NVMe: Implement doorbell stride capability
[linux-2.6-block.git] / drivers / block / nvme.c
index 903e7f15b60df342b56de7cf8247af2a202ef046..a17f80fa3881fc54a4bd849219baa4d540c1d40d 100644 (file)
 
 #include <linux/nvme.h>
 #include <linux/bio.h>
+#include <linux/bitops.h>
 #include <linux/blkdev.h>
+#include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/genhd.h>
+#include <linux/idr.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kdev_t.h>
+#include <linux/kthread.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/module.h>
@@ -50,15 +54,23 @@ module_param(nvme_major, int, 0);
 static int use_threaded_interrupts;
 module_param(use_threaded_interrupts, int, 0);
 
+static DEFINE_SPINLOCK(dev_list_lock);
+static LIST_HEAD(dev_list);
+static struct task_struct *nvme_thread;
+
 /*
  * Represents an NVM Express device.  Each nvme_dev is a PCI function.
  */
 struct nvme_dev {
+       struct list_head node;
        struct nvme_queue **queues;
        u32 __iomem *dbs;
        struct pci_dev *pci_dev;
+       struct dma_pool *prp_page_pool;
+       struct dma_pool *prp_small_pool;
        int instance;
        int queue_count;
+       int db_stride;
        u32 ctrl_config;
        struct msix_entry *entry;
        struct nvme_bar __iomem *bar;
@@ -88,12 +100,14 @@ struct nvme_ns {
  */
 struct nvme_queue {
        struct device *q_dmadev;
+       struct nvme_dev *dev;
        spinlock_t q_lock;
        struct nvme_command *sq_cmds;
        volatile struct nvme_completion *cqes;
        dma_addr_t sq_dma_addr;
        dma_addr_t cq_dma_addr;
        wait_queue_head_t sq_full;
+       wait_queue_t sq_cong_wait;
        struct bio_list sq_cong;
        u32 __iomem *q_db;
        u16 q_depth;
@@ -105,8 +119,6 @@ struct nvme_queue {
        unsigned long cmdid_data[];
 };
 
-static void nvme_resubmit_bio(struct nvme_queue *nvmeq, struct bio *bio);
-
 /*
  * Check we didin't inadvertently grow the command struct
  */
@@ -134,21 +146,24 @@ static struct nvme_cmd_info *nvme_cmd_info(struct nvme_queue *nvmeq)
 }
 
 /**
- * alloc_cmdid - Allocate a Command ID
- * @param nvmeq The queue that will be used for this command
- * @param ctx A pointer that will be passed to the handler
- * @param handler The ID of the handler to call
+ * alloc_cmdid() - Allocate a Command ID
+ * @nvmeq: The queue that will be used for this command
+ * @ctx: A pointer that will be passed to the handler
+ * @handler: The ID of the handler to call
  *
  * Allocate a Command ID for a queue.  The data passed in will
  * be passed to the completion handler.  This is implemented by using
  * the bottom two bits of the ctx pointer to store the handler ID.
  * Passing in a pointer that's not 4-byte aligned will cause a BUG.
  * We can change this if it becomes a problem.
+ *
+ * May be called with local interrupts disabled and the q_lock held,
+ * or with interrupts enabled and no locks held.
  */
 static int alloc_cmdid(struct nvme_queue *nvmeq, void *ctx, int handler,
                                                        unsigned timeout)
 {
-       int depth = nvmeq->q_depth;
+       int depth = nvmeq->q_depth - 1;
        struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
        int cmdid;
 
@@ -174,7 +189,8 @@ static int alloc_cmdid_killable(struct nvme_queue *nvmeq, void *ctx,
        return (cmdid < 0) ? -EINTR : cmdid;
 }
 
-/* If you need more than four handlers, you'll need to change how
+/*
+ * If you need more than four handlers, you'll need to change how
  * alloc_cmdid and nvme_process_cq work.  Consider using a special
  * CMD_CTX value instead, if that works for your situation.
  */
@@ -183,11 +199,16 @@ enum {
        bio_completion_id,
 };
 
