]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blobdiff - drivers/nvme/host/pci.c
nvme: use the block layer for userspace passthrough metadata
[mirror_ubuntu-artful-kernel.git] / drivers / nvme / host / pci.c
index 8187df20469535023ae9966aecfb1542260b4270..aa033f047aaf2564ad5e21b32e5809e8e118f872 100644 (file)
 #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)
 
-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");
 
@@ -88,9 +87,14 @@ static wait_queue_head_t nvme_kthread_wait;
 
 static struct class *nvme_class;
 
+struct nvme_dev;
+struct nvme_queue;
+struct nvme_iod;
+
 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_unmap_data(struct nvme_dev *dev, struct nvme_iod *iod);
 static void nvme_dead_ctrl(struct nvme_dev *dev);
 
 struct async_cmd_info {
@@ -102,6 +106,49 @@ struct async_cmd_info {
        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;
+       u32 ctrl_config;
+       struct msix_entry *entry;
+       void __iomem *bar;
+       struct list_head namespaces;
+       struct kref kref;
+       struct device *device;
+       struct work_struct reset_work;
+       struct work_struct probe_work;
+       struct work_struct scan_work;
+       bool subsystem;
+       u32 max_hw_sectors;
+       u32 stripe_size;
+       u32 page_size;
+       void __iomem *cmb;
+       dma_addr_t cmb_dma_addr;
+       u64 cmb_size;
+       u32 cmbsz;
+
+       struct nvme_ctrl ctrl;
+};
+
+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).
@@ -129,6 +176,23 @@ struct nvme_queue {
        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_alloc_iod to ensure there's enough space
+ * allocated to store the PRP list.
+ */
+struct nvme_iod {
+       unsigned long private;  /* For the use of the submitter of the I/O */
+       int npages;             /* In the PRP list. 0 means small pool in use */
+       int offset;             /* Of PRP list */
+       int nents;              /* Used in scatterlist */
+       int length;             /* Of data, in bytes */
+       dma_addr_t first_dma;
+       struct scatterlist meta_sg[1]; /* metadata requires single contiguous buffer */
+       struct scatterlist sg[0];
+};
+
 /*
  * Check we didin't inadvertently grow the command struct
  */
@@ -317,7 +381,7 @@ static void async_req_completion(struct nvme_queue *nvmeq, void *ctx,
        u16 status = le16_to_cpup(&cqe->status) >> 1;
 
        if (status == NVME_SC_SUCCESS || status == NVME_SC_ABORT_REQ)
-               ++nvmeq->dev->event_limit;
+               ++nvmeq->dev->ctrl.event_limit;
        if (status != NVME_SC_SUCCESS)
                return;
 
@@ -341,7 +405,7 @@ static void abort_completion(struct nvme_queue *nvmeq, void *ctx,
        blk_mq_free_request(req);
 
        dev_warn(nvmeq->q_dmadev, "Abort status:%x result:%x", status, result);
-       ++nvmeq->dev->abort_limit;
+       ++nvmeq->dev->ctrl.abort_limit;
 }
 
 static void async_completion(struct nvme_queue *nvmeq, void *ctx,
@@ -483,18 +547,6 @@ static void nvme_free_iod(struct nvme_dev *dev, struct nvme_iod *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;
-       }
-}
-
 #ifdef CONFIG_BLK_DEV_INTEGRITY
 static void nvme_dif_prep(u32 p, u32 v, struct t10_pi_tuple *pi)
 {
@@ -593,7 +645,6 @@ static void req_completion(struct nvme_queue *nvmeq, void *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)) {
@@ -601,13 +652,14 @@ static void req_completion(struct nvme_queue *nvmeq, void *ctx,
                    && (jiffies - req->start_time) < req->timeout) {
                        unsigned long flags;
 
