| #include <linux/module.h> |
| |
| #include <linux/moduleparam.h> |
| #include <linux/sched.h> |
| #include <linux/fs.h> |
| #include <linux/blkdev.h> |
| #include <linux/init.h> |
| #include <linux/slab.h> |
| #include <linux/blk-mq.h> |
| #include <linux/hrtimer.h> |
| #include <linux/lightnvm.h> |
| |
| struct nullb_cmd { |
| struct list_head list; |
| struct llist_node ll_list; |
| struct call_single_data csd; |
| struct request *rq; |
| struct bio *bio; |
| unsigned int tag; |
| struct nullb_queue *nq; |
| struct hrtimer timer; |
| }; |
| |
| struct nullb_queue { |
| unsigned long *tag_map; |
| wait_queue_head_t wait; |
| unsigned int queue_depth; |
| |
| struct nullb_cmd *cmds; |
| }; |
| |
| struct nullb { |
| struct list_head list; |
| unsigned int index; |
| struct request_queue *q; |
| struct gendisk *disk; |
| struct nvm_dev *ndev; |
| struct blk_mq_tag_set tag_set; |
| struct hrtimer timer; |
| unsigned int queue_depth; |
| spinlock_t lock; |
| |
| struct nullb_queue *queues; |
| unsigned int nr_queues; |
| char disk_name[DISK_NAME_LEN]; |
| }; |
| |
| static LIST_HEAD(nullb_list); |
| static struct mutex lock; |
| static int null_major; |
| static int nullb_indexes; |
| static struct kmem_cache *ppa_cache; |
| |
| enum { |
| NULL_IRQ_NONE = 0, |
| NULL_IRQ_SOFTIRQ = 1, |
| NULL_IRQ_TIMER = 2, |
| }; |
| |
| enum { |
| NULL_Q_BIO = 0, |
| NULL_Q_RQ = 1, |
| NULL_Q_MQ = 2, |
| }; |
| |
| static int submit_queues; |
| module_param(submit_queues, int, S_IRUGO); |
| MODULE_PARM_DESC(submit_queues, "Number of submission queues"); |
| |
| static int home_node = NUMA_NO_NODE; |
| module_param(home_node, int, S_IRUGO); |
| MODULE_PARM_DESC(home_node, "Home node for the device"); |
| |
| static int queue_mode = NULL_Q_MQ; |
| |
| static int null_param_store_val(const char *str, int *val, int min, int max) |
| { |
| int ret, new_val; |
| |
| ret = kstrtoint(str, 10, &new_val); |
| if (ret) |
| return -EINVAL; |
| |
| if (new_val < min || new_val > max) |
| return -EINVAL; |
| |
| *val = new_val; |
| return 0; |
| } |
| |
| static int null_set_queue_mode(const char *str, const struct kernel_param *kp) |
| { |
| return null_param_store_val(str, &queue_mode, NULL_Q_BIO, NULL_Q_MQ); |
| } |
| |
| static const struct kernel_param_ops null_queue_mode_param_ops = { |
| .set = null_set_queue_mode, |
| .get = param_get_int, |
| }; |
| |
| device_param_cb(queue_mode, &null_queue_mode_param_ops, &queue_mode, S_IRUGO); |
| MODULE_PARM_DESC(queue_mode, "Block interface to use (0=bio,1=rq,2=multiqueue)"); |
| |
| static int gb = 250; |
| module_param(gb, int, S_IRUGO); |
| MODULE_PARM_DESC(gb, "Size in GB"); |
| |
| static int bs = 512; |
| module_param(bs, int, S_IRUGO); |
| MODULE_PARM_DESC(bs, "Block size (in bytes)"); |
| |
| static int nr_devices = 2; |
| module_param(nr_devices, int, S_IRUGO); |
| MODULE_PARM_DESC(nr_devices, "Number of devices to register"); |
| |
| static bool use_lightnvm; |
| module_param(use_lightnvm, bool, S_IRUGO); |
| MODULE_PARM_DESC(use_lightnvm, "Register as a LightNVM device"); |
| |
| static int irqmode = NULL_IRQ_SOFTIRQ; |
| |
