ps3flash: Cache the last accessed FLASH chunk
[safe/jmp/linux-2.6] / drivers / char / ps3flash.c
1 /*
2  * PS3 FLASH ROM Storage Driver
3  *
4  * Copyright (C) 2007 Sony Computer Entertainment Inc.
5  * Copyright 2007 Sony Corp.
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License as published
9  * by the Free Software Foundation; version 2 of the License.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License along
17  * with this program; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19  */
20
21 #include <linux/fs.h>
22 #include <linux/miscdevice.h>
23 #include <linux/uaccess.h>
24
25 #include <asm/lv1call.h>
26 #include <asm/ps3stor.h>
27
28
29 #define DEVICE_NAME             "ps3flash"
30
31 #define FLASH_BLOCK_SIZE        (256*1024)
32
33
34 struct ps3flash_private {
35         struct mutex mutex;     /* Bounce buffer mutex */
36         u64 chunk_sectors;
37         int tag;                /* Start sector of buffer, -1 if invalid */
38         bool dirty;
39 };
40
41 static struct ps3_storage_device *ps3flash_dev;
42
43 static int ps3flash_read_write_sectors(struct ps3_storage_device *dev,
44                                        u64 lpar, u64 start_sector, u64 sectors,
45                                        int write)
46 {
47         u64 res = ps3stor_read_write_sectors(dev, lpar, start_sector, sectors,
48                                              write);
49         if (res) {
50                 dev_err(&dev->sbd.core, "%s:%u: %s failed 0x%llx\n", __func__,
51                         __LINE__, write ? "write" : "read", res);
52                 return -EIO;
53         }
54         return 0;
55 }
56
57 static int ps3flash_writeback(struct ps3_storage_device *dev)
58 {
59         struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
60         int res;
61
62         if (!priv->dirty || priv->tag < 0)
63                 return 0;
64
65         res = ps3flash_read_write_sectors(dev, dev->bounce_lpar, priv->tag,
66                                           priv->chunk_sectors, 1);
67         if (res)
68                 return res;
69
70         priv->dirty = false;
71         return 0;
72 }
73
74 static int ps3flash_fetch(struct ps3_storage_device *dev, u64 start_sector,
75                           u64 sectors)
76 {
77         struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
78         unsigned int tag, offset;
79         u64 lpar;
80         int res;
81
82         offset = start_sector % priv->chunk_sectors;
83         tag = start_sector - offset;
84         if (tag == priv->tag)
85                 return 0;
86
87         res = ps3flash_writeback(dev);
88         if (res)
89                 return res;
90
91         priv->tag = -1;
92
93         lpar = dev->bounce_lpar + offset * dev->blk_size;
94         res = ps3flash_read_write_sectors(dev, lpar, start_sector, sectors, 0);
95         if (res)
96                 return res;
97
98         /* We don't bother caching reads smaller than the chunk size */
99         if (sectors == priv->chunk_sectors)
100                 priv->tag = tag;
101
102         return 0;
103 }
104
105 static loff_t ps3flash_llseek(struct file *file, loff_t offset, int origin)
106 {
107         struct ps3_storage_device *dev = ps3flash_dev;
108         loff_t res;
109
110         mutex_lock(&file->f_mapping->host->i_mutex);
111         switch (origin) {
112         case 1:
113                 offset += file->f_pos;
114                 break;
115         case 2:
116                 offset += dev->regions[dev->region_idx].size*dev->blk_size;
117                 break;
118         }
119         if (offset < 0) {
120                 res = -EINVAL;
121                 goto out;
122         }
123
124         file->f_pos = offset;
125         res = file->f_pos;
126
127 out:
128         mutex_unlock(&file->f_mapping->host->i_mutex);
129         return res;
130 }
131
132 static ssize_t ps3flash_read(char __user *userbuf, void *kernelbuf,
133                              size_t count, loff_t *pos)
134 {
135         struct ps3_storage_device *dev = ps3flash_dev;