-                       requeue = true;
+                       nvme_unmap_data(nvmeq->dev, iod);
+
                        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;
+                       return;
                }
 
                if (req->cmd_type == REQ_TYPE_DRV_PRIV) {
@@ -630,26 +682,12 @@ static void req_completion(struct nvme_queue *nvmeq, void *ctx,
                        "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);
+       nvme_unmap_data(nvmeq->dev, iod);
+       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 nvme_iod *iod,
+               int total_len)
 {
        struct dma_pool *pool;
        int length = total_len;
@@ -665,7 +703,7 @@ static int nvme_setup_prps(struct nvme_dev *dev, struct nvme_iod *iod,
 
        length -= (page_size - offset);
        if (length <= 0)
-               return total_len;
+               return true;
 
        dma_len -= (page_size - offset);
        if (dma_len) {
@@ -678,7 +716,7 @@ 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 +728,11 @@ 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 +740,9 @@ 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 +762,105 @@ 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 nvme_iod *iod,
+               struct nvme_command *cmnd)
 {
-       struct nvme_command cmnd;
+       struct request *req = iod_get_private(iod);
+       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;
+
+       sg_init_table(iod->sg, req->nr_phys_segments);
+       iod->nents = blk_rq_map_sg(q, req, iod->sg);
+       if (!iod->nents)
+               goto out;
 
-       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);
-       }
+       ret = BLK_MQ_RQ_QUEUE_BUSY;
+       if (!dma_map_sg(dev->dev, iod->sg, iod->nents, dma_dir))
+               goto out;
 
-       __nvme_submit_cmd(nvmeq, &cmnd);
-}
+       if (!nvme_setup_prps(dev, iod, blk_rq_bytes(req)))
+               goto out_unmap;
 
-/*
- * 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;
+       ret = BLK_MQ_RQ_QUEUE_ERROR;
+       if (blk_integrity_rq(req)) {
+               if (blk_rq_count_integrity_sg(q, req->bio) != 1)
+                       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)));
+               sg_init_table(iod->meta_sg, 1);
+               if (blk_rq_map_integrity_sg(q, req->bio, iod->meta_sg) != 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);
+               if (rq_data_dir(req))
+                       nvme_dif_remap(req, nvme_dif_prep);
 
-       __nvme_submit_cmd(nvmeq, &cmnd);
+               if (!dma_map_sg(dev->dev, iod->meta_sg, 1, dma_dir))
+                       goto out_unmap;
+       }
+
+       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;
+
+out_unmap:
+       dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
+out:
+       return ret;
 }
 
-static void nvme_submit_flush(struct nvme_queue *nvmeq, struct nvme_ns *ns,
-                                                               int cmdid)
+static void nvme_unmap_data(struct nvme_dev *dev, struct nvme_iod *iod)
 {
-       struct nvme_command cmnd;
+       struct request *req = iod_get_private(iod);
+       enum dma_data_direction dma_dir = rq_data_dir(req) ?
+                       DMA_TO_DEVICE : DMA_FROM_DEVICE;
 
-       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);
+       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);
+               }
+       }
 
-       __nvme_submit_cmd(nvmeq, &cmnd);
+       nvme_free_iod(dev, iod);
 }
 
-static int nvme_submit_iod(struct nvme_queue *nvmeq, struct nvme_iod *iod,
-                                                       struct nvme_ns *ns)
+/*
+ * 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 nvme_iod *iod, struct nvme_command *cmnd)
 {
        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;
-               }
-               if (blk_integrity_rq(req))
-                       cmnd.rw.metadata =
-                               cpu_to_le64(sg_dma_address(iod->meta_sg));
-               else
-                       control |= NVME_RW_PRINFO_PRACT;
-       }
+       struct nvme_dsm_range *range;
 
-       cmnd.rw.control = cpu_to_le16(control);
-       cmnd.rw.dsmgmt = cpu_to_le32(dsmgmt);
+       range = dma_pool_alloc(nvmeq->dev->prp_small_pool, GFP_ATOMIC,
+                                               &iod->first_dma);
+       if (!range)
+               return BLK_MQ_RQ_QUEUE_BUSY;
+       iod_list(iod)[0] = (__le64 *)range;
+       iod->npages = 0;
 
