![Mike Snitzer](/assets/img/avatar_default.png)
Clear QUEUE_FLAG_ADD_RANDOM in all block drivers that set
QUEUE_FLAG_NONROT.
Historically, all block devices have automatically made entropy
contributions. But as previously stated in commit e2e1a148
("block: add
sysfs knob for turning off disk entropy contributions"):
- On SSD disks, the completion times aren't as random as they
are for rotational drives. So it's questionable whether they
should contribute to the random pool in the first place.
- Calling add_disk_randomness() has a lot of overhead.
There are more reliable sources for randomness than non-rotational block
devices. From a security perspective it is better to err on the side of
caution than to allow entropy contributions from unreliable "random"
sources.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
362 lines
8.6 KiB
C
362 lines
8.6 KiB
C
/*
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* Filename: dev.c
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*
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*
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* Authors: Joshua Morris <josh.h.morris@us.ibm.com>
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* Philip Kelleher <pjk1939@linux.vnet.ibm.com>
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*
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* (C) Copyright 2013 IBM Corporation
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/kernel.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <linux/slab.h>
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#include <linux/hdreg.h>
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#include <linux/genhd.h>
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#include <linux/blkdev.h>
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#include <linux/bio.h>
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#include <linux/fs.h>
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#include "rsxx_priv.h"
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static unsigned int blkdev_minors = 64;
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module_param(blkdev_minors, uint, 0444);
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MODULE_PARM_DESC(blkdev_minors, "Number of minors(partitions)");
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/*
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* For now I'm making this tweakable in case any applications hit this limit.
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* If you see a "bio too big" error in the log you will need to raise this
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* value.
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*/
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static unsigned int blkdev_max_hw_sectors = 1024;
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module_param(blkdev_max_hw_sectors, uint, 0444);
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MODULE_PARM_DESC(blkdev_max_hw_sectors, "Max hw sectors for a single BIO");
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static unsigned int enable_blkdev = 1;
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module_param(enable_blkdev , uint, 0444);
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MODULE_PARM_DESC(enable_blkdev, "Enable block device interfaces");
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struct rsxx_bio_meta {
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struct bio *bio;
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atomic_t pending_dmas;
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atomic_t error;
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unsigned long start_time;
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};
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static struct kmem_cache *bio_meta_pool;
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/*----------------- Block Device Operations -----------------*/
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static int rsxx_blkdev_ioctl(struct block_device *bdev,
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fmode_t mode,
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unsigned int cmd,
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unsigned long arg)
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{
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struct rsxx_cardinfo *card = bdev->bd_disk->private_data;
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switch (cmd) {
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case RSXX_GETREG:
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return rsxx_reg_access(card, (void __user *)arg, 1);
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case RSXX_SETREG:
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return rsxx_reg_access(card, (void __user *)arg, 0);
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}
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return -ENOTTY;
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}
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static int rsxx_getgeo(struct block_device *bdev, struct hd_geometry *geo)
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{
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struct rsxx_cardinfo *card = bdev->bd_disk->private_data;
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u64 blocks = card->size8 >> 9;
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/*
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* get geometry: Fake it. I haven't found any drivers that set
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* geo->start, so we won't either.
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*/
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if (card->size8) {
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geo->heads = 64;
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geo->sectors = 16;
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do_div(blocks, (geo->heads * geo->sectors));
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geo->cylinders = blocks;
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} else {
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geo->heads = 0;
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geo->sectors = 0;
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geo->cylinders = 0;
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}
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return 0;
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}
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static const struct block_device_operations rsxx_fops = {
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.owner = THIS_MODULE,
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.getgeo = rsxx_getgeo,
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.ioctl = rsxx_blkdev_ioctl,
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};
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static void disk_stats_start(struct rsxx_cardinfo *card, struct bio *bio)
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{
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struct hd_struct *part0 = &card->gendisk->part0;
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int rw = bio_data_dir(bio);
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int cpu;
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cpu = part_stat_lock();
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part_round_stats(cpu, part0);
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part_inc_in_flight(part0, rw);
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part_stat_unlock();
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}
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static void disk_stats_complete(struct rsxx_cardinfo *card,
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struct bio *bio,
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unsigned long start_time)
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{
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struct hd_struct *part0 = &card->gendisk->part0;
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unsigned long duration = jiffies - start_time;
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int rw = bio_data_dir(bio);
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int cpu;
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cpu = part_stat_lock();
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part_stat_add(cpu, part0, sectors[rw], bio_sectors(bio));
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part_stat_inc(cpu, part0, ios[rw]);
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part_stat_add(cpu, part0, ticks[rw], duration);
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part_round_stats(cpu, part0);
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part_dec_in_flight(part0, rw);
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part_stat_unlock();
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}
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static void bio_dma_done_cb(struct rsxx_cardinfo *card,
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void *cb_data,
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unsigned int error)
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{
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struct rsxx_bio_meta *meta = cb_data;
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if (error)
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atomic_set(&meta->error, 1);
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if (atomic_dec_and_test(&meta->pending_dmas)) {
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if (!card->eeh_state && card->gendisk)
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disk_stats_complete(card, meta->bio, meta->start_time);
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bio_endio(meta->bio, atomic_read(&meta->error) ? -EIO : 0);
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kmem_cache_free(bio_meta_pool, meta);
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}
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}
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static void rsxx_make_request(struct request_queue *q, struct bio *bio)
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{
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struct rsxx_cardinfo *card = q->queuedata;
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struct rsxx_bio_meta *bio_meta;
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int st = -EINVAL;
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might_sleep();
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if (!card)
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goto req_err;
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if (bio_end_sector(bio) > get_capacity(card->gendisk))
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goto req_err;
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if (unlikely(card->halt)) {
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st = -EFAULT;
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goto req_err;
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}
