Merge branch 'for-4.5/nvme' of git://git.kernel.dk/linux-block

Pull NVMe updates from Jens Axboe:
 "Last branch for this series is the nvme changes.  It's in a separate
  branch to avoid splitting too much between core and NVMe changes,
  since NVMe is still helping drive some blk-mq changes.  That said, not
  a huge amount of core changes in here.  The grunt of the work is the
  continued split of the code"

* 'for-4.5/nvme' of git://git.kernel.dk/linux-block: (67 commits)
  uapi: update install list after nvme.h rename
  NVMe: Export NVMe attributes to sysfs group
  NVMe: Shutdown controller only for power-off
  NVMe: IO queue deletion re-write
  NVMe: Remove queue freezing on resets
  NVMe: Use a retryable error code on reset
  NVMe: Fix admin queue ring wrap
  nvme: make SG_IO support optional
  nvme: fixes for NVME_IOCTL_IO_CMD on the char device
  nvme: synchronize access to ctrl->namespaces
  nvme: Move nvme_freeze/unfreeze_queues to nvme core
  PCI/AER: include header file
  NVMe: Export namespace attributes to sysfs
  NVMe: Add pci error handlers
  block: remove REQ_NO_TIMEOUT flag
  nvme: merge iod and cmd_info
  nvme: meta_sg doesn't have to be an array
  nvme: properly free resources for cancelled command
  nvme: simplify completion handling
  nvme: special case AEN requests
  ...

1 files changed, 719 insertions, 1981 deletions

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index f5c0e2613c7c..72ef8322d32a 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -12,6 +12,7 @@
  * more details.
  */
 
+#include <linux/aer.h>
 #include <linux/bitops.h>
 #include <linux/blkdev.h>
 #include <linux/blk-mq.h>
@@ -28,10 +29,10 @@
 #include <linux/kdev_t.h>
 #include <linux/kthread.h>
 #include <linux/kernel.h>
-#include <linux/list_sort.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/mutex.h>
 #include <linux/pci.h>
 #include <linux/poison.h>
 #include <linux/ptrace.h>
@@ -39,23 +40,24 @@
 #include <linux/slab.h>
 #include <linux/t10-pi.h>
 #include <linux/types.h>
-#include <linux/pr.h>
-#include <scsi/sg.h>
 #include <linux/io-64-nonatomic-lo-hi.h>
 #include <asm/unaligned.h>
 
-#include <uapi/linux/nvme_ioctl.h>
 #include "nvme.h"
 
-#define NVME_MINORS		(1U << MINORBITS)
 #define NVME_Q_DEPTH		1024
 #define NVME_AQ_DEPTH		256
 #define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
 #define CQ_SIZE(depth)		(depth * sizeof(struct nvme_completion))
-#define ADMIN_TIMEOUT		(admin_timeout * HZ)
-#define SHUTDOWN_TIMEOUT	(shutdown_timeout * HZ)
+		
+/*
+ * We handle AEN commands ourselves and don't even let the
+ * block layer know about them.
+ */
+#define NVME_NR_AEN_COMMANDS	1
+#define NVME_AQ_BLKMQ_DEPTH	(NVME_AQ_DEPTH - NVME_NR_AEN_COMMANDS)
 
-static unsigned char admin_timeout = 60;
+unsigned char admin_timeout = 60;
 module_param(admin_timeout, byte, 0644);
 MODULE_PARM_DESC(admin_timeout, "timeout in seconds for admin commands");
 
@@ -63,16 +65,10 @@ unsigned char nvme_io_timeout = 30;
 module_param_named(io_timeout, nvme_io_timeout, byte, 0644);
 MODULE_PARM_DESC(io_timeout, "timeout in seconds for I/O");
 
-static unsigned char shutdown_timeout = 5;
+unsigned char shutdown_timeout = 5;
 module_param(shutdown_timeout, byte, 0644);
 MODULE_PARM_DESC(shutdown_timeout, "timeout in seconds for controller shutdown");
 
-static int nvme_major;
-module_param(nvme_major, int, 0);
-
-static int nvme_char_major;
-module_param(nvme_char_major, int, 0);
-
 static int use_threaded_interrupts;
 module_param(use_threaded_interrupts, int, 0);
 
@@ -80,28 +76,60 @@ static bool use_cmb_sqes = true;
 module_param(use_cmb_sqes, bool, 0644);
 MODULE_PARM_DESC(use_cmb_sqes, "use controller's memory buffer for I/O SQes");
 
-static DEFINE_SPINLOCK(dev_list_lock);
 static LIST_HEAD(dev_list);
 static struct task_struct *nvme_thread;
 static struct workqueue_struct *nvme_workq;
 static wait_queue_head_t nvme_kthread_wait;
 
-static struct class *nvme_class;
+struct nvme_dev;
+struct nvme_queue;
 
-static int __nvme_reset(struct nvme_dev *dev);
 static int nvme_reset(struct nvme_dev *dev);
 static void nvme_process_cq(struct nvme_queue *nvmeq);
-static void nvme_dead_ctrl(struct nvme_dev *dev);
+static void nvme_remove_dead_ctrl(struct nvme_dev *dev);
+static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown);
 
-struct async_cmd_info {
-	struct kthread_work work;
-	struct kthread_worker *worker;
-	struct request *req;
-	u32 result;
-	int status;
-	void *ctx;
+/*
+ * Represents an NVM Express device.  Each nvme_dev is a PCI function.
+ */
+struct nvme_dev {
+	struct list_head node;
+	struct nvme_queue **queues;
+	struct blk_mq_tag_set tagset;
+	struct blk_mq_tag_set admin_tagset;
+	u32 __iomem *dbs;
+	struct device *dev;
+	struct dma_pool *prp_page_pool;
+	struct dma_pool *prp_small_pool;
+	unsigned queue_count;
+	unsigned online_queues;
+	unsigned max_qid;
+	int q_depth;
+	u32 db_stride;
+	struct msix_entry *entry;
+	void __iomem *bar;
+	struct work_struct reset_work;
+	struct work_struct scan_work;
+	struct work_struct remove_work;
+	struct mutex shutdown_lock;
+	bool subsystem;
+	void __iomem *cmb;
+	dma_addr_t cmb_dma_addr;
+	u64 cmb_size;
+	u32 cmbsz;
+	unsigned long flags;
+
+#define NVME_CTRL_RESETTING    0
+
+	struct nvme_ctrl ctrl;
+	struct completion ioq_wait;
 };
 
+static inline struct nvme_dev *to_nvme_dev(struct nvme_ctrl *ctrl)
+{
+	return container_of(ctrl, struct nvme_dev, ctrl);
+}
+
 /*
  * An NVM Express queue.  Each device has at least two (one for admin
  * commands and one for I/O commands).
@@ -126,7 +154,24 @@ struct nvme_queue {
 	u16 qid;
 	u8 cq_phase;
 	u8 cqe_seen;
-	struct async_cmd_info cmdinfo;
+};
+
+/*
+ * The nvme_iod describes the data in an I/O, including the list of PRP
+ * entries.  You can't see it in this data structure because C doesn't let
+ * me express that.  Use nvme_init_iod to ensure there's enough space
+ * allocated to store the PRP list.
+ */
+struct nvme_iod {
+	struct nvme_queue *nvmeq;
+	int aborted;
+	int npages;		/* In the PRP list. 0 means small pool in use */
+	int nents;		/* Used in scatterlist */
+	int length;		/* Of data, in bytes */
+	dma_addr_t first_dma;
+	struct scatterlist meta_sg; /* metadata requires single contiguous buffer */
+	struct scatterlist *sg;
+	struct scatterlist inline_sg[0];
 };
 
 /*
@@ -148,23 +193,11 @@ static inline void _nvme_check_size(void)
 	BUILD_BUG_ON(sizeof(struct nvme_smart_log) != 512);
 }
 
-typedef void (*nvme_completion_fn)(struct nvme_queue *, void *,
-						struct nvme_completion *);
-
-struct nvme_cmd_info {
-	nvme_completion_fn fn;
-	void *ctx;
-	int aborted;
-	struct nvme_queue *nvmeq;
-	struct nvme_iod iod[0];
-};
-
 /*
  * Max size of iod being embedded in the request payload
  */
 #define NVME_INT_PAGES		2
-#define NVME_INT_BYTES(dev)	(NVME_INT_PAGES * (dev)->page_size)
-#define NVME_INT_MASK		0x01
+#define NVME_INT_BYTES(dev)	(NVME_INT_PAGES * (dev)->ctrl.page_size)
 
 /*
  * Will slightly overestimate the number of pages needed.  This is OK
@@ -173,19 +206,22 @@ struct nvme_cmd_info {
  */
 static int nvme_npages(unsigned size, struct nvme_dev *dev)
 {
-	unsigned nprps = DIV_ROUND_UP(size + dev->page_size, dev->page_size);
+	unsigned nprps = DIV_ROUND_UP(size + dev->ctrl.page_size,
+				      dev->ctrl.page_size);
 	return DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
 }
 
-static unsigned int nvme_cmd_size(struct nvme_dev *dev)
+static unsigned int nvme_iod_alloc_size(struct nvme_dev *dev,
+		unsigned int size, unsigned int nseg)
 {
-	unsigned int ret = sizeof(struct nvme_cmd_info);
-
-	ret += sizeof(struct nvme_iod);
-	ret += sizeof(__le64 *) * nvme_npages(NVME_INT_BYTES(dev), dev);
-	ret += sizeof(struct scatterlist) * NVME_INT_PAGES;
+	return sizeof(__le64 *) * nvme_npages(size, dev) +
+			sizeof(struct scatterlist) * nseg;
+}
 
-	return ret;
+static unsigned int nvme_cmd_size(struct nvme_dev *dev)
+{
+	return sizeof(struct nvme_iod) +
+		nvme_iod_alloc_size(dev, NVME_INT_BYTES(dev), NVME_INT_PAGES);
 }
 
 static int nvme_admin_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
@@ -215,11 +251,11 @@ static int nvme_admin_init_request(void *data, struct request *req,
 				unsigned int numa_node)
 {
 	struct nvme_dev *dev = data;
-	struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
+	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
 	struct nvme_queue *nvmeq = dev->queues[0];
 
 	BUG_ON(!nvmeq);
-	cmd->nvmeq = nvmeq;
+	iod->nvmeq = nvmeq;
 	return 0;
 }
 
@@ -242,148 +278,36 @@ static int nvme_init_request(void *data, struct request *req,
 				unsigned int numa_node)
 {
 	struct nvme_dev *dev = data;
-	struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
+	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
 	struct nvme_queue *nvmeq = dev->queues[hctx_idx + 1];
 
 	BUG_ON(!nvmeq);
-	cmd->nvmeq = nvmeq;
+	iod->nvmeq = nvmeq;
 	return 0;
 }
 
-static void nvme_set_info(struct nvme_cmd_info *cmd, void *ctx,
-				nvme_completion_fn handler)
-{
-	cmd->fn = handler;
-	cmd->ctx = ctx;
-	cmd->aborted = 0;
-	blk_mq_start_request(blk_mq_rq_from_pdu(cmd));
-}
-
-static void *iod_get_private(struct nvme_iod *iod)
-{
-	return (void *) (iod->private & ~0x1UL);
-}
-
-/*
- * If bit 0 is set, the iod is embedded in the request payload.
- */
-static bool iod_should_kfree(struct nvme_iod *iod)
-{
-	return (iod->private & NVME_INT_MASK) == 0;
-}
-
-/* Special values must be less than 0x1000 */
-#define CMD_CTX_BASE		((void *)POISON_POINTER_DELTA)
-#define CMD_CTX_CANCELLED	(0x30C + CMD_CTX_BASE)
-#define CMD_CTX_COMPLETED	(0x310 + CMD_CTX_BASE)
-#define CMD_CTX_INVALID		(0x314 + CMD_CTX_BASE)
-
-static void special_completion(struct nvme_queue *nvmeq, void *ctx,
-						struct nvme_completion *cqe)
-{
-	if (ctx == CMD_CTX_CANCELLED)
-		return;
-	if (ctx == CMD_CTX_COMPLETED) {
-		dev_warn(nvmeq->q_dmadev,
-				"completed id %d twice on queue %d\n",
-				cqe->command_id, le16_to_cpup(&cqe->sq_id));
-		return;
-	}
-	if (ctx == CMD_CTX_INVALID) {
-		dev_warn(nvmeq->q_dmadev,
-				"invalid id %d completed on queue %d\n",
-				cqe->command_id, le16_to_cpup(&cqe->sq_id));
-		return;
-	}
-	dev_warn(nvmeq->q_dmadev, "Unknown special completion %p\n", ctx);
-}
-
-static void *cancel_cmd_info(struct nvme_cmd_info *cmd, nvme_completion_fn *fn)
-{
-	void *ctx;
-
-	if (fn)
-		*fn = cmd->fn;
-	ctx = cmd->ctx;
-	cmd->fn = special_completion;
-	cmd->ctx = CMD_CTX_CANCELLED;
-	return ctx;
-}
-
-static void async_req_completion(struct nvme_queue *nvmeq, void *ctx,
-						struct nvme_completion *cqe)
+static void nvme_complete_async_event(struct nvme_dev *dev,
+		struct nvme_completion *cqe)
 {
-	u32 result = le32_to_cpup(&cqe->result);
-	u16 status = le16_to_cpup(&cqe->status) >> 1;
+	u16 status = le16_to_cpu(cqe->status) >> 1;
+	u32 result = le32_to_cpu(cqe->result);
 
 	if (status == NVME_SC_SUCCESS || status == NVME_SC_ABORT_REQ)
-		++nvmeq->dev->event_limit;
+		++dev->ctrl.event_limit;
 	if (status != NVME_SC_SUCCESS)
 		return;
 
 	switch (result & 0xff07) {
 	case NVME_AER_NOTICE_NS_CHANGED:
-		dev_info(nvmeq->q_dmadev, "rescanning\n");
-		schedule_work(&nvmeq->dev->scan_work);
+		dev_info(dev->dev, "rescanning\n");
+		queue_work(nvme_workq, &dev->scan_work);
 	default:
-		dev_warn(nvmeq->q_dmadev, "async event result %08x\n", result);
+		dev_warn(dev->dev, "async event result %08x\n", result);
 	}
 }
 
-static void abort_completion(struct nvme_queue *nvmeq, void *ctx,
-						struct nvme_completion *cqe)
-{
-	struct request *req = ctx;
-
-	u16 status = le16_to_cpup(&cqe->status) >> 1;
-	u32 result = le32_to_cpup(&cqe->result);
-
-	blk_mq_free_request(req);
-
-	dev_warn(nvmeq->q_dmadev, "Abort status:%x result:%x", status, result);
-	++nvmeq->dev->abort_limit;
-}
-
-static void async_completion(struct nvme_queue *nvmeq, 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);
-	blk_mq_free_request(cmdinfo->req);
-}
-
-static inline struct nvme_cmd_info *get_cmd_from_tag(struct nvme_queue *nvmeq,
-				  unsigned int tag)
-{
-	struct request *req = blk_mq_tag_to_rq(*nvmeq->tags, tag);
-
-	return blk_mq_rq_to_pdu(req);
-}
-
-/*
- * Called with local interrupts disabled and the q_lock held.  May not sleep.
- */
-static void *nvme_finish_cmd(struct nvme_queue *nvmeq, int tag,
-						nvme_completion_fn *fn)
-{
-	struct nvme_cmd_info *cmd = get_cmd_from_tag(nvmeq, tag);
-	void *ctx;
-	if (tag >= nvmeq->q_depth) {
-		*fn = special_completion;
-		return CMD_CTX_INVALID;
-	}
-	if (fn)
-		*fn = cmd->fn;
-	ctx = cmd->ctx;
-	cmd->fn = special_completion;
-	cmd->ctx = CMD_CTX_COMPLETED;
-	return ctx;
-}
-
 /**
- * nvme_submit_cmd() - Copy a command into a queue and ring the doorbell
+ * __nvme_submit_cmd() - Copy a command into a queue and ring the doorbell
  * @nvmeq: The queue to use
  * @cmd: The command to send
  *
@@ -405,69 +329,44 @@ static void __nvme_submit_cmd(struct nvme_queue *nvmeq,
 	nvmeq->sq_tail = tail;
 }
 
-static void nvme_submit_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd)
-{
-	unsigned long flags;
-	spin_lock_irqsave(&nvmeq->q_lock, flags);
-	__nvme_submit_cmd(nvmeq, cmd);
-	spin_unlock_irqrestore(&nvmeq->q_lock, flags);
-}
-
-static __le64 **iod_list(struct nvme_iod *iod)
+static __le64 **iod_list(struct request *req)
 {
-	return ((void *)iod) + iod->offset;
+	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	return (__le64 **)(iod->sg + req->nr_phys_segments);
 }
 