-       __nvme_submit_cmd(nvmeq, &cmnd);
+       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)));
 
-       return 0;
+       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;
 }
 
 /*
@@ -847,7 +875,8 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
        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
@@ -867,72 +896,33 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
                return BLK_MQ_RQ_QUEUE_BUSY;
 
        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;
-
-               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 (!dma_map_sg(nvmeq->q_dmadev, iod->sg, iod->nents, dma_dir))
-                       goto retry_cmd;
-
-               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)
-                               goto error_cmd;
-
-                       sg_init_table(iod->meta_sg, 1);
-                       if (blk_rq_map_integrity_sg(
-                                       req->q, req->bio, iod->meta_sg) != 1)
-                               goto error_cmd;
-
-                       if (rq_data_dir(req))
-                               nvme_dif_remap(req, nvme_dif_prep);
+               ret = nvme_setup_discard(nvmeq, ns, iod, &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);
 
-                       if (!dma_map_sg(nvmeq->q_dmadev, iod->meta_sg, 1, dma_dir))
-                               goto error_cmd;
-               }
+               if (req->nr_phys_segments)
+                       ret = nvme_map_data(dev, iod, &cmnd);
        }
 
+       if (ret)
+               goto out;
+
+       cmnd.common.command_id = req->tag;
        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);
 
+       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;
-
- error_cmd:
+out:
        nvme_free_iod(dev, iod);
-       return BLK_MQ_RQ_QUEUE_ERROR;
- retry_cmd:
-       nvme_free_iod(dev, iod);
-       return BLK_MQ_RQ_QUEUE_BUSY;
+       return ret;
 }
 
 static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
@@ -968,7 +958,8 @@ static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
        if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
                return;
 
-       writel(head, nvmeq->q_db + nvmeq->dev->db_stride);
+       if (likely(nvmeq->cq_vector >= 0))
+               writel(head, nvmeq->q_db + nvmeq->dev->db_stride);
        nvmeq->cq_head = head;
        nvmeq->cq_phase = phase;
 
@@ -1018,65 +1009,6 @@ 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, GFP_KERNEL, false);
-       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)
 {
        struct nvme_queue *nvmeq = dev->queues[0];
@@ -1084,7 +1016,8 @@ static int nvme_submit_async_admin_req(struct nvme_dev *dev)
        struct nvme_cmd_info *cmd_info;
        struct request *req;
 
-       req = blk_mq_alloc_request(dev->admin_q, WRITE, GFP_ATOMIC, true);
+       req = blk_mq_alloc_request(dev->ctrl.admin_q, WRITE,
+                       BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED);
        if (IS_ERR(req))
                return PTR_ERR(req);
 
@@ -1109,7 +1042,7 @@ static int nvme_submit_admin_async_cmd(struct nvme_dev *dev,
        struct request *req;
        struct nvme_cmd_info *cmd_rq;
 
-       req = blk_mq_alloc_request(dev->admin_q, WRITE, GFP_KERNEL, false);
+       req = blk_mq_alloc_request(dev->ctrl.admin_q, WRITE, 0);
        if (IS_ERR(req))
                return PTR_ERR(req);
 
@@ -1133,7 +1066,7 @@ 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,
@@ -1154,7 +1087,7 @@ 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,
@@ -1175,7 +1108,7 @@ 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)
@@ -1188,99 +1121,6 @@ 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)
-{
-       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),
-
-       *log = kmalloc(sizeof(struct nvme_smart_log), GFP_KERNEL);
-       if (!*log)
-               return -ENOMEM;
-
-       error = nvme_submit_sync_cmd(dev->admin_q, &c, *log,
-                       sizeof(struct nvme_smart_log));
-       if (error)
-               kfree(*log);
-       return error;
-}
-
 /**
  * nvme_abort_req - Attempt aborting a request
  *
@@ -1307,11 +1147,11 @@ static void nvme_abort_req(struct request *req)
                return;
        }
 
-       if (!dev->abort_limit)
+       if (!dev->ctrl.abort_limit)
                return;
 