136         struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
137         u64 size, start_sector, end_sector, offset, sectors;
138         int res;
139         size_t remaining, n;
140         const void *src;
141
142         dev_dbg(&dev->sbd.core,
143                 "%s:%u: Reading %zu bytes at position %lld to U0x%p/K0x%p\n",
144                 __func__, __LINE__, count, *pos, userbuf, kernelbuf);
145
146         size = dev->regions[dev->region_idx].size*dev->blk_size;
147         if (*pos >= size || !count)
148                 return 0;
149
150         if (*pos + count > size) {
151                 dev_dbg(&dev->sbd.core,
152                         "%s:%u Truncating count from %zu to %llu\n", __func__,
153                         __LINE__, count, size - *pos);
154                 count = size - *pos;
155         }
156
157         start_sector = *pos / dev->blk_size;
158         offset = *pos % dev->bounce_size;
159         end_sector = DIV_ROUND_UP(*pos + count, dev->blk_size);
160
161         remaining = count;
162         do {
163                 sectors = min(end_sector - start_sector,
164                               priv->chunk_sectors -
165                               start_sector % priv->chunk_sectors);
166
167                 mutex_lock(&priv->mutex);
168
169                 res = ps3flash_fetch(dev, start_sector, sectors);
170                 if (res)
171                         goto fail;
172
173                 n = min_t(u64, remaining, dev->bounce_size - offset);
174                 src = dev->bounce_buf + offset;
175                 dev_dbg(&dev->sbd.core,
176                         "%s:%u: copy %lu bytes from 0x%p to U0x%p/K0x%p\n",
177                         __func__, __LINE__, n, src, userbuf, kernelbuf);
178                 if (userbuf) {
179                         if (copy_to_user(userbuf, src, n)) {
180                                 res = -EFAULT;
181                                 goto fail;
182                         }
183                         userbuf += n;
184                 }
185                 if (kernelbuf) {
186                         memcpy(kernelbuf, src, n);
187                         kernelbuf += n;
188                 }
189
190                 mutex_unlock(&priv->mutex);
191
192                 *pos += n;
193                 remaining -= n;
194                 start_sector += sectors;
195                 offset = 0;
196         } while (remaining > 0);
197
198         return count;
199
200 fail:
201         mutex_unlock(&priv->mutex);
202         return res;
203 }
204
205 static ssize_t ps3flash_write(const char __user *userbuf,
206                               const void *kernelbuf, size_t count, loff_t *pos)
207 {
208         struct ps3_storage_device *dev = ps3flash_dev;
209         struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
210         u64 size, sector, offset;
211         int res = 0;
212         size_t remaining, n;
213         void *dst;
214
215         dev_dbg(&dev->sbd.core,
216                 "%s:%u: Writing %zu bytes at position %lld from U0x%p/K0x%p\n",
217                 __func__, __LINE__, count, *pos, userbuf, kernelbuf);
218
219         size = dev->regions[dev->region_idx].size*dev->blk_size;
220         if (*pos >= size || !count)
221                 return 0;
222
223         if (*pos + count > size) {
224                 dev_dbg(&dev->sbd.core,
225                         "%s:%u Truncating count from %zu to %llu\n", __func__,
226                         __LINE__, count, size - *pos);
227                 count = size - *pos;
228         }
229
230         sector = *pos / dev->bounce_size * priv->chunk_sectors;
231         offset = *pos % dev->bounce_size;
232
233         remaining = count;
234         do {
235                 n = min_t(u64, remaining, dev->bounce_size - offset);
236
237                 mutex_lock(&priv->mutex);
238
239                 if (n != dev->bounce_size)
240                         res = ps3flash_fetch(dev, sector, priv->chunk_sectors);
241                 else if (sector != priv->tag)