+/* Special values must be a multiple of 4, and less than 0x1000 */
 #define CMD_CTX_BASE           (POISON_POINTER_DELTA + sync_completion_id)
 #define CMD_CTX_CANCELLED      (0x30C + CMD_CTX_BASE)
 #define CMD_CTX_COMPLETED      (0x310 + CMD_CTX_BASE)
 #define CMD_CTX_INVALID                (0x314 + CMD_CTX_BASE)
+#define CMD_CTX_FLUSH          (0x318 + CMD_CTX_BASE)
 
+/*
+ * Called with local interrupts disabled and the q_lock held.  May not sleep.
+ */
 static unsigned long free_cmdid(struct nvme_queue *nvmeq, int cmdid)
 {
        unsigned long data;
@@ -202,20 +223,18 @@ static unsigned long free_cmdid(struct nvme_queue *nvmeq, int cmdid)
        return data;
 }
 
-static void cancel_cmdid_data(struct nvme_queue *nvmeq, int cmdid)
+static unsigned long cancel_cmdid(struct nvme_queue *nvmeq, int cmdid)
 {
+       unsigned long data;
        struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
+       data = info[cmdid].ctx;
        info[cmdid].ctx = CMD_CTX_CANCELLED;
+       return data;
 }
 
 static struct nvme_queue *get_nvmeq(struct nvme_ns *ns)
 {
-       int qid, cpu = get_cpu();
-       if (cpu < ns->dev->queue_count)
-               qid = cpu + 1;
-       else
-               qid = (cpu % rounddown_pow_of_two(ns->dev->queue_count)) + 1;
-       return ns->dev->queues[qid];
+       return ns->dev->queues[get_cpu() + 1];
 }
 
 static void put_nvmeq(struct nvme_queue *nvmeq)
@@ -224,7 +243,7 @@ static void put_nvmeq(struct nvme_queue *nvmeq)
 }
 
 /**
- * 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
  *
@@ -234,65 +253,108 @@ static int nvme_submit_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd)
 {
        unsigned long flags;
        u16 tail;
-       /* XXX: Need to check tail isn't going to overrun head */
        spin_lock_irqsave(&nvmeq->q_lock, flags);
        tail = nvmeq->sq_tail;
        memcpy(&nvmeq->sq_cmds[tail], cmd, sizeof(*cmd));
-       writel(tail, nvmeq->q_db);
        if (++tail == nvmeq->q_depth)
                tail = 0;
+       writel(tail, nvmeq->q_db);
        nvmeq->sq_tail = tail;
        spin_unlock_irqrestore(&nvmeq->q_lock, flags);
 
        return 0;
 }
 
-struct nvme_req_info {
+struct nvme_prps {
+       int npages;             /* 0 means small pool in use */
+       dma_addr_t first_dma;
+       __le64 *list[0];
+};
+
+static void nvme_free_prps(struct nvme_dev *dev, struct nvme_prps *prps)
+{
+       const int last_prp = PAGE_SIZE / 8 - 1;
+       int i;
+       dma_addr_t prp_dma;
+
+       if (!prps)
+               return;
+
+       prp_dma = prps->first_dma;
+
+       if (prps->npages == 0)
+               dma_pool_free(dev->prp_small_pool, prps->list[0], prp_dma);
+       for (i = 0; i < prps->npages; i++) {
+               __le64 *prp_list = prps->list[i];
+               dma_addr_t next_prp_dma = le64_to_cpu(prp_list[last_prp]);
+               dma_pool_free(dev->prp_page_pool, prp_list, prp_dma);
+               prp_dma = next_prp_dma;
+       }
+       kfree(prps);
+}
+
+struct nvme_bio {
        struct bio *bio;
        int nents;
+       struct nvme_prps *prps;
        struct scatterlist sg[0];
 };
 
 /* XXX: use a mempool */
-static struct nvme_req_info *alloc_info(unsigned nseg, gfp_t gfp)
+static struct nvme_bio *alloc_nbio(unsigned nseg, gfp_t gfp)
 {
-       return kmalloc(sizeof(struct nvme_req_info) +
+       return kzalloc(sizeof(struct nvme_bio) +
                        sizeof(struct scatterlist) * nseg, gfp);
 }
 