-       abort_req = blk_mq_alloc_request(dev->admin_q, WRITE, GFP_ATOMIC,
-                                                                       false);
+       abort_req = blk_mq_alloc_request(dev->ctrl.admin_q, WRITE,
+                       BLK_MQ_REQ_NOWAIT);
        if (IS_ERR(abort_req))
                return;
 
@@ -1324,7 +1164,7 @@ static void nvme_abort_req(struct request *req)
        cmd.abort.sqid = cpu_to_le16(nvmeq->qid);
        cmd.abort.command_id = abort_req->tag;
 
-       --dev->abort_limit;
+       --dev->ctrl.abort_limit;
        cmd_rq->aborted = 1;
 
        dev_warn(nvmeq->q_dmadev, "Aborting I/O %d QID %d\n", req->tag,
@@ -1419,8 +1259,8 @@ 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_freeze_queue_start(nvmeq->dev->ctrl.admin_q);
 
        irq_set_affinity_hint(vector, NULL);
        free_irq(vector, nvmeq);
@@ -1447,7 +1287,7 @@ static void nvme_disable_queue(struct nvme_dev *dev, int qid)
 
        /* 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) {
+       if (qid && readl(dev->bar + NVME_REG_CSTS) != -1) {
                adapter_delete_sq(dev, qid);
                adapter_delete_cq(dev, qid);
        }
@@ -1516,7 +1356,7 @@ 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;
@@ -1600,7 +1440,7 @@ static int nvme_wait_ready(struct nvme_dev *dev, u64 cap, bool enabled)
 
        timeout = ((NVME_CAP_TIMEOUT(cap) + 1) * HZ / 2) + jiffies;
 
-       while ((readl(&dev->bar->csts) & NVME_CSTS_RDY) != bit) {
+       while ((readl(dev->bar + NVME_REG_CSTS) & NVME_CSTS_RDY) != bit) {
                msleep(100);
                if (fatal_signal_pending(current))
                        return -EINTR;
@@ -1625,7 +1465,7 @@ 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);
+       writel(dev->ctrl_config, dev->bar + NVME_REG_CC);
 
        return nvme_wait_ready(dev, cap, false);
 }
@@ -1634,7 +1474,7 @@ 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);
+       writel(dev->ctrl_config, dev->bar + NVME_REG_CC);
 
        return nvme_wait_ready(dev, cap, true);
 }
@@ -1646,10 +1486,10 @@ static int nvme_shutdown_ctrl(struct nvme_dev *dev)
        dev->ctrl_config &= ~NVME_CC_SHN_MASK;
        dev->ctrl_config |= NVME_CC_SHN_NORMAL;
 
-       writel(dev->ctrl_config, &dev->bar->cc);
+       writel(dev->ctrl_config, dev->bar + NVME_REG_CC);
 
        timeout = SHUTDOWN_TIMEOUT + jiffies;
-       while ((readl(&dev->bar->csts) & NVME_CSTS_SHST_MASK) !=
+       while ((readl(dev->bar + NVME_REG_CSTS) & NVME_CSTS_SHST_MASK) !=
                                                        NVME_CSTS_SHST_CMPLT) {
                msleep(100);
                if (fatal_signal_pending(current))
@@ -1684,15 +1524,15 @@ 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;
@@ -1705,18 +1545,18 @@ 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_unfreeze_queue(dev->ctrl.admin_q);
 
        return 0;
 }
@@ -1725,11 +1565,15 @@ 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;
-       unsigned page_shift = PAGE_SHIFT;
+       /*
+        * 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;
-       unsigned dev_page_max = NVME_CAP_MPSMAX(cap) + 12;
 
        if (page_shift < dev_page_min) {
                dev_err(dev->dev,
@@ -1738,19 +1582,13 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev)
                                1 << page_shift);
                return -ENODEV;
        }
-       if (page_shift > dev_page_max) {
-               dev_info(dev->dev,
-                               "Device maximum page size (%u) smaller than "
-                               "host (%u); enabling work-around\n",
-                               1 << dev_page_max, 1 << page_shift);
-               page_shift = dev_page_max;
-       }
 
