diff options
Diffstat (limited to 'drivers/block/rsxx/dev.c')
| -rw-r--r-- | drivers/block/rsxx/dev.c | 367 |
1 files changed, 367 insertions, 0 deletions
diff --git a/drivers/block/rsxx/dev.c b/drivers/block/rsxx/dev.c new file mode 100644 index 000000000000..96df053e0ed4 --- /dev/null +++ b/drivers/block/rsxx/dev.c @@ -0,0 +1,367 @@ +/* +* Filename: dev.c +* +* +* Authors: Joshua Morris <josh.h.morris@us.ibm.com> +* Philip Kelleher <pjk1939@linux.vnet.ibm.com> +* +* (C) Copyright 2013 IBM Corporation +* +* This program is free software; you can redistribute it and/or +* modify it under the terms of the GNU General Public License as +* published by the Free Software Foundation; either version 2 of the +* License, or (at your option) any later version. +* +* This program is distributed in the hope that it will be useful, but +* WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +* General Public License for more details. +* +* You should have received a copy of the GNU General Public License +* along with this program; if not, write to the Free Software Foundation, +* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/slab.h> + +#include <linux/hdreg.h> +#include <linux/genhd.h> +#include <linux/blkdev.h> +#include <linux/bio.h> + +#include <linux/fs.h> + +#include "rsxx_priv.h" + +static unsigned int blkdev_minors = 64; +module_param(blkdev_minors, uint, 0444); +MODULE_PARM_DESC(blkdev_minors, "Number of minors(partitions)"); + +/* + * For now I'm making this tweakable in case any applications hit this limit. + * If you see a "bio too big" error in the log you will need to raise this + * value. + */ +static unsigned int blkdev_max_hw_sectors = 1024; +module_param(blkdev_max_hw_sectors, uint, 0444); +MODULE_PARM_DESC(blkdev_max_hw_sectors, "Max hw sectors for a single BIO"); + +static unsigned int enable_blkdev = 1; +module_param(enable_blkdev , uint, 0444); +MODULE_PARM_DESC(enable_blkdev, "Enable block device interfaces"); + + +struct rsxx_bio_meta { + struct bio *bio; + atomic_t pending_dmas; + atomic_t error; + unsigned long start_time; +}; + +static struct kmem_cache *bio_meta_pool; + +/*----------------- Block Device Operations -----------------*/ +static int rsxx_blkdev_ioctl(struct block_device *bdev, + fmode_t mode, + unsigned int cmd, + unsigned long arg) +{ + struct rsxx_cardinfo *card = bdev->bd_disk->private_data; + + switch (cmd) { + case RSXX_GETREG: + return rsxx_reg_access(card, (void __user *)arg, 1); + case RSXX_SETREG: + return rsxx_reg_access(card, (void __user *)arg, 0); + } + + return -ENOTTY; +} + +static int rsxx_getgeo(struct block_device *bdev, struct hd_geometry *geo) +{ + struct rsxx_cardinfo *card = bdev->bd_disk->private_data; + u64 blocks = card->size8 >> 9; + + /* + * get geometry: Fake it. I haven't found any drivers that set + * geo->start, so we won't either. + */ + if (card->size8) { + geo->heads = 64; + geo->sectors = 16; + do_div(blocks, (geo->heads * geo->sectors)); + geo->cylinders = blocks; + } else { + geo->heads = 0; + geo->sectors = 0; + geo->cylinders = 0; + } + return 0; +} + +static const struct block_device_operations rsxx_fops = { + .owner = THIS_MODULE, + .getgeo = rsxx_getgeo, + .ioctl = rsxx_blkdev_ioctl, +}; + +static void disk_stats_start(struct rsxx_cardinfo *card, struct bio *bio) +{ + struct hd_struct *part0 = &card->gendisk->part0; + int rw = bio_data_dir(bio); + int cpu; + + cpu = part_stat_lock(); + + part_round_stats(cpu, part0); + part_inc_in_flight(part0, rw); + + part_stat_unlock(); +} + +static void disk_stats_complete(struct rsxx_cardinfo *card, + struct bio *bio, + unsigned long start_time) +{ + struct hd_struct *part0 = &card->gendisk->part0; + unsigned long duration = jiffies - start_time; + int rw = bio_data_dir(bio); + int cpu; + + cpu = part_stat_lock(); + + part_stat_add(cpu, part0, sectors[rw], bio_sectors(bio)); + part_stat_inc(cpu, part0, ios[rw]); + part_stat_add(cpu, part0, ticks[rw], duration); + + part_round_stats(cpu, part0); + part_dec_in_flight(part0, rw); + + part_stat_unlock(); +} + +static void bio_dma_done_cb(struct rsxx_cardinfo *card, + void *cb_data, + unsigned int error) +{ + struct rsxx_bio_meta *meta = (struct rsxx_bio_meta *)cb_data; + + if (error) + atomic_set(&meta->error, 1); + + if (atomic_dec_and_test(&meta->pending_dmas)) { + disk_stats_complete(card, meta->bio, meta->start_time); + + bio_endio(meta->bio, atomic_read(&meta->error) ? -EIO : 0); + kmem_cache_free(bio_meta_pool, meta); + } +} + +static void rsxx_make_request(struct request_queue *q, struct bio *bio) +{ + struct rsxx_cardinfo *card = q->queuedata; + struct rsxx_bio_meta *bio_meta; + int st = -EINVAL; + + might_sleep(); + + if (unlikely(card->halt)) { + st = -EFAULT; + goto req_err; + } + + if (unlikely(card->dma_fault)) { + st = (-EFAULT); + goto req_err; + } + + if (bio->bi_size == 0) { + dev_err(CARD_TO_DEV(card), "size zero BIO!