-static void free_info(struct nvme_req_info *info)
+static void free_nbio(struct nvme_queue *nvmeq, struct nvme_bio *nbio)
 {
-       kfree(info);
+       nvme_free_prps(nvmeq->dev, nbio->prps);
+       kfree(nbio);
 }
 
 static void bio_completion(struct nvme_queue *nvmeq, void *ctx,
                                                struct nvme_completion *cqe)
 {
-       struct nvme_req_info *info = ctx;
-       struct bio *bio = info->bio;
+       struct nvme_bio *nbio = ctx;
+       struct bio *bio = nbio->bio;
        u16 status = le16_to_cpup(&cqe->status) >> 1;
 
-       dma_unmap_sg(nvmeq->q_dmadev, info->sg, info->nents,
+       dma_unmap_sg(nvmeq->q_dmadev, nbio->sg, nbio->nents,
                        bio_data_dir(bio) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
-       free_info(info);
-       bio_endio(bio, status ? -EIO : 0);
-       bio = bio_list_pop(&nvmeq->sq_cong);
-       if (bio)
-               nvme_resubmit_bio(nvmeq, bio);
+       free_nbio(nvmeq, nbio);
+       if (status) {
+               bio_endio(bio, -EIO);
+       } else if (bio->bi_vcnt > bio->bi_idx) {
+               if (bio_list_empty(&nvmeq->sq_cong))
+                       add_wait_queue(&nvmeq->sq_full, &nvmeq->sq_cong_wait);
+               bio_list_add(&nvmeq->sq_cong, bio);
+               wake_up_process(nvme_thread);
+       } else {
+               bio_endio(bio, 0);
+       }
 }
 
-/* length is in bytes */
-static void nvme_setup_prps(struct nvme_common_command *cmd,
-                                       struct scatterlist *sg, int length)
+/* length is in bytes.  gfp flags indicates whether we may sleep. */
+static struct nvme_prps *nvme_setup_prps(struct nvme_dev *dev,
+                                       struct nvme_common_command *cmd,
+                                       struct scatterlist *sg, int *len,
+                                       gfp_t gfp)
 {
+       struct dma_pool *pool;
+       int length = *len;
        int dma_len = sg_dma_len(sg);
        u64 dma_addr = sg_dma_address(sg);
        int offset = offset_in_page(dma_addr);
+       __le64 *prp_list;
+       dma_addr_t prp_dma;
+       int nprps, npages, i;
+       struct nvme_prps *prps = NULL;
 
        cmd->prp1 = cpu_to_le64(dma_addr);
        length -= (PAGE_SIZE - offset);
        if (length <= 0)
-               return;
+               return prps;
 
        dma_len -= (PAGE_SIZE - offset);
        if (dma_len) {
@@ -305,51 +367,163 @@ static void nvme_setup_prps(struct nvme_common_command *cmd,
 