-       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);
        if (result < 0)
@@ -1773,9 +1611,9 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev)
        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);
        if (result)
@@ -1797,13 +1635,9 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev)
 
 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)))
@@ -1821,29 +1655,13 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
        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)
+       } else if (meta_len) {
+               if ((io.metadata & 3) || !io.metadata)
                        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));
@@ -1857,22 +1675,13 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
        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;
+       return __nvme_submit_user_cmd(ns->queue, &c,
+                       (void __user *)(uintptr_t)io.addr, length,
+                       metadata, meta_len, io.slba, NULL, 0);
 }
 
-static int nvme_user_cmd(struct nvme_dev *dev, struct nvme_ns *ns,
+static int nvme_user_cmd(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
                        struct nvme_passthru_cmd __user *ucmd)
 {
        struct nvme_passthru_cmd cmd;
@@ -1901,8 +1710,8 @@ static int nvme_user_cmd(struct nvme_dev *dev, struct nvme_ns *ns,
        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,
+       status = nvme_submit_user_cmd(ns ? ns->queue : ctrl->admin_q, &c,
+                       (void __user *)(uintptr_t)cmd.addr, cmd.data_len,
                        &cmd.result, timeout);
        if (status >= 0) {
                if (put_user(cmd.result, &ucmd->result))
@@ -1917,7 +1726,7 @@ static int nvme_subsys_reset(struct nvme_dev *dev)
        if (!dev->subsystem)
                return -ENOTTY;
 
-       writel(0x4E564D65, &dev->bar->nssr); /* "NVMe" */
+       writel(0x4E564D65, dev->bar + NVME_REG_NSSR); /* "NVMe" */
        return 0;
 }
 
@@ -1931,9 +1740,9 @@ static int nvme_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
                force_successful_syscall_return();
                return ns->ns_id;
        case NVME_IOCTL_ADMIN_CMD:
-               return nvme_user_cmd(ns->dev, NULL, (void __user *)arg);
+               return nvme_user_cmd(ns->ctrl, NULL, (void __user *)arg);
        case NVME_IOCTL_IO_CMD:
-               return nvme_user_cmd(ns->dev, ns, (void __user *)arg);
+               return nvme_user_cmd(ns->ctrl, ns, (void __user *)arg);
        case NVME_IOCTL_SUBMIT_IO:
                return nvme_submit_io(ns, (void __user *)arg);
        case SG_GET_VERSION_NUM:
@@ -1963,6 +1772,7 @@ 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);
+       struct nvme_dev *dev = to_nvme_dev(ns->ctrl);
 
        if (ns->type == NVME_NS_LIGHTNVM)
                nvme_nvm_unregister(ns->queue, ns->disk->disk_name);
@@ -1971,7 +1781,7 @@ static void nvme_free_ns(struct kref *kref)
        ns->disk->private_data = NULL;
        spin_unlock(&dev_list_lock);
 
-       kref_put(&ns->dev->kref, nvme_free_dev);
+       kref_put(&dev->kref, nvme_free_dev);
        put_disk(ns->disk);
        kfree(ns);
 }
@@ -2020,15 +1830,15 @@ static void nvme_config_discard(struct nvme_ns *ns)
 static int nvme_revalidate_disk(struct gendisk *disk)
 {
        struct nvme_ns *ns = disk->private_data;
-       struct nvme_dev *dev = ns->dev;
+       struct nvme_dev *dev = to_nvme_dev(ns->ctrl);
        struct nvme_id_ns *id;
        u8 lbaf, pi_type;
        u16 old_ms;
        unsigned short bs;
 
-       if (nvme_identify_ns(dev, ns->ns_id, &id)) {
+       if (nvme_identify_ns(&dev->ctrl, ns->ns_id, &id)) {
                dev_warn(dev->dev, "%s: Identify failure nvme%dn%d\n", __func__,
-                                               dev->instance, ns->ns_id);
+                                               dev->ctrl.instance, ns->ns_id);
                return -ENODEV;
        }
        if (id->ncap == 0) {
@@ -2084,7 +1894,7 @@ static int nvme_revalidate_disk(struct gendisk *disk)
        else
                set_capacity(disk, le64_to_cpup(&id->nsze) << (ns->lba_shift - 9));
 
