79 
80 #if CONFIG_PGTABLE_LEVELS == 3
81 		if (CPU_IS_020_OR_030) {
82 			int pmd_type = pmd_val(*pmd_dir) & _DESCTYPE_MASK;
83 
84 			if (pmd_type == _PAGE_PRESENT) {
85 				pmd_clear(pmd_dir);
86 				virtaddr += PMD_SIZE;
87 				size -= PMD_SIZE;
88 
89 			} else if (pmd_type == 0)
90 				continue;
91 		}
92 #endif
93 
94 		if (pmd_bad(*pmd_dir)) {
95 			printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
96 			pmd_clear(pmd_dir);
97 			return;
98 		}
99 		pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
100 
101 		pte_val(*pte_dir) = 0;
102 		virtaddr += PAGE_SIZE;
103 		size -= PAGE_SIZE;
104 	}
105 
106 	flush_tlb_all();
107 }
108 
109 static struct vm_struct *get_io_area(unsigned long size)
110 {
111 	unsigned long addr;
112 	struct vm_struct **p, *tmp, *area;
113 
114 	area = kmalloc(sizeof(*area), GFP_KERNEL);
115 	if (!area)
116 		return NULL;
117 	addr = KMAP_START;
118 	for (p = &iolist; (tmp = *p) ; p = &tmp->next) {
119 		if (size + addr < (unsigned long)tmp->addr)
120 			break;
121 		if (addr > KMAP_END-size) {
122 			kfree(area);
123 			return NULL;
124 		}
125 		addr = tmp->size + (unsigned long)tmp->addr;
126 	}
127 	area->addr = (void *)addr;
128 	area->size = size + IO_SIZE;
129 	area->next = *p;
130 	*p = area;
131 	return area;
132 }
133 
134 static inline void free_io_area(void *addr)
135 {
136 	struct vm_struct **p, *tmp;
137 
138 	if (!addr)
139 		return;
140 	addr = (void *)((unsigned long)addr & -IO_SIZE);
141 	for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
142 		if (tmp->addr == addr) {
143 			*p = tmp->next;
144 			/* remove gap added in get_io_area() */
145 			__free_io_area(tmp->addr, tmp->size - IO_SIZE);
146 			kfree(tmp);
147 			return;
148 		}
149 	}
150 }
151 
152 #endif
153 
154 /*
155  * Map some physical address range into the kernel address space.
156  */
157 /* Rewritten by Andreas Schwab to remove all races. */
158 
159 void __iomem *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
160 {
161 	struct vm_struct *area;
162 	unsigned long virtaddr, retaddr;
163 	long offset;
164 	pgd_t *pgd_dir;
165 	p4d_t *p4d_dir;
166 	pud_t *pud_dir;
167 	pmd_t *pmd_dir;
168 	pte_t *pte_dir;
169 
170 	/*
171 	 * Don't allow mappings that wrap..
172 	 */
173 	if (!size || physaddr > (unsigned long)(-size))
174 		return NULL;
175 
176 #ifdef CONFIG_AMIGA
177 	if (MACH_IS_AMIGA) {
178 		if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
179 		    && (cacheflag == IOMAP_NOCACHE_SER))
180 			return (void __iomem *)physaddr;
181 	}
182 #endif
183 #ifdef CONFIG_COLDFIRE
184 	if (__cf_internalio(physaddr))
185 		return (void __iomem *) physaddr;
186 #endif
187 
188 #ifdef DEBUG
189 	printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
190 #endif
191 	/*
192 	 * Mappings have to be aligned
193 	 */
194 	offset = physaddr & (IO_SIZE - 1);
195 	physaddr &= -IO_SIZE;
196 	size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
197 
198 	/*
199 	 * Ok, go for it..
