drivers/block/rsxx/dev.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3 * Filename: dev.c
   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
  11 #include <linux/kernel.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/module.h>
  14 #include <linux/pci.h>
  15 #include <linux/slab.h>
  16
  17 #include <linux/hdreg.h>
  18 #include <linux/genhd.h>
  19 #include <linux/blkdev.h>
  20 #include <linux/bio.h>
  21
  22 #include <linux/fs.h>
  23
  24 #include "rsxx_priv.h"
  25
  26 static unsigned int blkdev_minors = 64;
  27 module_param(blkdev_minors, uint, 0444);
  28 MODULE_PARM_DESC(blkdev_minors, "Number of minors(partitions)");
  29
  30 /*
  31  * For now I'm making this tweakable in case any applications hit this limit.
  32  * If you see a "bio too big" error in the log you will need to raise this
  33  * value.
  34  */
  35 static unsigned int blkdev_max_hw_sectors = 1024;
  36 module_param(blkdev_max_hw_sectors, uint, 0444);
  37 MODULE_PARM_DESC(blkdev_max_hw_sectors, "Max hw sectors for a single BIO");
  38
  39 static unsigned int enable_blkdev = 1;
  40 module_param(enable_blkdev , uint, 0444);
  41 MODULE_PARM_DESC(enable_blkdev, "Enable block device interfaces");
  42
  43
  44 struct rsxx_bio_meta {
  45         struct bio      *bio;
  46         atomic_t        pending_dmas;
  47         atomic_t        error;
  48         unsigned long   start_time;
  49 };
  50
  51 static struct kmem_cache *bio_meta_pool;
  52
  53 /*----------------- Block Device Operations -----------------*/
  54 static int rsxx_blkdev_ioctl(struct block_device *bdev,
  55                                  fmode_t mode,
  56                                  unsigned int cmd,
  57                                  unsigned long arg)
  58 {
  59         struct rsxx_cardinfo *card = bdev->bd_disk->private_data;
  60
  61         switch (cmd) {
  62         case RSXX_GETREG:
  63                 return rsxx_reg_access(card, (void __user *)arg, 1);
  64         case RSXX_SETREG:
  65                 return rsxx_reg_access(card, (void __user *)arg, 0);
  66         }
  67
  68         return -ENOTTY;
  69 }
  70
  71 static int rsxx_getgeo(struct block_device *bdev, struct hd_geometry *geo)
  72 {
  73         struct rsxx_cardinfo *card = bdev->bd_disk->private_data;
  74         u64 blocks = card->size8 >> 9;
  75
  76         /*
  77          * get geometry: Fake it. I haven't found any drivers that set
  78          * geo->start, so we won't either.
  79          */
  80         if (card->size8) {
  81                 geo->heads = 64;
  82                 geo->sectors = 16;
  83                 do_div(blocks, (geo->heads * geo->sectors));
  84                 geo->cylinders = blocks;
  85         } else {
  86                 geo->heads = 0;
  87                 geo->sectors = 0;
  88                 geo->cylinders = 0;
  89         }
  90         return 0;
  91 }
  92
  93 static const struct block_device_operations rsxx_fops = {
  94         .owner          = THIS_MODULE,
  95         .getgeo         = rsxx_getgeo,
  96         .ioctl          = rsxx_blkdev_ioctl,
  97 };
  98
  99 static void disk_stats_start(struct rsxx_cardinfo *card, struct bio *bio)
 100 {
 101         generic_start_io_acct(card->queue, bio_op(bio), bio_sectors(bio),
 102                              &card->gendisk->part0);
 103 }
 104
 105 static void disk_stats_complete(struct rsxx_cardinfo *card,
 106                                 struct bio *bio,
 107                                 unsigned long start_time)
 108 {
 109         generic_end_io_acct(card->queue, bio_op(bio),
 110                             &card->gendisk->part0, start_time);
 111 }
