X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=drivers%2Fblock%2Fnvme-core.c;h=51824d1f23ea53df5d49cd6d4e10e07b6b45b1fb;hb=8352650a5c1a3cd75476a25aaae8b1c6ade1c3f8;hp=1f14ac4039450e84137b4eab0dacf043aa46d16e;hpb=878a876b2e10888afe53766dcca33f723ae20edc;p=~andy%2Flinux

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 1f14ac40394..51824d1f23e 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -46,7 +46,6 @@
 #define NVME_Q_DEPTH 1024
 #define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
 #define CQ_SIZE(depth)		(depth * sizeof(struct nvme_completion))
-#define NVME_MINORS 64
 #define ADMIN_TIMEOUT	(60 * HZ)
 
 static int nvme_major;
@@ -58,6 +57,17 @@ module_param(use_threaded_interrupts, int, 0);
 static DEFINE_SPINLOCK(dev_list_lock);
 static LIST_HEAD(dev_list);
 static struct task_struct *nvme_thread;
+static struct workqueue_struct *nvme_workq;
+
+static void nvme_reset_failed_dev(struct work_struct *ws);
+
+struct async_cmd_info {
+	struct kthread_work work;
+	struct kthread_worker *worker;
+	u32 result;
+	int status;
+	void *ctx;
+};
 
 /*
  * An NVM Express queue.  Each device has at least two (one for admin
@@ -66,6 +76,7 @@ static struct task_struct *nvme_thread;
 struct nvme_queue {
 	struct device *q_dmadev;
 	struct nvme_dev *dev;
+	char irqname[24];	/* nvme4294967295-65535\0 */
 	spinlock_t q_lock;
 	struct nvme_command *sq_cmds;
 	volatile struct nvme_completion *cqes;
@@ -80,9 +91,11 @@ struct nvme_queue {
 	u16 sq_head;
 	u16 sq_tail;
 	u16 cq_head;
+	u16 qid;
 	u8 cq_phase;
 	u8 cqe_seen;
 	u8 q_suspended;
+	struct async_cmd_info cmdinfo;
 	unsigned long cmdid_data[];
 };
 
@@ -97,6 +110,7 @@ static inline void _nvme_check_size(void)
 	BUILD_BUG_ON(sizeof(struct nvme_delete_queue) != 64);
 	BUILD_BUG_ON(sizeof(struct nvme_features) != 64);
 	BUILD_BUG_ON(sizeof(struct nvme_format_cmd) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_abort_cmd) != 64);
 	BUILD_BUG_ON(sizeof(struct nvme_command) != 64);
 	BUILD_BUG_ON(sizeof(struct nvme_id_ctrl) != 4096);
 	BUILD_BUG_ON(sizeof(struct nvme_id_ns) != 4096);
@@ -111,6 +125,7 @@ struct nvme_cmd_info {
 	nvme_completion_fn fn;
 	void *ctx;
 	unsigned long timeout;
+	int aborted;
 };
 
 static struct nvme_cmd_info *nvme_cmd_info(struct nvme_queue *nvmeq)
@@ -154,6 +169,7 @@ static int alloc_cmdid(struct nvme_queue *nvmeq, void *ctx,
 	info[cmdid].fn = handler;
 	info[cmdid].ctx = ctx;
 	info[cmdid].timeout = jiffies + timeout;
+	info[cmdid].aborted = 0;
 	return cmdid;
 }
 
@@ -172,6 +188,7 @@ static int alloc_cmdid_killable(struct nvme_queue *nvmeq, void *ctx,
 #define CMD_CTX_COMPLETED	(0x310 + CMD_CTX_BASE)
 #define CMD_CTX_INVALID		(0x314 + CMD_CTX_BASE)
 #define CMD_CTX_FLUSH		(0x318 + CMD_CTX_BASE)
+#define CMD_CTX_ABORT		(0x31C + CMD_CTX_BASE)
 
 static void special_completion(struct nvme_dev *dev, void *ctx,
 						struct nvme_completion *cqe)
@@ -180,6 +197,10 @@ static void special_completion(struct nvme_dev *dev, void *ctx,
 		return;
 	if (ctx == CMD_CTX_FLUSH)
 		return;
+	if (ctx == CMD_CTX_ABORT) {
+		++dev->abort_limit;
+		return;
+	}
 	if (ctx == CMD_CTX_COMPLETED) {
 		dev_warn(&dev->pci_dev->dev,
 				"completed id %d twice on queue %d\n",
@@ -196,6 +217,15 @@ static void special_completion(struct nvme_dev *dev, void *ctx,
 	dev_warn(&dev->pci_dev->dev, "Unknown special completion %p\n", ctx);
 }
 
+static void async_completion(struct nvme_dev *dev, void *ctx,
+						struct nvme_completion *cqe)
+{
+	struct async_cmd_info *cmdinfo = ctx;
+	cmdinfo->result = le32_to_cpup(&cqe->result);
+	cmdinfo->status = le16_to_cpup(&cqe->status) >> 1;
+	queue_kthread_work(cmdinfo->worker, &cmdinfo->work);
+}
+
 /*
  * Called with local interrupts disabled and the q_lock held.  May not sleep.
  */
@@ -693,7 +723,7 @@ static int nvme_process_cq(struct nvme_queue *nvmeq)
 	if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
 		return 0;
 
