Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  * PS3 Disk 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/ata.h>
 22 #include <linux/blkdev.h>
 23 
 24 #include <asm/lv1call.h>
 25 #include <asm/ps3stor.h>
 26 #include <asm/firmware.h>
 27 
 28 
 29 #define DEVICE_NAME             "ps3disk"
 30 
 31 #define BOUNCE_SIZE             (64*1024)
 32 
 33 #define PS3DISK_MAX_DISKS       16
 34 #define PS3DISK_MINORS          16
 35 
 36 
 37 #define PS3DISK_NAME            "ps3d%c"
 38 
 39 
 40 struct ps3disk_private {
 41         spinlock_t lock;                /* Request queue spinlock */
 42         struct request_queue *queue;
 43         struct gendisk *gendisk;
 44         unsigned int blocking_factor;
 45         struct request *req;
 46         u64 raw_capacity;
 47         unsigned char model[ATA_ID_PROD_LEN+1];
 48 };
 49 
 50 
 51 #define LV1_STORAGE_SEND_ATA_COMMAND    (2)
 52 #define LV1_STORAGE_ATA_HDDOUT          (0x23)
 53 
 54 struct lv1_ata_cmnd_block {
 55         u16     features;
 56         u16     sector_count;
 57         u16     LBA_low;
 58         u16     LBA_mid;
 59         u16     LBA_high;
 60         u8      device;
 61         u8      command;
 62         u32     is_ext;
 63         u32     proto;
 64         u32     in_out;
 65         u32     size;
 66         u64     buffer;
 67         u32     arglen;
 68 };
 69 
 70 enum lv1_ata_proto {
 71         NON_DATA_PROTO     = 0,
 72         PIO_DATA_IN_PROTO  = 1,
 73         PIO_DATA_OUT_PROTO = 2,
 74         DMA_PROTO = 3
 75 };
 76 
 77 enum lv1_ata_in_out {
 78         DIR_WRITE = 0,                  /* memory -> device */
 79         DIR_READ = 1                    /* device -> memory */
 80 };
 81 
 82 static int ps3disk_major;
 83 
 84 
 85 static struct block_device_operations ps3disk_fops = {
 86         .owner          = THIS_MODULE,
 87 };
 88 
 89 
 90 static void ps3disk_scatter_gather(struct ps3_storage_device *dev,
 91                                    struct request *req, int gather)
 92 {
 93         unsigned int offset = 0;
 94         struct req_iterator iter;
 95         struct bio_vec *bvec;
 96         unsigned int i = 0;
 97         size_t size;
 98         void *buf;
 99 
100         rq_for_each_segment(bvec, req, iter) {
101                 unsigned long flags;
102                 dev_dbg(&dev->sbd.core,
103                         "%s:%u: bio %u: %u segs %u sectors from %lu\n",
104                         __func__, __LINE__, i, bio_segments(iter.bio),
105                         bio_sectors(iter.bio),
106                         (unsigned long)iter.bio->bi_sector);
107 
108                 size = bvec->bv_len;
109                 buf = bvec_kmap_irq(bvec, &flags);
110                 if (gather)
111                         memcpy(dev->bounce_buf+offset, buf, size);
112                 else
113                         memcpy(buf, dev->bounce_buf+offset, size);
114                 offset += size;
115                 flush_kernel_dcache_page(bvec->bv_page);
116                 bvec_kunmap_irq(bvec, &flags);
117                 i++;
118         }
119 }
120 
121 static int ps3disk_submit_request_sg(struct ps3_storage_device *dev,
122                                      struct request *req)
123 {
124         struct ps3disk_private *priv = dev->sbd.core.driver_data;
125         int write = rq_data_dir(req), res;
126         const char *op = write ? "write" : "read";
127         u64 start_sector, sectors;
128         unsigned int region_id = dev->regions[dev->region_idx].id;
129 
130 #ifdef DEBUG
131         unsigned int n = 0;
132         struct bio_vec *bv;
133         struct req_iterator iter;
134 
135         rq_for_each_segment(bv, req, iter)
136                 n++;
137         dev_dbg(&dev->sbd.core,
138                 "%s:%u: %s req has %u bvecs for %lu sectors %lu hard sectors\n",
139                 __func__, __LINE__, op, n, req->nr_sectors,
140                 req->hard_nr_sectors);
141 #endif
142 
143         start_sector = req->sector * priv->blocking_factor;
144         sectors = req->nr_sectors * priv->blocking_factor;