-       if (dev->oncs & NVME_CTRL_ONCS_DSM)
+       if (dev->ctrl.oncs & NVME_CTRL_ONCS_DSM)
                nvme_config_discard(ns);
        blk_mq_unfreeze_queue(disk->queue);
 
@@ -2204,14 +2014,14 @@ 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);
 
                        if ((dev->subsystem && (csts & NVME_CSTS_NSSRO)) ||
                                                        csts & NVME_CSTS_CFS) {
                                if (!__nvme_reset(dev)) {
                                        dev_warn(dev->dev,
                                                "Failed status: %x, reset controller\n",
-                                               readl(&dev->bar->csts));
+                                               readl(dev->bar + NVME_REG_CSTS));
                                }
                                continue;
                        }
@@ -2222,10 +2032,10 @@ static int nvme_kthread(void *data)
                                spin_lock_irq(&nvmeq->q_lock);
                                nvme_process_cq(nvmeq);
 
-                               while ((i == 0) && (dev->event_limit > 0)) {
+                               while (i == 0 && dev->ctrl.event_limit > 0) {
                                        if (nvme_submit_async_admin_req(dev))
                                                break;
-                                       dev->event_limit--;
+                                       dev->ctrl.event_limit--;
                                }
                                spin_unlock_irq(&nvmeq->q_lock);
                        }
@@ -2251,7 +2061,7 @@ static void nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid)
                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->ctrl = &dev->ctrl;
        ns->queue->queuedata = ns;
 
        disk = alloc_disk_node(0, node);
@@ -2268,11 +2078,11 @@ static void nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid)
        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 << 9) / dev->page_size) + 1);
+                       (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)
+       if (dev->ctrl.vwc & NVME_CTRL_VWC_PRESENT)
                blk_queue_flush(ns->queue, REQ_FLUSH | REQ_FUA);
        blk_queue_virt_boundary(ns->queue, dev->page_size - 1);
 
@@ -2283,7 +2093,7 @@ static void nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid)
        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);
+       sprintf(disk->disk_name, "nvme%dn%d", dev->ctrl.instance, nsid);
 
        /*
         * Initialize capacity to 0 until we establish the namespace format and
@@ -2348,7 +2158,7 @@ static int set_queue_count(struct nvme_dev *dev, int count)
        u32 result;
        u32 q_count = (count - 1) | ((count - 1) << 16);
 
-       status = nvme_set_features(dev, NVME_FEAT_NUM_QUEUES, q_count, 0,
+       status = nvme_set_features(&dev->ctrl, NVME_FEAT_NUM_QUEUES, q_count, 0,
                                                                &result);
        if (status < 0)
                return status;
@@ -2371,11 +2181,11 @@ 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);
@@ -2449,7 +2259,7 @@ 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;
        }
 
@@ -2525,13 +2335,15 @@ static struct nvme_ns *nvme_find_ns(struct nvme_dev *dev, unsigned nsid)
 
 static inline bool nvme_io_incapable(struct nvme_dev *dev)
 {
-       return (!dev->bar || readl(&dev->bar->csts) & NVME_CSTS_CFS ||
-                                                       dev->online_queues < 2);
+       return (!dev->bar ||
+               readl(dev->bar + NVME_REG_CSTS) & NVME_CSTS_CFS ||
+               dev->online_queues < 2);
 }
 
 static void nvme_ns_remove(struct nvme_ns *ns)
 {
-       bool kill = nvme_io_incapable(ns->dev) && !blk_queue_dying(ns->queue);
+       bool kill = nvme_io_incapable(to_nvme_dev(ns->ctrl)) &&
+                       !blk_queue_dying(ns->queue);
 