-	writel(head, nvmeq->q_db + (1 << nvmeq->dev->db_stride));
+	writel(head, nvmeq->q_db + nvmeq->dev->db_stride);
 	nvmeq->cq_head = head;
 	nvmeq->cq_phase = phase;
 
@@ -804,12 +834,34 @@ int nvme_submit_sync_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd,
 	return cmdinfo.status;
 }
 
+static int nvme_submit_async_cmd(struct nvme_queue *nvmeq,
+			struct nvme_command *cmd,
+			struct async_cmd_info *cmdinfo, unsigned timeout)
+{
+	int cmdid;
+
+	cmdid = alloc_cmdid_killable(nvmeq, cmdinfo, async_completion, timeout);
+	if (cmdid < 0)
+		return cmdid;
+	cmdinfo->status = -EINTR;
+	cmd->common.command_id = cmdid;
+	nvme_submit_cmd(nvmeq, cmd);
+	return 0;
+}
+
 int nvme_submit_admin_cmd(struct nvme_dev *dev, struct nvme_command *cmd,
 								u32 *result)
 {
 	return nvme_submit_sync_cmd(dev->queues[0], cmd, result, ADMIN_TIMEOUT);
 }
 
+static int nvme_submit_admin_cmd_async(struct nvme_dev *dev,
+		struct nvme_command *cmd, struct async_cmd_info *cmdinfo)
+{
+	return nvme_submit_async_cmd(dev->queues[0], cmd, cmdinfo,
+								ADMIN_TIMEOUT);
+}
+
 static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
 {
 	int status;
@@ -919,6 +971,56 @@ int nvme_set_features(struct nvme_dev *dev, unsigned fid, unsigned dword11,
 	return nvme_submit_admin_cmd(dev, &c, result);
 }
 
+/**
+ * nvme_abort_cmd - Attempt aborting a command
+ * @cmdid: Command id of a timed out IO
+ * @queue: The queue with timed out IO
+ *
+ * Schedule controller reset if the command was already aborted once before and
+ * still hasn't been returned to the driver, or if this is the admin queue.
+ */
+static void nvme_abort_cmd(int cmdid, struct nvme_queue *nvmeq)
+{
+	int a_cmdid;
+	struct nvme_command cmd;
+	struct nvme_dev *dev = nvmeq->dev;
+	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
+
+	if (!nvmeq->qid || info[cmdid].aborted) {
+		if (work_busy(&dev->reset_work))
+			return;
+		list_del_init(&dev->node);
+		dev_warn(&dev->pci_dev->dev,
+			"I/O %d QID %d timeout, reset controller\n", cmdid,
+								nvmeq->qid);
+		PREPARE_WORK(&dev->reset_work, nvme_reset_failed_dev);
+		queue_work(nvme_workq, &dev->reset_work);
+		return;
+	}
+
+	if (!dev->abort_limit)
+		return;
+
+	a_cmdid = alloc_cmdid(dev->queues[0], CMD_CTX_ABORT, special_completion,
+								ADMIN_TIMEOUT);
+	if (a_cmdid < 0)
+		return;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.abort.opcode = nvme_admin_abort_cmd;
+	cmd.abort.cid = cmdid;
+	cmd.abort.sqid = cpu_to_le16(nvmeq->qid);
+	cmd.abort.command_id = a_cmdid;
+
+	--dev->abort_limit;
+	info[cmdid].aborted = 1;
+	info[cmdid].timeout = jiffies + ADMIN_TIMEOUT;
+
+	dev_warn(nvmeq->q_dmadev, "Aborting I/O %d QID %d\n", cmdid,
+							nvmeq->qid);
+	nvme_submit_cmd(dev->queues[0], &cmd);
+}
+
 /**
  * nvme_cancel_ios - Cancel outstanding I/Os
  * @queue: The queue to cancel I/Os on
@@ -942,7 +1044,12 @@ static void nvme_cancel_ios(struct nvme_queue *nvmeq, bool timeout)
 			continue;
 		if (info[cmdid].ctx == CMD_CTX_CANCELLED)
 			continue;
-		dev_warn(nvmeq->q_dmadev, "Cancelling I/O %d\n", cmdid);
+		if (timeout && nvmeq->dev->initialized) {
+			nvme_abort_cmd(cmdid, nvmeq);
+			continue;
+		}
+		dev_warn(nvmeq->q_dmadev, "Cancelling I/O %d QID %d\n", cmdid,
+								nvmeq->qid);
 		ctx = cancel_cmdid(nvmeq, cmdid, &fn);
 		fn(nvmeq->dev, ctx, &cqe);
 	}
@@ -964,26 +1071,31 @@ static void nvme_free_queue(struct nvme_queue *nvmeq)
 	kfree(nvmeq);
 }
 
-static void nvme_free_queues(struct nvme_dev *dev)
+static void nvme_free_queues(struct nvme_dev *dev, int lowest)
 {
 	int i;
 
-	for (i = dev->queue_count - 1; i >= 0; i--) {
+	for (i = dev->queue_count - 1; i >= lowest; i--) {
 		nvme_free_queue(dev->queues[i]);
 		dev->queue_count--;
 		dev->queues[i] = NULL;
 	}
 }
 