-static inline void iod_init(struct nvme_iod *iod, unsigned nbytes,
-			    unsigned nseg, unsigned long private)
+static int nvme_init_iod(struct request *rq, struct nvme_dev *dev)
 {
-	iod->private = private;
-	iod->offset = offsetof(struct nvme_iod, sg[nseg]);
-	iod->npages = -1;
-	iod->length = nbytes;
-	iod->nents = 0;
-}
-
-static struct nvme_iod *
-__nvme_alloc_iod(unsigned nseg, unsigned bytes, struct nvme_dev *dev,
-		 unsigned long priv, gfp_t gfp)
-{
-	struct nvme_iod *iod = kmalloc(sizeof(struct nvme_iod) +
-				sizeof(__le64 *) * nvme_npages(bytes, dev) +
-				sizeof(struct scatterlist) * nseg, gfp);
-
-	if (iod)
-		iod_init(iod, bytes, nseg, priv);
-
-	return iod;
-}
-
-static struct nvme_iod *nvme_alloc_iod(struct request *rq, struct nvme_dev *dev,
-			               gfp_t gfp)
-{
-	unsigned size = !(rq->cmd_flags & REQ_DISCARD) ? blk_rq_bytes(rq) :
-                                                sizeof(struct nvme_dsm_range);
-	struct nvme_iod *iod;
+	struct nvme_iod *iod = blk_mq_rq_to_pdu(rq);
+	int nseg = rq->nr_phys_segments;
+	unsigned size;
 
-	if (rq->nr_phys_segments <= NVME_INT_PAGES &&
-	    size <= NVME_INT_BYTES(dev)) {
-		struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(rq);
+	if (rq->cmd_flags & REQ_DISCARD)
+		size = sizeof(struct nvme_dsm_range);
+	else
+		size = blk_rq_bytes(rq);
 
-		iod = cmd->iod;
-		iod_init(iod, size, rq->nr_phys_segments,
-				(unsigned long) rq | NVME_INT_MASK);
-		return iod;
+	if (nseg > NVME_INT_PAGES || size > NVME_INT_BYTES(dev)) {
+		iod->sg = kmalloc(nvme_iod_alloc_size(dev, size, nseg), GFP_ATOMIC);
+		if (!iod->sg)
+			return BLK_MQ_RQ_QUEUE_BUSY;
+	} else {
+		iod->sg = iod->inline_sg;
 	}
 
-	return __nvme_alloc_iod(rq->nr_phys_segments, size, dev,
-				(unsigned long) rq, gfp);
+	iod->aborted = 0;
+	iod->npages = -1;
+	iod->nents = 0;
+	iod->length = size;
+	return 0;
 }
 
-static void nvme_free_iod(struct nvme_dev *dev, struct nvme_iod *iod)
+static void nvme_free_iod(struct nvme_dev *dev, struct request *req)
 {
-	const int last_prp = dev->page_size / 8 - 1;
+	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	const int last_prp = dev->ctrl.page_size / 8 - 1;
 	int i;
-	__le64 **list = iod_list(iod);
+	__le64 **list = iod_list(req);
 	dma_addr_t prp_dma = iod->first_dma;
 
 	if (iod->npages == 0)
@@ -479,20 +378,8 @@ static void nvme_free_iod(struct nvme_dev *dev, struct nvme_iod *iod)
 		prp_dma = next_prp_dma;
 	}
 
-	if (iod_should_kfree(iod))
-		kfree(iod);
-}
-
-static int nvme_error_status(u16 status)
-{
-	switch (status & 0x7ff) {
-	case NVME_SC_SUCCESS:
-		return 0;
-	case NVME_SC_CAP_EXCEEDED:
-		return -ENOSPC;
-	default:
-		return -EIO;
-	}
+	if (iod->sg != iod->inline_sg)
+		kfree(iod->sg);
 }
 
 #ifdef CONFIG_BLK_DEV_INTEGRITY
@@ -549,27 +436,6 @@ static void nvme_dif_remap(struct request *req,
 	}
 	kunmap_atomic(pmap);
 }
-
-static void nvme_init_integrity(struct nvme_ns *ns)
-{
-	struct blk_integrity integrity;
-
-	switch (ns->pi_type) {
-	case NVME_NS_DPS_PI_TYPE3:
-		integrity.profile = &t10_pi_type3_crc;
-		break;
-	case NVME_NS_DPS_PI_TYPE1:
-	case NVME_NS_DPS_PI_TYPE2:
-		integrity.profile = &t10_pi_type1_crc;
-		break;
-	default:
-		integrity.profile = NULL;
-		break;
-	}
-	integrity.tuple_size = ns->ms;
-	blk_integrity_register(ns->disk, &integrity);
-	blk_queue_max_integrity_segments(ns->queue, 1);
-}
 #else /* CONFIG_BLK_DEV_INTEGRITY */
 static void nvme_dif_remap(struct request *req,
 			void (*dif_swap)(u32 p, u32 v, struct t10_pi_tuple *pi))
@@ -581,91 +447,27 @@ static void nvme_dif_prep(u32 p, u32 v, struct t10_pi_tuple *pi)
 static void nvme_dif_complete(u32 p, u32 v, struct t10_pi_tuple *pi)
 {
 }
-static void nvme_init_integrity(struct nvme_ns *ns)
-{
-}
 #endif
 
-static void req_completion(struct nvme_queue *nvmeq, void *ctx,
-						struct nvme_completion *cqe)
-{
-	struct nvme_iod *iod = ctx;
-	struct request *req = iod_get_private(iod);
-	struct nvme_cmd_info *cmd_rq = blk_mq_rq_to_pdu(req);
-	u16 status = le16_to_cpup(&cqe->status) >> 1;
-	bool requeue = false;
-	int error = 0;
-
-	if (unlikely(status)) {
-		if (!(status & NVME_SC_DNR || blk_noretry_request(req))
-		    && (jiffies - req->start_time) < req->timeout) {
-			unsigned long flags;
-
-			requeue = true;
-			blk_mq_requeue_request(req);
-			spin_lock_irqsave(req->q->queue_lock, flags);
-			if (!blk_queue_stopped(req->q))
-				blk_mq_kick_requeue_list(req->q);
-			spin_unlock_irqrestore(req->q->queue_lock, flags);
-			goto release_iod;
-		}
-
-		if (req->cmd_type == REQ_TYPE_DRV_PRIV) {
-			if (cmd_rq->ctx == CMD_CTX_CANCELLED)
-				error = -EINTR;
-			else
-				error = status;
-		} else {
-			error = nvme_error_status(status);
-		}
-	}
-
-	if (req->cmd_type == REQ_TYPE_DRV_PRIV) {
-		u32 result = le32_to_cpup(&cqe->result);
-		req->special = (void *)(uintptr_t)result;
-	}
-
-	if (cmd_rq->aborted)
-		dev_warn(nvmeq->dev->dev,
-			"completing aborted command with status:%04x\n",
-			error);
-
-release_iod:
-	if (iod->nents) {
-		dma_unmap_sg(nvmeq->dev->dev, iod->sg, iod->nents,
-			rq_data_dir(req) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
-		if (blk_integrity_rq(req)) {
-			if (!rq_data_dir(req))
-				nvme_dif_remap(req, nvme_dif_complete);
-			dma_unmap_sg(nvmeq->dev->dev, iod->meta_sg, 1,
-				rq_data_dir(req) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
-		}
-	}
-	nvme_free_iod(nvmeq->dev, iod);
-
-	if (likely(!requeue))
-		blk_mq_complete_request(req, error);
-}
-
-/* length is in bytes.  gfp flags indicates whether we may sleep. */
-static int nvme_setup_prps(struct nvme_dev *dev, struct nvme_iod *iod,
-		int total_len, gfp_t gfp)
+static bool nvme_setup_prps(struct nvme_dev *dev, struct request *req,
+		int total_len)
 {
+	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
 	struct dma_pool *pool;
 	int length = total_len;
 	struct scatterlist *sg = iod->sg;
 	int dma_len = sg_dma_len(sg);
 	u64 dma_addr = sg_dma_address(sg);
-	u32 page_size = dev->page_size;
+	u32 page_size = dev->ctrl.page_size;
 	int offset = dma_addr & (page_size - 1);
 	__le64 *prp_list;
-	__le64 **list = iod_list(iod);
+	__le64 **list = iod_list(req);
 	dma_addr_t prp_dma;
 	int nprps, i;
 
 	length -= (page_size - offset);
 	if (length <= 0)
-		return total_len;
+		return true;
 
 	dma_len -= (page_size - offset);
 	if (dma_len) {
@@ -678,7 +480,7 @@ static int nvme_setup_prps(struct nvme_dev *dev, struct nvme_iod *iod,
 
 	if (length <= page_size) {
 		iod->first_dma = dma_addr;
-		return total_len;
+		return true;
 	}
 
 	nprps = DIV_ROUND_UP(length, page_size);
@@ -690,11 +492,11 @@ static int nvme_setup_prps(struct nvme_dev *dev, struct nvme_iod *iod,
 		iod->npages = 1;
 	}
 
-	prp_list = dma_pool_alloc(pool, gfp, &prp_dma);
+	prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
 	if (!prp_list) {
 		iod->first_dma = dma_addr;
 		iod->npages = -1;
-		return (total_len - length) + page_size;
+		return false;
 	}
 	list[0] = prp_list;
 	iod->first_dma = prp_dma;
@@ -702,9 +504,9 @@ static int nvme_setup_prps(struct nvme_dev *dev, struct nvme_iod *iod,
 	for (;;) {
 		if (i == page_size >> 3) {
 			__le64 *old_prp_list = prp_list;
-			prp_list = dma_pool_alloc(pool, gfp, &prp_dma);
+			prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
 			if (!prp_list)
-				return total_len - length;
+				return false;
 			list[iod->npages++] = prp_list;
 			prp_list[0] = old_prp_list[i - 1];
 			old_prp_list[i - 1] = cpu_to_le64(prp_dma);
@@ -724,115 +526,105 @@ static int nvme_setup_prps(struct nvme_dev *dev, struct nvme_iod *iod,
 		dma_len = sg_dma_len(sg);
 	}
 
-	return total_len;
+	return true;
 }
 
-static void nvme_submit_priv(struct nvme_queue *nvmeq, struct request *req,
-		struct nvme_iod *iod)
+static int nvme_map_data(struct nvme_dev *dev, struct request *req,
+		struct nvme_command *cmnd)
 {
-	struct nvme_command cmnd;
+	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	struct request_queue *q = req->q;
+	enum dma_data_direction dma_dir = rq_data_dir(req) ?
+			DMA_TO_DEVICE : DMA_FROM_DEVICE;
+	int ret = BLK_MQ_RQ_QUEUE_ERROR;
 
-	memcpy(&cmnd, req->cmd, sizeof(cmnd));
-	cmnd.rw.command_id = req->tag;
-	if (req->nr_phys_segments) {
-		cmnd.rw.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
-		cmnd.rw.prp2 = cpu_to_le64(iod->first_dma);
-	}
+	sg_init_table(iod->sg, req->nr_phys_segments);
+	iod->nents = blk_rq_map_sg(q, req, iod->sg);
+	if (!iod->nents)
+		goto out;
 
-	__nvme_submit_cmd(nvmeq, &cmnd);
-}
+	ret = BLK_MQ_RQ_QUEUE_BUSY;
+	if (!dma_map_sg(dev->dev, iod->sg, iod->nents, dma_dir))
+		goto out;
 
-/*
- * We reuse the small pool to allocate the 16-byte range here as it is not
- * worth having a special pool for these or additional cases to handle freeing
- * the iod.
- */
-static void nvme_submit_discard(struct nvme_queue *nvmeq, struct nvme_ns *ns,
-		struct request *req, struct nvme_iod *iod)
-{
-	struct nvme_dsm_range *range =
-				(struct nvme_dsm_range *)iod_list(iod)[0];
-	struct nvme_command cmnd;
+	if (!nvme_setup_prps(dev, req, blk_rq_bytes(req)))
+		goto out_unmap;
 
-	range->cattr = cpu_to_le32(0);
-	range->nlb = cpu_to_le32(blk_rq_bytes(req) >> ns->lba_shift);
-	range->slba = cpu_to_le64(nvme_block_nr(ns, blk_rq_pos(req)));
+	ret = BLK_MQ_RQ_QUEUE_ERROR;
+	if (blk_integrity_rq(req)) {
+		if (blk_rq_count_integrity_sg(q, req->bio) != 1)
+			goto out_unmap;
 
-	memset(&cmnd, 0, sizeof(cmnd));
-	cmnd.dsm.opcode = nvme_cmd_dsm;
-	cmnd.dsm.command_id = req->tag;
-	cmnd.dsm.nsid = cpu_to_le32(ns->ns_id);
-	cmnd.dsm.prp1 = cpu_to_le64(iod->first_dma);
-	cmnd.dsm.nr = 0;
-	cmnd.dsm.attributes = cpu_to_le32(NVME_DSMGMT_AD);
+		sg_init_table(&iod->meta_sg, 1);
+		if (blk_rq_map_integrity_sg(q, req->bio, &iod->meta_sg) != 1)
+			goto out_unmap;
 
-	__nvme_submit_cmd(nvmeq, &cmnd);
-}
+		if (rq_data_dir(req))
+			nvme_dif_remap(req, nvme_dif_prep);
 
-static void nvme_submit_flush(struct nvme_queue *nvmeq, struct nvme_ns *ns,
-								int cmdid)
-{
-	struct nvme_command cmnd;
+		if (!dma_map_sg(dev->dev, &iod->meta_sg, 1, dma_dir))
+			goto out_unmap;
+	}
 
-	memset(&cmnd, 0, sizeof(cmnd));
-	cmnd.common.opcode = nvme_cmd_flush;
-	cmnd.common.command_id = cmdid;
-	cmnd.common.nsid = cpu_to_le32(ns->ns_id);
+	cmnd->rw.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
+	cmnd->rw.prp2 = cpu_to_le64(iod->first_dma);
+	if (blk_integrity_rq(req))
+		cmnd->rw.metadata = cpu_to_le64(sg_dma_address(&iod->meta_sg));
+	return BLK_MQ_RQ_QUEUE_OK;
 
-	__nvme_submit_cmd(nvmeq, &cmnd);
+out_unmap:
+	dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
+out:
+	return ret;
 }
 
-static int nvme_submit_iod(struct nvme_queue *nvmeq, struct nvme_iod *iod,
-							struct nvme_ns *ns)
+static void nvme_unmap_data(struct nvme_dev *dev, struct request *req)
 {
-	struct request *req = iod_get_private(iod);
-	struct nvme_command cmnd;
-	u16 control = 0;
-	u32 dsmgmt = 0;
-
-	if (req->cmd_flags & REQ_FUA)
-		control |= NVME_RW_FUA;
-	if (req->cmd_flags & (REQ_FAILFAST_DEV | REQ_RAHEAD))
-		control |= NVME_RW_LR;
-
-	if (req->cmd_flags & REQ_RAHEAD)
-		dsmgmt |= NVME_RW_DSM_FREQ_PREFETCH;
-
-	memset(&cmnd, 0, sizeof(cmnd));
-	cmnd.rw.opcode = (rq_data_dir(req) ? nvme_cmd_write : nvme_cmd_read);
-	cmnd.rw.command_id = req->tag;
-	cmnd.rw.nsid = cpu_to_le32(ns->ns_id);
-	cmnd.rw.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
-	cmnd.rw.prp2 = cpu_to_le64(iod->first_dma);
-	cmnd.rw.slba = cpu_to_le64(nvme_block_nr(ns, blk_rq_pos(req)));
-	cmnd.rw.length = cpu_to_le16((blk_rq_bytes(req) >> ns->lba_shift) - 1);
-
-	if (ns->ms) {
-		switch (ns->pi_type) {
-		case NVME_NS_DPS_PI_TYPE3:
-			control |= NVME_RW_PRINFO_PRCHK_GUARD;
-			break;
-		case NVME_NS_DPS_PI_TYPE1:
-		case NVME_NS_DPS_PI_TYPE2:
-			control |= NVME_RW_PRINFO_PRCHK_GUARD |
-					NVME_RW_PRINFO_PRCHK_REF;
-			cmnd.rw.reftag = cpu_to_le32(
-					nvme_block_nr(ns, blk_rq_pos(req)));
-			break;
+	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	enum dma_data_direction dma_dir = rq_data_dir(req) ?
+			DMA_TO_DEVICE : DMA_FROM_DEVICE;
+
+	if (iod->nents) {
+		dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
+		if (blk_integrity_rq(req)) {
+			if (!rq_data_dir(req))
+				nvme_dif_remap(req, nvme_dif_complete);
+			dma_unmap_sg(dev->dev, &iod->meta_sg, 1, dma_dir);
 		}
-		if (blk_integrity_rq(req))
-			cmnd.rw.metadata =
-				cpu_to_le64(sg_dma_address(iod->meta_sg));
-		else
-			control |= NVME_RW_PRINFO_PRACT;
 	}
 