\n"); + goto req_err; + } + + bio_meta = kmem_cache_alloc(bio_meta_pool, GFP_KERNEL); + if (!bio_meta) { + st = -ENOMEM; + goto req_err; + } + + bio_meta->bio = bio; + atomic_set(&bio_meta->error, 0); + atomic_set(&bio_meta->pending_dmas, 0); + bio_meta->start_time = jiffies; + + disk_stats_start(card, bio); + + dev_dbg(CARD_TO_DEV(card), "BIO[%c]: meta: %p addr8: x%llx size: %d\n", + bio_data_dir(bio) ? 'W' : 'R', bio_meta, + (u64)bio->bi_sector << 9, bio->bi_size); + + st = rsxx_dma_queue_bio(card, bio, &bio_meta->pending_dmas, + bio_dma_done_cb, bio_meta); + if (st) + goto queue_err; + + return; + +queue_err: + kmem_cache_free(bio_meta_pool, bio_meta); +req_err: + bio_endio(bio, st); +} + +/*----------------- Device Setup -------------------*/ +static bool rsxx_discard_supported(struct rsxx_cardinfo *card) +{ + unsigned char pci_rev; + + pci_read_config_byte(card->dev, PCI_REVISION_ID, &pci_rev); + + return (pci_rev >= RSXX_DISCARD_SUPPORT); +} + +static unsigned short rsxx_get_logical_block_size( + struct rsxx_cardinfo *card) +{ + u32 capabilities = 0; + int st; + + st = rsxx_get_card_capabilities(card, &capabilities); + if (st) + dev_warn(CARD_TO_DEV(card), + "Failed reading card capabilities register\n"); + + /* Earlier firmware did not have support for 512 byte accesses */ + if (capabilities & CARD_CAP_SUBPAGE_WRITES) + return 512; + else + return RSXX_HW_BLK_SIZE; +} + +int rsxx_attach_dev(struct rsxx_cardinfo *card) +{ + mutex_lock(&card->dev_lock); + + /* The block device requires the stripe size from the config. */ + if (enable_blkdev) { + if (card->config_valid) + set_capacity(card->gendisk, card->size8 >> 9); + else + set_capacity(card->gendisk, 0); + add_disk(card->gendisk); + + card->bdev_attached = 1; + } + + mutex_unlock(&card->dev_lock); + + return 0; +} + +void rsxx_detach_dev(struct rsxx_cardinfo *card) +{ + mutex_lock(&card->dev_lock); + + if (card->bdev_attached) { + del_gendisk(card->gendisk); + card->bdev_attached = 0; + } + + mutex_unlock(&card->dev_lock); +} + +int rsxx_setup_dev(struct rsxx_cardinfo *card) +{ + unsigned short blk_size; + + mutex_init(&card->dev_lock); + + if (!enable_blkdev) + return 0; + + card->major = register_blkdev(0, DRIVER_NAME); + if (card->major < 0) { + dev_err(CARD_TO_DEV(card), "Failed to get major number\n"); + return -ENOMEM; + } + + card->queue = blk_alloc_queue(GFP_KERNEL); + if (!card->queue) { + dev_err(CARD_TO_DEV(card), "Failed queue alloc\n"); + unregister_blkdev(card->major, DRIVER_NAME); + return -ENOMEM; + } + + card->gendisk = alloc_disk(blkdev_minors); + if (!card->gendisk) { + dev_err(CARD_TO_DEV(card), "Failed disk alloc\n"); + blk_cleanup_queue(card->queue); + unregister_blkdev(card->major, DRIVER_NAME); + return -ENOMEM; + } + + blk_size = rsxx_get_logical_block_size(card); + + blk_queue_make_request(card->queue, rsxx_make_request); + blk_queue_bounce_limit(card->queue, BLK_BOUNCE_ANY); + blk_queue_dma_alignment(card->queue, blk_size - 1); + blk_queue_max_hw_sectors(card->queue, blkdev_max_hw_sectors); + blk_queue_logical_block_size(card->queue, blk_size); + blk_queue_physical_block_size(card->queue, RSXX_HW_BLK_SIZE); + + queue_flag_set_unlocked(QUEUE_FLAG_NONROT, card->queue); + if (rsxx_discard_supported(card)) { + queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, card->queue); + blk_queue_max_discard_sectors(card->queue, + RSXX_HW_BLK_SIZE >> 9); + card->queue->limits.discard_granularity = RSXX_HW_BLK_SIZE; + card->queue->limits.discard_alignment = RSXX_HW_BLK_SIZE; + card->queue->limits.discard_zeroes_data = 1; + } + + card->queue->queuedata = card; + + snprintf(card->gendisk->disk_name, sizeof(card->gendisk->disk_name), + "rsxx%d", card->disk_id); + card->gendisk->driverfs_dev = &card->dev->dev; + card->gendisk->major = card->major; + card->gendisk->first_minor = 0; + card->gendisk->fops = &rsxx_fops; + card->gendisk->private_data = card; + card->gendisk->queue = card->queue; + + return 0; +} + +void rsxx_destroy_dev(struct rsxx_cardinfo *card) +{ + if (!enable_blkdev) + return; + + put_disk(card->gendisk); + card->gendisk = NULL; + + blk_cleanup_queue(card->queue); + unregister_blkdev(card->major, DRIVER_NAME); +} + +int rsxx_dev_init(void) +{ + bio_meta_pool = KMEM_CACHE(rsxx_bio_meta, SLAB_HWCACHE_ALIGN); + if (!bio_meta_pool) + return -ENOMEM; + + return 0; +} + +void rsxx_dev_cleanup(void) +{ + kmem_cache_destroy(bio_meta_pool); +} + + |