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if (unlikely(card->dma_fault)) {
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st = (-EFAULT);
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goto req_err;
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}
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if (bio->bi_iter.bi_size == 0) {
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dev_err(CARD_TO_DEV(card), "size zero BIO!\n");
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goto req_err;
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}
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bio_meta = kmem_cache_alloc(bio_meta_pool, GFP_KERNEL);
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if (!bio_meta) {
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st = -ENOMEM;
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goto req_err;
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}
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bio_meta->bio = bio;
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atomic_set(&bio_meta->error, 0);
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atomic_set(&bio_meta->pending_dmas, 0);
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bio_meta->start_time = jiffies;
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if (!unlikely(card->halt))
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disk_stats_start(card, bio);
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dev_dbg(CARD_TO_DEV(card), "BIO[%c]: meta: %p addr8: x%llx size: %d\n",
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bio_data_dir(bio) ? 'W' : 'R', bio_meta,
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(u64)bio->bi_iter.bi_sector << 9, bio->bi_iter.bi_size);
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st = rsxx_dma_queue_bio(card, bio, &bio_meta->pending_dmas,
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bio_dma_done_cb, bio_meta);
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if (st)
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goto queue_err;
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return;
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queue_err:
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kmem_cache_free(bio_meta_pool, bio_meta);
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req_err:
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bio_endio(bio, st);
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}
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/*----------------- Device Setup -------------------*/
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static bool rsxx_discard_supported(struct rsxx_cardinfo *card)
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{
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unsigned char pci_rev;
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pci_read_config_byte(card->dev, PCI_REVISION_ID, &pci_rev);
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return (pci_rev >= RSXX_DISCARD_SUPPORT);
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}
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int rsxx_attach_dev(struct rsxx_cardinfo *card)
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{
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mutex_lock(&card->dev_lock);
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/* The block device requires the stripe size from the config. */
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if (enable_blkdev) {
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if (card->config_valid)
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set_capacity(card->gendisk, card->size8 >> 9);
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else
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set_capacity(card->gendisk, 0);
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add_disk(card->gendisk);
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card->bdev_attached = 1;
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}
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mutex_unlock(&card->dev_lock);
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return 0;
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}
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void rsxx_detach_dev(struct rsxx_cardinfo *card)
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{
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mutex_lock(&card->dev_lock);
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if (card->bdev_attached) {
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del_gendisk(card->gendisk);
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card->bdev_attached = 0;
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}
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mutex_unlock(&card->dev_lock);
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}
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int rsxx_setup_dev(struct rsxx_cardinfo *card)
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{
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unsigned short blk_size;
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mutex_init(&card->dev_lock);
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if (!enable_blkdev)
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return 0;
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card->major = register_blkdev(0, DRIVER_NAME);
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if (card->major < 0) {
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dev_err(CARD_TO_DEV(card), "Failed to get major number\n");
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return -ENOMEM;
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}
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card->queue = blk_alloc_queue(GFP_KERNEL);
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if (!card->queue) {
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dev_err(CARD_TO_DEV(card), "Failed queue alloc\n");
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unregister_blkdev(card->major, DRIVER_NAME);
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return -ENOMEM;
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}
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card->gendisk = alloc_disk(blkdev_minors);
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if (!card->gendisk) {
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dev_err(CARD_TO_DEV(card), "Failed disk alloc\n");
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blk_cleanup_queue(card->queue);
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unregister_blkdev(card->major, DRIVER_NAME);
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return -ENOMEM;
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}
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if (card->config_valid) {
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blk_size = card->config.data.block_size;
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blk_queue_dma_alignment(card->queue, blk_size - 1);
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blk_queue_logical_block_size(card->queue, blk_size);
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}
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blk_queue_make_request(card->queue, rsxx_make_request);
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blk_queue_bounce_limit(card->queue, BLK_BOUNCE_ANY);
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blk_queue_max_hw_sectors(card->queue, blkdev_max_hw_sectors);
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blk_queue_physical_block_size(card->queue, RSXX_HW_BLK_SIZE);
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queue_flag_set_unlocked(QUEUE_FLAG_NONROT, card->queue);
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queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, card->queue);
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if (rsxx_discard_supported(card)) {
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queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, card->queue);
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blk_queue_max_discard_sectors(card->queue,
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RSXX_HW_BLK_SIZE >> 9);
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card->queue->limits.discard_granularity = RSXX_HW_BLK_SIZE;
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card->queue->limits.discard_alignment = RSXX_HW_BLK_SIZE;
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card->queue->limits.discard_zeroes_data = 1;
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}
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card->queue->queuedata = card;
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snprintf(card->gendisk->disk_name, sizeof(card->gendisk->disk_name),
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"rsxx%d", card->disk_id);
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card->gendisk->driverfs_dev = &card->dev->dev;
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card->gendisk->major = card->major;
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card->gendisk->first_minor = 0;
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card->gendisk->fops = &rsxx_fops;
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card->gendisk->private_data = card;
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card->gendisk->queue = card->queue;
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return 0;
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}
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void rsxx_destroy_dev(struct rsxx_cardinfo *card)
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{
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if (!enable_blkdev)
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return;
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put_disk(card->gendisk);
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card->gendisk = NULL;
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blk_cleanup_queue(card->queue);
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card->queue->queuedata = NULL;
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unregister_blkdev(card->major, DRIVER_NAME);
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}
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int rsxx_dev_init(void)
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{
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bio_meta_pool = KMEM_CACHE(rsxx_bio_meta, SLAB_HWCACHE_ALIGN);
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if (!bio_meta_pool)
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return -ENOMEM;
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return 0;
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}
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void rsxx_dev_cleanup(void)
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{
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kmem_cache_destroy(bio_meta_pool);
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}
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