-	cmnd.rw.control = cpu_to_le16(control);
-	cmnd.rw.dsmgmt = cpu_to_le32(dsmgmt);
+	nvme_free_iod(dev, req);
+}
 
-	__nvme_submit_cmd(nvmeq, &cmnd);
+/*
+ * We reuse the small pool to allocate the 16-byte range here as it is not
+ * worth having a special pool for these or additional cases to handle freeing
+ * the iod.
+ */
+static int nvme_setup_discard(struct nvme_queue *nvmeq, struct nvme_ns *ns,
+		struct request *req, struct nvme_command *cmnd)
+{
+	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	struct nvme_dsm_range *range;
 
-	return 0;
+	range = dma_pool_alloc(nvmeq->dev->prp_small_pool, GFP_ATOMIC,
+						&iod->first_dma);
+	if (!range)
+		return BLK_MQ_RQ_QUEUE_BUSY;
+	iod_list(req)[0] = (__le64 *)range;
+	iod->npages = 0;
+
+	range->cattr = cpu_to_le32(0);
+	range->nlb = cpu_to_le32(blk_rq_bytes(req) >> ns->lba_shift);
+	range->slba = cpu_to_le64(nvme_block_nr(ns, blk_rq_pos(req)));
+
+	memset(cmnd, 0, sizeof(*cmnd));
+	cmnd->dsm.opcode = nvme_cmd_dsm;
+	cmnd->dsm.nsid = cpu_to_le32(ns->ns_id);
+	cmnd->dsm.prp1 = cpu_to_le64(iod->first_dma);
+	cmnd->dsm.nr = 0;
+	cmnd->dsm.attributes = cpu_to_le32(NVME_DSMGMT_AD);
+	return BLK_MQ_RQ_QUEUE_OK;
 }
 
 /*
@@ -845,9 +637,8 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
 	struct nvme_queue *nvmeq = hctx->driver_data;
 	struct nvme_dev *dev = nvmeq->dev;
 	struct request *req = bd->rq;
-	struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
-	struct nvme_iod *iod;
-	enum dma_data_direction dma_dir;
+	struct nvme_command cmnd;
+	int ret = BLK_MQ_RQ_QUEUE_OK;
 
 	/*
 	 * If formated with metadata, require the block layer provide a buffer
@@ -857,91 +648,72 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
 	if (ns && ns->ms && !blk_integrity_rq(req)) {
 		if (!(ns->pi_type && ns->ms == 8) &&
 					req->cmd_type != REQ_TYPE_DRV_PRIV) {
-			blk_mq_complete_request(req, -EFAULT);
+			blk_mq_end_request(req, -EFAULT);
 			return BLK_MQ_RQ_QUEUE_OK;
 		}
 	}
 
-	iod = nvme_alloc_iod(req, dev, GFP_ATOMIC);
-	if (!iod)
-		return BLK_MQ_RQ_QUEUE_BUSY;
+	ret = nvme_init_iod(req, dev);
+	if (ret)
+		return ret;
 
 	if (req->cmd_flags & REQ_DISCARD) {
-		void *range;
-		/*
-		 * We reuse the small pool to allocate the 16-byte range here
-		 * as it is not worth having a special pool for these or
-		 * additional cases to handle freeing the iod.
-		 */
-		range = dma_pool_alloc(dev->prp_small_pool, GFP_ATOMIC,
-						&iod->first_dma);
-		if (!range)
-			goto retry_cmd;
-		iod_list(iod)[0] = (__le64 *)range;
-		iod->npages = 0;
-	} else if (req->nr_phys_segments) {
-		dma_dir = rq_data_dir(req) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+		ret = nvme_setup_discard(nvmeq, ns, req, &cmnd);
+	} else {
+		if (req->cmd_type == REQ_TYPE_DRV_PRIV)
+			memcpy(&cmnd, req->cmd, sizeof(cmnd));
+		else if (req->cmd_flags & REQ_FLUSH)
+			nvme_setup_flush(ns, &cmnd);
+		else
+			nvme_setup_rw(ns, req, &cmnd);
 
-		sg_init_table(iod->sg, req->nr_phys_segments);
-		iod->nents = blk_rq_map_sg(req->q, req, iod->sg);
-		if (!iod->nents)
-			goto error_cmd;
+		if (req->nr_phys_segments)
+			ret = nvme_map_data(dev, req, &cmnd);
+	}
 
-		if (!dma_map_sg(nvmeq->q_dmadev, iod->sg, iod->nents, dma_dir))
-			goto retry_cmd;
+	if (ret)
+		goto out;
 
-		if (blk_rq_bytes(req) !=
-                    nvme_setup_prps(dev, iod, blk_rq_bytes(req), GFP_ATOMIC)) {
-			dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
-			goto retry_cmd;
-		}
-		if (blk_integrity_rq(req)) {
-			if (blk_rq_count_integrity_sg(req->q, req->bio) != 1) {
-				dma_unmap_sg(dev->dev, iod->sg, iod->nents,
-						dma_dir);
-				goto error_cmd;
-			}
+	cmnd.common.command_id = req->tag;
+	blk_mq_start_request(req);
 
-			sg_init_table(iod->meta_sg, 1);
-			if (blk_rq_map_integrity_sg(
-					req->q, req->bio, iod->meta_sg) != 1) {
-				dma_unmap_sg(dev->dev, iod->sg, iod->nents,
-						dma_dir);
-				goto error_cmd;
-			}
+	spin_lock_irq(&nvmeq->q_lock);
+	__nvme_submit_cmd(nvmeq, &cmnd);
+	nvme_process_cq(nvmeq);
+	spin_unlock_irq(&nvmeq->q_lock);
+	return BLK_MQ_RQ_QUEUE_OK;
+out:
+	nvme_free_iod(dev, req);
+	return ret;
+}
 
-			if (rq_data_dir(req))
-				nvme_dif_remap(req, nvme_dif_prep);
+static void nvme_complete_rq(struct request *req)
+{
+	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	struct nvme_dev *dev = iod->nvmeq->dev;
+	int error = 0;
 
-			if (!dma_map_sg(nvmeq->q_dmadev, iod->meta_sg, 1, dma_dir)) {
-				dma_unmap_sg(dev->dev, iod->sg, iod->nents,
-						dma_dir);
-				goto error_cmd;
-			}
+	nvme_unmap_data(dev, req);
+
+	if (unlikely(req->errors)) {
+		if (nvme_req_needs_retry(req, req->errors)) {
+			nvme_requeue_req(req);
+			return;
 		}
-	}
 
-	nvme_set_info(cmd, iod, req_completion);
-	spin_lock_irq(&nvmeq->q_lock);
-	if (req->cmd_type == REQ_TYPE_DRV_PRIV)
-		nvme_submit_priv(nvmeq, req, iod);
-	else if (req->cmd_flags & REQ_DISCARD)
-		nvme_submit_discard(nvmeq, ns, req, iod);
-	else if (req->cmd_flags & REQ_FLUSH)
-		nvme_submit_flush(nvmeq, ns, req->tag);
-	else
-		nvme_submit_iod(nvmeq, iod, ns);
+		if (req->cmd_type == REQ_TYPE_DRV_PRIV)
+			error = req->errors;
+		else
+			error = nvme_error_status(req->errors);
+	}
 
-	nvme_process_cq(nvmeq);
-	spin_unlock_irq(&nvmeq->q_lock);
-	return BLK_MQ_RQ_QUEUE_OK;
+	if (unlikely(iod->aborted)) {
+		dev_warn(dev->dev,
+			"completing aborted command with status: %04x\n",
+			req->errors);
+	}
 
- error_cmd:
-	nvme_free_iod(dev, iod);
-	return BLK_MQ_RQ_QUEUE_ERROR;
- retry_cmd:
-	nvme_free_iod(dev, iod);
-	return BLK_MQ_RQ_QUEUE_BUSY;
+	blk_mq_end_request(req, error);
 }
 
 static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
@@ -952,20 +724,47 @@ static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
 	phase = nvmeq->cq_phase;
 
 	for (;;) {
-		void *ctx;
-		nvme_completion_fn fn;
 		struct nvme_completion cqe = nvmeq->cqes[head];
-		if ((le16_to_cpu(cqe.status) & 1) != phase)
+		u16 status = le16_to_cpu(cqe.status);
+		struct request *req;
+
+		if ((status & 1) != phase)
 			break;
 		nvmeq->sq_head = le16_to_cpu(cqe.sq_head);
 		if (++head == nvmeq->q_depth) {
 			head = 0;
 			phase = !phase;
 		}
+
 		if (tag && *tag == cqe.command_id)
 			*tag = -1;
-		ctx = nvme_finish_cmd(nvmeq, cqe.command_id, &fn);
-		fn(nvmeq, ctx, &cqe);
+
+		if (unlikely(cqe.command_id >= nvmeq->q_depth)) {
+			dev_warn(nvmeq->q_dmadev,
+				"invalid id %d completed on queue %d\n",
+				cqe.command_id, le16_to_cpu(cqe.sq_id));
+			continue;
+		}
+
+		/*
+		 * AEN requests are special as they don't time out and can
+		 * survive any kind of queue freeze and often don't respond to
+		 * aborts.  We don't even bother to allocate a struct request
+		 * for them but rather special case them here.
+		 */
+		if (unlikely(nvmeq->qid == 0 &&
+				cqe.command_id >= NVME_AQ_BLKMQ_DEPTH)) {
+			nvme_complete_async_event(nvmeq->dev, &cqe);
+			continue;
+		}
+
+		req = blk_mq_tag_to_rq(*nvmeq->tags, cqe.command_id);
+		if (req->cmd_type == REQ_TYPE_DRV_PRIV) {
+			u32 result = le32_to_cpu(cqe.result);
+			req->special = (void *)(uintptr_t)result;
+		}
+		blk_mq_complete_request(req, status >> 1);
+
 	}
 
 	/* If the controller ignores the cq head doorbell and continuously
@@ -1028,112 +827,15 @@ static int nvme_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
 	return 0;
 }
 
-/*
- * Returns 0 on success.  If the result is negative, it's a Linux error code;
- * if the result is positive, it's an NVM Express status code
- */
-int __nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
-		void *buffer, void __user *ubuffer, unsigned bufflen,
-		u32 *result, unsigned timeout)
-{
-	bool write = cmd->common.opcode & 1;
-	struct bio *bio = NULL;
-	struct request *req;
-	int ret;
-
-	req = blk_mq_alloc_request(q, write, 0);
-	if (IS_ERR(req))
-		return PTR_ERR(req);
-
-	req->cmd_type = REQ_TYPE_DRV_PRIV;
-	req->cmd_flags |= REQ_FAILFAST_DRIVER;
-	req->__data_len = 0;
-	req->__sector = (sector_t) -1;
-	req->bio = req->biotail = NULL;
-
-	req->timeout = timeout ? timeout : ADMIN_TIMEOUT;
-
-	req->cmd = (unsigned char *)cmd;
-	req->cmd_len = sizeof(struct nvme_command);
-	req->special = (void *)0;
-
-	if (buffer && bufflen) {
-		ret = blk_rq_map_kern(q, req, buffer, bufflen,
-				      __GFP_DIRECT_RECLAIM);
-		if (ret)
-			goto out;
-	} else if (ubuffer && bufflen) {
-		ret = blk_rq_map_user(q, req, NULL, ubuffer, bufflen,
-				      __GFP_DIRECT_RECLAIM);
-		if (ret)
-			goto out;
-		bio = req->bio;
-	}
-
-	blk_execute_rq(req->q, NULL, req, 0);
-	if (bio)
-		blk_rq_unmap_user(bio);
-	if (result)
-		*result = (u32)(uintptr_t)req->special;
-	ret = req->errors;
- out:
-	blk_mq_free_request(req);
-	return ret;
-}
-
-int nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
-		void *buffer, unsigned bufflen)
-{
-	return __nvme_submit_sync_cmd(q, cmd, buffer, NULL, bufflen, NULL, 0);
-}
-
-static int nvme_submit_async_admin_req(struct nvme_dev *dev)
+static void nvme_submit_async_event(struct nvme_dev *dev)
 {
-	struct nvme_queue *nvmeq = dev->queues[0];
 	struct nvme_command c;
-	struct nvme_cmd_info *cmd_info;
-	struct request *req;
-
-	req = blk_mq_alloc_request(dev->admin_q, WRITE,
-			BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED);
-	if (IS_ERR(req))
-		return PTR_ERR(req);
-
-	req->cmd_flags |= REQ_NO_TIMEOUT;
-	cmd_info = blk_mq_rq_to_pdu(req);
-	nvme_set_info(cmd_info, NULL, async_req_completion);
 
 	memset(&c, 0, sizeof(c));
 	c.common.opcode = nvme_admin_async_event;
-	c.common.command_id = req->tag;
-
-	blk_mq_free_request(req);
-	__nvme_submit_cmd(nvmeq, &c);
-	return 0;
-}
-
-static int nvme_submit_admin_async_cmd(struct nvme_dev *dev,
-			struct nvme_command *cmd,
-			struct async_cmd_info *cmdinfo, unsigned timeout)
-{
-	struct nvme_queue *nvmeq = dev->queues[0];
-	struct request *req;
-	struct nvme_cmd_info *cmd_rq;
-
-	req = blk_mq_alloc_request(dev->admin_q, WRITE, 0);
-	if (IS_ERR(req))
-		return PTR_ERR(req);
-
-	req->timeout = timeout;
-	cmd_rq = blk_mq_rq_to_pdu(req);
-	cmdinfo->req = req;
-	nvme_set_info(cmd_rq, cmdinfo, async_completion);
-	cmdinfo->status = -EINTR;
+	c.common.command_id = NVME_AQ_BLKMQ_DEPTH + --dev->ctrl.event_limit;
 
-	cmd->common.command_id = req->tag;
-
-	nvme_submit_cmd(nvmeq, cmd);
-	return 0;
+	__nvme_submit_cmd(dev->queues[0], &c);
 }
 
 static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
@@ -1144,7 +846,7 @@ static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
 	c.delete_queue.opcode = opcode;
 	c.delete_queue.qid = cpu_to_le16(id);
 
-	return nvme_submit_sync_cmd(dev->admin_q, &c, NULL, 0);
+	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
 }
 
 static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
@@ -1165,7 +867,7 @@ static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
 	c.create_cq.cq_flags = cpu_to_le16(flags);
 	c.create_cq.irq_vector = cpu_to_le16(nvmeq->cq_vector);
 
-	return nvme_submit_sync_cmd(dev->admin_q, &c, NULL, 0);
+	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
 }
 
 static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
@@ -1186,7 +888,7 @@ static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
 	c.create_sq.sq_flags = cpu_to_le16(flags);
 	c.create_sq.cqid = cpu_to_le16(qid);
 
-	return nvme_submit_sync_cmd(dev->admin_q, &c, NULL, 0);
+	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
 }
 
 static int adapter_delete_cq(struct nvme_dev *dev, u16 cqid)
@@ -1199,195 +901,111 @@ static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
 	return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
 }
 