242                         res = ps3flash_writeback(dev);
243                 if (res)
244                         goto fail;
245
246                 dst = dev->bounce_buf + offset;
247                 dev_dbg(&dev->sbd.core,
248                         "%s:%u: copy %lu bytes from U0x%p/K0x%p to 0x%p\n",
249                         __func__, __LINE__, n, userbuf, kernelbuf, dst);
250                 if (userbuf) {
251                         if (copy_from_user(dst, userbuf, n)) {
252                                 res = -EFAULT;
253                                 goto fail;
254                         }
255                         userbuf += n;
256                 }
257                 if (kernelbuf) {
258                         memcpy(dst, kernelbuf, n);
259                         kernelbuf += n;
260                 }
261
262                 priv->tag = sector;
263                 priv->dirty = true;
264
265                 mutex_unlock(&priv->mutex);
266
267                 *pos += n;
268                 remaining -= n;
269                 sector += priv->chunk_sectors;
270                 offset = 0;
271         } while (remaining > 0);
272
273         return count;
274
275 fail:
276         mutex_unlock(&priv->mutex);
277         return res;
278 }
279
280 static ssize_t ps3flash_user_read(struct file *file, char __user *buf,
281                                   size_t count, loff_t *pos)
282 {
283         return ps3flash_read(buf, NULL, count, pos);
284 }
285
286 static ssize_t ps3flash_user_write(struct file *file, const char __user *buf,
287                                    size_t count, loff_t *pos)
288 {
289         return ps3flash_write(buf, NULL, count, pos);
290 }
291
292 static ssize_t ps3flash_kernel_read(void *buf, size_t count, loff_t pos)
293 {
294         return ps3flash_read(NULL, buf, count, &pos);
295 }
296
297 static ssize_t ps3flash_kernel_write(const void *buf, size_t count,
298                                      loff_t pos)
299 {
300         ssize_t res;
301         int wb;
302
303         res = ps3flash_write(NULL, buf, count, &pos);
304         if (res < 0)
305                 return res;
306
307         /* Make kernel writes synchronous */
308         wb = ps3flash_writeback(ps3flash_dev);
309         if (wb)
310                 return wb;
311
312         return res;
313 }
314
315 static int ps3flash_flush(struct file *file, fl_owner_t id)
316 {
317         return ps3flash_writeback(ps3flash_dev);
318 }
319
320 static int ps3flash_fsync(struct file *file, struct dentry *dentry,
321                           int datasync)
322 {
323         return ps3flash_writeback(ps3flash_dev);
324 }
325
326 static irqreturn_t ps3flash_interrupt(int irq, void *data)
327 {
328         struct ps3_storage_device *dev = data;
329         int res;
330         u64 tag, status;
331
332         res = lv1_storage_get_async_status(dev->sbd.dev_id, &tag, &status);
333
334         if (tag != dev->tag)
335                 dev_err(&dev->sbd.core,
336                         "%s:%u: tag mismatch, got %llx, expected %llx\n",
337                         __func__, __LINE__, tag, dev->tag);
338
339         if (res) {
340                 dev_err(&dev->sbd.core, "%s:%u: res=%d status=0x%llx\n",
341                         __func__, __LINE__, res, status);
342         } else {
343                 dev->lv1_status = status;
344                 complete(&dev->done);
345         }
346         return IRQ_HANDLED;
347 }
348
349 static const struct file_operations ps3flash_fops = {
350         .owner  = THIS_MODULE,
351         .llseek = ps3flash_llseek,
352         .read   = ps3flash_user_read,
353         .write  = ps3flash_user_write,
354         .flush  = ps3flash_flush,
355         .fsync  = ps3flash_fsync,
356 };
357
358 static const struct ps3_os_area_flash_ops ps3flash_kernel_ops = {
359         .read   = ps3flash_kernel_read,
360         .write  = ps3flash_kernel_write,
361 };
362
363 static struct miscdevice ps3flash_misc = {
364         .minor  = MISC_DYNAMIC_MINOR,