| static int null_set_irqmode(const char *str, const struct kernel_param *kp) |
| { |
| return null_param_store_val(str, &irqmode, NULL_IRQ_NONE, |
| NULL_IRQ_TIMER); |
| } |
| |
| static const struct kernel_param_ops null_irqmode_param_ops = { |
| .set = null_set_irqmode, |
| .get = param_get_int, |
| }; |
| |
| device_param_cb(irqmode, &null_irqmode_param_ops, &irqmode, S_IRUGO); |
| MODULE_PARM_DESC(irqmode, "IRQ completion handler. 0-none, 1-softirq, 2-timer"); |
| |
| static unsigned long completion_nsec = 10000; |
| module_param(completion_nsec, ulong, S_IRUGO); |
| MODULE_PARM_DESC(completion_nsec, "Time in ns to complete a request in hardware. Default: 10,000ns"); |
| |
| static int hw_queue_depth = 64; |
| module_param(hw_queue_depth, int, S_IRUGO); |
| MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64"); |
| |
| static bool use_per_node_hctx = false; |
| module_param(use_per_node_hctx, bool, S_IRUGO); |
| MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false"); |
| |
| static void put_tag(struct nullb_queue *nq, unsigned int tag) |
| { |
| clear_bit_unlock(tag, nq->tag_map); |
| |
| if (waitqueue_active(&nq->wait)) |
| wake_up(&nq->wait); |
| } |
| |
| static unsigned int get_tag(struct nullb_queue *nq) |
| { |
| unsigned int tag; |
| |
| do { |
| tag = find_first_zero_bit(nq->tag_map, nq->queue_depth); |
| if (tag >= nq->queue_depth) |
| return -1U; |
| } while (test_and_set_bit_lock(tag, nq->tag_map)); |
| |
| return tag; |
| } |
| |
| static void free_cmd(struct nullb_cmd *cmd) |
| { |
| put_tag(cmd->nq, cmd->tag); |
| } |
| |
| static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer); |
| |
| static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq) |
| { |
| struct nullb_cmd *cmd; |
| unsigned int tag; |
| |
| tag = get_tag(nq); |
| if (tag != -1U) { |
| cmd = &nq->cmds[tag]; |
| cmd->tag = tag; |
| cmd->nq = nq; |
| if (irqmode == NULL_IRQ_TIMER) { |
| hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, |
| HRTIMER_MODE_REL); |
| cmd->timer.function = null_cmd_timer_expired; |
| } |
| return cmd; |
| } |
| |
| return NULL; |
| } |
| |
| static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, int can_wait) |
| { |
| struct nullb_cmd *cmd; |
| DEFINE_WAIT(wait); |
| |
| cmd = __alloc_cmd(nq); |
| if (cmd || !can_wait) |
| return cmd; |
| |
| do { |
| prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE); |
| cmd = __alloc_cmd(nq); |
| if (cmd) |
| break; |
| |
| io_schedule(); |
| } while (1); |
| |
| finish_wait(&nq->wait, &wait); |
| return cmd; |
| } |
| |
| static void end_cmd(struct nullb_cmd *cmd) |
| { |
| struct request_queue *q = NULL; |
| |
| if (cmd->rq) |
| q = cmd->rq->q; |
| |
| switch (queue_mode) { |
| case NULL_Q_MQ: |
| blk_mq_end_request(cmd->rq, 0); |
| return; |
| case NULL_Q_RQ: |
| INIT_LIST_HEAD(&cmd->rq->queuelist); |
| blk_end_request_all(cmd->rq, 0); |
| break; |
| case NULL_Q_BIO: |
| bio_endio(cmd->bio); |
| break; |
| } |
| |
| free_cmd(cmd); |
| |
| /* Restart queue if needed, as we are freeing a tag */ |
| if (queue_mode == NULL_Q_RQ && blk_queue_stopped(q)) { |
| unsigned long flags; |
| |
| spin_lock_irqsave(q->queue_lock, flags); |