-int nvme_identify_ctrl(struct nvme_dev *dev, struct nvme_id_ctrl **id)
-{
-	struct nvme_command c = { };
-	int error;
-
-	/* gcc-4.4.4 (at least) has issues with initializers and anon unions */
-	c.identify.opcode = nvme_admin_identify;
-	c.identify.cns = cpu_to_le32(1);
-
-	*id = kmalloc(sizeof(struct nvme_id_ctrl), GFP_KERNEL);
-	if (!*id)
-		return -ENOMEM;
-
-	error = nvme_submit_sync_cmd(dev->admin_q, &c, *id,
-			sizeof(struct nvme_id_ctrl));
-	if (error)
-		kfree(*id);
-	return error;
-}
-
-int nvme_identify_ns(struct nvme_dev *dev, unsigned nsid,
-		struct nvme_id_ns **id)
-{
-	struct nvme_command c = { };
-	int error;
-
-	/* gcc-4.4.4 (at least) has issues with initializers and anon unions */
-	c.identify.opcode = nvme_admin_identify,
-	c.identify.nsid = cpu_to_le32(nsid),
-
-	*id = kmalloc(sizeof(struct nvme_id_ns), GFP_KERNEL);
-	if (!*id)
-		return -ENOMEM;
-
-	error = nvme_submit_sync_cmd(dev->admin_q, &c, *id,
-			sizeof(struct nvme_id_ns));
-	if (error)
-		kfree(*id);
-	return error;
-}
-
-int nvme_get_features(struct nvme_dev *dev, unsigned fid, unsigned nsid,
-					dma_addr_t dma_addr, u32 *result)
-{
-	struct nvme_command c;
-
-	memset(&c, 0, sizeof(c));
-	c.features.opcode = nvme_admin_get_features;
-	c.features.nsid = cpu_to_le32(nsid);
-	c.features.prp1 = cpu_to_le64(dma_addr);
-	c.features.fid = cpu_to_le32(fid);
-
-	return __nvme_submit_sync_cmd(dev->admin_q, &c, NULL, NULL, 0,
-			result, 0);
-}
-
-int nvme_set_features(struct nvme_dev *dev, unsigned fid, unsigned dword11,
-					dma_addr_t dma_addr, u32 *result)
-{
-	struct nvme_command c;
-
-	memset(&c, 0, sizeof(c));
-	c.features.opcode = nvme_admin_set_features;
-	c.features.prp1 = cpu_to_le64(dma_addr);
-	c.features.fid = cpu_to_le32(fid);
-	c.features.dword11 = cpu_to_le32(dword11);
-
-	return __nvme_submit_sync_cmd(dev->admin_q, &c, NULL, NULL, 0,
-			result, 0);
-}
-
-int nvme_get_log_page(struct nvme_dev *dev, struct nvme_smart_log **log)
+static void abort_endio(struct request *req, int error)
 {
-	struct nvme_command c = { };
-	int error;
-
-	c.common.opcode = nvme_admin_get_log_page,
-	c.common.nsid = cpu_to_le32(0xFFFFFFFF),
-	c.common.cdw10[0] = cpu_to_le32(
-			(((sizeof(struct nvme_smart_log) / 4) - 1) << 16) |
-			 NVME_LOG_SMART),
+	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	struct nvme_queue *nvmeq = iod->nvmeq;
+	u32 result = (u32)(uintptr_t)req->special;
+	u16 status = req->errors;
 
-	*log = kmalloc(sizeof(struct nvme_smart_log), GFP_KERNEL);
-	if (!*log)
-		return -ENOMEM;
+	dev_warn(nvmeq->q_dmadev, "Abort status:%x result:%x", status, result);
+	atomic_inc(&nvmeq->dev->ctrl.abort_limit);
 
-	error = nvme_submit_sync_cmd(dev->admin_q, &c, *log,
-			sizeof(struct nvme_smart_log));
-	if (error)
-		kfree(*log);
-	return error;
+	blk_mq_free_request(req);
 }
 
-/**
- * nvme_abort_req - Attempt aborting a request
- *
- * 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_req(struct request *req)
+static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
 {
-	struct nvme_cmd_info *cmd_rq = blk_mq_rq_to_pdu(req);
-	struct nvme_queue *nvmeq = cmd_rq->nvmeq;
+	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	struct nvme_queue *nvmeq = iod->nvmeq;
 	struct nvme_dev *dev = nvmeq->dev;
 	struct request *abort_req;
-	struct nvme_cmd_info *abort_cmd;
 	struct nvme_command cmd;
 
-	if (!nvmeq->qid || cmd_rq->aborted) {
-		spin_lock(&dev_list_lock);
-		if (!__nvme_reset(dev)) {
-			dev_warn(dev->dev,
-				 "I/O %d QID %d timeout, reset controller\n",
-				 req->tag, nvmeq->qid);
-		}
-		spin_unlock(&dev_list_lock);
-		return;
+	/*
+	 * Shutdown immediately if controller times out while starting. The
+	 * reset work will see the pci device disabled when it gets the forced
+	 * cancellation error. All outstanding requests are completed on
+	 * shutdown, so we return BLK_EH_HANDLED.
+	 */
+	if (test_bit(NVME_CTRL_RESETTING, &dev->flags)) {
+		dev_warn(dev->dev,
+			 "I/O %d QID %d timeout, disable controller\n",
+			 req->tag, nvmeq->qid);
+		nvme_dev_disable(dev, false);
+		req->errors = NVME_SC_CANCELLED;
+		return BLK_EH_HANDLED;
 	}
 
-	if (!dev->abort_limit)
-		return;
+	/*
+ 	 * Shutdown the controller immediately and schedule a 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.
+	 */
+	if (!nvmeq->qid || iod->aborted) {
+		dev_warn(dev->dev,
+			 "I/O %d QID %d timeout, reset controller\n",
+			 req->tag, nvmeq->qid);
+		nvme_dev_disable(dev, false);
+		queue_work(nvme_workq, &dev->reset_work);
 
-	abort_req = blk_mq_alloc_request(dev->admin_q, WRITE,
-			BLK_MQ_REQ_NOWAIT);
-	if (IS_ERR(abort_req))
-		return;
+		/*
+		 * Mark the request as handled, since the inline shutdown
+		 * forces all outstanding requests to complete.
+		 */
+		req->errors = NVME_SC_CANCELLED;
+		return BLK_EH_HANDLED;
+	}
 
-	abort_cmd = blk_mq_rq_to_pdu(abort_req);
-	nvme_set_info(abort_cmd, abort_req, abort_completion);
+	iod->aborted = 1;
+
+	if (atomic_dec_return(&dev->ctrl.abort_limit) < 0) {
+		atomic_inc(&dev->ctrl.abort_limit);
+		return BLK_EH_RESET_TIMER;
+	}
 
 	memset(&cmd, 0, sizeof(cmd));
 	cmd.abort.opcode = nvme_admin_abort_cmd;
 	cmd.abort.cid = req->tag;
 	cmd.abort.sqid = cpu_to_le16(nvmeq->qid);
-	cmd.abort.command_id = abort_req->tag;
 
-	--dev->abort_limit;
-	cmd_rq->aborted = 1;
+	dev_warn(nvmeq->q_dmadev, "I/O %d QID %d timeout, aborting\n",
+				 req->tag, nvmeq->qid);
 
-	dev_warn(nvmeq->q_dmadev, "Aborting I/O %d QID %d\n", req->tag,
-							nvmeq->qid);
-	nvme_submit_cmd(dev->queues[0], &cmd);
+	abort_req = nvme_alloc_request(dev->ctrl.admin_q, &cmd,
+			BLK_MQ_REQ_NOWAIT);
+	if (IS_ERR(abort_req)) {
+		atomic_inc(&dev->ctrl.abort_limit);
+		return BLK_EH_RESET_TIMER;
+	}
+
+	abort_req->timeout = ADMIN_TIMEOUT;
+	abort_req->end_io_data = NULL;
+	blk_execute_rq_nowait(abort_req->q, NULL, abort_req, 0, abort_endio);
+
+	/*
+	 * The aborted req will be completed on receiving the abort req.
+	 * We enable the timer again. If hit twice, it'll cause a device reset,
+	 * as the device then is in a faulty state.
+	 */
+	return BLK_EH_RESET_TIMER;
 }
 
 static void nvme_cancel_queue_ios(struct request *req, void *data, bool reserved)
 {
 	struct nvme_queue *nvmeq = data;
-	void *ctx;
-	nvme_completion_fn fn;
-	struct nvme_cmd_info *cmd;
-	struct nvme_completion cqe;
+	int status;
 
 	if (!blk_mq_request_started(req))
 		return;
 
-	cmd = blk_mq_rq_to_pdu(req);
-
-	if (cmd->ctx == CMD_CTX_CANCELLED)
-		return;
+	dev_warn(nvmeq->q_dmadev,
+		 "Cancelling I/O %d QID %d\n", req->tag, nvmeq->qid);
 
+	status = NVME_SC_ABORT_REQ;
 	if (blk_queue_dying(req->q))
-		cqe.status = cpu_to_le16((NVME_SC_ABORT_REQ | NVME_SC_DNR) << 1);
-	else
-		cqe.status = cpu_to_le16(NVME_SC_ABORT_REQ << 1);
-
-
-	dev_warn(nvmeq->q_dmadev, "Cancelling I/O %d QID %d\n",
-						req->tag, nvmeq->qid);
-	ctx = cancel_cmd_info(cmd, &fn);
-	fn(nvmeq, ctx, &cqe);
-}
-
-static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
-{
-	struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
-	struct nvme_queue *nvmeq = cmd->nvmeq;
-
-	dev_warn(nvmeq->q_dmadev, "Timeout I/O %d QID %d\n", req->tag,
-							nvmeq->qid);
-	spin_lock_irq(&nvmeq->q_lock);
-	nvme_abort_req(req);
-	spin_unlock_irq(&nvmeq->q_lock);
-
-	/*
-	 * The aborted req will be completed on receiving the abort req.
-	 * We enable the timer again. If hit twice, it'll cause a device reset,
-	 * as the device then is in a faulty state.
-	 */
-	return BLK_EH_RESET_TIMER;
+		status |= NVME_SC_DNR;
+	blk_mq_complete_request(req, status);
 }
 
 static void nvme_free_queue(struct nvme_queue *nvmeq)
@@ -1430,8 +1048,8 @@ static int nvme_suspend_queue(struct nvme_queue *nvmeq)
 	nvmeq->cq_vector = -1;
 	spin_unlock_irq(&nvmeq->q_lock);
 
-	if (!nvmeq->qid && nvmeq->dev->admin_q)
-		blk_mq_freeze_queue_start(nvmeq->dev->admin_q);
+	if (!nvmeq->qid && nvmeq->dev->ctrl.admin_q)
+		blk_mq_stop_hw_queues(nvmeq->dev->ctrl.admin_q);
 
 	irq_set_affinity_hint(vector, NULL);
 	free_irq(vector, nvmeq);
@@ -1447,21 +1065,20 @@ static void nvme_clear_queue(struct nvme_queue *nvmeq)
 	spin_unlock_irq(&nvmeq->q_lock);
 }
 
-static void nvme_disable_queue(struct nvme_dev *dev, int qid)
+static void nvme_disable_admin_queue(struct nvme_dev *dev, bool shutdown)
 {
-	struct nvme_queue *nvmeq = dev->queues[qid];
+	struct nvme_queue *nvmeq = dev->queues[0];
 
 	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);
-	}
+	if (shutdown)
+		nvme_shutdown_ctrl(&dev->ctrl);
+	else
+		nvme_disable_ctrl(&dev->ctrl, lo_hi_readq(
+						dev->bar + NVME_REG_CAP));
 
 	spin_lock_irq(&nvmeq->q_lock);
 	nvme_process_cq(nvmeq);
@@ -1472,11 +1089,12 @@ static int nvme_cmb_qdepth(struct nvme_dev *dev, int nr_io_queues,
 				int entry_size)
 {
 	int q_depth = dev->q_depth;
-	unsigned q_size_aligned = roundup(q_depth * entry_size, dev->page_size);
+	unsigned q_size_aligned = roundup(q_depth * entry_size,
+					  dev->ctrl.page_size);
 
 	if (q_size_aligned * nr_io_queues > dev->cmb_size) {
 		u64 mem_per_q = div_u64(dev->cmb_size, nr_io_queues);
-		mem_per_q = round_down(mem_per_q, dev->page_size);
+		mem_per_q = round_down(mem_per_q, dev->ctrl.page_size);
 		q_depth = div_u64(mem_per_q, entry_size);
 
 		/*
@@ -1495,8 +1113,8 @@ static int nvme_alloc_sq_cmds(struct nvme_dev *dev, struct nvme_queue *nvmeq,
 				int qid, int depth)
 {
 	if (qid && dev->cmb && use_cmb_sqes && NVME_CMB_SQS(dev->cmbsz)) {
-		unsigned offset = (qid - 1) *
-					roundup(SQ_SIZE(depth), dev->page_size);
+		unsigned offset = (qid - 1) * roundup(SQ_SIZE(depth),
+						      dev->ctrl.page_size);
 		nvmeq->sq_dma_addr = dev->cmb_dma_addr + offset;
 		nvmeq->sq_cmds_io = dev->cmb + offset;
 	} else {
@@ -1527,7 +1145,7 @@ static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
 	nvmeq->q_dmadev = dev->dev;
 	nvmeq->dev = dev;
 	snprintf(nvmeq->irqname, sizeof(nvmeq->irqname), "nvme%dq%d",
-			dev->instance, qid);
+			dev->ctrl.instance, qid);
 	spin_lock_init(&nvmeq->q_lock);
 	nvmeq->cq_head = 0;
 	nvmeq->cq_phase = 1;
@@ -1604,79 +1222,9 @@ static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
 	return result;
 }
 
-static int nvme_wait_ready(struct nvme_dev *dev, u64 cap, bool enabled)
-{
-	unsigned long timeout;
-	u32 bit = enabled ? NVME_CSTS_RDY : 0;
-
-	timeout = ((NVME_CAP_TIMEOUT(cap) + 1) * HZ / 2) + jiffies;
-
-	while ((readl(&dev->bar->csts) & NVME_CSTS_RDY) != bit) {
-		msleep(100);
-		if (fatal_signal_pending(current))
-			return -EINTR;
-		if (time_after(jiffies, timeout)) {
-			dev_err(dev->dev,
-				"Device not ready; aborting %s\n", enabled ?
-						"initialisation" : "reset");
-			return -ENODEV;
-		}
-	}
-
-	return 0;
-}
-
-/*
- * If the device has been passed off to us in an enabled state, just clear
- * the enabled bit.  The spec says we should set the 'shutdown notification
- * bits', but doing so may cause the device to complete commands to the
- * admin queue ... and we don't know what memory that might be pointing at!
- */
-static int nvme_disable_ctrl(struct nvme_dev *dev, u64 cap)
-{
-	dev->ctrl_config &= ~NVME_CC_SHN_MASK;
-	dev->ctrl_config &= ~NVME_CC_ENABLE;
-	writel(dev->ctrl_config, &dev->bar->cc);
-
-	return nvme_wait_ready(dev, cap, false);
-}
-
-static int nvme_enable_ctrl(struct nvme_dev *dev, u64 cap)
-{
-	dev->ctrl_config &= ~NVME_CC_SHN_MASK;
-	dev->ctrl_config |= NVME_CC_ENABLE;
-	writel(dev->ctrl_config, &dev->bar->cc);
-
-	return nvme_wait_ready(dev, cap, true);
-}
-
-static int nvme_shutdown_ctrl(struct nvme_dev *dev)
-{
-	unsigned long timeout;
-
-	dev->ctrl_config &= ~NVME_CC_SHN_MASK;
-	dev->ctrl_config |= NVME_CC_SHN_NORMAL;
-
-	writel(dev->ctrl_config, &dev->bar->cc);
-
-	timeout = SHUTDOWN_TIMEOUT + jiffies;
-	while ((readl(&dev->bar->csts) & NVME_CSTS_SHST_MASK) !=
-							NVME_CSTS_SHST_CMPLT) {
-		msleep(100);
-		if (fatal_signal_pending(current))
-			return -EINTR;
-		if (time_after(jiffies, timeout)) {
-			dev_err(dev->dev,
-				"Device shutdown incomplete; abort shutdown\n");
-			return -ENODEV;
-		}
-	}
-
-	return 0;
-}
-
 static struct blk_mq_ops nvme_mq_admin_ops = {
 	.queue_rq	= nvme_queue_rq,
+	.complete	= nvme_complete_rq,
 	.map_queue	= blk_mq_map_queue,
 	.init_hctx	= nvme_admin_init_hctx,
 	.exit_hctx      = nvme_admin_exit_hctx,
@@ -1686,6 +1234,7 @@ static struct blk_mq_ops nvme_mq_admin_ops = {
 
 static struct blk_mq_ops nvme_mq_ops = {
 	.queue_rq	= nvme_queue_rq,
+	.complete	= nvme_complete_rq,
 	.map_queue	= blk_mq_map_queue,
 	.init_hctx	= nvme_init_hctx,
 	.init_request	= nvme_init_request,
@@ -1695,19 +1244,23 @@ static struct blk_mq_ops nvme_mq_ops = {
 
 static void nvme_dev_remove_admin(struct nvme_dev *dev)
 {
-	if (dev->admin_q && !blk_queue_dying(dev->admin_q)) {
-		blk_cleanup_queue(dev->admin_q);
+	if (dev->ctrl.admin_q && !blk_queue_dying(dev->ctrl.admin_q)) {
+		blk_cleanup_queue(dev->ctrl.admin_q);
 		blk_mq_free_tag_set(&dev->admin_tagset);
 	}
 }
 
 static int nvme_alloc_admin_tags(struct nvme_dev *dev)
 {
-	if (!dev->admin_q) {
+	if (!dev->ctrl.admin_q) {
 		dev->admin_tagset.ops = &nvme_mq_admin_ops;
 		dev->admin_tagset.nr_hw_queues = 1;
-		dev->admin_tagset.queue_depth = NVME_AQ_DEPTH - 1;
-		dev->admin_tagset.reserved_tags = 1;
+
+		/*
+		 * Subtract one to leave an empty queue entry for 'Full Queue'
+		 * condition. See NVM-Express 1.2 specification, section 4.1.2.
+		 */
+		dev->admin_tagset.queue_depth = NVME_AQ_BLKMQ_DEPTH - 1;
 		dev->admin_tagset.timeout = ADMIN_TIMEOUT;
 		dev->admin_tagset.numa_node = dev_to_node(dev->dev);
 		dev->admin_tagset.cmd_size = nvme_cmd_size(dev);
@@ -1716,18 +1269,18 @@ static int nvme_alloc_admin_tags(struct nvme_dev *dev)
 		if (blk_mq_alloc_tag_set(&dev->admin_tagset))
 			return -ENOMEM;
 