365         .name   = DEVICE_NAME,
366         .fops   = &ps3flash_fops,
367 };
368
369 static int __devinit ps3flash_probe(struct ps3_system_bus_device *_dev)
370 {
371         struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
372         struct ps3flash_private *priv;
373         int error;
374         unsigned long tmp;
375
376         tmp = dev->regions[dev->region_idx].start*dev->blk_size;
377         if (tmp % FLASH_BLOCK_SIZE) {
378                 dev_err(&dev->sbd.core,
379                         "%s:%u region start %lu is not aligned\n", __func__,
380                         __LINE__, tmp);
381                 return -EINVAL;
382         }
383         tmp = dev->regions[dev->region_idx].size*dev->blk_size;
384         if (tmp % FLASH_BLOCK_SIZE) {
385                 dev_err(&dev->sbd.core,
386                         "%s:%u region size %lu is not aligned\n", __func__,
387                         __LINE__, tmp);
388                 return -EINVAL;
389         }
390
391         /* use static buffer, kmalloc cannot allocate 256 KiB */
392         if (!ps3flash_bounce_buffer.address)
393                 return -ENODEV;
394
395         if (ps3flash_dev) {
396                 dev_err(&dev->sbd.core,
397                         "Only one FLASH device is supported\n");
398                 return -EBUSY;
399         }
400
401         ps3flash_dev = dev;
402
403         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
404         if (!priv) {
405                 error = -ENOMEM;
406                 goto fail;
407         }
408
409         ps3_system_bus_set_drvdata(&dev->sbd, priv);
410         mutex_init(&priv->mutex);
411         priv->tag = -1;
412
413         dev->bounce_size = ps3flash_bounce_buffer.size;
414         dev->bounce_buf = ps3flash_bounce_buffer.address;
415         priv->chunk_sectors = dev->bounce_size / dev->blk_size;
416
417         error = ps3stor_setup(dev, ps3flash_interrupt);
418         if (error)
419                 goto fail_free_priv;
420
421         ps3flash_misc.parent = &dev->sbd.core;
422         error = misc_register(&ps3flash_misc);
423         if (error) {
424                 dev_err(&dev->sbd.core, "%s:%u: misc_register failed %d\n",
425                         __func__, __LINE__, error);
426                 goto fail_teardown;
427         }
428
429         dev_info(&dev->sbd.core, "%s:%u: registered misc device %d\n",
430                  __func__, __LINE__, ps3flash_misc.minor);
431
432         ps3_os_area_flash_register(&ps3flash_kernel_ops);
433         return 0;
434
435 fail_teardown:
436         ps3stor_teardown(dev);
437 fail_free_priv:
438         kfree(priv);
439         ps3_system_bus_set_drvdata(&dev->sbd, NULL);
440 fail:
441         ps3flash_dev = NULL;
442         return error;
443 }
444
445 static int ps3flash_remove(struct ps3_system_bus_device *_dev)
446 {
447         struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
448
449         ps3_os_area_flash_register(NULL);
450         misc_deregister(&ps3flash_misc);
451         ps3stor_teardown(dev);
452         kfree(ps3_system_bus_get_drvdata(&dev->sbd));
453         ps3_system_bus_set_drvdata(&dev->sbd, NULL);
454         ps3flash_dev = NULL;
455         return 0;
456 }
457
458
459 static struct ps3_system_bus_driver ps3flash = {
460         .match_id       = PS3_MATCH_ID_STOR_FLASH,
461         .core.name      = DEVICE_NAME,
462         .core.owner     = THIS_MODULE,
463         .probe          = ps3flash_probe,
464         .remove         = ps3flash_remove,
465         .shutdown       = ps3flash_remove,
466 };
467
468
469 static int __init ps3flash_init(void)
470 {
471         return ps3_system_bus_driver_register(&ps3flash);
472 }
473
474 static void __exit ps3flash_exit(void)
475 {
476         ps3_system_bus_driver_unregister(&ps3flash);
477 }
478
479 module_init(ps3flash_init);
480 module_exit(ps3flash_exit);
481
482 MODULE_LICENSE("GPL");
483 MODULE_DESCRIPTION("PS3 FLASH ROM Storage Driver");
484 MODULE_AUTHOR("Sony Corporation");
485 MODULE_ALIAS(PS3_MODULE_ALIAS_STOR_FLASH);