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 static void rsxx_submit_bio(struct bio *bio);
  54
  55 /*----------------- Block Device Operations -----------------*/
  56 static int rsxx_blkdev_ioctl(struct block_device *bdev,
  57                                  fmode_t mode,
  58                                  unsigned int cmd,
  59                                  unsigned long arg)
  60 {
  61         struct rsxx_cardinfo *card = bdev->bd_disk->private_data;
  62
  63         switch (cmd) {
  64         case RSXX_GETREG:
  65                 return rsxx_reg_access(card, (void __user *)arg, 1);
  66         case RSXX_SETREG:
  67                 return rsxx_reg_access(card, (void __user *)arg, 0);
  68         }
  69
  70         return -ENOTTY;
  71 }
  72
  73 static int rsxx_getgeo(struct block_device *bdev, struct hd_geometry *geo)
  74 {
  75         struct rsxx_cardinfo *card = bdev->bd_disk->private_data;
  76         u64 blocks = card->size8 >> 9;
  77
  78         /*
  79          * get geometry: Fake it. I haven't found any drivers that set
  80          * geo->start, so we won't either.
  81          */
  82         if (card->size8) {
  83                 geo->heads = 64;
  84                 geo->sectors = 16;
  85                 do_div(blocks, (geo->heads * geo->sectors));
  86                 geo->cylinders = blocks;
  87         } else {
  88                 geo->heads = 0;
  89                 geo->sectors = 0;
  90                 geo->cylinders = 0;
  91         }
  92         return 0;
  93 }
  94
  95 static const struct block_device_operations rsxx_fops = {
  96         .owner          = THIS_MODULE,
  97         .submit_bio     = rsxx_submit_bio,
  98         .getgeo         = rsxx_getgeo,
  99         .ioctl          = rsxx_blkdev_ioctl,
 100 };
 101
 102 static void bio_dma_done_cb(struct rsxx_cardinfo *card,
 103                             void *cb_data,
 104                             unsigned int error)
 105 {
 106         struct rsxx_bio_meta *meta = cb_data;
 107
 108         if (error)
 109                 atomic_set(&meta->error, 1);
 110
 111         if (atomic_dec_and_test(&meta->pending_dmas)) {
 112                 if (!card->eeh_state && card->gendisk)
 113                         bio_end_io_acct(meta->bio, meta->start_time);
 114
 115                 if (atomic_read(&meta->error))
 116                         bio_io_error(meta->bio);
 117                 else
 118                         bio_endio(meta->bio);
 119                 kmem_cache_free(bio_meta_pool, meta);
 120         }
 121 }
 122
 123 static void rsxx_submit_bio(struct bio *bio)
 124 {
 125         struct rsxx_cardinfo *card = bio->bi_bdev->bd_disk->private_data;
 126         struct rsxx_bio_meta *bio_meta;
 127         blk_status_t st = BLK_STS_IOERR;
 128
 129         blk_queue_split(&bio);
 130
 131         might_sleep();
 132
 133         if (!card)
 134                 goto req_err;
 135
 136         if (bio_end_sector(bio) > get_capacity(card->gendisk))
 137                 goto req_err;
 138
 139         if (unlikely(card->halt))
 140                 goto req_err;
 141
 142         if (unlikely(card->dma_fault))
 143                 goto req_err;
 144
 145         if (bio->bi_iter.bi_size == 0) {
 146                 dev_err(CARD_TO_DEV(card), "size zero BIO!\n");
 147                 goto req_err;
 148         }
 149
 150         bio_meta = kmem_cache_alloc(bio_meta_pool, GFP_KERNEL);
 151         if (!bio_meta) {
 152                 st = BLK_STS_RESOURCE;
 153                 goto req_err;
 154         }
 155
 156         bio_meta->bio = bio;
 157         atomic_set(&bio_meta->error, 0);
 158         atomic_set(&bio_meta->pending_dmas, 0);
 159
 160         if (!unlikely(card->halt))
 161                 bio_meta->start_time = bio_start_io_acct(bio);
 162
 163         dev_dbg(CARD_TO_DEV(card), "BIO[%c]: meta: %p addr8: x%llx size: %d\n",
 164                  bio_data_dir(bio) ? 'W' : 'R', bio_meta,
 165                  (u64)bio->bi_iter.bi_sector << 9, bio->bi_iter.bi_size);
 166
 167         st = rsxx_dma_queue_bio(card, bio, &bio_meta->pending_dmas,
 168                                     bio_dma_done_cb, bio_meta);
 169         if (st)
 170                 goto queue_err;
 171
 172         return;
 173
 174 queue_err:
 175         kmem_cache_free(bio_meta_pool, bio_meta);
 176 req_err:
 177         if (st)
