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         generic_start_io_acct(bio_data_dir(bio), bio_sectors(bio),
 116                              &card->gendisk->part0);
 117 }
 118
 119 static void disk_stats_complete(struct rsxx_cardinfo *card,
 120                                 struct bio *bio,
 121                                 unsigned long start_time)
 122 {
 123         generic_end_io_acct(bio_data_dir(bio), &card->gendisk->part0,
 124                            start_time);
 125 }
 126
 127 static void bio_dma_done_cb(struct rsxx_cardinfo *card,
 128                             void *cb_data,
 129                             unsigned int error)
 130 {
 131         struct rsxx_bio_meta *meta = cb_data;
 132
 133         if (error)
 134                 atomic_set(&meta->error, 1);
 135
 136         if (atomic_dec_and_test(&meta->pending_dmas)) {
 137                 if (!card->eeh_state && card->gendisk)
 138                         disk_stats_complete(card, meta->bio, meta->start_time);
 139
 140                 if (atomic_read(&meta->error))
 141                         bio_io_error(meta->bio);
 142                 else
 143                         bio_endio(meta->bio);
 144                 kmem_cache_free(bio_meta_pool, meta);
 145         }
 146 }
 147
 148 static blk_qc_t rsxx_make_request(struct request_queue *q, struct bio *bio)
 149 {
 150         struct rsxx_cardinfo *card = q->queuedata;
 151         struct rsxx_bio_meta *bio_meta;
 152         int st = -EINVAL;
 153
 154         blk_queue_split(q, &bio, q->bio_split);
 155
 156         might_sleep();
 157
 158         if (!card)
 159                 goto req_err;
 160
 161         if (bio_end_sector(bio) > get_capacity(card->gendisk))
 162                 goto req_err;
 163
 164         if (unlikely(card->halt)) {
 165                 st = -EFAULT;
 166                 goto req_err;
 167         }
 168
 169         if (unlikely(card->dma_fault)) {
 170                 st = (-EFAULT);
 171                 goto req_err;
 172         }
 173
 174         if (bio->bi_iter.bi_size == 0) {
 175                 dev_err(CARD_TO_DEV(card), "size zero BIO!\n");
 176                 goto req_err;
 177         }
 178
 179         bio_meta = kmem_cache_alloc(bio_meta_pool, GFP_KERNEL);
 180         if (!bio_meta) {
 181                 st = -ENOMEM;
 182                 goto req_err;
 183         }
 184
 185         bio_meta->bio = bio;
 186         atomic_set(&bio_meta->error, 0);
 187         atomic_set(&bio_meta->pending_dmas, 0);
 188         bio_meta->start_time = jiffies;
 189
 190         if (!unlikely(card->halt))
 191                 disk_stats_start(card, bio);
 192
 193         dev_dbg(CARD_TO_DEV(card), "BIO[%c]: meta: %p addr8: x%llx size: %d\n",
 194                  bio_data_dir(bio) ? 'W' : 'R', bio_meta,
 195                  (u64)bio->bi_iter.bi_sector << 9, bio->bi_iter.bi_size);
 196
 197         st = rsxx_dma_queue_bio(card, bio, &bio_meta->pending_dmas,
 198                                     bio_dma_done_cb, bio_meta);
 199         if (st)
 200                 goto queue_err;
 201
 202         return BLK_QC_T_NONE;
 203
 204 queue_err:
 205         kmem_cache_free(bio_meta_pool, bio_meta);
 206 req_err:
 207         if (st)
 208                 bio->bi_error = st;
 209         bio_endio(bio);
 210         return BLK_QC_T_NONE;
 211 }
 212
 213 /*----------------- Device Setup -------------------*/
 214 static bool rsxx_discard_supported(struct rsxx_cardinfo *card)
 215 {
 216         unsigned char pci_rev;
 217
 218         pci_read_config_byte(card->dev, PCI_REVISION_ID, &pci_rev);
 219
 220         return (pci_rev >= RSXX_DISCARD_SUPPORT);
 221 }
 222
 223 int rsxx_attach_dev(struct rsxx_cardinfo *card)
 224 {
 225         mutex_lock(&card->dev_lock);
 226
 227         /* The block device requires the stripe size from the config. */
 228         if (enable_blkdev) {
 229                 if (card->config_valid)
 230                         set_capacity(card->gendisk, card->size8 >> 9);
 231                 else
