drivers/block/rsxx/dev.c

   1 /*
   2 * Filename: dev.c
   3 *
   4 *
   5 * Authors: Joshua Morris <josh.h.morris@us.ibm.com>
   6 *       Philip Kelleher <pjk1939@linux.vnet.ibm.com>
   7 *
   8 * (C) Copyright 2013 IBM Corporation
   9 *
  10 * This program is free software; you can redistribute it and/or
  11 * modify it under the terms of the GNU General Public License as
  12 * published by the Free Software Foundation; either version 2 of the
  13 * License, or (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful, but
  16 * WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18 * General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program; if not, write to the Free Software Foundation,
  22 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23 */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/module.h>
  28 #include <linux/pci.h>
  29 #include <linux/slab.h>
  30
  31 #include <linux/hdreg.h>
  32 #include <linux/genhd.h>
  33 #include <linux/blkdev.h>
  34 #include <linux/bio.h>
  35
  36 #include <linux/fs.h>
  37
  38 #include "rsxx_priv.h"
  39
  40 static unsigned int blkdev_minors = 64;
  41 module_param(blkdev_minors, uint, 0444);
  42 MODULE_PARM_DESC(blkdev_minors, "Number of minors(partitions)");
  43
  44 /*
  45  * For now I'm making this tweakable in case any applications hit this limit.
  46  * If you see a "bio too big" error in the log you will need to raise this
  47  * value.
  48  */
  49 static unsigned int blkdev_max_hw_sectors = 1024;
  50 module_param(blkdev_max_hw_sectors, uint, 0444);
  51 MODULE_PARM_DESC(blkdev_max_hw_sectors, "Max hw sectors for a single BIO");
  52
  53 static unsigned int enable_blkdev = 1;
  54 module_param(enable_blkdev , uint, 0444);
  55 MODULE_PARM_DESC(enable_blkdev, "Enable block device interfaces");
  56
  57
  58 struct rsxx_bio_meta {
  59         struct bio      *bio;
  60         atomic_t        pending_dmas;
  61         atomic_t        error;
  62         unsigned long   start_time;
  63 };
  64
  65 static struct kmem_cache *bio_meta_pool;
  66
  67 /*----------------- Block Device Operations -----------------*/
  68 static int rsxx_blkdev_ioctl(struct block_device *bdev,
  69                                  fmode_t mode,
  70                                  unsigned int cmd,
  71                                  unsigned long arg)
  72 {
  73         struct rsxx_cardinfo *card = bdev->bd_disk->private_data;
  74
  75         switch (cmd) {
  76         case RSXX_GETREG:
  77                 return rsxx_reg_access(card, (void __user *)arg, 1);
  78         case RSXX_SETREG:
  79                 return rsxx_reg_access(card, (void __user *)arg, 0);
  80         }
  81
  82         return -ENOTTY;
  83 }
  84
  85 static int rsxx_getgeo(struct block_device *bdev, struct hd_geometry *geo)
  86 {
  87         struct rsxx_cardinfo *card = bdev->bd_disk->private_data;
  88         u64 blocks = card->size8 >> 9;
  89
  90         /*
  91          * get geometry: Fake it. I haven't found any drivers that set
  92          * geo->start, so we won't either.