        if (kill)
                blk_set_queue_dying(ns->queue);
@@ -2588,7 +2400,7 @@ static void nvme_dev_scan(struct work_struct *work)
 
        if (!dev->tagset.tags)
                return;
-       if (nvme_identify_ctrl(dev, &ctrl))
+       if (nvme_identify_ctrl(&dev->ctrl, &ctrl))
                return;
        nvme_scan_namespaces(dev, le32_to_cpup(&ctrl->nn));
        kfree(ctrl);
@@ -2606,20 +2418,20 @@ 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;
+       int shift = NVME_CAP_MPSMIN(lo_hi_readq(dev->bar + NVME_REG_CAP)) + 12;
 
-       res = nvme_identify_ctrl(dev, &ctrl);
+       res = nvme_identify_ctrl(&dev->ctrl, &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));
+       dev->ctrl.oncs = le16_to_cpup(&ctrl->oncs);
+       dev->ctrl.abort_limit = ctrl->acl + 1;
+       dev->ctrl.vwc = ctrl->vwc;
+       memcpy(dev->ctrl.serial, ctrl->sn, sizeof(ctrl->sn));
+       memcpy(dev->ctrl.model, ctrl->mn, sizeof(ctrl->mn));
+       memcpy(dev->ctrl.firmware_rev, ctrl->fr, sizeof(ctrl->fr));
        if (ctrl->mdts)
                dev->max_hw_sectors = 1 << (ctrl->mdts + shift - 9);
        else
@@ -2682,7 +2494,7 @@ 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;
        }
@@ -2697,11 +2509,12 @@ 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;
-       if (readl(&dev->bar->vs) >= NVME_VS(1, 2))
+       dev->dbs = dev->bar + 4096;
+       if (readl(dev->bar + NVME_REG_VS) >= NVME_VS(1, 2))
                dev->cmb = nvme_map_cmb(dev);
 
        return 0;
@@ -2760,7 +2573,8 @@ static void nvme_wait_dq(struct nvme_delq_ctx *dq, struct nvme_dev *dev)
                         * queues than admin tags.
                         */
                        set_current_state(TASK_RUNNING);
-                       nvme_disable_ctrl(dev, lo_hi_readq(&dev->bar->cap));
+                       nvme_disable_ctrl(dev,
+                               lo_hi_readq(dev->bar + NVME_REG_CAP));
                        nvme_clear_queue(dev->queues[0]);
                        flush_kthread_worker(dq->worker);
                        nvme_disable_queue(dev, 0);
@@ -2787,6 +2601,10 @@ 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,
@@ -2848,7 +2666,7 @@ static void nvme_disable_io_queues(struct nvme_dev *dev)
        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);
+                                       &worker, "nvme%d", dev->ctrl.instance);
 
        if (IS_ERR(kworker_task)) {
                dev_err(dev->dev,
@@ -2932,7 +2750,7 @@ static void nvme_dev_shutdown(struct nvme_dev *dev)
 
        if (dev->bar) {
                nvme_freeze_queues(dev);
-               csts = readl(&dev->bar->csts);
+               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--) {
@@ -2999,14 +2817,14 @@ static int nvme_set_instance(struct nvme_dev *dev)
        if (error)
                return -ENODEV;
 
-       dev->instance = instance;
+       dev->ctrl.instance = instance;
        return 0;
 }
 
 static void nvme_release_instance(struct nvme_dev *dev)
 {
        spin_lock(&dev_list_lock);
-       ida_remove(&nvme_instance_ida, dev->instance);
+       ida_remove(&nvme_instance_ida, dev->ctrl.instance);
        spin_unlock(&dev_list_lock);
 }
 