| blk_start_queue_async(q); |
| spin_unlock_irqrestore(q->queue_lock, flags); |
| } |
| } |
| |
| static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer) |
| { |
| end_cmd(container_of(timer, struct nullb_cmd, timer)); |
| |
| return HRTIMER_NORESTART; |
| } |
| |
| static void null_cmd_end_timer(struct nullb_cmd *cmd) |
| { |
| ktime_t kt = ktime_set(0, completion_nsec); |
| |
| hrtimer_start(&cmd->timer, kt, HRTIMER_MODE_REL); |
| } |
| |
| static void null_softirq_done_fn(struct request *rq) |
| { |
| if (queue_mode == NULL_Q_MQ) |
| end_cmd(blk_mq_rq_to_pdu(rq)); |
| else |
| end_cmd(rq->special); |
| } |
| |
| static inline void null_handle_cmd(struct nullb_cmd *cmd) |
| { |
| /* Complete IO by inline, softirq or timer */ |
| switch (irqmode) { |
| case NULL_IRQ_SOFTIRQ: |
| switch (queue_mode) { |
| case NULL_Q_MQ: |
| blk_mq_complete_request(cmd->rq, cmd->rq->errors); |
| break; |
| case NULL_Q_RQ: |
| blk_complete_request(cmd->rq); |
| break; |
| case NULL_Q_BIO: |
| /* |
| * XXX: no proper submitting cpu information available. |
| */ |
| end_cmd(cmd); |
| break; |
| } |
| break; |
| case NULL_IRQ_NONE: |
| end_cmd(cmd); |
| break; |
| case NULL_IRQ_TIMER: |
| null_cmd_end_timer(cmd); |
| break; |
| } |
| } |
| |
| static struct nullb_queue *nullb_to_queue(struct nullb *nullb) |
| { |
| int index = 0; |
| |
| if (nullb->nr_queues != 1) |
| index = raw_smp_processor_id() / ((nr_cpu_ids + nullb->nr_queues - 1) / nullb->nr_queues); |
| |
| return &nullb->queues[index]; |
| } |
| |
| static blk_qc_t null_queue_bio(struct request_queue *q, struct bio *bio) |
| { |
| struct nullb *nullb = q->queuedata; |
| struct nullb_queue *nq = nullb_to_queue(nullb); |
| struct nullb_cmd *cmd; |
| |
| cmd = alloc_cmd(nq, 1); |
| cmd->bio = bio; |
| |
| null_handle_cmd(cmd); |
| return BLK_QC_T_NONE; |
| } |
| |
| static int null_rq_prep_fn(struct request_queue *q, struct request *req) |
| { |
| struct nullb *nullb = q->queuedata; |
| struct nullb_queue *nq = nullb_to_queue(nullb); |
| struct nullb_cmd *cmd; |
| |
| cmd = alloc_cmd(nq, 0); |
| if (cmd) { |
| cmd->rq = req; |
| req->special = cmd; |
| return BLKPREP_OK; |
| } |
| blk_stop_queue(q); |
| |
| return BLKPREP_DEFER; |
| } |
| |
| static void null_request_fn(struct request_queue *q) |
| { |
| struct request *rq; |
| |
| while ((rq = blk_fetch_request(q)) != NULL) { |
| struct nullb_cmd *cmd = rq->special; |
| |
| spin_unlock_irq(q->queue_lock); |
| null_handle_cmd(cmd); |
| spin_lock_irq(q->queue_lock); |
| } |
| } |
| |
| static int null_queue_rq(struct blk_mq_hw_ctx *hctx, |
| const struct blk_mq_queue_data *bd) |
| { |
| struct nullb_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); |
| |
| if (irqmode == NULL_IRQ_TIMER) { |
| hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
| cmd->timer.function = null_cmd_timer_expired; |
| } |
| cmd->rq = bd->rq; |
| cmd->nq = hctx->driver_data; |
| |
| blk_mq_start_request(bd->rq); |
| |
| null_handle_cmd(cmd); |
| return BLK_MQ_RQ_QUEUE_OK; |
| } |
| |
| static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq) |
| { |
| BUG_ON(!nullb); |