145         dev_dbg(&dev->sbd.core, "%s:%u: %s %lu sectors starting at %lu\n",
146                 __func__, __LINE__, op, sectors, start_sector);
147 
148         if (write) {
149                 ps3disk_scatter_gather(dev, req, 1);
150 
151                 res = lv1_storage_write(dev->sbd.dev_id, region_id,
152                                         start_sector, sectors, 0,
153                                         dev->bounce_lpar, &dev->tag);
154         } else {
155                 res = lv1_storage_read(dev->sbd.dev_id, region_id,
156                                        start_sector, sectors, 0,
157                                        dev->bounce_lpar, &dev->tag);
158         }
159         if (res) {
160                 dev_err(&dev->sbd.core, "%s:%u: %s failed %d\n", __func__,
161                         __LINE__, op, res);
162                 end_request(req, 0);
163                 return 0;
164         }
165 
166         priv->req = req;
167         return 1;
168 }
169 
170 static int ps3disk_submit_flush_request(struct ps3_storage_device *dev,
171                                         struct request *req)
172 {
173         struct ps3disk_private *priv = dev->sbd.core.driver_data;
174         u64 res;
175 
176         dev_dbg(&dev->sbd.core, "%s:%u: flush request\n", __func__, __LINE__);
177 
178         res = lv1_storage_send_device_command(dev->sbd.dev_id,
179                                               LV1_STORAGE_ATA_HDDOUT, 0, 0, 0,
180                                               0, &dev->tag);
181         if (res) {
182                 dev_err(&dev->sbd.core, "%s:%u: sync cache failed 0x%lx\n",
183                         __func__, __LINE__, res);
184                 end_request(req, 0);
185                 return 0;
186         }
187 
188         priv->req = req;
189         return 1;
190 }
191 
192 static void ps3disk_do_request(struct ps3_storage_device *dev,
193                                struct request_queue *q)
194 {
195         struct request *req;
196 
197         dev_dbg(&dev->sbd.core, "%s:%u\n", __func__, __LINE__);
198 
199         while ((req = elv_next_request(q))) {
200                 if (blk_fs_request(req)) {
201                         if (ps3disk_submit_request_sg(dev, req))
202                                 break;
203                 } else if (req->cmd_type == REQ_TYPE_FLUSH) {
204                         if (ps3disk_submit_flush_request(dev, req))
205                                 break;
206                 } else {
207                         blk_dump_rq_flags(req, DEVICE_NAME " bad request");
208                         end_request(req, 0);
209                         continue;
210                 }
211         }
212 }
213 
214 static void ps3disk_request(struct request_queue *q)
215 {
216         struct ps3_storage_device *dev = q->queuedata;
217         struct ps3disk_private *priv = dev->sbd.core.driver_data;
218 
219         if (priv->req) {
220                 dev_dbg(&dev->sbd.core, "%s:%u busy\n", __func__, __LINE__);
221                 return;
222         }
223 
224         ps3disk_do_request(dev, q);
225 }
226 
227 static irqreturn_t ps3disk_interrupt(int irq, void *data)
228 {
229         struct ps3_storage_device *dev = data;
230         struct ps3disk_private *priv;
231         struct request *req;
232         int res, read, error;
233         u64 tag, status;
234         unsigned long num_sectors;
235         const char *op;
236 
237         res = lv1_storage_get_async_status(dev->sbd.dev_id, &tag, &status);
238 
239         if (tag != dev->tag)
240                 dev_err(&dev->sbd.core,
241                         "%s:%u: tag mismatch, got %lx, expected %lx\n",
242                         __func__, __LINE__, tag, dev->tag);
243 
244         if (res) {
245                 dev_err(&dev->sbd.core, "%s:%u: res=%d status=0x%lx\n",
246                         __func__, __LINE__, res, status);
247                 return IRQ_HANDLED;
248         }
249 
250         priv = dev->sbd.core.driver_data;
251         req = priv->req;
252         if (!req) {
253                 dev_dbg(&dev->sbd.core,