-static void nvme_disable_queue(struct nvme_dev *dev, int qid)
+/**
+ * nvme_suspend_queue - put queue into suspended state
+ * @nvmeq - queue to suspend
+ *
+ * Returns 1 if already suspended, 0 otherwise.
+ */
+static int nvme_suspend_queue(struct nvme_queue *nvmeq)
 {
-	struct nvme_queue *nvmeq = dev->queues[qid];
-	int vector = dev->entry[nvmeq->cq_vector].vector;
+	int vector = nvmeq->dev->entry[nvmeq->cq_vector].vector;
 
 	spin_lock_irq(&nvmeq->q_lock);
 	if (nvmeq->q_suspended) {
 		spin_unlock_irq(&nvmeq->q_lock);
-		return;
+		return 1;
 	}
 	nvmeq->q_suspended = 1;
 	spin_unlock_irq(&nvmeq->q_lock);
@@ -991,18 +1103,35 @@ static void nvme_disable_queue(struct nvme_dev *dev, int qid)
 	irq_set_affinity_hint(vector, NULL);
 	free_irq(vector, nvmeq);
 
-	/* Don't tell the adapter to delete the admin queue */
-	if (qid) {
-		adapter_delete_sq(dev, qid);
-		adapter_delete_cq(dev, qid);
-	}
+	return 0;
+}
 
+static void nvme_clear_queue(struct nvme_queue *nvmeq)
+{
 	spin_lock_irq(&nvmeq->q_lock);
 	nvme_process_cq(nvmeq);
 	nvme_cancel_ios(nvmeq, false);
 	spin_unlock_irq(&nvmeq->q_lock);
 }
 
+static void nvme_disable_queue(struct nvme_dev *dev, int qid)
+{
+	struct nvme_queue *nvmeq = dev->queues[qid];
+
+	if (!nvmeq)
+		return;
+	if (nvme_suspend_queue(nvmeq))
+		return;
+
+	/* Don't tell the adapter to delete the admin queue.
+	 * Don't tell a removed adapter to delete IO queues. */
+	if (qid && readl(&dev->bar->csts) != -1) {
+		adapter_delete_sq(dev, qid);
+		adapter_delete_cq(dev, qid);
+	}
+	nvme_clear_queue(nvmeq);
+}
+
 static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
 							int depth, int vector)
 {
@@ -1025,15 +1154,18 @@ static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
 
 	nvmeq->q_dmadev = dmadev;
 	nvmeq->dev = dev;
+	snprintf(nvmeq->irqname, sizeof(nvmeq->irqname), "nvme%dq%d",
+			dev->instance, qid);
 	spin_lock_init(&nvmeq->q_lock);
 	nvmeq->cq_head = 0;
 	nvmeq->cq_phase = 1;
 	init_waitqueue_head(&nvmeq->sq_full);
 	init_waitqueue_entry(&nvmeq->sq_cong_wait, nvme_thread);
 	bio_list_init(&nvmeq->sq_cong);
-	nvmeq->q_db = &dev->dbs[qid << (dev->db_stride + 1)];
+	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
 	nvmeq->q_depth = depth;
 	nvmeq->cq_vector = vector;
+	nvmeq->qid = qid;
 	nvmeq->q_suspended = 1;
 	dev->queue_count++;
 
@@ -1052,11 +1184,10 @@ static int queue_request_irq(struct nvme_dev *dev, struct nvme_queue *nvmeq,
 {
 	if (use_threaded_interrupts)
 		return request_threaded_irq(dev->entry[nvmeq->cq_vector].vector,
-					nvme_irq_check, nvme_irq,
-					IRQF_DISABLED | IRQF_SHARED,
+					nvme_irq_check, nvme_irq, IRQF_SHARED,
 					name, nvmeq);
 	return request_irq(dev->entry[nvmeq->cq_vector].vector, nvme_irq,
-				IRQF_DISABLED | IRQF_SHARED, name, nvmeq);
+				IRQF_SHARED, name, nvmeq);
 }
 
 static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid)
@@ -1067,7 +1198,7 @@ static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid)
 	nvmeq->sq_tail = 0;
 	nvmeq->cq_head = 0;
 	nvmeq->cq_phase = 1;
-	nvmeq->q_db = &dev->dbs[qid << (dev->db_stride + 1)];
+	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
 	memset(nvmeq->cmdid_data, 0, extra);
 	memset((void *)nvmeq->cqes, 0, CQ_SIZE(nvmeq->q_depth));
 	nvme_cancel_ios(nvmeq, false);
@@ -1087,13 +1218,13 @@ static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
 	if (result < 0)
 		goto release_cq;
 
-	result = queue_request_irq(dev, nvmeq, "nvme");
+	result = queue_request_irq(dev, nvmeq, nvmeq->irqname);
 	if (result < 0)
 		goto release_sq;
 
-	spin_lock(&nvmeq->q_lock);
+	spin_lock_irq(&nvmeq->q_lock);
 	nvme_init_queue(nvmeq, qid);
-	spin_unlock(&nvmeq->q_lock);
+	spin_unlock_irq(&nvmeq->q_lock);
 
 	return result;
 