@@ -3019,8 +2837,8 @@ static void nvme_free_dev(struct kref *kref)
        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);
@@ -3034,8 +2852,8 @@ static int nvme_dev_open(struct inode *inode, struct file *f)
 
        spin_lock(&dev_list_lock);
        list_for_each_entry(dev, &dev_list, node) {
-               if (dev->instance == instance) {
-                       if (!dev->admin_q) {
+               if (dev->ctrl.instance == instance) {
+                       if (!dev->ctrl.admin_q) {
                                ret = -EWOULDBLOCK;
                                break;
                        }
@@ -3065,12 +2883,12 @@ static long nvme_dev_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
 
        switch (cmd) {
        case NVME_IOCTL_ADMIN_CMD:
-               return nvme_user_cmd(dev, NULL, (void __user *)arg);
+               return nvme_user_cmd(&dev->ctrl, 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);
+               return nvme_user_cmd(&dev->ctrl, ns, (void __user *)arg);
        case NVME_IOCTL_RESET:
                dev_warn(dev->dev, "resetting controller\n");
                return nvme_reset(dev);
@@ -3131,7 +2949,7 @@ static void nvme_probe_work(struct work_struct *work)
        if (result)
                goto free_tags;
 
-       dev->event_limit = 1;
+       dev->ctrl.event_limit = 1;
 
        /*
         * Keep the controller around but remove all namespaces if we don't have
@@ -3149,8 +2967,8 @@ static void nvme_probe_work(struct work_struct *work)
 
  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);
@@ -3178,7 +2996,7 @@ static void nvme_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->ctrl.instance))) {
                dev_err(dev->dev,
                        "Failed to start controller remove task\n");
                kref_put(&dev->kref, nvme_free_dev);
@@ -3220,7 +3038,7 @@ static int nvme_reset(struct nvme_dev *dev)
 {
        int ret;
 
-       if (!dev->admin_q || blk_queue_dying(dev->admin_q))
+       if (!dev->ctrl.admin_q || blk_queue_dying(dev->ctrl.admin_q))
                return -ENODEV;
 
        spin_lock(&dev_list_lock);
@@ -3251,6 +3069,16 @@ static ssize_t nvme_sysfs_reset(struct device *dev,
 }
 static DEVICE_ATTR(reset_controller, S_IWUSR, NULL, nvme_sysfs_reset);
 
+static int nvme_pci_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)
+{
+       *val = readl(to_nvme_dev(ctrl)->bar + off);
+       return 0;
+}
+
+static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
+       .reg_read32             = nvme_pci_reg_read32,
+};
+
 static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
        int node, result = -ENOMEM;
@@ -3276,6 +3104,10 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
        INIT_WORK(&dev->reset_work, nvme_reset_work);
        dev->dev = get_device(&pdev->dev);
        pci_set_drvdata(pdev, dev);
+
+       dev->ctrl.ops = &nvme_pci_ctrl_ops;
+       dev->ctrl.dev = dev->dev;
+
        result = nvme_set_instance(dev);
        if (result)
                goto put_pci;
@@ -3286,8 +3118,8 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
        kref_init(&dev->kref);
        dev->device = device_create(nvme_class, &pdev->dev,
-                               MKDEV(nvme_char_major, dev->instance),
-                               dev, "nvme%d", dev->instance);
+                               MKDEV(nvme_char_major, dev->ctrl.instance),
+                               dev, "nvme%d", dev->ctrl.instance);
        if (IS_ERR(dev->device)) {
                result = PTR_ERR(dev->device);
                goto release_pools;
@@ -3306,7 +3138,7 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
        return 0;
 
  put_dev:
-       device_destroy(nvme_class, MKDEV(nvme_char_major, dev->instance));
+       device_destroy(nvme_class, MKDEV(nvme_char_major, dev->ctrl.instance));
        put_device(dev->device);
  release_pools:
        nvme_release_prp_pools(dev);
@@ -3353,7 +3185,7 @@ static void nvme_remove(struct pci_dev *pdev)
        nvme_dev_remove(dev);
        nvme_dev_shutdown(dev);
        nvme_dev_remove_admin(dev);
-       device_destroy(nvme_class, MKDEV(nvme_char_major, dev->instance));
+       device_destroy(nvme_class, MKDEV(nvme_char_major, dev->ctrl.instance));
        nvme_free_queues(dev, 0);
        nvme_release_cmb(dev);
        nvme_release_prp_pools(dev);