| BUG_ON(!nq); |
| |
| init_waitqueue_head(&nq->wait); |
| nq->queue_depth = nullb->queue_depth; |
| } |
| |
| static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, |
| unsigned int index) |
| { |
| struct nullb *nullb = data; |
| struct nullb_queue *nq = &nullb->queues[index]; |
| |
| hctx->driver_data = nq; |
| null_init_queue(nullb, nq); |
| nullb->nr_queues++; |
| |
| return 0; |
| } |
| |
| static struct blk_mq_ops null_mq_ops = { |
| .queue_rq = null_queue_rq, |
| .init_hctx = null_init_hctx, |
| .complete = null_softirq_done_fn, |
| }; |
| |
| static void cleanup_queue(struct nullb_queue *nq) |
| { |
| kfree(nq->tag_map); |
| kfree(nq->cmds); |
| } |
| |
| static void cleanup_queues(struct nullb *nullb) |
| { |
| int i; |
| |
| for (i = 0; i < nullb->nr_queues; i++) |
| cleanup_queue(&nullb->queues[i]); |
| |
| kfree(nullb->queues); |
| } |
| |
| #ifdef CONFIG_NVM |
| |
| static void null_lnvm_end_io(struct request *rq, int error) |
| { |
| struct nvm_rq *rqd = rq->end_io_data; |
| |
| nvm_end_io(rqd, error); |
| |
| blk_put_request(rq); |
| } |
| |
| static int null_lnvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd) |
| { |
| struct request_queue *q = dev->q; |
| struct request *rq; |
| struct bio *bio = rqd->bio; |
| |
| rq = blk_mq_alloc_request(q, bio_data_dir(bio), 0); |
| if (IS_ERR(rq)) |
| return -ENOMEM; |
| |
| rq->cmd_type = REQ_TYPE_DRV_PRIV; |
| rq->__sector = bio->bi_iter.bi_sector; |
| rq->ioprio = bio_prio(bio); |
| |
| if (bio_has_data(bio)) |
| rq->nr_phys_segments = bio_phys_segments(q, bio); |
| |
| rq->__data_len = bio->bi_iter.bi_size; |
| rq->bio = rq->biotail = bio; |
| |
| rq->end_io_data = rqd; |
| |
| blk_execute_rq_nowait(q, NULL, rq, 0, null_lnvm_end_io); |
| |
| return 0; |
| } |
| |
| static int null_lnvm_id(struct nvm_dev *dev, struct nvm_id *id) |
| { |
| sector_t size = gb * 1024 * 1024 * 1024ULL; |
| sector_t blksize; |
| struct nvm_id_group *grp; |
| |
| id->ver_id = 0x1; |
| id->vmnt = 0; |
| id->cgrps = 1; |
| id->cap = 0x2; |
| id->dom = 0x1; |
| |
| id->ppaf.blk_offset = 0; |
| id->ppaf.blk_len = 16; |
| id->ppaf.pg_offset = 16; |
| id->ppaf.pg_len = 16; |
| id->ppaf.sect_offset = 32; |
| id->ppaf.sect_len = 8; |
| id->ppaf.pln_offset = 40; |
| id->ppaf.pln_len = 8; |
| id->ppaf.lun_offset = 48; |
| id->ppaf.lun_len = 8; |
| id->ppaf.ch_offset = 56; |
| id->ppaf.ch_len = 8; |
| |
| sector_div(size, bs); /* convert size to pages */ |
| size >>= 8; /* concert size to pgs pr blk */ |
| grp = &id->groups[0]; |
| grp->mtype = 0; |
| grp->fmtype = 0; |
| grp->num_ch = 1; |
| grp->num_pg = 256; |
| blksize = size; |
| size >>= 16; |
| grp->num_lun = size + 1; |
| sector_div(blksize, grp->num_lun); |
| grp->num_blk = blksize; |
| grp->num_pln = 1; |
| |
| grp->fpg_sz = bs; |
| grp->csecs = bs; |
| grp->trdt = 25000; |
| grp->trdm = 25000; |
| grp->tprt = 500000; |
| grp->tprm = 500000; |
| grp->tbet = 1500000; |
| grp->tbem = 1500000; |
| grp->mpos = 0x010101; /* single plane rwe */ |
| grp->cpar = hw_queue_depth; |
| |
| return 0; |
| } |
| |
| static void *null_lnvm_create_dma_pool(struct nvm_dev *dev, char *name) |
| { |