-		dev->admin_q = blk_mq_init_queue(&dev->admin_tagset);
-		if (IS_ERR(dev->admin_q)) {
+		dev->ctrl.admin_q = blk_mq_init_queue(&dev->admin_tagset);
+		if (IS_ERR(dev->ctrl.admin_q)) {
 			blk_mq_free_tag_set(&dev->admin_tagset);
 			return -ENOMEM;
 		}
-		if (!blk_get_queue(dev->admin_q)) {
+		if (!blk_get_queue(dev->ctrl.admin_q)) {
 			nvme_dev_remove_admin(dev);
-			dev->admin_q = NULL;
+			dev->ctrl.admin_q = NULL;
 			return -ENODEV;
 		}
 	} else
-		blk_mq_unfreeze_queue(dev->admin_q);
+		blk_mq_start_stopped_hw_queues(dev->ctrl.admin_q, true);
 
 	return 0;
 }
@@ -1736,31 +1289,17 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev)
 {
 	int result;
 	u32 aqa;
-	u64 cap = lo_hi_readq(&dev->bar->cap);
+	u64 cap = lo_hi_readq(dev->bar + NVME_REG_CAP);
 	struct nvme_queue *nvmeq;
-	/*
-	 * default to a 4K page size, with the intention to update this
-	 * path in the future to accomodate architectures with differing
-	 * kernel and IO page sizes.
-	 */
-	unsigned page_shift = 12;
-	unsigned dev_page_min = NVME_CAP_MPSMIN(cap) + 12;
-
-	if (page_shift < dev_page_min) {
-		dev_err(dev->dev,
-				"Minimum device page size (%u) too large for "
-				"host (%u)\n", 1 << dev_page_min,
-				1 << page_shift);
-		return -ENODEV;
-	}
 
-	dev->subsystem = readl(&dev->bar->vs) >= NVME_VS(1, 1) ?
+	dev->subsystem = readl(dev->bar + NVME_REG_VS) >= NVME_VS(1, 1) ?
 						NVME_CAP_NSSRC(cap) : 0;
 
-	if (dev->subsystem && (readl(&dev->bar->csts) & NVME_CSTS_NSSRO))
-		writel(NVME_CSTS_NSSRO, &dev->bar->csts);
+	if (dev->subsystem &&
+	    (readl(dev->bar + NVME_REG_CSTS) & NVME_CSTS_NSSRO))
+		writel(NVME_CSTS_NSSRO, dev->bar + NVME_REG_CSTS);
 
-	result = nvme_disable_ctrl(dev, cap);
+	result = nvme_disable_ctrl(&dev->ctrl, cap);
 	if (result < 0)
 		return result;
 
@@ -1774,18 +1313,11 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev)
 	aqa = nvmeq->q_depth - 1;
 	aqa |= aqa << 16;
 
-	dev->page_size = 1 << page_shift;
-
-	dev->ctrl_config = NVME_CC_CSS_NVM;
-	dev->ctrl_config |= (page_shift - 12) << NVME_CC_MPS_SHIFT;
-	dev->ctrl_config |= NVME_CC_ARB_RR | NVME_CC_SHN_NONE;
-	dev->ctrl_config |= NVME_CC_IOSQES | NVME_CC_IOCQES;
-
-	writel(aqa, &dev->bar->aqa);
-	lo_hi_writeq(nvmeq->sq_dma_addr, &dev->bar->asq);
-	lo_hi_writeq(nvmeq->cq_dma_addr, &dev->bar->acq);
+	writel(aqa, dev->bar + NVME_REG_AQA);
+	lo_hi_writeq(nvmeq->sq_dma_addr, dev->bar + NVME_REG_ASQ);
+	lo_hi_writeq(nvmeq->cq_dma_addr, dev->bar + NVME_REG_ACQ);
 
-	result = nvme_enable_ctrl(dev, cap);
+	result = nvme_enable_ctrl(&dev->ctrl, cap);
 	if (result)
 		goto free_nvmeq;
 
@@ -1803,406 +1335,6 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev)
 	return result;
 }
 
-static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
-{
-	struct nvme_dev *dev = ns->dev;
-	struct nvme_user_io io;
-	struct nvme_command c;
-	unsigned length, meta_len;
-	int status, write;
-	dma_addr_t meta_dma = 0;
-	void *meta = NULL;
-	void __user *metadata;
-
-	if (copy_from_user(&io, uio, sizeof(io)))
-		return -EFAULT;
-
-	switch (io.opcode) {
-	case nvme_cmd_write:
-	case nvme_cmd_read:
-	case nvme_cmd_compare:
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	length = (io.nblocks + 1) << ns->lba_shift;
-	meta_len = (io.nblocks + 1) * ns->ms;
-	metadata = (void __user *)(uintptr_t)io.metadata;
-	write = io.opcode & 1;
-
-	if (ns->ext) {
-		length += meta_len;
-		meta_len = 0;
-	}
-	if (meta_len) {
-		if (((io.metadata & 3) || !io.metadata) && !ns->ext)
-			return -EINVAL;
-
-		meta = dma_alloc_coherent(dev->dev, meta_len,
-						&meta_dma, GFP_KERNEL);
-
-		if (!meta) {
-			status = -ENOMEM;
-			goto unmap;
-		}
-		if (write) {
-			if (copy_from_user(meta, metadata, meta_len)) {
-				status = -EFAULT;
-				goto unmap;
-			}
-		}
-	}
-
-	memset(&c, 0, sizeof(c));
-	c.rw.opcode = io.opcode;
-	c.rw.flags = io.flags;
-	c.rw.nsid = cpu_to_le32(ns->ns_id);
-	c.rw.slba = cpu_to_le64(io.slba);
-	c.rw.length = cpu_to_le16(io.nblocks);
-	c.rw.control = cpu_to_le16(io.control);
-	c.rw.dsmgmt = cpu_to_le32(io.dsmgmt);
-	c.rw.reftag = cpu_to_le32(io.reftag);
-	c.rw.apptag = cpu_to_le16(io.apptag);
-	c.rw.appmask = cpu_to_le16(io.appmask);
-	c.rw.metadata = cpu_to_le64(meta_dma);
-
-	status = __nvme_submit_sync_cmd(ns->queue, &c, NULL,
-			(void __user *)(uintptr_t)io.addr, length, NULL, 0);
- unmap:
-	if (meta) {
-		if (status == NVME_SC_SUCCESS && !write) {
-			if (copy_to_user(metadata, meta, meta_len))
-				status = -EFAULT;
-		}
-		dma_free_coherent(dev->dev, meta_len, meta, meta_dma);
-	}
-	return status;
-}
-
-static int nvme_user_cmd(struct nvme_dev *dev, struct nvme_ns *ns,
-			struct nvme_passthru_cmd __user *ucmd)
-{
-	struct nvme_passthru_cmd cmd;
-	struct nvme_command c;
-	unsigned timeout = 0;
-	int status;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EACCES;
-	if (copy_from_user(&cmd, ucmd, sizeof(cmd)))
-		return -EFAULT;
-
-	memset(&c, 0, sizeof(c));
-	c.common.opcode = cmd.opcode;
-	c.common.flags = cmd.flags;
-	c.common.nsid = cpu_to_le32(cmd.nsid);
-	c.common.cdw2[0] = cpu_to_le32(cmd.cdw2);
-	c.common.cdw2[1] = cpu_to_le32(cmd.cdw3);
-	c.common.cdw10[0] = cpu_to_le32(cmd.cdw10);
-	c.common.cdw10[1] = cpu_to_le32(cmd.cdw11);
-	c.common.cdw10[2] = cpu_to_le32(cmd.cdw12);
-	c.common.cdw10[3] = cpu_to_le32(cmd.cdw13);
-	c.common.cdw10[4] = cpu_to_le32(cmd.cdw14);
-	c.common.cdw10[5] = cpu_to_le32(cmd.cdw15);
-
-	if (cmd.timeout_ms)
-		timeout = msecs_to_jiffies(cmd.timeout_ms);
-
-	status = __nvme_submit_sync_cmd(ns ? ns->queue : dev->admin_q, &c,
-			NULL, (void __user *)(uintptr_t)cmd.addr, cmd.data_len,
-			&cmd.result, timeout);
-	if (status >= 0) {
-		if (put_user(cmd.result, &ucmd->result))
-			return -EFAULT;
-	}
-
-	return status;
-}
-
-static int nvme_subsys_reset(struct nvme_dev *dev)
-{
-	if (!dev->subsystem)
-		return -ENOTTY;
-
-	writel(0x4E564D65, &dev->bar->nssr); /* "NVMe" */
-	return 0;
-}
-
-static int nvme_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 NVME_IOCTL_ID:
-		force_successful_syscall_return();
-		return ns->ns_id;
-	case NVME_IOCTL_ADMIN_CMD:
-		return nvme_user_cmd(ns->dev, NULL, (void __user *)arg);
-	case NVME_IOCTL_IO_CMD:
-		return nvme_user_cmd(ns->dev, ns, (void __user *)arg);
-	case NVME_IOCTL_SUBMIT_IO:
-		return nvme_submit_io(ns, (void __user *)arg);
-	case SG_GET_VERSION_NUM:
-		return nvme_sg_get_version_num((void __user *)arg);
-	case SG_IO:
-		return nvme_sg_io(ns, (void __user *)arg);
-	default:
-		return -ENOTTY;
-	}
-}
-
-#ifdef CONFIG_COMPAT
-static int nvme_compat_ioctl(struct block_device *bdev, fmode_t mode,
-					unsigned int cmd, unsigned long arg)
-{
-	switch (cmd) {
-	case SG_IO:
-		return -ENOIOCTLCMD;
-	}
-	return nvme_ioctl(bdev, mode, cmd, arg);
-}
-#else
-#define nvme_compat_ioctl	NULL
-#endif
-
-static void nvme_free_dev(struct kref *kref);
-static void nvme_free_ns(struct kref *kref)
-{
-	struct nvme_ns *ns = container_of(kref, struct nvme_ns, kref);
-
-	if (ns->type == NVME_NS_LIGHTNVM)
-		nvme_nvm_unregister(ns->queue, ns->disk->disk_name);
-
-	spin_lock(&dev_list_lock);
-	ns->disk->private_data = NULL;
-	spin_unlock(&dev_list_lock);
-
-	kref_put(&ns->dev->kref, nvme_free_dev);
-	put_disk(ns->disk);
-	kfree(ns);
-}
-
-static int nvme_open(struct block_device *bdev, fmode_t mode)
-{
-	int ret = 0;
-	struct nvme_ns *ns;
-
-	spin_lock(&dev_list_lock);
-	ns = bdev->bd_disk->private_data;
-	if (!ns)
-		ret = -ENXIO;
-	else if (!kref_get_unless_zero(&ns->kref))
-		ret = -ENXIO;
-	spin_unlock(&dev_list_lock);
-
-	return ret;
-}
-
-static void nvme_release(struct gendisk *disk, fmode_t mode)
-{
-	struct nvme_ns *ns = disk->private_data;
-	kref_put(&ns->kref, nvme_free_ns);
-}
-
-static int nvme_getgeo(struct block_device *bd, struct hd_geometry *geo)
-{
-	/* some standard values */
-	geo->heads = 1 << 6;
-	geo->sectors = 1 << 5;
-	geo->cylinders = get_capacity(bd->bd_disk) >> 11;
-	return 0;
-}
-
-static void nvme_config_discard(struct nvme_ns *ns)
-{
-	u32 logical_block_size = queue_logical_block_size(ns->queue);
-	ns->queue->limits.discard_zeroes_data = 0;
-	ns->queue->limits.discard_alignment = logical_block_size;
-	ns->queue->limits.discard_granularity = logical_block_size;
-	blk_queue_max_discard_sectors(ns->queue, 0xffffffff);
-	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, ns->queue);
-}
-
-static int nvme_revalidate_disk(struct gendisk *disk)
-{
-	struct nvme_ns *ns = disk->private_data;
-	struct nvme_dev *dev = ns->dev;
-	struct nvme_id_ns *id;
-	u8 lbaf, pi_type;
-	u16 old_ms;
-	unsigned short bs;
-
-	if (nvme_identify_ns(dev, ns->ns_id, &id)) {
-		dev_warn(dev->dev, "%s: Identify failure nvme%dn%d\n", __func__,
-						dev->instance, ns->ns_id);
-		return -ENODEV;
-	}
-	if (id->ncap == 0) {
-		kfree(id);
-		return -ENODEV;
-	}
-
-	if (nvme_nvm_ns_supported(ns, id) && ns->type != NVME_NS_LIGHTNVM) {
-		if (nvme_nvm_register(ns->queue, disk->disk_name)) {
-			dev_warn(dev->dev,
-				"%s: LightNVM init failure\n", __func__);
-			kfree(id);
-			return -ENODEV;
-		}
-		ns->type = NVME_NS_LIGHTNVM;
-	}
-
-	old_ms = ns->ms;
-	lbaf = id->flbas & NVME_NS_FLBAS_LBA_MASK;
-	ns->lba_shift = id->lbaf[lbaf].ds;
-	ns->ms = le16_to_cpu(id->lbaf[lbaf].ms);
-	ns->ext = ns->ms && (id->flbas & NVME_NS_FLBAS_META_EXT);
-
-	/*
-	 * If identify namespace failed, use default 512 byte block size so
-	 * block layer can use before failing read/write for 0 capacity.
-	 */
-	if (ns->lba_shift == 0)
-		ns->lba_shift = 9;
-	bs = 1 << ns->lba_shift;
-
-	/* XXX: PI implementation requires metadata equal t10 pi tuple size */
-	pi_type = ns->ms == sizeof(struct t10_pi_tuple) ?
-					id->dps & NVME_NS_DPS_PI_MASK : 0;
-
-	blk_mq_freeze_queue(disk->queue);
-	if (blk_get_integrity(disk) && (ns->pi_type != pi_type ||
-				ns->ms != old_ms ||
-				bs != queue_logical_block_size(disk->queue) ||
-				(ns->ms && ns->ext)))
-		blk_integrity_unregister(disk);
-
-	ns->pi_type = pi_type;
-	blk_queue_logical_block_size(ns->queue, bs);
-
-	if (ns->ms && !ns->ext)
-		nvme_init_integrity(ns);
-
-	if ((ns->ms && !(ns->ms == 8 && ns->pi_type) &&
-						!blk_get_integrity(disk)) ||
-						ns->type == NVME_NS_LIGHTNVM)
-		set_capacity(disk, 0);
-	else
-		set_capacity(disk, le64_to_cpup(&id->nsze) << (ns->lba_shift - 9));
-
-	if (dev->oncs & NVME_CTRL_ONCS_DSM)
-		nvme_config_discard(ns);
-	blk_mq_unfreeze_queue(disk->queue);
-
-	kfree(id);
-	return 0;
-}
-
-static char nvme_pr_type(enum pr_type type)
-{
-	switch (type) {
-	case PR_WRITE_EXCLUSIVE:
-		return 1;
-	case PR_EXCLUSIVE_ACCESS:
-		return 2;
-	case PR_WRITE_EXCLUSIVE_REG_ONLY:
-		return 3;
-	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
-		return 4;
-	case PR_WRITE_EXCLUSIVE_ALL_REGS:
-		return 5;
-	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
-		return 6;
-	default:
-		return 0;
-	}
-};
-
-static int nvme_pr_command(struct block_device *bdev, u32 cdw10,
-				u64 key, u64 sa_key, u8 op)
-{
-	struct nvme_ns *ns = bdev->bd_disk->private_data;
-	struct nvme_command c;
-	u8 data[16] = { 0, };
-
-	put_unaligned_le64(key, &data[0]);
-	put_unaligned_le64(sa_key, &data[8]);
-
-	memset(&c, 0, sizeof(c));
-	c.common.opcode = op;
-	c.common.nsid = cpu_to_le32(ns->ns_id);
-	c.common.cdw10[0] = cpu_to_le32(cdw10);
-
-	return nvme_submit_sync_cmd(ns->queue, &c, data, 16);
-}
-
-static int nvme_pr_register(struct block_device *bdev, u64 old,
-		u64 new, unsigned flags)
-{
-	u32 cdw10;
-
-	if (flags & ~PR_FL_IGNORE_KEY)
-		return -EOPNOTSUPP;
-
-	cdw10 = old ? 2 : 0;
-	cdw10 |= (flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0;
-	cdw10 |= (1 << 30) | (1 << 31); /* PTPL=1 */
-	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_register);
-}
-
-static int nvme_pr_reserve(struct block_device *bdev, u64 key,
-		enum pr_type type, unsigned flags)
-{
-	u32 cdw10;
-
-	if (flags & ~PR_FL_IGNORE_KEY)
-		return -EOPNOTSUPP;
-
-	cdw10 = nvme_pr_type(type) << 8;
-	cdw10 |= ((flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0);
-	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_acquire);
-}
-
-static int nvme_pr_preempt(struct block_device *bdev, u64 old, u64 new,
-		enum pr_type type, bool abort)
-{
-	u32 cdw10 = nvme_pr_type(type) << 8 | abort ? 2 : 1;
-	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_acquire);
-}
-
-static int nvme_pr_clear(struct block_device *bdev, u64 key)
-{
-	u32 cdw10 = 1 | (key ? 1 << 3 : 0);
-	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_register);
-}
-
-static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
-{
-	u32 cdw10 = nvme_pr_type(type) << 8 | key ? 1 << 3 : 0;
-	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
-}
-
-static const struct pr_ops nvme_pr_ops = {
-	.pr_register	= nvme_pr_register,
-	.pr_reserve	= nvme_pr_reserve,
-	.pr_release	= nvme_pr_release,
-	.pr_preempt	= nvme_pr_preempt,
-	.pr_clear	= nvme_pr_clear,
-};
-
-static const struct block_device_operations nvme_fops = {
-	.owner		= THIS_MODULE,
-	.ioctl		= nvme_ioctl,
-	.compat_ioctl	= nvme_compat_ioctl,
-	.open		= nvme_open,
-	.release	= nvme_release,
-	.getgeo		= nvme_getgeo,
-	.revalidate_disk= nvme_revalidate_disk,
-	.pr_ops		= &nvme_pr_ops,
-};
-
 static int nvme_kthread(void *data)
 {
 	struct nvme_dev *dev, *next;
@@ -2212,14 +1344,20 @@ static int nvme_kthread(void *data)
 		spin_lock(&dev_list_lock);
 		list_for_each_entry_safe(dev, next, &dev_list, node) {
 			int i;
-			u32 csts = readl(&dev->bar->csts);
+			u32 csts = readl(dev->bar + NVME_REG_CSTS);
+
+			/*
+			 * Skip controllers currently under reset.
+			 */
+			if (work_pending(&dev->reset_work) || work_busy(&dev->reset_work))
+				continue;
 