@@ -1205,13 +1336,13 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev)
 	if (result)
 		return result;
 
-	result = queue_request_irq(dev, nvmeq, "nvme admin");
+	result = queue_request_irq(dev, nvmeq, nvmeq->irqname);
 	if (result)
 		return result;
 
-	spin_lock(&nvmeq->q_lock);
+	spin_lock_irq(&nvmeq->q_lock);
 	nvme_init_queue(nvmeq, 0);
-	spin_unlock(&nvmeq->q_lock);
+	spin_unlock_irq(&nvmeq->q_lock);
 	return result;
 }
 
@@ -1487,10 +1618,47 @@ static int nvme_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
 	}
 }
 
+#ifdef CONFIG_COMPAT
+static int nvme_compat_ioctl(struct block_device *bdev, fmode_t mode,
+					unsigned int cmd, unsigned long arg)
+{
+	struct nvme_ns *ns = bdev->bd_disk->private_data;
+
+	switch (cmd) {
+	case SG_IO:
+		return nvme_sg_io32(ns, arg);
+	}
+	return nvme_ioctl(bdev, mode, cmd, arg);
+}
+#else
+#define nvme_compat_ioctl	NULL
+#endif
+
+static int nvme_open(struct block_device *bdev, fmode_t mode)
+{
+	struct nvme_ns *ns = bdev->bd_disk->private_data;
+	struct nvme_dev *dev = ns->dev;
+
+	kref_get(&dev->kref);
+	return 0;
+}
+
+static void nvme_free_dev(struct kref *kref);
+
+static void nvme_release(struct gendisk *disk, fmode_t mode)
+{
+	struct nvme_ns *ns = disk->private_data;
+	struct nvme_dev *dev = ns->dev;
+
+	kref_put(&dev->kref, nvme_free_dev);
+}
+
 static const struct block_device_operations nvme_fops = {
 	.owner		= THIS_MODULE,
 	.ioctl		= nvme_ioctl,
-	.compat_ioctl	= nvme_ioctl,
+	.compat_ioctl	= nvme_compat_ioctl,
+	.open		= nvme_open,
+	.release	= nvme_release,
 };
 
 static void nvme_resubmit_bios(struct nvme_queue *nvmeq)
@@ -1514,13 +1682,25 @@ static void nvme_resubmit_bios(struct nvme_queue *nvmeq)
 
 static int nvme_kthread(void *data)
 {
-	struct nvme_dev *dev;
+	struct nvme_dev *dev, *next;
 
 	while (!kthread_should_stop()) {
 		set_current_state(TASK_INTERRUPTIBLE);
 		spin_lock(&dev_list_lock);
-		list_for_each_entry(dev, &dev_list, node) {
+		list_for_each_entry_safe(dev, next, &dev_list, node) {
 			int i;
+			if (readl(&dev->bar->csts) & NVME_CSTS_CFS &&
+							dev->initialized) {
+				if (work_busy(&dev->reset_work))
+					continue;
+				list_del_init(&dev->node);
+				dev_warn(&dev->pci_dev->dev,
+					"Failed status, reset controller\n");
+				PREPARE_WORK(&dev->reset_work,
+							nvme_reset_failed_dev);
+				queue_work(nvme_workq, &dev->reset_work);
+				continue;
+			}
 			for (i = 0; i < dev->queue_count; i++) {
 				struct nvme_queue *nvmeq = dev->queues[i];
 				if (!nvmeq)
@@ -1541,33 +1721,6 @@ static int nvme_kthread(void *data)
 	return 0;
 }
 
-static DEFINE_IDA(nvme_index_ida);
-
-static int nvme_get_ns_idx(void)
-{
-	int index, error;
-
-	do {
-		if (!ida_pre_get(&nvme_index_ida, GFP_KERNEL))
-			return -1;
-
-		spin_lock(&dev_list_lock);
-		error = ida_get_new(&nvme_index_ida, &index);
-		spin_unlock(&dev_list_lock);
-	} while (error == -EAGAIN);
-
-	if (error)
-		index = -1;
-	return index;
-}
-
-static void nvme_put_ns_idx(int index)
-{
-	spin_lock(&dev_list_lock);
-	ida_remove(&nvme_index_ida, index);
-	spin_unlock(&dev_list_lock);
-}
-
 static void nvme_config_discard(struct nvme_ns *ns)
 {
 	u32 logical_block_size = queue_logical_block_size(ns->queue);
@@ -1601,7 +1754,7 @@ static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid,
 	ns->dev = dev;
 	ns->queue->queuedata = ns;
 
-	disk = alloc_disk(NVME_MINORS);
+	disk = alloc_disk(0);
 	if (!disk)
 		goto out_free_queue;
 	ns->ns_id = nsid;
@@ -1614,12 +1767,12 @@ static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid,
 		blk_queue_max_hw_sectors(ns->queue, dev->max_hw_sectors);
 
 	disk->major = nvme_major;
-	disk->minors = NVME_MINORS;
-	disk->first_minor = NVME_MINORS * nvme_get_ns_idx();
+	disk->first_minor = 0;
 	disk->fops = &nvme_fops;
 	disk->private_data = ns;
 	disk->queue = ns->queue;
 	disk->driverfs_dev = &dev->pci_dev->dev;
+	disk->flags = GENHD_FL_EXT_DEVT;
 	sprintf(disk->disk_name, "nvme%dn%d", dev->instance, nsid);
 	set_capacity(disk, le64_to_cpup(&id->nsze) << (ns->lba_shift - 9));
 