254                         "%s:%u non-block layer request completed\n", __func__,
255                         __LINE__);
256                 dev->lv1_status = status;
257                 complete(&dev->done);
258                 return IRQ_HANDLED;
259         }
260 
261         if (req->cmd_type == REQ_TYPE_FLUSH) {
262                 read = 0;
263                 num_sectors = req->hard_cur_sectors;
264                 op = "flush";
265         } else {
266                 read = !rq_data_dir(req);
267                 num_sectors = req->nr_sectors;
268                 op = read ? "read" : "write";
269         }
270         if (status) {
271                 dev_dbg(&dev->sbd.core, "%s:%u: %s failed 0x%lx\n", __func__,
272                         __LINE__, op, status);
273                 error = -EIO;
274         } else {
275                 dev_dbg(&dev->sbd.core, "%s:%u: %s completed\n", __func__,
276                         __LINE__, op);
277                 error = 0;
278                 if (read)
279                         ps3disk_scatter_gather(dev, req, 0);
280         }
281 
282         spin_lock(&priv->lock);
283         __blk_end_request(req, error, num_sectors << 9);
284         priv->req = NULL;
285         ps3disk_do_request(dev, priv->queue);
286         spin_unlock(&priv->lock);
287 
288         return IRQ_HANDLED;
289 }
290 
291 static int ps3disk_sync_cache(struct ps3_storage_device *dev)
292 {
293         u64 res;
294 
295         dev_dbg(&dev->sbd.core, "%s:%u: sync cache\n", __func__, __LINE__);
296 
297         res = ps3stor_send_command(dev, LV1_STORAGE_ATA_HDDOUT, 0, 0, 0, 0);
298         if (res) {
299                 dev_err(&dev->sbd.core, "%s:%u: sync cache failed 0x%lx\n",
300                         __func__, __LINE__, res);
301                 return -EIO;
302         }
303         return 0;
304 }
305 
306 
307 /* ATA helpers copied from drivers/ata/libata-core.c */
308 
309 static void swap_buf_le16(u16 *buf, unsigned int buf_words)
310 {
311 #ifdef __BIG_ENDIAN
312         unsigned int i;
313 
314         for (i = 0; i < buf_words; i++)
315                 buf[i] = le16_to_cpu(buf[i]);
316 #endif /* __BIG_ENDIAN */
317 }
318 
319 static u64 ata_id_n_sectors(const u16 *id)
320 {
321         if (ata_id_has_lba(id)) {
322                 if (ata_id_has_lba48(id))
323                         return ata_id_u64(id, 100);
324                 else
325                         return ata_id_u32(id, 60);
326         } else {
327                 if (ata_id_current_chs_valid(id))
328                         return ata_id_u32(id, 57);
329                 else
330                         return id[1] * id[3] * id[6];
331         }
332 }
333 
334 static void ata_id_string(const u16 *id, unsigned char *s, unsigned int ofs,
335                           unsigned int len)
336 {
337         unsigned int c;
338 
339         while (len > 0) {
340                 c = id[ofs] >> 8;
341                 *s = c;
342                 s++;
343 
344                 c = id[ofs] & 0xff;
345                 *s = c;
346                 s++;
347 
348                 ofs++;
349                 len -= 2;
350         }
351 }
352 
353 static void ata_id_c_string(const u16 *id, unsigned char *s, unsigned int ofs,
354                             unsigned int len)
355 {
356         unsigned char *p;
357 
358         WARN_ON(!(len & 1));
359 
360         ata_id_string(id, s, ofs, len - 1);
361 
362         p = s + strnlen(s, len - 1);
363         while (p > s && p[-1] == ' ')
364                 p--;
365         *p = '\0';
366 }
367 
368 static int ps3disk_identify(struct ps3_storage_device *dev)
369 {
370         struct ps3disk_private *priv = dev->sbd.core.driver_data;
371         struct lv1_ata_cmnd_block ata_cmnd;
372         u16 *id = dev->bounce_buf;
373         u64 res;
374 
375         dev_dbg(&dev->sbd.core, "%s:%u: identify disk\n", __func__, __LINE__);
376 
377         memset(&ata_cmnd, 0, sizeof(struct lv1_ata_cmnd_block));
378         ata_cmnd.command = ATA_CMD_ID_ATA;
379         ata_cmnd.sector_count = 1;
380         ata_cmnd.size = ata_cmnd.arglen = ATA_ID_WORDS * 2;