  93          */
  94         if (card->size8) {
  95                 geo->heads = 64;
  96                 geo->sectors = 16;
  97                 do_div(blocks, (geo->heads * geo->sectors));
  98                 geo->cylinders = blocks;
  99         } else {
 100                 geo->heads = 0;
 101                 geo->sectors = 0;
 102                 geo->cylinders = 0;
 103         }
 104         return 0;
 105 }
 106
 107 static const struct block_device_operations rsxx_fops = {
 108         .owner          = THIS_MODULE,
 109         .getgeo         = rsxx_getgeo,
 110         .ioctl          = rsxx_blkdev_ioctl,
 111 };
 112
 113 static void disk_stats_start(struct rsxx_cardinfo *card, struct bio *bio)
 114 {
 115         struct hd_struct *part0 = &card->gendisk->part0;
 116         int rw = bio_data_dir(bio);
 117         int cpu;
 118
 119         cpu = part_stat_lock();
 120
 121         part_round_stats(cpu, part0);
 122         part_inc_in_flight(part0, rw);
 123
 124         part_stat_unlock();
 125 }
 126
 127 static void disk_stats_complete(struct rsxx_cardinfo *card,
 128                                 struct bio *bio,
 129                                 unsigned long start_time)
 130 {
 131         struct hd_struct *part0 = &card->gendisk->part0;
 132         unsigned long duration = jiffies - start_time;
 133         int rw = bio_data_dir(bio);
 134         int cpu;
 135
 136         cpu = part_stat_lock();
 137
 138         part_stat_add(cpu, part0, sectors[rw], bio_sectors(bio));
 139         part_stat_inc(cpu, part0, ios[rw]);
 140         part_stat_add(cpu, part0, ticks[rw], duration);
 141
 142         part_round_stats(cpu, part0);
 143         part_dec_in_flight(part0, rw);
 144
 145         part_stat_unlock();
 146 }
 147
 148 static void bio_dma_done_cb(struct rsxx_cardinfo *card,
 149                             void *cb_data,
 150                             unsigned int error)
 151 {
 152         struct rsxx_bio_meta *meta = cb_data;
 153
 154         if (error)
 155                 atomic_set(&meta->error, 1);
 156
 157         if (atomic_dec_and_test(&meta->pending_dmas)) {
 158                 disk_stats_complete(card, meta->bio, meta->start_time);
 159
 160                 bio_endio(meta->bio, atomic_read(&meta->error) ? -EIO : 0);
 161                 kmem_cache_free(bio_meta_pool, meta);
 162         }
 163 }
 164
 165 static void rsxx_make_request(struct request_queue *q, struct bio *bio)
 166 {
 167         struct rsxx_cardinfo *card = q->queuedata;
 168         struct rsxx_bio_meta *bio_meta;
 169         int st = -EINVAL;
 170
 171         might_sleep();
 172
 173         if (unlikely(card->halt)) {
 174                 st = -EFAULT;
 175                 goto req_err;
 176         }
 177
 178         if (unlikely(card->dma_fault)) {
 179                 st = (-EFAULT);
 180                 goto req_err;
 181         }
 182
 183         if (bio->bi_size == 0) {
 184                 dev_err(CARD_TO_DEV(card), "size zero BIO!\n");
 185                 goto req_err;
 186         }
 187
 188         bio_meta = kmem_cache_alloc(bio_meta_pool, GFP_KERNEL);
 189         if (!bio_meta) {
 190                 st = -ENOMEM;
 191                 goto req_err;
 192         }
 193
 194         bio_meta->bio = bio;
 195         atomic_set(&bio_meta->error, 0);
 196         atomic_set(&bio_meta->pending_dmas, 0);
 197         bio_meta->start_time = jiffies;
 198
 199         disk_stats_start(card, bio);
 200
 201         dev_dbg(CARD_TO_DEV(card), "BIO[%c]: meta: %p addr8: x%llx size: %d\n",
 202                  bio_data_dir(bio) ? 'W' : 'R', bio_meta,
 203                  (u64)bio->bi_sector << 9, bio->bi_size);
 204
 205         st = rsxx_dma_queue_bio(card, bio, &bio_meta->pending_dmas,
 206                                     bio_dma_done_cb, bio_meta);
 207         if (st)
 208                 goto queue_err;
 209
 210         return;
 211
 212 queue_err:
 213         kmem_cache_free(bio_meta_pool, bio_meta);
 214 req_err:
 215         bio_endio(bio, st);
 216 }
 217
 218 /*----------------- Device Setup -------------------*/
 219 static bool rsxx_discard_supported(struct rsxx_cardinfo *card)
 220 {
 221         unsigned char pci_rev;
 222
 223         pci_read_config_byte(card->dev, PCI_REVISION_ID, &pci_rev);
 224
 225         return (pci_rev >= RSXX_DISCARD_SUPPORT);
 226 }
 227
 228 static unsigned short rsxx_get_logical_block_size(
 229                                         struct rsxx_cardinfo *card)
 230 {
 231         u32 capabilities = 0;
 232         int st;
 233
 234         st = rsxx_get_card_capabilities(card, &capabilities);