        if (length <= PAGE_SIZE) {
                cmd->prp2 = cpu_to_le64(dma_addr);
-               return;
+               return prps;
+       }
+
+       nprps = DIV_ROUND_UP(length, PAGE_SIZE);
+       npages = DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
+       prps = kmalloc(sizeof(*prps) + sizeof(__le64 *) * npages, gfp);
+       if (!prps) {
+               cmd->prp2 = cpu_to_le64(dma_addr);
+               *len = (*len - length) + PAGE_SIZE;
+               return prps;
+       }
+
+       if (nprps <= (256 / 8)) {
+               pool = dev->prp_small_pool;
+               prps->npages = 0;
+       } else {
+               pool = dev->prp_page_pool;
+               prps->npages = 1;
+       }
+
+       prp_list = dma_pool_alloc(pool, gfp, &prp_dma);
+       if (!prp_list) {
+               cmd->prp2 = cpu_to_le64(dma_addr);
+               *len = (*len - length) + PAGE_SIZE;
+               kfree(prps);
+               return NULL;
+       }
+       prps->list[0] = prp_list;
+       prps->first_dma = prp_dma;
+       cmd->prp2 = cpu_to_le64(prp_dma);
+       i = 0;
+       for (;;) {
+               if (i == PAGE_SIZE / 8) {
+                       __le64 *old_prp_list = prp_list;
+                       prp_list = dma_pool_alloc(pool, gfp, &prp_dma);
+                       if (!prp_list) {
+                               *len = (*len - length);
+                               return prps;
+                       }
+                       prps->list[prps->npages++] = prp_list;
+                       prp_list[0] = old_prp_list[i - 1];
+                       old_prp_list[i - 1] = cpu_to_le64(prp_dma);
+                       i = 1;
+               }
+               prp_list[i++] = cpu_to_le64(dma_addr);
+               dma_len -= PAGE_SIZE;
+               dma_addr += PAGE_SIZE;
+               length -= PAGE_SIZE;
+               if (length <= 0)
+                       break;
+               if (dma_len > 0)
+                       continue;
+               BUG_ON(dma_len < 0);
+               sg = sg_next(sg);
+               dma_addr = sg_dma_address(sg);
+               dma_len = sg_dma_len(sg);
        }
 
-       /* XXX: support PRP lists */
+       return prps;
 }
 
-static int nvme_map_bio(struct device *dev, struct nvme_req_info *info,
+/* NVMe scatterlists require no holes in the virtual address */
+#define BIOVEC_NOT_VIRT_MERGEABLE(vec1, vec2)  ((vec2)->bv_offset || \
+                       (((vec1)->bv_offset + (vec1)->bv_len) % PAGE_SIZE))
+
+static int nvme_map_bio(struct device *dev, struct nvme_bio *nbio,
                struct bio *bio, enum dma_data_direction dma_dir, int psegs)
 {
-       struct bio_vec *bvec;
-       struct scatterlist *sg = info->sg;
-       int i, nsegs;
+       struct bio_vec *bvec, *bvprv = NULL;
+       struct scatterlist *sg = NULL;
+       int i, old_idx, length = 0, nsegs = 0;
 
-       sg_init_table(sg, psegs);
+       sg_init_table(nbio->sg, psegs);
+       old_idx = bio->bi_idx;
        bio_for_each_segment(bvec, bio, i) {
-               sg_set_page(sg, bvec->bv_page, bvec->bv_len, bvec->bv_offset);
-               sg++;
-               /* XXX: handle non-mergable here */
-               nsegs++;
+               if (bvprv && BIOVEC_PHYS_MERGEABLE(bvprv, bvec)) {
+                       sg->length += bvec->bv_len;
+               } else {
+                       if (bvprv && BIOVEC_NOT_VIRT_MERGEABLE(bvprv, bvec))
+                               break;
+                       sg = sg ? sg + 1 : nbio->sg;
+                       sg_set_page(sg, bvec->bv_page, bvec->bv_len,
+                                                       bvec->bv_offset);
+                       nsegs++;
+               }
+               length += bvec->bv_len;
+               bvprv = bvec;
+       }
+       bio->bi_idx = i;
+       nbio->nents = nsegs;
+       sg_mark_end(sg);
+       if (dma_map_sg(dev, nbio->sg, nbio->nents, dma_dir) == 0) {
+               bio->bi_idx = old_idx;
+               return -ENOMEM;
        }
-       info->nents = nsegs;
+       return length;
+}
+
+static int nvme_submit_flush(struct nvme_queue *nvmeq, struct nvme_ns *ns,
+                                                               int cmdid)
+{
+       struct nvme_command *cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail];
+
+       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 (++nvmeq->sq_tail == nvmeq->q_depth)
+               nvmeq->sq_tail = 0;
+       writel(nvmeq->sq_tail, nvmeq->q_db);
 
-       return dma_map_sg(dev, info->sg, info->nents, dma_dir);
+       return 0;
 }
 