| mempool_t *virtmem_pool; |
| |
| virtmem_pool = mempool_create_slab_pool(64, ppa_cache); |
| if (!virtmem_pool) { |
| pr_err("null_blk: Unable to create virtual memory pool\n"); |
| return NULL; |
| } |
| |
| return virtmem_pool; |
| } |
| |
| static void null_lnvm_destroy_dma_pool(void *pool) |
| { |
| mempool_destroy(pool); |
| } |
| |
| static void *null_lnvm_dev_dma_alloc(struct nvm_dev *dev, void *pool, |
| gfp_t mem_flags, dma_addr_t *dma_handler) |
| { |
| return mempool_alloc(pool, mem_flags); |
| } |
| |
| static void null_lnvm_dev_dma_free(void *pool, void *entry, |
| dma_addr_t dma_handler) |
| { |
| mempool_free(entry, pool); |
| } |
| |
| static struct nvm_dev_ops null_lnvm_dev_ops = { |
| .identity = null_lnvm_id, |
| .submit_io = null_lnvm_submit_io, |
| |
| .create_dma_pool = null_lnvm_create_dma_pool, |
| .destroy_dma_pool = null_lnvm_destroy_dma_pool, |
| .dev_dma_alloc = null_lnvm_dev_dma_alloc, |
| .dev_dma_free = null_lnvm_dev_dma_free, |
| |
| /* Simulate nvme protocol restriction */ |
| .max_phys_sect = 64, |
| }; |
| |
| static int null_nvm_register(struct nullb *nullb) |
| { |
| struct nvm_dev *dev; |
| int rv; |
| |
| dev = nvm_alloc_dev(0); |
| if (!dev) |
| return -ENOMEM; |
| |
| dev->q = nullb->q; |
| memcpy(dev->name, nullb->disk_name, DISK_NAME_LEN); |
| dev->ops = &null_lnvm_dev_ops; |
| |
| rv = nvm_register(dev); |
| if (rv) { |
| kfree(dev); |
| return rv; |
| } |
| nullb->ndev = dev; |
| return 0; |
| } |
| |
| static void null_nvm_unregister(struct nullb *nullb) |
| { |
| nvm_unregister(nullb->ndev); |
| } |
| #else |
| static int null_nvm_register(struct nullb *nullb) |
| { |
| pr_err("null_blk: CONFIG_NVM needs to be enabled for LightNVM\n"); |
| return -EINVAL; |
| } |
| static void null_nvm_unregister(struct nullb *nullb) {} |
| #endif /* CONFIG_NVM */ |
| |
| static void null_del_dev(struct nullb *nullb) |
| { |
| list_del_init(&nullb->list); |
| |
| if (use_lightnvm) |
| null_nvm_unregister(nullb); |
| else |
| del_gendisk(nullb->disk); |
| blk_cleanup_queue(nullb->q); |
| if (queue_mode == NULL_Q_MQ) |
| blk_mq_free_tag_set(&nullb->tag_set); |
| if (!use_lightnvm) |
| put_disk(nullb->disk); |
| cleanup_queues(nullb); |
| kfree(nullb); |
| } |
| |
| static int null_open(struct block_device *bdev, fmode_t mode) |
| { |
| return 0; |
| } |
| |
| static void null_release(struct gendisk *disk, fmode_t mode) |
| { |
| } |
| |
| static const struct block_device_operations null_fops = { |
| .owner = THIS_MODULE, |
| .open = null_open, |
| .release = null_release, |
| }; |
| |
| static int setup_commands(struct nullb_queue *nq) |
| { |
| struct nullb_cmd *cmd; |
| int i, tag_size; |
| |
| nq->cmds = kzalloc(nq->queue_depth * sizeof(*cmd), GFP_KERNEL); |
| if (!nq->cmds) |
| return -ENOMEM; |
| |
| tag_size = ALIGN(nq->queue_depth, BITS_PER_LONG) / BITS_PER_LONG; |
| nq->tag_map = kzalloc(tag_size * sizeof(unsigned long), GFP_KERNEL); |
| if (!nq->tag_map) { |
| kfree(nq->cmds); |
| return -ENOMEM; |
| } |
| |
| for (i = 0; i < nq->queue_depth; i++) { |
| cmd = &nq->cmds[i]; |
| INIT_LIST_HEAD(&cmd->list); |
| cmd->ll_list.next = NULL; |