 112
 113 static void bio_dma_done_cb(struct rsxx_cardinfo *card,
 114                             void *cb_data,
 115                             unsigned int error)
 116 {
 117         struct rsxx_bio_meta *meta = cb_data;
 118
 119         if (error)
 120                 atomic_set(&meta->error, 1);
 121
 122         if (atomic_dec_and_test(&meta->pending_dmas)) {
 123                 if (!card->eeh_state && card->gendisk)
 124                         disk_stats_complete(card, meta->bio, meta->start_time);
 125
 126                 if (atomic_read(&meta->error))
 127                         bio_io_error(meta->bio);
 128                 else
 129                         bio_endio(meta->bio);
 130                 kmem_cache_free(bio_meta_pool, meta);
 131         }
 132 }
 133
 134 static blk_qc_t rsxx_make_request(struct request_queue *q, struct bio *bio)
 135 {
 136         struct rsxx_cardinfo *card = q->queuedata;
 137         struct rsxx_bio_meta *bio_meta;
 138         blk_status_t st = BLK_STS_IOERR;
 139
 140         blk_queue_split(q, &bio);
 141
 142         might_sleep();
 143
 144         if (!card)
 145                 goto req_err;
 146
 147         if (bio_end_sector(bio) > get_capacity(card->gendisk))
 148                 goto req_err;
 149
 150         if (unlikely(card->halt))
 151                 goto req_err;
 152
 153         if (unlikely(card->dma_fault))
 154                 goto req_err;
 155
 156         if (bio->bi_iter.bi_size == 0) {
 157                 dev_err(CARD_TO_DEV(card), "size zero BIO!\n");
 158                 goto req_err;
 159         }
 160
 161         bio_meta = kmem_cache_alloc(bio_meta_pool, GFP_KERNEL);
 162         if (!bio_meta) {
 163                 st = BLK_STS_RESOURCE;
 164                 goto req_err;
 165         }
 166
 167         bio_meta->bio = bio;
 168         atomic_set(&bio_meta->error, 0);
 169         atomic_set(&bio_meta->pending_dmas, 0);
 170         bio_meta->start_time = jiffies;
 171
 172         if (!unlikely(card->halt))
 173                 disk_stats_start(card, bio);
 174
 175         dev_dbg(CARD_TO_DEV(card), "BIO[%c]: meta: %p addr8: x%llx size: %d\n",
 176                  bio_data_dir(bio) ? 'W' : 'R', bio_meta,
 177                  (u64)bio->bi_iter.bi_sector << 9, bio->bi_iter.bi_size);
 178
 179         st = rsxx_dma_queue_bio(card, bio, &bio_meta->pending_dmas,
 180                                     bio_dma_done_cb, bio_meta);
 181         if (st)
 182                 goto queue_err;
 183
 184         return BLK_QC_T_NONE;
 185
 186 queue_err:
 187         kmem_cache_free(bio_meta_pool, bio_meta);
 188 req_err:
 189         if (st)
 190                 bio->bi_status = st;
 191         bio_endio(bio);
 192         return BLK_QC_T_NONE;
 193 }
 194
 195 /*----------------- Device Setup -------------------*/
 196 static bool rsxx_discard_supported(struct rsxx_cardinfo *card)
 197 {
 198         unsigned char pci_rev;
 199
 200         pci_read_config_byte(card->dev, PCI_REVISION_ID, &pci_rev);
 201
 202         return (pci_rev >= RSXX_DISCARD_SUPPORT);
 203 }
 204
 205 int rsxx_attach_dev(struct rsxx_cardinfo *card)
 206 {
 207         mutex_lock(&card->dev_lock);
 208
 209         /* The block device requires the stripe size from the config. */
 210         if (enable_blkdev) {
 211                 if (card->config_valid)
 212                         set_capacity(card->gendisk, card->size8 >> 9);
 213                 else
 214                         set_capacity(card->gendisk, 0);
 215                 device_add_disk(CARD_TO_DEV(card), card->gendisk, NULL);
 216                 card->bdev_attached = 1;
 217         }
 218