 			if ((dev->subsystem && (csts & NVME_CSTS_NSSRO)) ||
 							csts & NVME_CSTS_CFS) {
-				if (!__nvme_reset(dev)) {
+				if (queue_work(nvme_workq, &dev->reset_work)) {
 					dev_warn(dev->dev,
 						"Failed status: %x, reset controller\n",
-						readl(&dev->bar->csts));
+						readl(dev->bar + NVME_REG_CSTS));
 				}
 				continue;
 			}
@@ -2230,11 +1368,8 @@ static int nvme_kthread(void *data)
 				spin_lock_irq(&nvmeq->q_lock);
 				nvme_process_cq(nvmeq);
 
-				while ((i == 0) && (dev->event_limit > 0)) {
-					if (nvme_submit_async_admin_req(dev))
-						break;
-					dev->event_limit--;
-				}
+				while (i == 0 && dev->ctrl.event_limit > 0)
+					nvme_submit_async_event(dev);
 				spin_unlock_irq(&nvmeq->q_lock);
 			}
 		}
@@ -2244,127 +1379,33 @@ static int nvme_kthread(void *data)
 	return 0;
 }
 
-static void nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid)
-{
-	struct nvme_ns *ns;
-	struct gendisk *disk;
-	int node = dev_to_node(dev->dev);
-
-	ns = kzalloc_node(sizeof(*ns), GFP_KERNEL, node);
-	if (!ns)
-		return;
-
-	ns->queue = blk_mq_init_queue(&dev->tagset);
-	if (IS_ERR(ns->queue))
-		goto out_free_ns;
-	queue_flag_set_unlocked(QUEUE_FLAG_NOMERGES, ns->queue);
-	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, ns->queue);
-	ns->dev = dev;
-	ns->queue->queuedata = ns;
-
-	disk = alloc_disk_node(0, node);
-	if (!disk)
-		goto out_free_queue;
-
-	kref_init(&ns->kref);
-	ns->ns_id = nsid;
-	ns->disk = disk;
-	ns->lba_shift = 9; /* set to a default value for 512 until disk is validated */
-	list_add_tail(&ns->list, &dev->namespaces);
-
-	blk_queue_logical_block_size(ns->queue, 1 << ns->lba_shift);
-	if (dev->max_hw_sectors) {
-		blk_queue_max_hw_sectors(ns->queue, dev->max_hw_sectors);
-		blk_queue_max_segments(ns->queue,
-			(dev->max_hw_sectors / (dev->page_size >> 9)) + 1);
-	}
-	if (dev->stripe_size)
-		blk_queue_chunk_sectors(ns->queue, dev->stripe_size >> 9);
-	if (dev->vwc & NVME_CTRL_VWC_PRESENT)
-		blk_queue_flush(ns->queue, REQ_FLUSH | REQ_FUA);
-	blk_queue_virt_boundary(ns->queue, dev->page_size - 1);
-
-	disk->major = nvme_major;
-	disk->first_minor = 0;
-	disk->fops = &nvme_fops;
-	disk->private_data = ns;
-	disk->queue = ns->queue;
-	disk->driverfs_dev = dev->device;
-	disk->flags = GENHD_FL_EXT_DEVT;
-	sprintf(disk->disk_name, "nvme%dn%d", dev->instance, nsid);
-
-	/*
-	 * Initialize capacity to 0 until we establish the namespace format and
-	 * setup integrity extentions if necessary. The revalidate_disk after
-	 * add_disk allows the driver to register with integrity if the format
-	 * requires it.
-	 */
-	set_capacity(disk, 0);
-	if (nvme_revalidate_disk(ns->disk))
-		goto out_free_disk;
-
-	kref_get(&dev->kref);
-	if (ns->type != NVME_NS_LIGHTNVM) {
-		add_disk(ns->disk);
-		if (ns->ms) {
-			struct block_device *bd = bdget_disk(ns->disk, 0);
-			if (!bd)
-				return;
-			if (blkdev_get(bd, FMODE_READ, NULL)) {
-				bdput(bd);
-				return;
-			}
-			blkdev_reread_part(bd);
-			blkdev_put(bd, FMODE_READ);
-		}
-	}
-	return;
- out_free_disk:
-	kfree(disk);
-	list_del(&ns->list);
- out_free_queue:
-	blk_cleanup_queue(ns->queue);
- out_free_ns:
-	kfree(ns);
-}
-
-/*
- * Create I/O queues.  Failing to create an I/O queue is not an issue,
- * we can continue with less than the desired amount of queues, and
- * even a controller without I/O queues an still be used to issue
- * admin commands.  This might be useful to upgrade a buggy firmware
- * for example.
- */
-static void nvme_create_io_queues(struct nvme_dev *dev)
+static int nvme_create_io_queues(struct nvme_dev *dev)
 {
 	unsigned i;
+	int ret = 0;
 
-	for (i = dev->queue_count; i <= dev->max_qid; i++)
-		if (!nvme_alloc_queue(dev, i, dev->q_depth))
+	for (i = dev->queue_count; i <= dev->max_qid; i++) {
+		if (!nvme_alloc_queue(dev, i, dev->q_depth)) {
+			ret = -ENOMEM;
 			break;
+		}
+	}
 
-	for (i = dev->online_queues; i <= dev->queue_count - 1; i++)
-		if (nvme_create_queue(dev->queues[i], i)) {
+	for (i = dev->online_queues; i <= dev->queue_count - 1; i++) {
+		ret = nvme_create_queue(dev->queues[i], i);
+		if (ret) {
 			nvme_free_queues(dev, i);
 			break;
 		}
-}
-
-static int set_queue_count(struct nvme_dev *dev, int count)
-{
-	int status;
-	u32 result;
-	u32 q_count = (count - 1) | ((count - 1) << 16);
-
-	status = nvme_set_features(dev, NVME_FEAT_NUM_QUEUES, q_count, 0,
-								&result);
-	if (status < 0)
-		return status;
-	if (status > 0) {
-		dev_err(dev->dev, "Could not set queue count (%d)\n", status);
-		return 0;
 	}
-	return min(result & 0xffff, result >> 16) + 1;
+
+	/*
+	 * Ignore failing Create SQ/CQ commands, we can continue with less
+	 * than the desired aount of queues, and even a controller without
+	 * I/O queues an still be used to issue admin commands.  This might
+	 * be useful to upgrade a buggy firmware for example.
+	 */
+	return ret >= 0 ? 0 : ret;
 }
 
 static void __iomem *nvme_map_cmb(struct nvme_dev *dev)
@@ -2379,11 +1420,11 @@ static void __iomem *nvme_map_cmb(struct nvme_dev *dev)
 	if (!use_cmb_sqes)
 		return NULL;
 
-	dev->cmbsz = readl(&dev->bar->cmbsz);
+	dev->cmbsz = readl(dev->bar + NVME_REG_CMBSZ);
 	if (!(NVME_CMB_SZ(dev->cmbsz)))
 		return NULL;
 
-	cmbloc = readl(&dev->bar->cmbloc);
+	cmbloc = readl(dev->bar + NVME_REG_CMBLOC);
 
 	szu = (u64)1 << (12 + 4 * NVME_CMB_SZU(dev->cmbsz));
 	size = szu * NVME_CMB_SZ(dev->cmbsz);
@@ -2431,11 +1472,20 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
 	int result, i, vecs, nr_io_queues, size;
 
 	nr_io_queues = num_possible_cpus();
-	result = set_queue_count(dev, nr_io_queues);
-	if (result <= 0)
+	result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
+	if (result < 0)
 		return result;
-	if (result < nr_io_queues)
-		nr_io_queues = result;
+
+	/*
+	 * Degraded controllers might return an error when setting the queue
+	 * count.  We still want to be able to bring them online and offer
+	 * access to the admin queue, as that might be only way to fix them up.
+	 */
+	if (result > 0) {
+		dev_err(dev->dev, "Could not set queue count (%d)\n", result);
+		nr_io_queues = 0;
+		result = 0;
+	}
 
 	if (dev->cmb && NVME_CMB_SQS(dev->cmbsz)) {
 		result = nvme_cmb_qdepth(dev, nr_io_queues,
@@ -2457,7 +1507,7 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
 				return -ENOMEM;
 			size = db_bar_size(dev, nr_io_queues);
 		} while (1);
-		dev->dbs = ((void __iomem *)dev->bar) + 4096;
+		dev->dbs = dev->bar + 4096;
 		adminq->q_db = dev->dbs;
 	}
 
@@ -2501,115 +1551,115 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
 
 	/* Free previously allocated queues that are no longer usable */
 	nvme_free_queues(dev, nr_io_queues + 1);
-	nvme_create_io_queues(dev);
-
-	return 0;
+	return nvme_create_io_queues(dev);
 
  free_queues:
 	nvme_free_queues(dev, 1);
 	return result;
 }
 
-static int ns_cmp(void *priv, struct list_head *a, struct list_head *b)
+static void nvme_set_irq_hints(struct nvme_dev *dev)
 {
-	struct nvme_ns *nsa = container_of(a, struct nvme_ns, list);
-	struct nvme_ns *nsb = container_of(b, struct nvme_ns, list);
+	struct nvme_queue *nvmeq;
+	int i;
 
-	return nsa->ns_id - nsb->ns_id;
-}
+	for (i = 0; i < dev->online_queues; i++) {
+		nvmeq = dev->queues[i];
 
-static struct nvme_ns *nvme_find_ns(struct nvme_dev *dev, unsigned nsid)
-{
-	struct nvme_ns *ns;
+		if (!nvmeq->tags || !(*nvmeq->tags))
+			continue;
 
-	list_for_each_entry(ns, &dev->namespaces, list) {
-		if (ns->ns_id == nsid)
-			return ns;
-		if (ns->ns_id > nsid)
-			break;
+		irq_set_affinity_hint(dev->entry[nvmeq->cq_vector].vector,
+					blk_mq_tags_cpumask(*nvmeq->tags));
 	}
-	return NULL;
 }
 
-static inline bool nvme_io_incapable(struct nvme_dev *dev)
+static void nvme_dev_scan(struct work_struct *work)
 {
-	return (!dev->bar || readl(&dev->bar->csts) & NVME_CSTS_CFS ||
-							dev->online_queues < 2);
+	struct nvme_dev *dev = container_of(work, struct nvme_dev, scan_work);
+
+	if (!dev->tagset.tags)
+		return;
+	nvme_scan_namespaces(&dev->ctrl);
+	nvme_set_irq_hints(dev);
 }
 
-static void nvme_ns_remove(struct nvme_ns *ns)
+static void nvme_del_queue_end(struct request *req, int error)
 {
-	bool kill = nvme_io_incapable(ns->dev) && !blk_queue_dying(ns->queue);
+	struct nvme_queue *nvmeq = req->end_io_data;
 
-	if (kill) {
-		blk_set_queue_dying(ns->queue);
-
-		/*
-		 * The controller was shutdown first if we got here through
-		 * device removal. The shutdown may requeue outstanding
-		 * requests. These need to be aborted immediately so
-		 * del_gendisk doesn't block indefinitely for their completion.
-		 */
-		blk_mq_abort_requeue_list(ns->queue);
-	}
-	if (ns->disk->flags & GENHD_FL_UP)
-		del_gendisk(ns->disk);
-	if (kill || !blk_queue_dying(ns->queue)) {
-		blk_mq_abort_requeue_list(ns->queue);
-		blk_cleanup_queue(ns->queue);
-	}
-	list_del_init(&ns->list);
-	kref_put(&ns->kref, nvme_free_ns);
+	blk_mq_free_request(req);
+	complete(&nvmeq->dev->ioq_wait);
 }
 
-static void nvme_scan_namespaces(struct nvme_dev *dev, unsigned nn)
+static void nvme_del_cq_end(struct request *req, int error)
 {
-	struct nvme_ns *ns, *next;
-	unsigned i;
+	struct nvme_queue *nvmeq = req->end_io_data;
 
-	for (i = 1; i <= nn; i++) {
-		ns = nvme_find_ns(dev, i);
-		if (ns) {
-			if (revalidate_disk(ns->disk))
-				nvme_ns_remove(ns);
-		} else
-			nvme_alloc_ns(dev, i);
-	}
-	list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
-		if (ns->ns_id > nn)
-			nvme_ns_remove(ns);
+	if (!error) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&nvmeq->q_lock, flags);
+		nvme_process_cq(nvmeq);
+		spin_unlock_irqrestore(&nvmeq->q_lock, flags);
 	}
-	list_sort(NULL, &dev->namespaces, ns_cmp);
+
+	nvme_del_queue_end(req, error);
 }
 
-static void nvme_set_irq_hints(struct nvme_dev *dev)
+static int nvme_delete_queue(struct nvme_queue *nvmeq, u8 opcode)
 {
-	struct nvme_queue *nvmeq;
-	int i;
+	struct request_queue *q = nvmeq->dev->ctrl.admin_q;
+	struct request *req;
+	struct nvme_command cmd;
 
-	for (i = 0; i < dev->online_queues; i++) {
-		nvmeq = dev->queues[i];
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.delete_queue.opcode = opcode;
+	cmd.delete_queue.qid = cpu_to_le16(nvmeq->qid);
 