+static int nvme_submit_flush_data(struct nvme_queue *nvmeq, struct nvme_ns *ns)
+{
+       int cmdid = alloc_cmdid(nvmeq, (void *)CMD_CTX_FLUSH,
+                                               sync_completion_id, IO_TIMEOUT);
+       if (unlikely(cmdid < 0))
+               return cmdid;
+
+       return nvme_submit_flush(nvmeq, ns, cmdid);
+}
+
+/*
+ * Called with local interrupts disabled and the q_lock held.  May not sleep.
+ */
 static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
                                                                struct bio *bio)
 {
        struct nvme_command *cmnd;
-       struct nvme_req_info *info;
+       struct nvme_bio *nbio;
        enum dma_data_direction dma_dir;
-       int cmdid;
+       int cmdid, length, result = -ENOMEM;
        u16 control;
        u32 dsmgmt;
-       unsigned long flags;
        int psegs = bio_phys_segments(ns->queue, bio);
 
-       info = alloc_info(psegs, GFP_NOIO);
-       if (!info)
-               goto congestion;
-       info->bio = bio;
+       if ((bio->bi_rw & REQ_FLUSH) && psegs) {
+               result = nvme_submit_flush_data(nvmeq, ns);
+               if (result)
+                       return result;
+       }
+
+       nbio = alloc_nbio(psegs, GFP_ATOMIC);
+       if (!nbio)
+               goto nomem;
+       nbio->bio = bio;
 
-       cmdid = alloc_cmdid(nvmeq, info, bio_completion_id, IO_TIMEOUT);
+       result = -EBUSY;
+       cmdid = alloc_cmdid(nvmeq, nbio, bio_completion_id, IO_TIMEOUT);
        if (unlikely(cmdid < 0))
-               goto free_info;
+               goto free_nbio;
+
+       if ((bio->bi_rw & REQ_FLUSH) && !psegs)
+               return nvme_submit_flush(nvmeq, ns, cmdid);
 
        control = 0;
        if (bio->bi_rw & REQ_FUA)
@@ -361,7 +535,6 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
        if (bio->bi_rw & REQ_RAHEAD)
                dsmgmt |= NVME_RW_DSM_FREQ_PREFETCH;
 
-       spin_lock_irqsave(&nvmeq->q_lock, flags);
        cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail];
 
        memset(cmnd, 0, sizeof(*cmnd));
@@ -373,39 +546,32 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
                dma_dir = DMA_FROM_DEVICE;
        }
 
-       nvme_map_bio(nvmeq->q_dmadev, info, bio, dma_dir, psegs);
+       result = nvme_map_bio(nvmeq->q_dmadev, nbio, bio, dma_dir, psegs);
+       if (result < 0)
+               goto free_nbio;
+       length = result;
 
-       cmnd->rw.flags = 1;
        cmnd->rw.command_id = cmdid;
        cmnd->rw.nsid = cpu_to_le32(ns->ns_id);
-       nvme_setup_prps(&cmnd->common, info->sg, bio->bi_size);
+       nbio->prps = nvme_setup_prps(nvmeq->dev, &cmnd->common, nbio->sg,
+                                                       &length, GFP_ATOMIC);
        cmnd->rw.slba = cpu_to_le64(bio->bi_sector >> (ns->lba_shift - 9));
-       cmnd->rw.length = cpu_to_le16((bio->bi_size >> ns->lba_shift) - 1);
+       cmnd->rw.length = cpu_to_le16((length >> ns->lba_shift) - 1);
        cmnd->rw.control = cpu_to_le16(control);
        cmnd->rw.dsmgmt = cpu_to_le32(dsmgmt);
 
-       writel(nvmeq->sq_tail, nvmeq->q_db);
+       bio->bi_sector += length >> 9;
+
        if (++nvmeq->sq_tail == nvmeq->q_depth)
                nvmeq->sq_tail = 0;
-
-       spin_unlock_irqrestore(&nvmeq->q_lock, flags);
+       writel(nvmeq->sq_tail, nvmeq->q_db);
 
        return 0;
 