 235         if (st)
 236                 dev_warn(CARD_TO_DEV(card),
 237                         "Failed reading card capabilities register\n");
 238
 239         /* Earlier firmware did not have support for 512 byte accesses */
 240         if (capabilities & CARD_CAP_SUBPAGE_WRITES)
 241                 return 512;
 242         else
 243                 return RSXX_HW_BLK_SIZE;
 244 }
 245
 246 int rsxx_attach_dev(struct rsxx_cardinfo *card)
 247 {
 248         mutex_lock(&card->dev_lock);
 249
 250         /* The block device requires the stripe size from the config. */
 251         if (enable_blkdev) {
 252                 if (card->config_valid)
 253                         set_capacity(card->gendisk, card->size8 >> 9);
 254                 else
 255                         set_capacity(card->gendisk, 0);
 256                 add_disk(card->gendisk);
 257
 258                 card->bdev_attached = 1;
 259         }
 260
 261         mutex_unlock(&card->dev_lock);
 262
 263         return 0;
 264 }
 265
 266 void rsxx_detach_dev(struct rsxx_cardinfo *card)
 267 {
 268         mutex_lock(&card->dev_lock);
 269
 270         if (card->bdev_attached) {
 271                 del_gendisk(card->gendisk);
 272                 card->bdev_attached = 0;
 273         }
 274
 275         mutex_unlock(&card->dev_lock);
 276 }
 277
 278 int rsxx_setup_dev(struct rsxx_cardinfo *card)
 279 {
 280         unsigned short blk_size;
 281
 282         mutex_init(&card->dev_lock);
 283
 284         if (!enable_blkdev)
 285                 return 0;
 286
 287         card->major = register_blkdev(0, DRIVER_NAME);
 288         if (card->major < 0) {
 289                 dev_err(CARD_TO_DEV(card), "Failed to get major number\n");
 290                 return -ENOMEM;
 291         }
 292
 293         card->queue = blk_alloc_queue(GFP_KERNEL);
 294         if (!card->queue) {
 295                 dev_err(CARD_TO_DEV(card), "Failed queue alloc\n");
 296                 unregister_blkdev(card->major, DRIVER_NAME);
 297                 return -ENOMEM;
 298         }
 299
 300         card->gendisk = alloc_disk(blkdev_minors);
 301         if (!card->gendisk) {
 302                 dev_err(CARD_TO_DEV(card), "Failed disk alloc\n");
 303                 blk_cleanup_queue(card->queue);
 304                 unregister_blkdev(card->major, DRIVER_NAME);
 305                 return -ENOMEM;
 306         }
 307
 308         blk_size = rsxx_get_logical_block_size(card);
 309
 310         blk_queue_make_request(card->queue, rsxx_make_request);
 311         blk_queue_bounce_limit(card->queue, BLK_BOUNCE_ANY);
 312         blk_queue_dma_alignment(card->queue, blk_size - 1);
 313         blk_queue_max_hw_sectors(card->queue, blkdev_max_hw_sectors);
 314         blk_queue_logical_block_size(card->queue, blk_size);
 315         blk_queue_physical_block_size(card->queue, RSXX_HW_BLK_SIZE);
 316
 317         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, card->queue);
 318         if (rsxx_discard_supported(card)) {
 319                 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, card->queue);
 320                 blk_queue_max_discard_sectors(card->queue,
 321                                                 RSXX_HW_BLK_SIZE >> 9);
 322                 card->queue->limits.discard_granularity = RSXX_HW_BLK_SIZE;
 323                 card->queue->limits.discard_alignment   = RSXX_HW_BLK_SIZE;
 324                 card->queue->limits.discard_zeroes_data = 1;
 325         }
 326
 327         card->queue->queuedata = card;
 328
 329         snprintf(card->gendisk->disk_name, sizeof(card->gendisk->disk_name),
 330                  "rsxx%d", card->disk_id);
 331         card->gendisk->driverfs_dev = &card->dev->dev;
 332         card->gendisk->major = card->major;
 333         card->gendisk->first_minor = 0;
 334         card->gendisk->fops = &rsxx_fops;
 335         card->gendisk->private_data = card;
 336         card->gendisk->queue = card->queue;
 337
 338         return 0;
 339 }
 340
 341 void rsxx_destroy_dev(struct rsxx_cardinfo *card)
 342 {
 343         if (!enable_blkdev)
 344                 return;
 345
 346         put_disk(card->gendisk);
 347         card->gendisk = NULL;
 348
 349         blk_cleanup_queue(card->queue);
 350         unregister_blkdev(card->major, DRIVER_NAME);
 351 }
 352
 353 int rsxx_dev_init(void)
 354 {
 355         bio_meta_pool = KMEM_CACHE(rsxx_bio_meta, SLAB_HWCACHE_ALIGN);
 356         if (!bio_meta_pool)
 357                 return -ENOMEM;
 358
 359         return 0;
 360 }
 361
 362 void rsxx_dev_cleanup(void)
 363 {
 364         kmem_cache_destroy(bio_meta_pool);
 365 }
 366
 367