1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org> et al.
4  */
5 
6 /* Overhauled routines for dealing with different mmap regions of flash */
7 
8 #ifndef __LINUX_MTD_MAP_H__
9 #define __LINUX_MTD_MAP_H__
10 
11 #include <linux/types.h>
12 #include <linux/list.h>
13 #include <linux/string.h>
14 #include <linux/bug.h>
15 #include <linux/kernel.h>
16 #include <linux/io.h>
17 
18 #include <asm/unaligned.h>
19 #include <asm/barrier.h>
20 
21 #ifdef CONFIG_MTD_MAP_BANK_WIDTH_1
22 #define map_bankwidth(map) 1
23 #define map_bankwidth_is_1(map) (map_bankwidth(map) == 1)
24 #define map_bankwidth_is_large(map) (0)
25 #define map_words(map) (1)
26 #define MAX_MAP_BANKWIDTH 1
27 #else
28 #define map_bankwidth_is_1(map) (0)
29 #endif
30 
31 #ifdef CONFIG_MTD_MAP_BANK_WIDTH_2
32 # ifdef map_bankwidth
33 #  undef map_bankwidth
34 #  define map_bankwidth(map) ((map)->bankwidth)
35 # else
36 #  define map_bankwidth(map) 2
37 #  define map_bankwidth_is_large(map) (0)
38 #  define map_words(map) (1)
39 # endif
40 #define map_bankwidth_is_2(map) (map_bankwidth(map) == 2)
41 #undef MAX_MAP_BANKWIDTH
42 #define MAX_MAP_BANKWIDTH 2
43 #else
44 #define map_bankwidth_is_2(map) (0)
45 #endif
46 
47 #ifdef CONFIG_MTD_MAP_BANK_WIDTH_4
48 # ifdef map_bankwidth
49 #  undef map_bankwidth
50 #  define map_bankwidth(map) ((map)->bankwidth)
51 # else
52 #  define map_bankwidth(map) 4
53 #  define map_bankwidth_is_large(map) (0)
54 #  define map_words(map) (1)
55 # endif
56 #define map_bankwidth_is_4(map) (map_bankwidth(map) == 4)
57 #undef MAX_MAP_BANKWIDTH
58 #define MAX_MAP_BANKWIDTH 4
59 #else
60 #define map_bankwidth_is_4(map) (0)
61 #endif
62 
63 /* ensure we never evaluate anything shorted than an unsigned long
64  * to zero, and ensure we'll never miss the end of an comparison (bjd) */
65 
66 #define map_calc_words(map) ((map_bankwidth(map) + (sizeof(unsigned long)-1)) / sizeof(unsigned long))
67 
68 #ifdef CONFIG_MTD_MAP_BANK_WIDTH_8
69 # ifdef map_bankwidth
70 #  undef map_bankwidth
71 #  define map_bankwidth(map) ((map)->bankwidth)
72 #  if BITS_PER_LONG < 64
73 #   undef map_bankwidth_is_large
74 #   define map_bankwidth_is_large(map) (map_bankwidth(map) > BITS_PER_LONG/8)
75 #   undef map_words
76 #   define map_words(map) map_calc_words(map)
77 #  endif
78 # else
79 #  define map_bankwidth(map) 8
80 #  define map_bankwidth_is_large(map) (BITS_PER_LONG < 64)
81 #  define map_words(map) map_calc_words(map)
82 # endif
83 #define map_bankwidth_is_8(map) (map_bankwidth(map) == 8)
84 #undef MAX_MAP_BANKWIDTH
85 #define MAX_MAP_BANKWIDTH 8
86 #else
87 #define map_bankwidth_is_8(map) (0)
88 #endif
89 
90 #ifdef CONFIG_MTD_MAP_BANK_WIDTH_16
91 # ifdef map_bankwidth
92 #  undef map_bankwidth
93 #  define map_bankwidth(map) ((map)->bankwidth)
94 #  undef map_bankwidth_is_large
95 #  define map_bankwidth_is_large(map) (map_bankwidth(map) > BITS_PER_LONG/8)
96 #  undef map_words
97 #  define map_words(map) map_calc_words(map)
98 # else
99 #  define map_bankwidth(map) 16
100 #  define map_bankwidth_is_large(map) (1)
101 #  define map_words(map) map_calc_words(map)
102 # endif
103 #define map_bankwidth_is_16(map) (map_bankwidth(map) == 16)
104 #undef MAX_MAP_BANKWIDTH
105 #define MAX_MAP_BANKWIDTH 16
106 #else
107 #define map_bankwidth_is_16(map) (0)
108 #endif
109 
110 #ifdef CONFIG_MTD_MAP_BANK_WIDTH_32
111 /* always use indirect access for 256-bit to preserve kernel stack */
112 # undef map_bankwidth
113 # define map_bankwidth(map) ((map)->bankwidth)
114 # undef map_bankwidth_is_large
115 # define map_bankwidth_is_large(map) (map_bankwidth(map) > BITS_PER_LONG/8)
116 # undef map_words
117 # define map_words(map) map_calc_words(map)
118 #define map_bankwidth_is_32(map) (map_bankwidth(map) == 32)
119 #undef MAX_MAP_BANKWIDTH
120 #define MAX_MAP_BANKWIDTH 32
121 #else
122 #define map_bankwidth_is_32(map) (0)
123 #endif
124 