| cmd->tag = -1U; |
| } |
| |
| return 0; |
| } |
| |
| static int setup_queues(struct nullb *nullb) |
| { |
| nullb->queues = kzalloc(submit_queues * sizeof(struct nullb_queue), |
| GFP_KERNEL); |
| if (!nullb->queues) |
| return -ENOMEM; |
| |
| nullb->nr_queues = 0; |
| nullb->queue_depth = hw_queue_depth; |
| |
| return 0; |
| } |
| |
| static int init_driver_queues(struct nullb *nullb) |
| { |
| struct nullb_queue *nq; |
| int i, ret = 0; |
| |
| for (i = 0; i < submit_queues; i++) { |
| nq = &nullb->queues[i]; |
| |
| null_init_queue(nullb, nq); |
| |
| ret = setup_commands(nq); |
| if (ret) |
| return ret; |
| nullb->nr_queues++; |
| } |
| return 0; |
| } |
| |
| static int null_gendisk_register(struct nullb *nullb) |
| { |
| struct gendisk *disk; |
| sector_t size; |
| |
| disk = nullb->disk = alloc_disk_node(1, home_node); |
| if (!disk) |
| return -ENOMEM; |
| size = gb * 1024 * 1024 * 1024ULL; |
| set_capacity(disk, size >> 9); |
| |
| disk->flags |= GENHD_FL_EXT_DEVT | GENHD_FL_SUPPRESS_PARTITION_INFO; |
| disk->major = null_major; |
| disk->first_minor = nullb->index; |
| disk->fops = &null_fops; |
| disk->private_data = nullb; |
| disk->queue = nullb->q; |
| strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN); |
| |
| add_disk(disk); |
| return 0; |
| } |
| |
| static int null_add_dev(void) |
| { |
| struct nullb *nullb; |
| int rv; |
| |
| nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, home_node); |
| if (!nullb) { |
| rv = -ENOMEM; |
| goto out; |
| } |
| |
| spin_lock_init(&nullb->lock); |
| |
| if (queue_mode == NULL_Q_MQ && use_per_node_hctx) |
| submit_queues = nr_online_nodes; |
| |
| rv = setup_queues(nullb); |
| if (rv) |
| goto out_free_nullb; |
| |
| if (queue_mode == NULL_Q_MQ) { |
| nullb->tag_set.ops = &null_mq_ops; |
| nullb->tag_set.nr_hw_queues = submit_queues; |
| nullb->tag_set.queue_depth = hw_queue_depth; |
| nullb->tag_set.numa_node = home_node; |
| nullb->tag_set.cmd_size = sizeof(struct nullb_cmd); |
| nullb->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; |
| nullb->tag_set.driver_data = nullb; |
| |
| rv = blk_mq_alloc_tag_set(&nullb->tag_set); |
| if (rv) |
| goto out_cleanup_queues; |
| |
| nullb->q = blk_mq_init_queue(&nullb->tag_set); |
| if (IS_ERR(nullb->q)) { |
| rv = -ENOMEM; |
| goto out_cleanup_tags; |
| } |
| } else if (queue_mode == NULL_Q_BIO) { |
| nullb->q = blk_alloc_queue_node(GFP_KERNEL, home_node); |
| if (!nullb->q) { |
| rv = -ENOMEM; |
| goto out_cleanup_queues; |
| } |
| blk_queue_make_request(nullb->q, null_queue_bio); |
| rv = init_driver_queues(nullb); |
| if (rv) |
| goto out_cleanup_blk_queue; |
| } else { |
| nullb->q = blk_init_queue_node(null_request_fn, &nullb->lock, home_node); |
| if (!nullb->q) { |
| rv = -ENOMEM; |
| goto out_cleanup_queues; |
| } |
| blk_queue_prep_rq(nullb->q, null_rq_prep_fn); |
| blk_queue_softirq_done(nullb->q, null_softirq_done_fn); |
| rv = init_driver_queues(nullb); |
| if (rv) |
| goto out_cleanup_blk_queue; |
| } |
| |
| nullb->q->queuedata = nullb; |
| queue_flag_set_unlocked(QUEUE_FLAG_NONROT, nullb->q); |
| queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, nullb->q); |