 219         mutex_unlock(&card->dev_lock);
 220
 221         return 0;
 222 }
 223
 224 void rsxx_detach_dev(struct rsxx_cardinfo *card)
 225 {
 226         mutex_lock(&card->dev_lock);
 227
 228         if (card->bdev_attached) {
 229                 del_gendisk(card->gendisk);
 230                 card->bdev_attached = 0;
 231         }
 232
 233         mutex_unlock(&card->dev_lock);
 234 }
 235
 236 int rsxx_setup_dev(struct rsxx_cardinfo *card)
 237 {
 238         unsigned short blk_size;
 239
 240         mutex_init(&card->dev_lock);
 241
 242         if (!enable_blkdev)
 243                 return 0;
 244
 245         card->major = register_blkdev(0, DRIVER_NAME);
 246         if (card->major < 0) {
 247                 dev_err(CARD_TO_DEV(card), "Failed to get major number\n");
 248                 return -ENOMEM;
 249         }
 250
 251         card->queue = blk_alloc_queue(GFP_KERNEL);
 252         if (!card->queue) {
 253                 dev_err(CARD_TO_DEV(card), "Failed queue alloc\n");
 254                 unregister_blkdev(card->major, DRIVER_NAME);
 255                 return -ENOMEM;
 256         }
 257
 258         card->gendisk = alloc_disk(blkdev_minors);
 259         if (!card->gendisk) {
 260                 dev_err(CARD_TO_DEV(card), "Failed disk alloc\n");
 261                 blk_cleanup_queue(card->queue);
 262                 unregister_blkdev(card->major, DRIVER_NAME);
 263                 return -ENOMEM;
 264         }
 265
 266         if (card->config_valid) {
 267                 blk_size = card->config.data.block_size;
 268                 blk_queue_dma_alignment(card->queue, blk_size - 1);
 269                 blk_queue_logical_block_size(card->queue, blk_size);
 270         }
 271
 272         blk_queue_make_request(card->queue, rsxx_make_request);
 273         blk_queue_max_hw_sectors(card->queue, blkdev_max_hw_sectors);
 274         blk_queue_physical_block_size(card->queue, RSXX_HW_BLK_SIZE);
 275
 276         blk_queue_flag_set(QUEUE_FLAG_NONROT, card->queue);
 277         blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, card->queue);
 278         if (rsxx_discard_supported(card)) {
 279                 blk_queue_flag_set(QUEUE_FLAG_DISCARD, card->queue);
 280                 blk_queue_max_discard_sectors(card->queue,
 281                                                 RSXX_HW_BLK_SIZE >> 9);
 282                 card->queue->limits.discard_granularity = RSXX_HW_BLK_SIZE;
 283                 card->queue->limits.discard_alignment   = RSXX_HW_BLK_SIZE;
 284         }
 285
 286         card->queue->queuedata = card;
 287
 288         snprintf(card->gendisk->disk_name, sizeof(card->gendisk->disk_name),
 289                  "rsxx%d", card->disk_id);
 290         card->gendisk->major = card->major;
 291         card->gendisk->first_minor = 0;
 292         card->gendisk->fops = &rsxx_fops;
 293         card->gendisk->private_data = card;
 294         card->gendisk->queue = card->queue;
 295
 296         return 0;
 297 }
 298
 299 void rsxx_destroy_dev(struct rsxx_cardinfo *card)
 300 {
 301         if (!enable_blkdev)
 302                 return;
 303
 304         put_disk(card->gendisk);
 305         card->gendisk = NULL;
 306
 307         blk_cleanup_queue(card->queue);
 308         card->queue->queuedata = NULL;
 309         unregister_blkdev(card->major, DRIVER_NAME);
 310 }
 311
 312 int rsxx_dev_init(void)
 313 {
 314         bio_meta_pool = KMEM_CACHE(rsxx_bio_meta, SLAB_HWCACHE_ALIGN);
 315         if (!bio_meta_pool)
 316                 return -ENOMEM;
 317
 318         return 0;
 319 }
 320
 321 void rsxx_dev_cleanup(void)
 322 {
 323         kmem_cache_destroy(bio_meta_pool);
 324 }
 325
 326