@@ -1635,15 +1788,6 @@ static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid,
 	return NULL;
 }
 
-static void nvme_ns_free(struct nvme_ns *ns)
-{
-	int index = ns->disk->first_minor / NVME_MINORS;
-	put_disk(ns->disk);
-	nvme_put_ns_idx(index);
-	blk_cleanup_queue(ns->queue);
-	kfree(ns);
-}
-
 static int set_queue_count(struct nvme_dev *dev, int count)
 {
 	int status;
@@ -1659,11 +1803,12 @@ static int set_queue_count(struct nvme_dev *dev, int count)
 
 static size_t db_bar_size(struct nvme_dev *dev, unsigned nr_io_queues)
 {
-	return 4096 + ((nr_io_queues + 1) << (dev->db_stride + 3));
+	return 4096 + ((nr_io_queues + 1) * 8 * dev->db_stride);
 }
 
 static int nvme_setup_io_queues(struct nvme_dev *dev)
 {
+	struct nvme_queue *adminq = dev->queues[0];
 	struct pci_dev *pdev = dev->pci_dev;
 	int result, cpu, i, vecs, nr_io_queues, size, q_depth;
 
@@ -1690,7 +1835,7 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
 	}
 
 	/* Deregister the admin queue's interrupt */
-	free_irq(dev->entry[0].vector, dev->queues[0]);
+	free_irq(dev->entry[0].vector, adminq);
 
 	vecs = nr_io_queues;
 	for (i = 0; i < vecs; i++)
@@ -1728,9 +1873,9 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
 	 */
 	nr_io_queues = vecs;
 
-	result = queue_request_irq(dev, dev->queues[0], "nvme admin");
+	result = queue_request_irq(dev, adminq, adminq->irqname);
 	if (result) {
-		dev->queues[0]->q_suspended = 1;
+		adminq->q_suspended = 1;
 		goto free_queues;
 	}
 
@@ -1739,9 +1884,9 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
 	for (i = dev->queue_count - 1; i > nr_io_queues; i--) {
 		struct nvme_queue *nvmeq = dev->queues[i];
 
-		spin_lock(&nvmeq->q_lock);
+		spin_lock_irq(&nvmeq->q_lock);
 		nvme_cancel_ios(nvmeq, false);
-		spin_unlock(&nvmeq->q_lock);
+		spin_unlock_irq(&nvmeq->q_lock);
 
 		nvme_free_queue(nvmeq);
 		dev->queue_count--;
@@ -1782,7 +1927,7 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
 	return 0;
 
  free_queues:
-	nvme_free_queues(dev);
+	nvme_free_queues(dev, 1);
 	return result;
 }
 
@@ -1794,6 +1939,7 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
  */
 static int nvme_dev_add(struct nvme_dev *dev)
 {
+	struct pci_dev *pdev = dev->pci_dev;
 	int res;
 	unsigned nn, i;
 	struct nvme_ns *ns;
@@ -1803,8 +1949,7 @@ static int nvme_dev_add(struct nvme_dev *dev)
 	dma_addr_t dma_addr;
 	int shift = NVME_CAP_MPSMIN(readq(&dev->bar->cap)) + 12;
 
-	mem = dma_alloc_coherent(&dev->pci_dev->dev, 8192, &dma_addr,
-								GFP_KERNEL);
+	mem = dma_alloc_coherent(&pdev->dev, 8192, &dma_addr, GFP_KERNEL);
 	if (!mem)
 		return -ENOMEM;
 
@@ -1817,13 +1962,14 @@ static int nvme_dev_add(struct nvme_dev *dev)
 	ctrl = mem;
 	nn = le32_to_cpup(&ctrl->nn);
 	dev->oncs = le16_to_cpup(&ctrl->oncs);
+	dev->abort_limit = ctrl->acl + 1;
 	memcpy(dev->serial, ctrl->sn, sizeof(ctrl->sn));
 	memcpy(dev->model, ctrl->mn, sizeof(ctrl->mn));
 	memcpy(dev->firmware_rev, ctrl->fr, sizeof(ctrl->fr));
 	if (ctrl->mdts)
 		dev->max_hw_sectors = 1 << (ctrl->mdts + shift - 9);
-	if ((dev->pci_dev->vendor == PCI_VENDOR_ID_INTEL) &&
-			(dev->pci_dev->device == 0x0953) && ctrl->vs[3])
+	if ((pdev->vendor == PCI_VENDOR_ID_INTEL) &&
+			(pdev->device == 0x0953) && ctrl->vs[3])
 		dev->stripe_size = 1 << (ctrl->vs[3] + shift);
 
 	id_ns = mem;
@@ -1871,16 +2017,21 @@ static int nvme_dev_map(struct nvme_dev *dev)
 	    dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)))
 		goto disable;
 