-		if (!nvmeq->tags || !(*nvmeq->tags))
-			continue;
+	req = nvme_alloc_request(q, &cmd, BLK_MQ_REQ_NOWAIT);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
 
-		irq_set_affinity_hint(dev->entry[nvmeq->cq_vector].vector,
-					blk_mq_tags_cpumask(*nvmeq->tags));
-	}
+	req->timeout = ADMIN_TIMEOUT;
+	req->end_io_data = nvmeq;
+
+	blk_execute_rq_nowait(q, NULL, req, false,
+			opcode == nvme_admin_delete_cq ?
+				nvme_del_cq_end : nvme_del_queue_end);
+	return 0;
 }
 
-static void nvme_dev_scan(struct work_struct *work)
+static void nvme_disable_io_queues(struct nvme_dev *dev)
 {
-	struct nvme_dev *dev = container_of(work, struct nvme_dev, scan_work);
-	struct nvme_id_ctrl *ctrl;
+	int pass;
+	unsigned long timeout;
+	u8 opcode = nvme_admin_delete_sq;
 
-	if (!dev->tagset.tags)
-		return;
-	if (nvme_identify_ctrl(dev, &ctrl))
-		return;
-	nvme_scan_namespaces(dev, le32_to_cpup(&ctrl->nn));
-	kfree(ctrl);
-	nvme_set_irq_hints(dev);
+	for (pass = 0; pass < 2; pass++) {
+		int sent = 0, i = dev->queue_count - 1;
+
+		reinit_completion(&dev->ioq_wait);
+ retry:
+		timeout = ADMIN_TIMEOUT;
+		for (; i > 0; i--) {
+			struct nvme_queue *nvmeq = dev->queues[i];
+
+			if (!pass)
+				nvme_suspend_queue(nvmeq);
+			if (nvme_delete_queue(nvmeq, opcode))
+				break;
+			++sent;
+		}
+		while (sent--) {
+			timeout = wait_for_completion_io_timeout(&dev->ioq_wait, timeout);
+			if (timeout == 0)
+				return;
+			if (i)
+				goto retry;
+		}
+		opcode = nvme_admin_delete_cq;
+	}
 }
 
 /*
@@ -2620,42 +1670,7 @@ static void nvme_dev_scan(struct work_struct *work)
  */
 static int nvme_dev_add(struct nvme_dev *dev)
 {
-	struct pci_dev *pdev = to_pci_dev(dev->dev);
-	int res;
-	struct nvme_id_ctrl *ctrl;
-	int shift = NVME_CAP_MPSMIN(lo_hi_readq(&dev->bar->cap)) + 12;
-
-	res = nvme_identify_ctrl(dev, &ctrl);
-	if (res) {
-		dev_err(dev->dev, "Identify Controller failed (%d)\n", res);
-		return -EIO;
-	}
-
-	dev->oncs = le16_to_cpup(&ctrl->oncs);
-	dev->abort_limit = ctrl->acl + 1;
-	dev->vwc = ctrl->vwc;
-	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);
-	else
-		dev->max_hw_sectors = UINT_MAX;
-	if ((pdev->vendor == PCI_VENDOR_ID_INTEL) &&
-			(pdev->device == 0x0953) && ctrl->vs[3]) {
-		unsigned int max_hw_sectors;
-
-		dev->stripe_size = 1 << (ctrl->vs[3] + shift);
-		max_hw_sectors = dev->stripe_size >> (shift - 9);
-		if (dev->max_hw_sectors) {
-			dev->max_hw_sectors = min(max_hw_sectors,
-							dev->max_hw_sectors);
-		} else
-			dev->max_hw_sectors = max_hw_sectors;
-	}
-	kfree(ctrl);
-
-	if (!dev->tagset.tags) {
+	if (!dev->ctrl.tagset) {
 		dev->tagset.ops = &nvme_mq_ops;
 		dev->tagset.nr_hw_queues = dev->online_queues - 1;
 		dev->tagset.timeout = NVME_IO_TIMEOUT;
@@ -2668,8 +1683,9 @@ static int nvme_dev_add(struct nvme_dev *dev)
 
 		if (blk_mq_alloc_tag_set(&dev->tagset))
 			return 0;
+		dev->ctrl.tagset = &dev->tagset;
 	}
-	schedule_work(&dev->scan_work);
+	queue_work(nvme_workq, &dev->scan_work);
 	return 0;
 }
 
@@ -2699,7 +1715,7 @@ static int nvme_dev_map(struct nvme_dev *dev)
 	if (!dev->bar)
 		goto disable;
 
-	if (readl(&dev->bar->csts) == -1) {
+	if (readl(dev->bar + NVME_REG_CSTS) == -1) {
 		result = -ENODEV;
 		goto unmap;
 	}
@@ -2714,10 +1730,11 @@ static int nvme_dev_map(struct nvme_dev *dev)
 			goto unmap;
 	}
 
-	cap = lo_hi_readq(&dev->bar->cap);
+	cap = lo_hi_readq(dev->bar + NVME_REG_CAP);
+
 	dev->q_depth = min_t(int, NVME_CAP_MQES(cap) + 1, NVME_Q_DEPTH);
 	dev->db_stride = 1 << NVME_CAP_STRIDE(cap);
-	dev->dbs = ((void __iomem *)dev->bar) + 4096;
+	dev->dbs = dev->bar + 4096;
 
 	/*
 	 * Temporary fix for the Apple controller found in the MacBook8,1 and
@@ -2730,9 +1747,11 @@ static int nvme_dev_map(struct nvme_dev *dev)
 			dev->q_depth);
 	}
 
-	if (readl(&dev->bar->vs) >= NVME_VS(1, 2))
+	if (readl(dev->bar + NVME_REG_VS) >= NVME_VS(1, 2))
 		dev->cmb = nvme_map_cmb(dev);
 
+	pci_enable_pcie_error_reporting(pdev);
+	pci_save_state(pdev);
 	return 0;
 
  unmap:
@@ -2760,152 +1779,34 @@ static void nvme_dev_unmap(struct nvme_dev *dev)
 		pci_release_regions(pdev);
 	}
 
-	if (pci_is_enabled(pdev))
+	if (pci_is_enabled(pdev)) {
+		pci_disable_pcie_error_reporting(pdev);
 		pci_disable_device(pdev);
-}
-
-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)) {
-			/*
-			 * Disable the controller first since we can't trust it
-			 * at this point, but leave the admin queue enabled
-			 * until all queue deletion requests are flushed.
-			 * FIXME: This may take a while if there are more h/w
-			 * queues than admin tags.
-			 */
-			set_current_state(TASK_RUNNING);
-			nvme_disable_ctrl(dev, lo_hi_readq(&dev->bar->cap));
-			nvme_clear_queue(dev->queues[0]);
-			flush_kthread_worker(dq->worker);
-			nvme_disable_queue(dev, 0);
-			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_put_dq(dq);
-
-	spin_lock_irq(&nvmeq->q_lock);
-	nvme_process_cq(nvmeq);
-	spin_unlock_irq(&nvmeq->q_lock);
-}
-
-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_async_cmd(nvmeq->dev, &c, &nvmeq->cmdinfo,
-								ADMIN_TIMEOUT);
-}
-
-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)
+static int nvme_dev_list_add(struct nvme_dev *dev)
 {
-	struct nvme_queue *nvmeq = container_of(work, struct nvme_queue,
-							cmdinfo.work);
-	if (nvme_delete_sq(nvmeq))
-		nvme_del_queue_end(nvmeq);
-}
+	bool start_thread = false;
 
-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->dev,
-			"Failed to create queue del task\n");
-		for (i = dev->queue_count - 1; i > 0; i--)
-			nvme_disable_queue(dev, i);
-		return;
+	spin_lock(&dev_list_lock);
+	if (list_empty(&dev_list) && IS_ERR_OR_NULL(nvme_thread)) {
+		start_thread = true;
+		nvme_thread = NULL;
 	}
+	list_add(&dev->node, &dev_list);
+	spin_unlock(&dev_list_lock);
 
-	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 (start_thread) {
+		nvme_thread = kthread_run(nvme_kthread, NULL, "nvme");
+		wake_up_all(&nvme_kthread_wait);
+	} else
+		wait_event_killable(nvme_kthread_wait, nvme_thread);
 
-		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);
+	if (IS_ERR_OR_NULL(nvme_thread))
+		return nvme_thread ? PTR_ERR(nvme_thread) : -EINTR;
+
+	return 0;
 }
 
 /*
@@ -2928,44 +1829,17 @@ static void nvme_dev_list_remove(struct nvme_dev *dev)
 		kthread_stop(tmp);
 }
 
-static void nvme_freeze_queues(struct nvme_dev *dev)
-{
-	struct nvme_ns *ns;
-
-	list_for_each_entry(ns, &dev->namespaces, list) {
-		blk_mq_freeze_queue_start(ns->queue);
-
-		spin_lock_irq(ns->queue->queue_lock);
-		queue_flag_set(QUEUE_FLAG_STOPPED, ns->queue);
-		spin_unlock_irq(ns->queue->queue_lock);
-
-		blk_mq_cancel_requeue_work(ns->queue);
-		blk_mq_stop_hw_queues(ns->queue);
-	}
-}
-
-static void nvme_unfreeze_queues(struct nvme_dev *dev)
-{
-	struct nvme_ns *ns;
-
-	list_for_each_entry(ns, &dev->namespaces, list) {
-		queue_flag_clear_unlocked(QUEUE_FLAG_STOPPED, ns->queue);
-		blk_mq_unfreeze_queue(ns->queue);
-		blk_mq_start_stopped_hw_queues(ns->queue, true);
-		blk_mq_kick_requeue_list(ns->queue);
-	}
-}
-
-static void nvme_dev_shutdown(struct nvme_dev *dev)
+static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
 {
 	int i;
 	u32 csts = -1;
 
 	nvme_dev_list_remove(dev);
 
+	mutex_lock(&dev->shutdown_lock);
 	if (dev->bar) {
-		nvme_freeze_queues(dev);
-		csts = readl(&dev->bar->csts);
+		nvme_stop_queues(&dev->ctrl);
+		csts = readl(dev->bar + NVME_REG_CSTS);
 	}
 	if (csts & NVME_CSTS_CFS || !(csts & NVME_CSTS_RDY)) {
 		for (i = dev->queue_count - 1; i >= 0; i--) {
@@ -2974,30 +1848,13 @@ static void nvme_dev_shutdown(struct nvme_dev *dev)
 		}
 	} else {
 		nvme_disable_io_queues(dev);
-		nvme_shutdown_ctrl(dev);
-		nvme_disable_queue(dev, 0);
+		nvme_disable_admin_queue(dev, shutdown);
 	}
 	nvme_dev_unmap(dev);
 
 	for (i = dev->queue_count - 1; i >= 0; i--)
 		nvme_clear_queue(dev->queues[i]);
-}
-
-static void nvme_dev_remove(struct nvme_dev *dev)
-{
-	struct nvme_ns *ns, *next;
-
-	if (nvme_io_incapable(dev)) {
-		/*
-		 * If the device is not capable of IO (surprise hot-removal,
-		 * for example), we need to quiesce prior to deleting the
-		 * namespaces. This will end outstanding requests and prevent
-		 * attempts to sync dirty data.
-		 */
-		nvme_dev_shutdown(dev);
-	}
-	list_for_each_entry_safe(ns, next, &dev->namespaces, list)
-		nvme_ns_remove(ns);
+	mutex_unlock(&dev->shutdown_lock);
 }
 
 static int nvme_setup_prp_pools(struct nvme_dev *dev)
@@ -3023,119 +1880,36 @@ static void nvme_release_prp_pools(struct nvme_dev *dev)
 	dma_pool_destroy(dev->prp_small_pool);
 }
 
-static DEFINE_IDA(nvme_instance_ida);
-
-static int nvme_set_instance(struct nvme_dev *dev)
-{
-	int instance, error;
-
-	do {
-		if (!ida_pre_get(&nvme_instance_ida, GFP_KERNEL))
-			return -ENODEV;
-
-		spin_lock(&dev_list_lock);
-		error = ida_get_new(&nvme_instance_ida, &instance);
-		spin_unlock(&dev_list_lock);
-	} while (error == -EAGAIN);
-
-	if (error)
-		return -ENODEV;
-
-	dev->instance = instance;
-	return 0;
-}
-
-static void nvme_release_instance(struct nvme_dev *dev)
+static void nvme_pci_free_ctrl(struct nvme_ctrl *ctrl)
 {
-	spin_lock(&dev_list_lock);
-	ida_remove(&nvme_instance_ida, dev->instance);
-	spin_unlock(&dev_list_lock);
-}
-
-static void nvme_free_dev(struct kref *kref)
-{
-	struct nvme_dev *dev = container_of(kref, struct nvme_dev, kref);
+	struct nvme_dev *dev = to_nvme_dev(ctrl);
 
 	put_device(dev->dev);
-	put_device(dev->device);
-	nvme_release_instance(dev);
 	if (dev->tagset.tags)
 		blk_mq_free_tag_set(&dev->tagset);
-	if (dev->admin_q)
-		blk_put_queue(dev->admin_q);
+	if (dev->ctrl.admin_q)
+		blk_put_queue(dev->ctrl.admin_q);
 	kfree(dev->queues);
 	kfree(dev->entry);
 	kfree(dev);
 }
 
-static int nvme_dev_open(struct inode *inode, struct file *f)
+static void nvme_reset_work(struct work_struct *work)
 {
-	struct nvme_dev *dev;
-	int instance = iminor(inode);
-	int ret = -ENODEV;
-
-	spin_lock(&dev_list_lock);
-	list_for_each_entry(dev, &dev_list, node) {
-		if (dev->instance == instance) {
-			if (!dev->admin_q) {
-				ret = -EWOULDBLOCK;
-				break;
-			}
-			if (!kref_get_unless_zero(&dev->kref))
-				break;
-			f->private_data = dev;
-			ret = 0;
-			break;
-		}
-	}
-	spin_unlock(&dev_list_lock);
-
-	return ret;
-}
+	struct nvme_dev *dev = container_of(work, struct nvme_dev, reset_work);
+	int result;
 
-static int nvme_dev_release(struct inode *inode, struct file *f)
-{
-	struct nvme_dev *dev = f->private_data;
-	kref_put(&dev->kref, nvme_free_dev);
-	return 0;
-}
+	if (WARN_ON(test_bit(NVME_CTRL_RESETTING, &dev->flags)))
+		goto out;
 
-static long nvme_dev_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
-{
-	struct nvme_dev *dev = f->private_data;
-	struct nvme_ns *ns;
-
-	switch (cmd) {
-	case NVME_IOCTL_ADMIN_CMD:
-		return nvme_user_cmd(dev, NULL, (void __user *)arg);
-	case NVME_IOCTL_IO_CMD:
-		if (list_empty(&dev->namespaces))
-			return -ENOTTY;
-		ns = list_first_entry(&dev->namespaces, struct nvme_ns, list);
-		return nvme_user_cmd(dev, ns, (void __user *)arg);
-	case NVME_IOCTL_RESET:
-		dev_warn(dev->dev, "resetting controller\n");
-		return nvme_reset(dev);
-	case NVME_IOCTL_SUBSYS_RESET:
-		return nvme_subsys_reset(dev);
-	default:
-		return -ENOTTY;
-	}
-}
+	/*
+	 * If we're called to reset a live controller first shut it down before
+	 * moving on.
+	 */
+	if (dev->bar)
+		nvme_dev_disable(dev, false);
 
-static const struct file_operations nvme_dev_fops = {
-	.owner		= THIS_MODULE,
-	.open		= nvme_dev_open,
-	.release	= nvme_dev_release,
-	.unlocked_ioctl	= nvme_dev_ioctl,
-	.compat_ioctl	= nvme_dev_ioctl,
-};
-
-static void nvme_probe_work(struct work_struct *work)
-{
-	struct nvme_dev *dev = container_of(work, struct nvme_dev, probe_work);
-	bool start_thread = false;
-	int result;
+	set_bit(NVME_CTRL_RESETTING, &dev->flags);
 
 	result = nvme_dev_map(dev);
 	if (result)
@@ -3145,35 +1919,24 @@ static void nvme_probe_work(struct work_struct *work)
 	if (result)
 		goto unmap;
 