125 #ifndef map_bankwidth
126 #ifdef CONFIG_MTD
127 #warning "No CONFIG_MTD_MAP_BANK_WIDTH_xx selected. No NOR chip support can work"
128 #endif
map_bankwidth(void * map)129 static inline int map_bankwidth(void *map)
130 {
131 	BUG();
132 	return 0;
133 }
134 #define map_bankwidth_is_large(map) (0)
135 #define map_words(map) (0)
136 #define MAX_MAP_BANKWIDTH 1
137 #endif
138 
map_bankwidth_supported(int w)139 static inline int map_bankwidth_supported(int w)
140 {
141 	switch (w) {
142 #ifdef CONFIG_MTD_MAP_BANK_WIDTH_1
143 	case 1:
144 #endif
145 #ifdef CONFIG_MTD_MAP_BANK_WIDTH_2
146 	case 2:
147 #endif
148 #ifdef CONFIG_MTD_MAP_BANK_WIDTH_4
149 	case 4:
150 #endif
151 #ifdef CONFIG_MTD_MAP_BANK_WIDTH_8
152 	case 8:
153 #endif
154 #ifdef CONFIG_MTD_MAP_BANK_WIDTH_16
155 	case 16:
156 #endif
157 #ifdef CONFIG_MTD_MAP_BANK_WIDTH_32
158 	case 32:
159 #endif
160 		return 1;
161 
162 	default:
163 		return 0;
164 	}
165 }
166 
167 #define MAX_MAP_LONGS (((MAX_MAP_BANKWIDTH * 8) + BITS_PER_LONG - 1) / BITS_PER_LONG)
168 
169 typedef union {
170 	unsigned long x[MAX_MAP_LONGS];
171 } map_word;
172 
173 /* The map stuff is very simple. You fill in your struct map_info with
174    a handful of routines for accessing the device, making sure they handle
175    paging etc. correctly if your device needs it. Then you pass it off
176    to a chip probe routine -- either JEDEC or CFI probe or both -- via
177    do_map_probe(). If a chip is recognised, the probe code will invoke the
178    appropriate chip driver (if present) and return a struct mtd_info.
179    At which point, you fill in the mtd->module with your own module
180    address, and register it with the MTD core code. Or you could partition
181    it and register the partitions instead, or keep it for your own private
182    use; whatever.
183 
184    The mtd->priv field will point to the struct map_info, and any further
185    private data required by the chip driver is linked from the
186    mtd->priv->fldrv_priv field. This allows the map driver to get at
187    the destructor function map->fldrv_destroy() when it's tired
188    of living.
189 */
190 
191 struct map_info {
192 	const char *name;
193 	unsigned long size;
194 	resource_size_t phys;
195 #define NO_XIP (-1UL)
196 
197 	void __iomem *virt;
198 	void *cached;
199 
200 	int swap; /* this mapping's byte-swapping requirement */
201 	int bankwidth; /* in octets. This isn't necessarily the width
202 		       of actual bus cycles -- it's the repeat interval
203 		      in bytes, before you are talking to the first chip again.
204 		      */
205 
206 #ifdef CONFIG_MTD_COMPLEX_MAPPINGS
207 	map_word (*read)(struct map_info *, unsigned long);
208 	void (*copy_from)(struct map_info *, void *, unsigned long, ssize_t);
209 
210 	void (*write)(struct map_info *, const map_word, unsigned long);
211 	void (*copy_to)(struct map_info *, unsigned long, const void *, ssize_t);
212 
213 	/* We can perhaps put in 'point' and 'unpoint' methods, if we really
214 	   want to enable XIP for non-linear mappings. Not yet though. */
215 #endif
216 	/* It's possible for the map driver to use cached memory in its
217 	   copy_from implementation (and _only_ with copy_from).  However,
218 	   when the chip driver knows some flash area has changed contents,
219 	   it will signal it to the map driver through this routine to let
220 	   the map driver invalidate the corresponding cache as needed.
221 	   If there is no cache to care about this can be set to NULL. */
222 	void (*inval_cache)(struct map_info *, unsigned long, ssize_t);
223 
224 	/* This will be called with 1 as parameter when the first map user
225 	 * needs VPP, and called with 0 when the last user exits. The map
226 	 * core maintains a reference counter, and assumes that VPP is a
227 	 * global resource applying to all mapped flash chips on the system.