200 	 */
201 	area = get_io_area(size);
202 	if (!area)
203 		return NULL;
204 
205 	virtaddr = (unsigned long)area->addr;
206 	retaddr = virtaddr + offset;
207 #ifdef DEBUG
208 	printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
209 #endif
210 
211 	/*
212 	 * add cache and table flags to physical address
213 	 */
214 	if (CPU_IS_040_OR_060) {
215 		physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
216 			     _PAGE_ACCESSED | _PAGE_DIRTY);
217 		switch (cacheflag) {
218 		case IOMAP_FULL_CACHING:
219 			physaddr |= _PAGE_CACHE040;
220 			break;
221 		case IOMAP_NOCACHE_SER:
222 		default:
223 			physaddr |= _PAGE_NOCACHE_S;
224 			break;
225 		case IOMAP_NOCACHE_NONSER:
226 			physaddr |= _PAGE_NOCACHE;
227 			break;
228 		case IOMAP_WRITETHROUGH:
229 			physaddr |= _PAGE_CACHE040W;
230 			break;
231 		}
232 	} else {
233 		physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED |
234 			     _PAGE_DIRTY | _PAGE_READWRITE);
235 		switch (cacheflag) {
236 		case IOMAP_NOCACHE_SER:
237 		case IOMAP_NOCACHE_NONSER:
238 		default:
239 			physaddr |= _PAGE_NOCACHE030;
240 			break;
241 		case IOMAP_FULL_CACHING:
242 		case IOMAP_WRITETHROUGH:
243 			break;
244 		}
245 	}
246 
247 	while ((long)size > 0) {
248 #ifdef DEBUG
249 		if (!(virtaddr & (PMD_SIZE-1)))
250 			printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
251 #endif
252 		pgd_dir = pgd_offset_k(virtaddr);
253 		p4d_dir = p4d_offset(pgd_dir, virtaddr);
254 		pud_dir = pud_offset(p4d_dir, virtaddr);
255 		pmd_dir = pmd_alloc(&init_mm, pud_dir, virtaddr);
256 		if (!pmd_dir) {
257 			printk("ioremap: no mem for pmd_dir\n");
258 			return NULL;
259 		}
260 
261 #if CONFIG_PGTABLE_LEVELS == 3
262 		if (CPU_IS_020_OR_030) {
263 			pmd_val(*pmd_dir) = physaddr;
264 			physaddr += PMD_SIZE;
265 			virtaddr += PMD_SIZE;
266 			size -= PMD_SIZE;
267 		} else
268 #endif
269 		{
270 			pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
271 			if (!pte_dir) {
272 				printk("ioremap: no mem for pte_dir\n");
273 				return NULL;
274 			}
275 
276 			pte_val(*pte_dir) = physaddr;
277 			virtaddr += PAGE_SIZE;
278 			physaddr += PAGE_SIZE;
279 			size -= PAGE_SIZE;
280 		}
281 	}
282 #ifdef DEBUG
283 	printk("\n");
284 #endif
285 	flush_tlb_all();
286 
287 	return (void __iomem *)retaddr;
288 }
289 EXPORT_SYMBOL(__ioremap);
290 
291 /*
292  * Unmap an ioremap()ed region again
293  */
294 void iounmap(void __iomem *addr)
295 {
296 #ifdef CONFIG_AMIGA
297 	if ((!MACH_IS_AMIGA) ||
298 	    (((unsigned long)addr < 0x40000000) ||
299 	     ((unsigned long)addr > 0x60000000)))
300 			free_io_area((__force void *)addr);
301 #else
302 #ifdef CONFIG_COLDFIRE
303 	if (cf_internalio(addr))
304 		return;
305 #endif
306 	free_io_area((__force void *)addr);
307 #endif
308 }
309 EXPORT_SYMBOL(iounmap);
310 
311 /*
312  * Set new cache mode for some kernel address space.
313  * The caller must push data for that range itself, if such data may already
314  * be in the cache.
315  */
316 void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
317 {
318 	unsigned long virtaddr = (unsigned long)addr;
319 	pgd_t *pgd_dir;
320 	p4d_t *p4d_dir;
321 	pud_t *pud_dir;
322 	pmd_t *pmd_dir;
323 	pte_t *pte_dir;
324 
325 	if (CPU_IS_040_OR_060) {
326 		switch (cmode) {
327 		case IOMAP_FULL_CACHING:
328 			cmode = _PAGE_CACHE040;
329 			break;
330 		case IOMAP_NOCACHE_SER:
331 		default:
332 			cmode = _PAGE_NOCACHE_S;
333 			break;
334 		case IOMAP_NOCACHE_NONSER:
335 			cmode = _PAGE_NOCACHE;
336 			break;
337 		case IOMAP_WRITETHROUGH:
338 			cmode = _PAGE_CACHE040W;
339 			break;
340 		}
341 	} else {
342 		switch (cmode) {
343 		case IOMAP_NOCACHE_SER:
344 		case IOMAP_NOCACHE_NONSER:
345 		default:
346 			cmode = _PAGE_NOCACHE030;
347 			break;
348 		case IOMAP_FULL_CACHING:
349 		case IOMAP_WRITETHROUGH:
350 			cmode = 0;
351 		}
352 	}
353 
354 	while ((long)size > 0) {
355 		pgd_dir = pgd_offset_k(virtaddr);
356 		p4d_dir = p4d_offset(pgd_dir, virtaddr);
357 		pud_dir = pud_offset(p4d_dir, virtaddr);
358 		if (pud_bad(*pud_dir)) {
359 			printk("iocachemode: bad pud(%08lx)\n", pud_val(*pud_dir));
360 			pud_clear(pud_dir);
361 			return;
362 		}
363 		pmd_dir = pmd_offset(pud_dir, virtaddr);
364 
365 #if CONFIG_PGTABLE_LEVELS == 3
366 		if (CPU_IS_020_OR_030) {
367 			unsigned long pmd = pmd_val(*pmd_dir);
368 
369 			if ((pmd & _DESCTYPE_MASK) == _PAGE_PRESENT) {
370 				*pmd_dir = __pmd((pmd & _CACHEMASK040) | cmode);
371 				virtaddr += PMD_SIZE;
372 				size -= PMD_SIZE;
373 				continue;
374 			}
375 		}
376 #endif
377 
378 		if (pmd_bad(*pmd_dir)) {
379 			printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
380 			pmd_clear(pmd_dir);
381 			return;
382 		}
383 		pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
384 
385 		pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
386 		virtaddr += PAGE_SIZE;
387 		size -= PAGE_SIZE;
388 	}
389 
390 	flush_tlb_all();
391 }
392 EXPORT_SYMBOL(kernel_set_cachemode);
393