-	pci_set_drvdata(pdev, dev);
 	dev->bar = ioremap(pci_resource_start(pdev, 0), 8192);
 	if (!dev->bar)
 		goto disable;
-
-	dev->db_stride = NVME_CAP_STRIDE(readq(&dev->bar->cap));
+	if (readl(&dev->bar->csts) == -1) {
+		result = -ENODEV;
+		goto unmap;
+	}
+	dev->db_stride = 1 << NVME_CAP_STRIDE(readq(&dev->bar->cap));
 	dev->dbs = ((void __iomem *)dev->bar) + 4096;
 
 	return 0;
 
+ unmap:
+	iounmap(dev->bar);
+	dev->bar = NULL;
  disable:
 	pci_release_regions(pdev);
  disable_pci:
@@ -1898,37 +2049,183 @@ static void nvme_dev_unmap(struct nvme_dev *dev)
 	if (dev->bar) {
 		iounmap(dev->bar);
 		dev->bar = NULL;
+		pci_release_regions(dev->pci_dev);
 	}
 
-	pci_release_regions(dev->pci_dev);
 	if (pci_is_enabled(dev->pci_dev))
 		pci_disable_device(dev->pci_dev);
 }
 
+struct nvme_delq_ctx {
+	struct task_struct *waiter;
+	struct kthread_worker *worker;
+	atomic_t refcount;
+};
+
+static void nvme_wait_dq(struct nvme_delq_ctx *dq, struct nvme_dev *dev)
+{
+	dq->waiter = current;
+	mb();
+
+	for (;;) {
+		set_current_state(TASK_KILLABLE);
+		if (!atomic_read(&dq->refcount))
+			break;
+		if (!schedule_timeout(ADMIN_TIMEOUT) ||
+					fatal_signal_pending(current)) {
+			set_current_state(TASK_RUNNING);
+
+			nvme_disable_ctrl(dev, readq(&dev->bar->cap));
+			nvme_disable_queue(dev, 0);
+
+			send_sig(SIGKILL, dq->worker->task, 1);
+			flush_kthread_worker(dq->worker);
+			return;
+		}
+	}
+	set_current_state(TASK_RUNNING);
+}
+
+static void nvme_put_dq(struct nvme_delq_ctx *dq)
+{
+	atomic_dec(&dq->refcount);
+	if (dq->waiter)
+		wake_up_process(dq->waiter);
+}
+
+static struct nvme_delq_ctx *nvme_get_dq(struct nvme_delq_ctx *dq)
+{
+	atomic_inc(&dq->refcount);
+	return dq;
+}
+
+static void nvme_del_queue_end(struct nvme_queue *nvmeq)
+{
+	struct nvme_delq_ctx *dq = nvmeq->cmdinfo.ctx;
+
+	nvme_clear_queue(nvmeq);
+	nvme_put_dq(dq);
+}
+
+static int adapter_async_del_queue(struct nvme_queue *nvmeq, u8 opcode,
+						kthread_work_func_t fn)
+{
+	struct nvme_command c;
+
+	memset(&c, 0, sizeof(c));
+	c.delete_queue.opcode = opcode;
+	c.delete_queue.qid = cpu_to_le16(nvmeq->qid);
+
+	init_kthread_work(&nvmeq->cmdinfo.work, fn);
+	return nvme_submit_admin_cmd_async(nvmeq->dev, &c, &nvmeq->cmdinfo);
+}
+
+static void nvme_del_cq_work_handler(struct kthread_work *work)
+{
+	struct nvme_queue *nvmeq = container_of(work, struct nvme_queue,
+							cmdinfo.work);
+	nvme_del_queue_end(nvmeq);
+}
+
+static int nvme_delete_cq(struct nvme_queue *nvmeq)
+{
+	return adapter_async_del_queue(nvmeq, nvme_admin_delete_cq,
+						nvme_del_cq_work_handler);
+}
+
+static void nvme_del_sq_work_handler(struct kthread_work *work)
+{
+	struct nvme_queue *nvmeq = container_of(work, struct nvme_queue,
+							cmdinfo.work);
+	int status = nvmeq->cmdinfo.status;
+
+	if (!status)
+		status = nvme_delete_cq(nvmeq);
+	if (status)
+		nvme_del_queue_end(nvmeq);
+}
+
+static int nvme_delete_sq(struct nvme_queue *nvmeq)
+{
+	return adapter_async_del_queue(nvmeq, nvme_admin_delete_sq,
+						nvme_del_sq_work_handler);
+}
+
+static void nvme_del_queue_start(struct kthread_work *work)
+{
+	struct nvme_queue *nvmeq = container_of(work, struct nvme_queue,
+							cmdinfo.work);
+	allow_signal(SIGKILL);
+	if (nvme_delete_sq(nvmeq))
+		nvme_del_queue_end(nvmeq);
+}
+
+static void nvme_disable_io_queues(struct nvme_dev *dev)
+{
+	int i;
+	DEFINE_KTHREAD_WORKER_ONSTACK(worker);
+	struct nvme_delq_ctx dq;
+	struct task_struct *kworker_task = kthread_run(kthread_worker_fn,
+					&worker, "nvme%d", dev->instance);
+
+	if (IS_ERR(kworker_task)) {
+		dev_err(&dev->pci_dev->dev,
+			"Failed to create queue del task\n");
+		for (i = dev->queue_count - 1; i > 0; i--)
+			nvme_disable_queue(dev, i);
+		return;
+	}
+
+	dq.waiter = NULL;
+	atomic_set(&dq.refcount, 0);
+	dq.worker = &worker;
+	for (i = dev->queue_count - 1; i > 0; i--) {
+		struct nvme_queue *nvmeq = dev->queues[i];
+
+		if (nvme_suspend_queue(nvmeq))
+			continue;
+		nvmeq->cmdinfo.ctx = nvme_get_dq(&dq);
+		nvmeq->cmdinfo.worker = dq.worker;
+		init_kthread_work(&nvmeq->cmdinfo.work, nvme_del_queue_start);
+		queue_kthread_work(dq.worker, &nvmeq->cmdinfo.work);
+	}
+	nvme_wait_dq(&dq, dev);
+	kthread_stop(kworker_task);
+}
+
 static void nvme_dev_shutdown(struct nvme_dev *dev)
 {
 	int i;
 