228 	 */
229 	void (*set_vpp)(struct map_info *, int);
230 
231 	unsigned long pfow_base;
232 	unsigned long map_priv_1;
233 	unsigned long map_priv_2;
234 	struct device_node *device_node;
235 	void *fldrv_priv;
236 	struct mtd_chip_driver *fldrv;
237 };
238 
239 struct mtd_chip_driver {
240 	struct mtd_info *(*probe)(struct map_info *map);
241 	void (*destroy)(struct mtd_info *);
242 	struct module *module;
243 	char *name;
244 	struct list_head list;
245 };
246 
247 void register_mtd_chip_driver(struct mtd_chip_driver *);
248 void unregister_mtd_chip_driver(struct mtd_chip_driver *);
249 
250 struct mtd_info *do_map_probe(const char *name, struct map_info *map);
251 void map_destroy(struct mtd_info *mtd);
252 
253 #define ENABLE_VPP(map) do { if (map->set_vpp) map->set_vpp(map, 1); } while (0)
254 #define DISABLE_VPP(map) do { if (map->set_vpp) map->set_vpp(map, 0); } while (0)
255 
256 #define INVALIDATE_CACHED_RANGE(map, from, size) \
257 	do { if (map->inval_cache) map->inval_cache(map, from, size); } while (0)
258 
259 #define map_word_equal(map, val1, val2)					\
260 ({									\
261 	int i, ret = 1;							\
262 	for (i = 0; i < map_words(map); i++)				\
263 		if ((val1).x[i] != (val2).x[i]) {			\
264 			ret = 0;					\
265 			break;						\
266 		}							\
267 	ret;								\
268 })
269 
270 #define map_word_and(map, val1, val2)					\
271 ({									\
272 	map_word r;							\
273 	int i;								\
274 	for (i = 0; i < map_words(map); i++)				\
275 		r.x[i] = (val1).x[i] & (val2).x[i];			\
276 	r;								\
277 })
278 
279 #define map_word_clr(map, val1, val2)					\
280 ({									\
281 	map_word r;							\
282 	int i;								\
283 	for (i = 0; i < map_words(map); i++)				\
284 		r.x[i] = (val1).x[i] & ~(val2).x[i];			\
285 	r;								\
286 })
287 
288 #define map_word_or(map, val1, val2)					\
289 ({									\
290 	map_word r;							\
291 	int i;								\
292 	for (i = 0; i < map_words(map); i++)				\
293 		r.x[i] = (val1).x[i] | (val2).x[i];			\
294 	r;								\
295 })
296 
297 #define map_word_andequal(map, val1, val2, val3)			\
298 ({									\
299 	int i, ret = 1;							\
300 	for (i = 0; i < map_words(map); i++) {				\
301 		if (((val1).x[i] & (val2).x[i]) != (val3).x[i]) {	\
302 			ret = 0;					\
303 			break;						\
304 		}							\
305 	}								\
306 	ret;								\
307 })
308 
309 #define map_word_bitsset(map, val1, val2)				\
310 ({									\
311 	int i, ret = 0;							\
312 	for (i = 0; i < map_words(map); i++) {				\
313 		if ((val1).x[i] & (val2).x[i]) {			\
314 			ret = 1;					\
315 			break;						\
316 		}							\
317 	}								\
318 	ret;								\
319 })
320 
map_word_load(struct map_info * map,const void * ptr)321 static inline map_word map_word_load(struct map_info *map, const void *ptr)
322 {
323 	map_word r;
324 
325 	if (map_bankwidth_is_1(map))
326 		r.x[0] = *(unsigned char *)ptr;
327 	else if (map_bankwidth_is_2(map))
328 		r.x[0] = get_unaligned((uint16_t *)ptr);
329 	else if (map_bankwidth_is_4(map))
330 		r.x[0] = get_unaligned((uint32_t *)ptr);
331 #if BITS_PER_LONG >= 64
332 	else if (map_bankwidth_is_8(map))
333 		r.x[0] = get_unaligned((uint64_t *)ptr);
334 #endif
335 	else if (map_bankwidth_is_large(map))
336 		memcpy(r.x, ptr, map->bankwidth);
337 	else
338 		BUG();
339 
340 	return r;
341 }
342 
map_word_load_partial(struct map_info * map,map_word orig,const unsigned char * buf,int start,int len)343 static inline map_word map_word_load_partial(struct map_info *map, map_word orig, const unsigned char *buf, int start, int len)
344 {
345 	int i;
346 
347 	if (map_bankwidth_is_large(map)) {
348 		char *dest = (char *)&orig;
349 
350 		memcpy(dest+start, buf, len);
351 	} else {
352 		for (i = start; i < start+len; i++) {
353 			int bitpos;