 178                 bio->bi_status = st;
 179         bio_endio(bio);
 180 }
 181
 182 /*----------------- Device Setup -------------------*/
 183 static bool rsxx_discard_supported(struct rsxx_cardinfo *card)
 184 {
 185         unsigned char pci_rev;
 186
 187         pci_read_config_byte(card->dev, PCI_REVISION_ID, &pci_rev);
 188
 189         return (pci_rev >= RSXX_DISCARD_SUPPORT);
 190 }
 191
 192 int rsxx_attach_dev(struct rsxx_cardinfo *card)
 193 {
 194         int err = 0;
 195
 196         mutex_lock(&card->dev_lock);
 197
 198         /* The block device requires the stripe size from the config. */
 199         if (enable_blkdev) {
 200                 if (card->config_valid)
 201                         set_capacity(card->gendisk, card->size8 >> 9);
 202                 else
 203                         set_capacity(card->gendisk, 0);
 204                 err = device_add_disk(CARD_TO_DEV(card), card->gendisk, NULL);
 205                 if (err == 0)
 206                         card->bdev_attached = 1;
 207         }
 208
 209         mutex_unlock(&card->dev_lock);
 210
 211         if (err)
 212                 blk_cleanup_disk(card->gendisk);
 213
 214         return err;
 215 }
 216
 217 void rsxx_detach_dev(struct rsxx_cardinfo *card)
 218 {
 219         mutex_lock(&card->dev_lock);
 220
 221         if (card->bdev_attached) {
 222                 del_gendisk(card->gendisk);
 223                 card->bdev_attached = 0;
 224         }
 225
 226         mutex_unlock(&card->dev_lock);
 227 }
 228
 229 int rsxx_setup_dev(struct rsxx_cardinfo *card)
 230 {
 231         unsigned short blk_size;
 232
 233         mutex_init(&card->dev_lock);
 234
 235         if (!enable_blkdev)
 236                 return 0;
 237
 238         card->major = register_blkdev(0, DRIVER_NAME);
 239         if (card->major < 0) {
 240                 dev_err(CARD_TO_DEV(card), "Failed to get major number\n");
 241                 return -ENOMEM;
 242         }
 243
 244         card->gendisk = blk_alloc_disk(blkdev_minors);
 245         if (!card->gendisk) {
 246                 dev_err(CARD_TO_DEV(card), "Failed disk alloc\n");
 247                 unregister_blkdev(card->major, DRIVER_NAME);
 248                 return -ENOMEM;
 249         }
 250
 251         if (card->config_valid) {
 252                 blk_size = card->config.data.block_size;
 253                 blk_queue_dma_alignment(card->gendisk->queue, blk_size - 1);
 254                 blk_queue_logical_block_size(card->gendisk->queue, blk_size);
 255         }
 256
 257         blk_queue_max_hw_sectors(card->gendisk->queue, blkdev_max_hw_sectors);
 258         blk_queue_physical_block_size(card->gendisk->queue, RSXX_HW_BLK_SIZE);
 259
 260         blk_queue_flag_set(QUEUE_FLAG_NONROT, card->gendisk->queue);
 261         blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, card->gendisk->queue);
 262         if (rsxx_discard_supported(card)) {
 263                 blk_queue_flag_set(QUEUE_FLAG_DISCARD, card->gendisk->queue);
 264                 blk_queue_max_discard_sectors(card->gendisk->queue,
 265                                                 RSXX_HW_BLK_SIZE >> 9);
 266                 card->gendisk->queue->limits.discard_granularity =
 267                         RSXX_HW_BLK_SIZE;
 268                 card->gendisk->queue->limits.discard_alignment =
 269                         RSXX_HW_BLK_SIZE;
 270         }
 271
 272         snprintf(card->gendisk->disk_name, sizeof(card->gendisk->disk_name),
 273                  "rsxx%d", card->disk_id);
 274         card->gendisk->major = card->major;
 275         card->gendisk->minors = blkdev_minors;
 276         card->gendisk->fops = &rsxx_fops;
 277         card->gendisk->private_data = card;
 278
 279         return 0;
 280 }
 281
 282 void rsxx_destroy_dev(struct rsxx_cardinfo *card)
 283 {
 284         if (!enable_blkdev)
 285                 return;
 286
 287         blk_cleanup_disk(card->gendisk);
 288         card->gendisk = NULL;
 289         unregister_blkdev(card->major, DRIVER_NAME);
 290 }
 291
 292 int rsxx_dev_init(void)
 293 {
 294         bio_meta_pool = KMEM_CACHE(rsxx_bio_meta, SLAB_HWCACHE_ALIGN);
 295         if (!bio_meta_pool)
 296                 return -ENOMEM;
 297
 298         return 0;
 299 }
 300
 301 void rsxx_dev_cleanup(void)
 302 {
 303         kmem_cache_destroy(bio_meta_pool);
 304 }
 305
 306