 232                         set_capacity(card->gendisk, 0);
 233                 device_add_disk(CARD_TO_DEV(card), card->gendisk);
 234                 card->bdev_attached = 1;
 235         }
 236
 237         mutex_unlock(&card->dev_lock);
 238
 239         return 0;
 240 }
 241
 242 void rsxx_detach_dev(struct rsxx_cardinfo *card)
 243 {
 244         mutex_lock(&card->dev_lock);
 245
 246         if (card->bdev_attached) {
 247                 del_gendisk(card->gendisk);
 248                 card->bdev_attached = 0;
 249         }
 250
 251         mutex_unlock(&card->dev_lock);
 252 }
 253
 254 int rsxx_setup_dev(struct rsxx_cardinfo *card)
 255 {
 256         unsigned short blk_size;
 257
 258         mutex_init(&card->dev_lock);
 259
 260         if (!enable_blkdev)
 261                 return 0;
 262
 263         card->major = register_blkdev(0, DRIVER_NAME);
 264         if (card->major < 0) {
 265                 dev_err(CARD_TO_DEV(card), "Failed to get major number\n");
 266                 return -ENOMEM;
 267         }
 268
 269         card->queue = blk_alloc_queue(GFP_KERNEL);
 270         if (!card->queue) {
 271                 dev_err(CARD_TO_DEV(card), "Failed queue alloc\n");
 272                 unregister_blkdev(card->major, DRIVER_NAME);
 273                 return -ENOMEM;
 274         }
 275
 276         card->gendisk = alloc_disk(blkdev_minors);
 277         if (!card->gendisk) {
 278                 dev_err(CARD_TO_DEV(card), "Failed disk alloc\n");
 279                 blk_cleanup_queue(card->queue);
 280                 unregister_blkdev(card->major, DRIVER_NAME);
 281                 return -ENOMEM;
 282         }
 283
 284         if (card->config_valid) {
 285                 blk_size = card->config.data.block_size;
 286                 blk_queue_dma_alignment(card->queue, blk_size - 1);
 287                 blk_queue_logical_block_size(card->queue, blk_size);
 288         }
 289
 290         blk_queue_make_request(card->queue, rsxx_make_request);
 291         blk_queue_bounce_limit(card->queue, BLK_BOUNCE_ANY);
 292         blk_queue_max_hw_sectors(card->queue, blkdev_max_hw_sectors);
 293         blk_queue_physical_block_size(card->queue, RSXX_HW_BLK_SIZE);
 294
 295         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, card->queue);
 296         queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, card->queue);
 297         if (rsxx_discard_supported(card)) {
 298                 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, card->queue);
 299                 blk_queue_max_discard_sectors(card->queue,
 300                                                 RSXX_HW_BLK_SIZE >> 9);
 301                 card->queue->limits.discard_granularity = RSXX_HW_BLK_SIZE;
 302                 card->queue->limits.discard_alignment   = RSXX_HW_BLK_SIZE;
 303                 card->queue->limits.discard_zeroes_data = 1;
 304         }
 305
 306         card->queue->queuedata = card;
 307
 308         snprintf(card->gendisk->disk_name, sizeof(card->gendisk->disk_name),
 309                  "rsxx%d", card->disk_id);
 310         card->gendisk->major = card->major;
 311         card->gendisk->first_minor = 0;
 312         card->gendisk->fops = &rsxx_fops;
 313         card->gendisk->private_data = card;
 314         card->gendisk->queue = card->queue;
 315
 316         return 0;
 317 }
 318
 319 void rsxx_destroy_dev(struct rsxx_cardinfo *card)
 320 {
 321         if (!enable_blkdev)
 322                 return;
 323
 324         put_disk(card->gendisk);
 325         card->gendisk = NULL;
 326
 327         blk_cleanup_queue(card->queue);
 328         card->queue->queuedata = NULL;
 329         unregister_blkdev(card->major, DRIVER_NAME);
 330 }
 331
 332 int rsxx_dev_init(void)
 333 {
 334         bio_meta_pool = KMEM_CACHE(rsxx_bio_meta, SLAB_HWCACHE_ALIGN);
 335         if (!bio_meta_pool)
 336                 return -ENOMEM;
 337
 338         return 0;
 339 }
 340
 341 void rsxx_dev_cleanup(void)
 342 {
 343         kmem_cache_destroy(bio_meta_pool);
 344 }
 345
 346