-	for (i = dev->queue_count - 1; i >= 0; i--)
-		nvme_disable_queue(dev, i);
+	dev->initialized = 0;
 
 	spin_lock(&dev_list_lock);
 	list_del_init(&dev->node);
 	spin_unlock(&dev_list_lock);
 
-	if (dev->bar)
+	if (!dev->bar || (dev->bar && readl(&dev->bar->csts) == -1)) {
+		for (i = dev->queue_count - 1; i >= 0; i--) {
+			struct nvme_queue *nvmeq = dev->queues[i];
+			nvme_suspend_queue(nvmeq);
+			nvme_clear_queue(nvmeq);
+		}
+	} else {
+		nvme_disable_io_queues(dev);
 		nvme_shutdown_ctrl(dev);
+		nvme_disable_queue(dev, 0);
+	}
 	nvme_dev_unmap(dev);
 }
 
 static void nvme_dev_remove(struct nvme_dev *dev)
 {
-	struct nvme_ns *ns, *next;
+	struct nvme_ns *ns;
 
-	list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
-		list_del(&ns->list);
-		del_gendisk(ns->disk);
-		nvme_ns_free(ns);
+	list_for_each_entry(ns, &dev->namespaces, list) {
+		if (ns->disk->flags & GENHD_FL_UP)
+			del_gendisk(ns->disk);
+		if (!blk_queue_dying(ns->queue))
+			blk_cleanup_queue(ns->queue);
 	}
 }
 
@@ -1985,14 +2282,22 @@ static void nvme_release_instance(struct nvme_dev *dev)
 	spin_unlock(&dev_list_lock);
 }
 
+static void nvme_free_namespaces(struct nvme_dev *dev)
+{
+	struct nvme_ns *ns, *next;
+
+	list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
+		list_del(&ns->list);
+		put_disk(ns->disk);
+		kfree(ns);
+	}
+}
+
 static void nvme_free_dev(struct kref *kref)
 {
 	struct nvme_dev *dev = container_of(kref, struct nvme_dev, kref);
-	nvme_dev_remove(dev);
-	nvme_dev_shutdown(dev);
-	nvme_free_queues(dev);
-	nvme_release_instance(dev);
-	nvme_release_prp_pools(dev);
+
+	nvme_free_namespaces(dev);
 	kfree(dev->queues);
 	kfree(dev->entry);
 	kfree(dev);
@@ -2056,6 +2361,7 @@ static int nvme_dev_start(struct nvme_dev *dev)
 	return result;
 
  disable:
+	nvme_disable_queue(dev, 0);
 	spin_lock(&dev_list_lock);
 	list_del_init(&dev->node);
 	spin_unlock(&dev_list_lock);
@@ -2064,6 +2370,71 @@ static int nvme_dev_start(struct nvme_dev *dev)
 	return result;
 }
 
+static int nvme_remove_dead_ctrl(void *arg)
+{
+	struct nvme_dev *dev = (struct nvme_dev *)arg;
+	struct pci_dev *pdev = dev->pci_dev;
+
+	if (pci_get_drvdata(pdev))
+		pci_stop_and_remove_bus_device(pdev);
+	kref_put(&dev->kref, nvme_free_dev);
+	return 0;
+}
+
+static void nvme_remove_disks(struct work_struct *ws)
+{
+	int i;
+	struct nvme_dev *dev = container_of(ws, struct nvme_dev, reset_work);
+
+	nvme_dev_remove(dev);
+	spin_lock(&dev_list_lock);
+	for (i = dev->queue_count - 1; i > 0; i--) {
+		BUG_ON(!dev->queues[i] || !dev->queues[i]->q_suspended);
+		nvme_free_queue(dev->queues[i]);
+		dev->queue_count--;
+		dev->queues[i] = NULL;
+	}
+	spin_unlock(&dev_list_lock);
+}
+
+static int nvme_dev_resume(struct nvme_dev *dev)
+{
+	int ret;
+
+	ret = nvme_dev_start(dev);
+	if (ret && ret != -EBUSY)
+		return ret;
+	if (ret == -EBUSY) {
+		spin_lock(&dev_list_lock);
+		PREPARE_WORK(&dev->reset_work, nvme_remove_disks);
+		queue_work(nvme_workq, &dev->reset_work);
+		spin_unlock(&dev_list_lock);
+	}
+	dev->initialized = 1;
+	return 0;
+}
+
+static void nvme_dev_reset(struct nvme_dev *dev)
+{
+	nvme_dev_shutdown(dev);
+	if (nvme_dev_resume(dev)) {
+		dev_err(&dev->pci_dev->dev, "Device failed to resume\n");
+		kref_get(&dev->kref);
+		if (IS_ERR(kthread_run(nvme_remove_dead_ctrl, dev, "nvme%d",
+							dev->instance))) {
+			dev_err(&dev->pci_dev->dev,
+				"Failed to start controller remove task\n");
+			kref_put(&dev->kref, nvme_free_dev);
+		}
+	}
+}
+
+static void nvme_reset_failed_dev(struct work_struct *ws)
+{
+	struct nvme_dev *dev = container_of(ws, struct nvme_dev, reset_work);
+	nvme_dev_reset(dev);
+}
+
 static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	int result = -ENOMEM;
@@ -2082,8 +2453,9 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		goto free;
 