381         ata_cmnd.buffer = dev->bounce_lpar;
382         ata_cmnd.proto = PIO_DATA_IN_PROTO;
383         ata_cmnd.in_out = DIR_READ;
384 
385         res = ps3stor_send_command(dev, LV1_STORAGE_SEND_ATA_COMMAND,
386                                    ps3_mm_phys_to_lpar(__pa(&ata_cmnd)),
387                                    sizeof(ata_cmnd), ata_cmnd.buffer,
388                                    ata_cmnd.arglen);
389         if (res) {
390                 dev_err(&dev->sbd.core, "%s:%u: identify disk failed 0x%lx\n",
391                         __func__, __LINE__, res);
392                 return -EIO;
393         }
394 
395         swap_buf_le16(id, ATA_ID_WORDS);
396 
397         /* All we're interested in are raw capacity and model name */
398         priv->raw_capacity = ata_id_n_sectors(id);
399         ata_id_c_string(id, priv->model, ATA_ID_PROD, sizeof(priv->model));
400         return 0;
401 }
402 
403 static void ps3disk_prepare_flush(struct request_queue *q, struct request *req)
404 {
405         struct ps3_storage_device *dev = q->queuedata;
406 
407         dev_dbg(&dev->sbd.core, "%s:%u\n", __func__, __LINE__);
408 
409         memset(req->cmd, 0, sizeof(req->cmd));
410         req->cmd_type = REQ_TYPE_FLUSH;
411 }
412 
413 static unsigned long ps3disk_mask;
414 
415 static DEFINE_MUTEX(ps3disk_mask_mutex);
416 
417 static int __devinit ps3disk_probe(struct ps3_system_bus_device *_dev)
418 {
419         struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
420         struct ps3disk_private *priv;
421         int error;
422         unsigned int devidx;
423         struct request_queue *queue;
424         struct gendisk *gendisk;
425 
426         if (dev->blk_size < 512) {
427                 dev_err(&dev->sbd.core,
428                         "%s:%u: cannot handle block size %lu\n", __func__,
429                         __LINE__, dev->blk_size);
430                 return -EINVAL;
431         }
432 
433         BUILD_BUG_ON(PS3DISK_MAX_DISKS > BITS_PER_LONG);
434         mutex_lock(&ps3disk_mask_mutex);
435         devidx = find_first_zero_bit(&ps3disk_mask, PS3DISK_MAX_DISKS);
436         if (devidx >= PS3DISK_MAX_DISKS) {
437                 dev_err(&dev->sbd.core, "%s:%u: Too many disks\n", __func__,
438                         __LINE__);
439                 mutex_unlock(&ps3disk_mask_mutex);
440                 return -ENOSPC;
441         }
442         __set_bit(devidx, &ps3disk_mask);
443         mutex_unlock(&ps3disk_mask_mutex);
444 
445         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
446         if (!priv) {
447                 error = -ENOMEM;
448                 goto fail;
449         }
450 
451         dev->sbd.core.driver_data = priv;
452         spin_lock_init(&priv->lock);
453 
454         dev->bounce_size = BOUNCE_SIZE;
455         dev->bounce_buf = kmalloc(BOUNCE_SIZE, GFP_DMA);
456         if (!dev->bounce_buf) {
457                 error = -ENOMEM;
458                 goto fail_free_priv;
459         }
460 
461         error = ps3stor_setup(dev, ps3disk_interrupt);
462         if (error)
463                 goto fail_free_bounce;
464 
465         ps3disk_identify(dev);
466 
467         queue = blk_init_queue(ps3disk_request, &priv->lock);
468         if (!queue) {
469                 dev_err(&dev->sbd.core, "%s:%u: blk_init_queue failed\n",
470                         __func__, __LINE__);
471                 error = -ENOMEM;
472                 goto fail_teardown;
473         }
474 
475         priv->queue = queue;
476         queue->queuedata = dev;
477 
478         blk_queue_bounce_limit(queue, BLK_BOUNCE_HIGH);
479 
480         blk_queue_max_sectors(queue, dev->bounce_size >> 9);
481         blk_queue_segment_boundary(queue, -1UL);
482         blk_queue_dma_alignment(queue, dev->blk_size-1);
483         blk_queue_hardsect_size(queue, dev->blk_size);
484 
485         blk_queue_ordered(queue, QUEUE_ORDERED_DRAIN_FLUSH,
486                           ps3disk_prepare_flush);
487 
488         blk_queue_max_phys_segments(queue, -1);
489         blk_queue_max_hw_segments(queue, -1);