| |
| mutex_lock(&lock); |
| nullb->index = nullb_indexes++; |
| mutex_unlock(&lock); |
| |
| blk_queue_logical_block_size(nullb->q, bs); |
| blk_queue_physical_block_size(nullb->q, bs); |
| |
| sprintf(nullb->disk_name, "nullb%d", nullb->index); |
| |
| if (use_lightnvm) |
| rv = null_nvm_register(nullb); |
| else |
| rv = null_gendisk_register(nullb); |
| |
| if (rv) |
| goto out_cleanup_blk_queue; |
| |
| mutex_lock(&lock); |
| list_add_tail(&nullb->list, &nullb_list); |
| mutex_unlock(&lock); |
| |
| return 0; |
| out_cleanup_blk_queue: |
| blk_cleanup_queue(nullb->q); |
| out_cleanup_tags: |
| if (queue_mode == NULL_Q_MQ) |
| blk_mq_free_tag_set(&nullb->tag_set); |
| out_cleanup_queues: |
| cleanup_queues(nullb); |
| out_free_nullb: |
| kfree(nullb); |
| out: |
| return rv; |
| } |
| |
| static int __init null_init(void) |
| { |
| int ret = 0; |
| unsigned int i; |
| struct nullb *nullb; |
| |
| if (bs > PAGE_SIZE) { |
| pr_warn("null_blk: invalid block size\n"); |
| pr_warn("null_blk: defaults block size to %lu\n", PAGE_SIZE); |
| bs = PAGE_SIZE; |
| } |
| |
| if (use_lightnvm && bs != 4096) { |
| pr_warn("null_blk: LightNVM only supports 4k block size\n"); |
| pr_warn("null_blk: defaults block size to 4k\n"); |
| bs = 4096; |
| } |
| |
| if (use_lightnvm && queue_mode != NULL_Q_MQ) { |
| pr_warn("null_blk: LightNVM only supported for blk-mq\n"); |
| pr_warn("null_blk: defaults queue mode to blk-mq\n"); |
| queue_mode = NULL_Q_MQ; |
| } |
| |
| if (queue_mode == NULL_Q_MQ && use_per_node_hctx) { |
| if (submit_queues < nr_online_nodes) { |
| pr_warn("null_blk: submit_queues param is set to %u.", |
| nr_online_nodes); |
| submit_queues = nr_online_nodes; |
| } |
| } else if (submit_queues > nr_cpu_ids) |
| submit_queues = nr_cpu_ids; |
| else if (!submit_queues) |
| submit_queues = 1; |
| |
| mutex_init(&lock); |
| |
| null_major = register_blkdev(0, "nullb"); |
| if (null_major < 0) |
| return null_major; |
| |
| if (use_lightnvm) { |
| ppa_cache = kmem_cache_create("ppa_cache", 64 * sizeof(u64), |
| 0, 0, NULL); |
| if (!ppa_cache) { |
| pr_err("null_blk: unable to create ppa cache\n"); |
| ret = -ENOMEM; |
| goto err_ppa; |
| } |
| } |
| |
| for (i = 0; i < nr_devices; i++) { |
| ret = null_add_dev(); |
| if (ret) |
| goto err_dev; |
| } |
| |
| pr_info("null: module loaded\n"); |
| return 0; |
| |
| err_dev: |
| while (!list_empty(&nullb_list)) { |
| nullb = list_entry(nullb_list.next, struct nullb, list); |
| null_del_dev(nullb); |
| } |
| kmem_cache_destroy(ppa_cache); |
| err_ppa: |
| unregister_blkdev(null_major, "nullb"); |
| return ret; |
| } |
| |
| static void __exit null_exit(void) |
| { |
| struct nullb *nullb; |
| |
| unregister_blkdev(null_major, "nullb"); |
| |
| mutex_lock(&lock); |
| while (!list_empty(&nullb_list)) { |
| nullb = list_entry(nullb_list.next, struct nullb, list); |
| null_del_dev(nullb); |
| } |
| mutex_unlock(&lock); |
| |
| kmem_cache_destroy(ppa_cache); |
| } |
| |
| module_init(null_init); |
| module_exit(null_exit); |
| |
| MODULE_AUTHOR("Jens Axboe <jaxboe@fusionio.com>"); |
| MODULE_LICENSE("GPL"); |