-	spin_lock(&dev_list_lock);
-	if (list_empty(&dev_list) && IS_ERR_OR_NULL(nvme_thread)) {
-		start_thread = true;
-		nvme_thread = NULL;
-	}
-	list_add(&dev->node, &dev_list);
-	spin_unlock(&dev_list_lock);
-
-	if (start_thread) {
-		nvme_thread = kthread_run(nvme_kthread, NULL, "nvme");
-		wake_up_all(&nvme_kthread_wait);
-	} else
-		wait_event_killable(nvme_kthread_wait, nvme_thread);
-
-	if (IS_ERR_OR_NULL(nvme_thread)) {
-		result = nvme_thread ? PTR_ERR(nvme_thread) : -EINTR;
-		goto disable;
-	}
-
 	nvme_init_queue(dev->queues[0], 0);
 	result = nvme_alloc_admin_tags(dev);
 	if (result)
 		goto disable;
 
+	result = nvme_init_identify(&dev->ctrl);
+	if (result)
+		goto free_tags;
+
 	result = nvme_setup_io_queues(dev);
 	if (result)
 		goto free_tags;
 
-	dev->event_limit = 1;
+	dev->ctrl.event_limit = NVME_NR_AEN_COMMANDS;
+
+	result = nvme_dev_list_add(dev);
+	if (result)
+		goto remove;
 
 	/*
 	 * Keep the controller around but remove all namespaces if we don't have
@@ -3181,117 +1944,98 @@ static void nvme_probe_work(struct work_struct *work)
 	 */
 	if (dev->online_queues < 2) {
 		dev_warn(dev->dev, "IO queues not created\n");
-		nvme_dev_remove(dev);
+		nvme_remove_namespaces(&dev->ctrl);
 	} else {
-		nvme_unfreeze_queues(dev);
+		nvme_start_queues(&dev->ctrl);
 		nvme_dev_add(dev);
 	}
 
+	clear_bit(NVME_CTRL_RESETTING, &dev->flags);
 	return;
 
+ remove:
+	nvme_dev_list_remove(dev);
  free_tags:
 	nvme_dev_remove_admin(dev);
-	blk_put_queue(dev->admin_q);
-	dev->admin_q = NULL;
+	blk_put_queue(dev->ctrl.admin_q);
+	dev->ctrl.admin_q = NULL;
 	dev->queues[0]->tags = NULL;
  disable:
-	nvme_disable_queue(dev, 0);
-	nvme_dev_list_remove(dev);
+	nvme_disable_admin_queue(dev, false);
  unmap:
 	nvme_dev_unmap(dev);
  out:
-	if (!work_busy(&dev->reset_work))
-		nvme_dead_ctrl(dev);
+	nvme_remove_dead_ctrl(dev);
 }
 
-static int nvme_remove_dead_ctrl(void *arg)
+static void nvme_remove_dead_ctrl_work(struct work_struct *work)
 {
-	struct nvme_dev *dev = (struct nvme_dev *)arg;
+	struct nvme_dev *dev = container_of(work, struct nvme_dev, remove_work);
 	struct pci_dev *pdev = to_pci_dev(dev->dev);
 
 	if (pci_get_drvdata(pdev))
 		pci_stop_and_remove_bus_device_locked(pdev);
-	kref_put(&dev->kref, nvme_free_dev);
-	return 0;
+	nvme_put_ctrl(&dev->ctrl);
 }
 
-static void nvme_dead_ctrl(struct nvme_dev *dev)
+static void nvme_remove_dead_ctrl(struct nvme_dev *dev)
 {
-	dev_warn(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->dev,
-			"Failed to start controller remove task\n");
-		kref_put(&dev->kref, nvme_free_dev);
-	}
+	dev_warn(dev->dev, "Removing after probe failure\n");
+	kref_get(&dev->ctrl.kref);
+	if (!schedule_work(&dev->remove_work))
+		nvme_put_ctrl(&dev->ctrl);
 }
 
-static void nvme_reset_work(struct work_struct *ws)
+static int nvme_reset(struct nvme_dev *dev)
 {
-	struct nvme_dev *dev = container_of(ws, struct nvme_dev, reset_work);
-	bool in_probe = work_busy(&dev->probe_work);
-
-	nvme_dev_shutdown(dev);
+	if (!dev->ctrl.admin_q || blk_queue_dying(dev->ctrl.admin_q))
+		return -ENODEV;
 
-	/* Synchronize with device probe so that work will see failure status
-	 * and exit gracefully without trying to schedule another reset */
-	flush_work(&dev->probe_work);
+	if (!queue_work(nvme_workq, &dev->reset_work))
+		return -EBUSY;
 
-	/* Fail this device if reset occured during probe to avoid
-	 * infinite initialization loops. */
-	if (in_probe) {
-		nvme_dead_ctrl(dev);
-		return;
-	}
-	/* Schedule device resume asynchronously so the reset work is available
-	 * to cleanup errors that may occur during reinitialization */
-	schedule_work(&dev->probe_work);
+	flush_work(&dev->reset_work);
+	return 0;
 }
 
-static int __nvme_reset(struct nvme_dev *dev)
+static int nvme_pci_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)
 {
-	if (work_pending(&dev->reset_work))
-		return -EBUSY;
-	list_del_init(&dev->node);
-	queue_work(nvme_workq, &dev->reset_work);
+	*val = readl(to_nvme_dev(ctrl)->bar + off);
 	return 0;
 }
 
-static int nvme_reset(struct nvme_dev *dev)
+static int nvme_pci_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val)
 {
-	int ret;
-
-	if (!dev->admin_q || blk_queue_dying(dev->admin_q))
-		return -ENODEV;
-
-	spin_lock(&dev_list_lock);
-	ret = __nvme_reset(dev);
-	spin_unlock(&dev_list_lock);
-
-	if (!ret) {
-		flush_work(&dev->reset_work);
-		flush_work(&dev->probe_work);
-		return 0;
-	}
+	writel(val, to_nvme_dev(ctrl)->bar + off);
+	return 0;
+}
 
-	return ret;
+static int nvme_pci_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val)
+{
+	*val = readq(to_nvme_dev(ctrl)->bar + off);
+	return 0;
 }
 
-static ssize_t nvme_sysfs_reset(struct device *dev,
-				struct device_attribute *attr, const char *buf,
-				size_t count)
+static bool nvme_pci_io_incapable(struct nvme_ctrl *ctrl)
 {
-	struct nvme_dev *ndev = dev_get_drvdata(dev);
-	int ret;
+	struct nvme_dev *dev = to_nvme_dev(ctrl);
 
-	ret = nvme_reset(ndev);
-	if (ret < 0)
-		return ret;
+	return !dev->bar || dev->online_queues < 2;
+}
 
-	return count;
+static int nvme_pci_reset_ctrl(struct nvme_ctrl *ctrl)
+{
+	return nvme_reset(to_nvme_dev(ctrl));
 }
-static DEVICE_ATTR(reset_controller, S_IWUSR, NULL, nvme_sysfs_reset);
+
+static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
+	.reg_read32		= nvme_pci_reg_read32,
+	.reg_write32		= nvme_pci_reg_write32,
+	.reg_read64		= nvme_pci_reg_read64,
+	.io_incapable		= nvme_pci_io_incapable,
+	.reset_ctrl		= nvme_pci_reset_ctrl,
+	.free_ctrl		= nvme_pci_free_ctrl,
+};
 
 static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
@@ -3314,46 +2058,30 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (!dev->queues)
 		goto free;
 
-	INIT_LIST_HEAD(&dev->namespaces);
-	INIT_WORK(&dev->reset_work, nvme_reset_work);
 	dev->dev = get_device(&pdev->dev);
 	pci_set_drvdata(pdev, dev);
-	result = nvme_set_instance(dev);
-	if (result)
-		goto put_pci;
+
+	INIT_LIST_HEAD(&dev->node);
+	INIT_WORK(&dev->scan_work, nvme_dev_scan);
+	INIT_WORK(&dev->reset_work, nvme_reset_work);
+	INIT_WORK(&dev->remove_work, nvme_remove_dead_ctrl_work);
+	mutex_init(&dev->shutdown_lock);
+	init_completion(&dev->ioq_wait);
 
 	result = nvme_setup_prp_pools(dev);
 	if (result)
-		goto release;
-
-	kref_init(&dev->kref);
-	dev->device = device_create(nvme_class, &pdev->dev,
-				MKDEV(nvme_char_major, dev->instance),
-				dev, "nvme%d", dev->instance);
-	if (IS_ERR(dev->device)) {
-		result = PTR_ERR(dev->device);
-		goto release_pools;
-	}
-	get_device(dev->device);
-	dev_set_drvdata(dev->device, dev);
+		goto put_pci;
 
-	result = device_create_file(dev->device, &dev_attr_reset_controller);
+	result = nvme_init_ctrl(&dev->ctrl, &pdev->dev, &nvme_pci_ctrl_ops,
+			id->driver_data);
 	if (result)
-		goto put_dev;
+		goto release_pools;
 
-	INIT_LIST_HEAD(&dev->node);
-	INIT_WORK(&dev->scan_work, nvme_dev_scan);
-	INIT_WORK(&dev->probe_work, nvme_probe_work);
-	schedule_work(&dev->probe_work);
+	queue_work(nvme_workq, &dev->reset_work);
 	return 0;
 
- put_dev:
-	device_destroy(nvme_class, MKDEV(nvme_char_major, dev->instance));
-	put_device(dev->device);
  release_pools:
 	nvme_release_prp_pools(dev);
- release:
-	nvme_release_instance(dev);
  put_pci:
 	put_device(dev->dev);
  free:
@@ -3368,15 +2096,15 @@ static void nvme_reset_notify(struct pci_dev *pdev, bool prepare)
 	struct nvme_dev *dev = pci_get_drvdata(pdev);
 
 	if (prepare)
-		nvme_dev_shutdown(dev);
+		nvme_dev_disable(dev, false);
 	else
-		schedule_work(&dev->probe_work);
+		queue_work(nvme_workq, &dev->reset_work);
 }
 
 static void nvme_shutdown(struct pci_dev *pdev)
 {
 	struct nvme_dev *dev = pci_get_drvdata(pdev);
-	nvme_dev_shutdown(dev);
+	nvme_dev_disable(dev, true);
 }
 
 static void nvme_remove(struct pci_dev *pdev)
@@ -3388,34 +2116,25 @@ static void nvme_remove(struct pci_dev *pdev)
 	spin_unlock(&dev_list_lock);
 
 	pci_set_drvdata(pdev, NULL);
-	flush_work(&dev->probe_work);
 	flush_work(&dev->reset_work);
 	flush_work(&dev->scan_work);
-	device_remove_file(dev->device, &dev_attr_reset_controller);
-	nvme_dev_remove(dev);
-	nvme_dev_shutdown(dev);
+	nvme_remove_namespaces(&dev->ctrl);
+	nvme_uninit_ctrl(&dev->ctrl);
+	nvme_dev_disable(dev, true);
 	nvme_dev_remove_admin(dev);
-	device_destroy(nvme_class, MKDEV(nvme_char_major, dev->instance));
 	nvme_free_queues(dev, 0);
 	nvme_release_cmb(dev);
 	nvme_release_prp_pools(dev);
-	kref_put(&dev->kref, nvme_free_dev);
+	nvme_put_ctrl(&dev->ctrl);
 }
 
-/* These functions are yet to be implemented */
-#define nvme_error_detected NULL
-#define nvme_dump_registers NULL
-#define nvme_link_reset NULL
-#define nvme_slot_reset NULL
-#define nvme_error_resume NULL
-
 #ifdef CONFIG_PM_SLEEP
 static int nvme_suspend(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct nvme_dev *ndev = pci_get_drvdata(pdev);
 
-	nvme_dev_shutdown(ndev);
+	nvme_dev_disable(ndev, true);
 	return 0;
 }
 
@@ -3424,17 +2143,53 @@ static int nvme_resume(struct device *dev)
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct nvme_dev *ndev = pci_get_drvdata(pdev);
 
-	schedule_work(&ndev->probe_work);
+	queue_work(nvme_workq, &ndev->reset_work);
 	return 0;
 }
 #endif
 
 static SIMPLE_DEV_PM_OPS(nvme_dev_pm_ops, nvme_suspend, nvme_resume);
 
+static pci_ers_result_t nvme_error_detected(struct pci_dev *pdev,
+						pci_channel_state_t state)
+{
+	struct nvme_dev *dev = pci_get_drvdata(pdev);
+
+	/*
+	 * A frozen channel requires a reset. When detected, this method will
+	 * shutdown the controller to quiesce. The controller will be restarted
+	 * after the slot reset through driver's slot_reset callback.
+	 */
+	dev_warn(&pdev->dev, "error detected: state:%d\n", state);
+	switch (state) {
+	case pci_channel_io_normal:
+		return PCI_ERS_RESULT_CAN_RECOVER;
+	case pci_channel_io_frozen:
+		nvme_dev_disable(dev, false);
+		return PCI_ERS_RESULT_NEED_RESET;
+	case pci_channel_io_perm_failure:
+		return PCI_ERS_RESULT_DISCONNECT;
+	}
+	return PCI_ERS_RESULT_NEED_RESET;
+}
+
+static pci_ers_result_t nvme_slot_reset(struct pci_dev *pdev)
+{
+	struct nvme_dev *dev = pci_get_drvdata(pdev);
+
+	dev_info(&pdev->dev, "restart after slot reset\n");
+	pci_restore_state(pdev);
+	queue_work(nvme_workq, &dev->reset_work);
+	return PCI_ERS_RESULT_RECOVERED;
+}
+
+static void nvme_error_resume(struct pci_dev *pdev)
+{
+	pci_cleanup_aer_uncorrect_error_status(pdev);
+}
+
 static const struct pci_error_handlers nvme_err_handler = {
 	.error_detected	= nvme_error_detected,
-	.mmio_enabled	= nvme_dump_registers,
-	.link_reset	= nvme_link_reset,
 	.slot_reset	= nvme_slot_reset,
 	.resume		= nvme_error_resume,
 	.reset_notify	= nvme_reset_notify,
@@ -3444,6 +2199,10 @@ static const struct pci_error_handlers nvme_err_handler = {
 #define PCI_CLASS_STORAGE_EXPRESS	0x010802
 
 static const struct pci_device_id nvme_id_table[] = {
+	{ PCI_VDEVICE(INTEL, 0x0953),
+		.driver_data = NVME_QUIRK_STRIPE_SIZE, },
+	{ PCI_VDEVICE(INTEL, 0x5845),	/* Qemu emulated controller */
+		.driver_data = NVME_QUIRK_IDENTIFY_CNS, },
 	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2001) },
 	{ 0, }
@@ -3468,40 +2227,21 @@ static int __init nvme_init(void)
 
 	init_waitqueue_head(&nvme_kthread_wait);
 
-	nvme_workq = create_singlethread_workqueue("nvme");
+	nvme_workq = alloc_workqueue("nvme", WQ_UNBOUND | WQ_MEM_RECLAIM, 0);
 	if (!nvme_workq)
 		return -ENOMEM;
 
-	result = register_blkdev(nvme_major, "nvme");
+	result = nvme_core_init();
 	if (result < 0)
 		goto kill_workq;
-	else if (result > 0)
-		nvme_major = result;
-
-	result = __register_chrdev(nvme_char_major, 0, NVME_MINORS, "nvme",
-							&nvme_dev_fops);
-	if (result < 0)
-		goto unregister_blkdev;
-	else if (result > 0)
-		nvme_char_major = result;
-
-	nvme_class = class_create(THIS_MODULE, "nvme");
-	if (IS_ERR(nvme_class)) {
-		result = PTR_ERR(nvme_class);
-		goto unregister_chrdev;
-	}
 
 	result = pci_register_driver(&nvme_driver);
 	if (result)
-		goto destroy_class;
+		goto core_exit;
 	return 0;
 
- destroy_class:
-	class_destroy(nvme_class);
- unregister_chrdev:
-	__unregister_chrdev(nvme_char_major, 0, NVME_MINORS, "nvme");
- unregister_blkdev:
-	unregister_blkdev(nvme_major, "nvme");
+ core_exit:
+	nvme_core_exit();
  kill_workq:
 	destroy_workqueue(nvme_workq);
 	return result;
@@ -3510,10 +2250,8 @@ static int __init nvme_init(void)
 static void __exit nvme_exit(void)
 {
 	pci_unregister_driver(&nvme_driver);
-	unregister_blkdev(nvme_major, "nvme");
+	nvme_core_exit();
 	destroy_workqueue(nvme_workq);
-	class_destroy(nvme_class);
-	__unregister_chrdev(nvme_char_major, 0, NVME_MINORS, "nvme");
 	BUG_ON(nvme_thread && !IS_ERR(nvme_thread));
 	_nvme_check_size();
 }