 	INIT_LIST_HEAD(&dev->namespaces);
+	INIT_WORK(&dev->reset_work, nvme_reset_failed_dev);
 	dev->pci_dev = pdev;
-
+	pci_set_drvdata(pdev, dev);
 	result = nvme_set_instance(dev);
 	if (result)
 		goto free;
@@ -2099,6 +2471,7 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		goto release_pools;
 	}
 
+	kref_init(&dev->kref);
 	result = nvme_dev_add(dev);
 	if (result)
 		goto shutdown;
@@ -2113,15 +2486,16 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (result)
 		goto remove;
 
-	kref_init(&dev->kref);
+	dev->initialized = 1;
 	return 0;
 
  remove:
 	nvme_dev_remove(dev);
+	nvme_free_namespaces(dev);
  shutdown:
 	nvme_dev_shutdown(dev);
  release_pools:
-	nvme_free_queues(dev);
+	nvme_free_queues(dev, 0);
 	nvme_release_prp_pools(dev);
  release:
 	nvme_release_instance(dev);
@@ -2132,10 +2506,28 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	return result;
 }
 
+static void nvme_shutdown(struct pci_dev *pdev)
+{
+	struct nvme_dev *dev = pci_get_drvdata(pdev);
+	nvme_dev_shutdown(dev);
+}
+
 static void nvme_remove(struct pci_dev *pdev)
 {
 	struct nvme_dev *dev = pci_get_drvdata(pdev);
+
+	spin_lock(&dev_list_lock);
+	list_del_init(&dev->node);
+	spin_unlock(&dev_list_lock);
+
+	pci_set_drvdata(pdev, NULL);
+	flush_work(&dev->reset_work);
 	misc_deregister(&dev->miscdev);
+	nvme_dev_remove(dev);
+	nvme_dev_shutdown(dev);
+	nvme_free_queues(dev, 0);
+	nvme_release_instance(dev);
+	nvme_release_prp_pools(dev);
 	kref_put(&dev->kref, nvme_free_dev);
 }
 
@@ -2159,13 +2551,12 @@ static int nvme_resume(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct nvme_dev *ndev = pci_get_drvdata(pdev);
-	int ret;
 
-	ret = nvme_dev_start(ndev);
-	/* XXX: should remove gendisks if resume fails */
-	if (ret)
-		nvme_free_queues(ndev);
-	return ret;
+	if (nvme_dev_resume(ndev) && !work_busy(&ndev->reset_work)) {
+		PREPARE_WORK(&ndev->reset_work, nvme_reset_failed_dev);
+		queue_work(nvme_workq, &ndev->reset_work);
+	}
+	return 0;
 }
 
 static SIMPLE_DEV_PM_OPS(nvme_dev_pm_ops, nvme_suspend, nvme_resume);
@@ -2192,6 +2583,7 @@ static struct pci_driver nvme_driver = {
 	.id_table	= nvme_id_table,
 	.probe		= nvme_probe,
 	.remove		= nvme_remove,
+	.shutdown	= nvme_shutdown,
 	.driver		= {
 		.pm	= &nvme_dev_pm_ops,
 	},
@@ -2206,9 +2598,14 @@ static int __init nvme_init(void)
 	if (IS_ERR(nvme_thread))
 		return PTR_ERR(nvme_thread);
 
+	result = -ENOMEM;
+	nvme_workq = create_singlethread_workqueue("nvme");
+	if (!nvme_workq)
+		goto kill_kthread;
+
 	result = register_blkdev(nvme_major, "nvme");
 	if (result < 0)
-		goto kill_kthread;
+		goto kill_workq;
 	else if (result > 0)
 		nvme_major = result;
 
@@ -2219,6 +2616,8 @@ static int __init nvme_init(void)
 
  unregister_blkdev:
 	unregister_blkdev(nvme_major, "nvme");
+ kill_workq:
+	destroy_workqueue(nvme_workq);
  kill_kthread:
 	kthread_stop(nvme_thread);
 	return result;
@@ -2228,6 +2627,7 @@ static void __exit nvme_exit(void)
 {
 	pci_unregister_driver(&nvme_driver);
 	unregister_blkdev(nvme_major, "nvme");
+	destroy_workqueue(nvme_workq);
 	kthread_stop(nvme_thread);
 }