490         blk_queue_max_segment_size(queue, dev->bounce_size);
491 
492         gendisk = alloc_disk(PS3DISK_MINORS);
493         if (!gendisk) {
494                 dev_err(&dev->sbd.core, "%s:%u: alloc_disk failed\n", __func__,
495                         __LINE__);
496                 error = -ENOMEM;
497                 goto fail_cleanup_queue;
498         }
499 
500         priv->gendisk = gendisk;
501         gendisk->major = ps3disk_major;
502         gendisk->first_minor = devidx * PS3DISK_MINORS;
503         gendisk->fops = &ps3disk_fops;
504         gendisk->queue = queue;
505         gendisk->private_data = dev;
506         gendisk->driverfs_dev = &dev->sbd.core;
507         snprintf(gendisk->disk_name, sizeof(gendisk->disk_name), PS3DISK_NAME,
508                  devidx+'a');
509         priv->blocking_factor = dev->blk_size >> 9;
510         set_capacity(gendisk,
511                      dev->regions[dev->region_idx].size*priv->blocking_factor);
512 
513         dev_info(&dev->sbd.core,
514                  "%s is a %s (%lu MiB total, %lu MiB for OtherOS)\n",
515                  gendisk->disk_name, priv->model, priv->raw_capacity >> 11,
516                  get_capacity(gendisk) >> 11);
517 
518         add_disk(gendisk);
519         return 0;
520 
521 fail_cleanup_queue:
522         blk_cleanup_queue(queue);
523 fail_teardown:
524         ps3stor_teardown(dev);
525 fail_free_bounce:
526         kfree(dev->bounce_buf);
527 fail_free_priv:
528         kfree(priv);
529         dev->sbd.core.driver_data = NULL;
530 fail:
531         mutex_lock(&ps3disk_mask_mutex);
532         __clear_bit(devidx, &ps3disk_mask);
533         mutex_unlock(&ps3disk_mask_mutex);
534         return error;
535 }
536 
537 static int ps3disk_remove(struct ps3_system_bus_device *_dev)
538 {
539         struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
540         struct ps3disk_private *priv = dev->sbd.core.driver_data;
541 
542         mutex_lock(&ps3disk_mask_mutex);
543         __clear_bit(priv->gendisk->first_minor / PS3DISK_MINORS,
544                     &ps3disk_mask);
545         mutex_unlock(&ps3disk_mask_mutex);
546         del_gendisk(priv->gendisk);
547         blk_cleanup_queue(priv->queue);
548         put_disk(priv->gendisk);
549         dev_notice(&dev->sbd.core, "Synchronizing disk cache\n");
550         ps3disk_sync_cache(dev);
551         ps3stor_teardown(dev);
552         kfree(dev->bounce_buf);
553         kfree(priv);
554         dev->sbd.core.driver_data = NULL;
555         return 0;
556 }
557 
558 static struct ps3_system_bus_driver ps3disk = {
559         .match_id       = PS3_MATCH_ID_STOR_DISK,
560         .core.name      = DEVICE_NAME,
561         .core.owner     = THIS_MODULE,
562         .probe          = ps3disk_probe,
563         .remove         = ps3disk_remove,
564         .shutdown       = ps3disk_remove,
565 };
566 
567 
568 static int __init ps3disk_init(void)
569 {
570         int error;
571 
572         if (!firmware_has_feature(FW_FEATURE_PS3_LV1))
573                 return -ENODEV;
574 
575         error = register_blkdev(0, DEVICE_NAME);
576         if (error <= 0) {
577                 printk(KERN_ERR "%s:%u: register_blkdev failed %d\n", __func__,
578                        __LINE__, error);
579                 return error;
580         }
581         ps3disk_major = error;
582 
583         pr_info("%s:%u: registered block device major %d\n", __func__,
584                 __LINE__, ps3disk_major);
585 
586         error = ps3_system_bus_driver_register(&ps3disk);
587         if (error)
588                 unregister_blkdev(ps3disk_major, DEVICE_NAME);
589 
590         return error;
591 }
592 
593 static void __exit ps3disk_exit(void)
594 {
595         ps3_system_bus_driver_unregister(&ps3disk);
596         unregister_blkdev(ps3disk_major, DEVICE_NAME);
597 }
598 
599 module_init(ps3disk_init);
600 module_exit(ps3disk_exit);
601 
602 MODULE_LICENSE("GPL");
603 MODULE_DESCRIPTION("PS3 Disk Storage Driver");
604 MODULE_AUTHOR("Sony Corporation");
605 MODULE_ALIAS(PS3_MODULE_ALIAS_STOR_DISK);
606 
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