354 
355 #ifdef __LITTLE_ENDIAN
356 			bitpos = i * 8;
357 #else /* __BIG_ENDIAN */
358 			bitpos = (map_bankwidth(map) - 1 - i) * 8;
359 #endif
360 			orig.x[0] &= ~(0xff << bitpos);
361 			orig.x[0] |= (unsigned long)buf[i-start] << bitpos;
362 		}
363 	}
364 	return orig;
365 }
366 
367 #if BITS_PER_LONG < 64
368 #define MAP_FF_LIMIT 4
369 #else
370 #define MAP_FF_LIMIT 8
371 #endif
372 
map_word_ff(struct map_info * map)373 static inline map_word map_word_ff(struct map_info *map)
374 {
375 	map_word r;
376 	int i;
377 
378 	if (map_bankwidth(map) < MAP_FF_LIMIT) {
379 		int bw = 8 * map_bankwidth(map);
380 
381 		r.x[0] = (1UL << bw) - 1;
382 	} else {
383 		for (i = 0; i < map_words(map); i++)
384 			r.x[i] = ~0UL;
385 	}
386 	return r;
387 }
388 
inline_map_read(struct map_info * map,unsigned long ofs)389 static inline map_word inline_map_read(struct map_info *map, unsigned long ofs)
390 {
391 	map_word r;
392 
393 	if (map_bankwidth_is_1(map))
394 		r.x[0] = __raw_readb(map->virt + ofs);
395 	else if (map_bankwidth_is_2(map))
396 		r.x[0] = __raw_readw(map->virt + ofs);
397 	else if (map_bankwidth_is_4(map))
398 		r.x[0] = __raw_readl(map->virt + ofs);
399 #if BITS_PER_LONG >= 64
400 	else if (map_bankwidth_is_8(map))
401 		r.x[0] = __raw_readq(map->virt + ofs);
402 #endif
403 	else if (map_bankwidth_is_large(map))
404 		memcpy_fromio(r.x, map->virt + ofs, map->bankwidth);
405 	else
406 		BUG();
407 
408 	return r;
409 }
410 
inline_map_write(struct map_info * map,const map_word datum,unsigned long ofs)411 static inline void inline_map_write(struct map_info *map, const map_word datum, unsigned long ofs)
412 {
413 	if (map_bankwidth_is_1(map))
414 		__raw_writeb(datum.x[0], map->virt + ofs);
415 	else if (map_bankwidth_is_2(map))
416 		__raw_writew(datum.x[0], map->virt + ofs);
417 	else if (map_bankwidth_is_4(map))
418 		__raw_writel(datum.x[0], map->virt + ofs);
419 #if BITS_PER_LONG >= 64
420 	else if (map_bankwidth_is_8(map))
421 		__raw_writeq(datum.x[0], map->virt + ofs);
422 #endif
423 	else if (map_bankwidth_is_large(map))
424 		memcpy_toio(map->virt+ofs, datum.x, map->bankwidth);
425 	else
426 		BUG();
427 	mb();
428 }
429 
inline_map_copy_from(struct map_info * map,void * to,unsigned long from,ssize_t len)430 static inline void inline_map_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
431 {
432 	if (map->cached)
433 		memcpy(to, (char *)map->cached + from, len);
434 	else
435 		memcpy_fromio(to, map->virt + from, len);
436 }
437 
inline_map_copy_to(struct map_info * map,unsigned long to,const void * from,ssize_t len)438 static inline void inline_map_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
439 {
440 	memcpy_toio(map->virt + to, from, len);
441 }
442 
443 #ifdef CONFIG_MTD_COMPLEX_MAPPINGS
444 #define map_read(map, ofs) (map)->read(map, ofs)
445 #define map_copy_from(map, to, from, len) (map)->copy_from(map, to, from, len)
446 #define map_write(map, datum, ofs) (map)->write(map, datum, ofs)
447 #define map_copy_to(map, to, from, len) (map)->copy_to(map, to, from, len)
448 
449 extern void simple_map_init(struct map_info *);
450 #define map_is_linear(map) (map->phys != NO_XIP)
451 
452 #else
453 #define map_read(map, ofs) inline_map_read(map, ofs)
454 #define map_copy_from(map, to, from, len) inline_map_copy_from(map, to, from, len)
455 #define map_write(map, datum, ofs) inline_map_write(map, datum, ofs)
456 #define map_copy_to(map, to, from, len) inline_map_copy_to(map, to, from, len)
457 
458 
459 #define simple_map_init(map) BUG_ON(!map_bankwidth_supported((map)->bankwidth))
460 #define map_is_linear(map) ({ (void)(map); 1; })
461 
462 #endif /* !CONFIG_MTD_COMPLEX_MAPPINGS */
463 
464 #endif /* __LINUX_MTD_MAP_H__ */
465