- free_info:
-       free_info(info);
- congestion:
-       return -EBUSY;
-}
-
-static void nvme_resubmit_bio(struct nvme_queue *nvmeq, struct bio *bio)
-{
-       struct nvme_ns *ns = bio->bi_bdev->bd_disk->private_data;
-       if (nvme_submit_bio_queue(nvmeq, ns, bio))
-               bio_list_add_head(&nvmeq->sq_cong, bio);
-       else if (bio_list_empty(&nvmeq->sq_cong))
-               blk_clear_queue_congested(ns->queue, rw_is_sync(bio->bi_rw));
-       /* XXX: Need to duplicate the logic from __freed_request here */
+ free_nbio:
+       free_nbio(nvmeq, nbio);
+ nomem:
+       return result;
 }
 
 /*
@@ -416,13 +582,18 @@ static int nvme_make_request(struct request_queue *q, struct bio *bio)
 {
        struct nvme_ns *ns = q->queuedata;
        struct nvme_queue *nvmeq = get_nvmeq(ns);
+       int result = -EBUSY;
 
-       if (nvme_submit_bio_queue(nvmeq, ns, bio)) {
-               blk_set_queue_congested(q, rw_is_sync(bio->bi_rw));
-               spin_lock_irq(&nvmeq->q_lock);
+       spin_lock_irq(&nvmeq->q_lock);
+       if (bio_list_empty(&nvmeq->sq_cong))
+               result = nvme_submit_bio_queue(nvmeq, ns, bio);
+       if (unlikely(result)) {
+               if (bio_list_empty(&nvmeq->sq_cong))
+                       add_wait_queue(&nvmeq->sq_full, &nvmeq->sq_cong_wait);
                bio_list_add(&nvmeq->sq_cong, bio);
-               spin_unlock_irq(&nvmeq->q_lock);
        }
+
+       spin_unlock_irq(&nvmeq->q_lock);
        put_nvmeq(nvmeq);
 
        return 0;
@@ -438,7 +609,9 @@ static void sync_completion(struct nvme_queue *nvmeq, void *ctx,
                                                struct nvme_completion *cqe)
 {
        struct sync_cmd_info *cmdinfo = ctx;
-       if ((unsigned long)cmdinfo == CMD_CTX_CANCELLED)
+       if (unlikely((unsigned long)cmdinfo == CMD_CTX_CANCELLED))
+               return;
+       if ((unsigned long)cmdinfo == CMD_CTX_FLUSH)
                return;
        if (unlikely((unsigned long)cmdinfo == CMD_CTX_COMPLETED)) {
                dev_warn(nvmeq->q_dmadev,
@@ -460,15 +633,15 @@ static void sync_completion(struct nvme_queue *nvmeq, void *ctx,
 typedef void (*completion_fn)(struct nvme_queue *, void *,
                                                struct nvme_completion *);
 
+static const completion_fn nvme_completions[4] = {
+       [sync_completion_id] = sync_completion,
+       [bio_completion_id]  = bio_completion,
+};
+
 static irqreturn_t nvme_process_cq(struct nvme_queue *nvmeq)
 {
        u16 head, phase;
 
-       static const completion_fn completions[4] = {
-               [sync_completion_id] = sync_completion,
-               [bio_completion_id]  = bio_completion,
-       };
-
        head = nvmeq->cq_head;
        phase = nvmeq->cq_phase;
 
@@ -488,7 +661,7 @@ static irqreturn_t nvme_process_cq(struct nvme_queue *nvmeq)
                data = free_cmdid(nvmeq, cqe.command_id);
                handler = data & 3;
                ptr = (void *)(data & ~3UL);
-               completions[handler](nvmeq, ptr, &cqe);
+               nvme_completions[handler](nvmeq, ptr, &cqe);
        }
 
        /* If the controller ignores the cq head doorbell and continuously
@@ -500,7 +673,7 @@ static irqreturn_t nvme_process_cq(struct nvme_queue *nvmeq)
        if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
                return IRQ_NONE;
 
-       writel(head, nvmeq->q_db + 1);
+       writel(head, nvmeq->q_db + (1 << nvmeq->dev->db_stride));
        nvmeq->cq_head = head;
        nvmeq->cq_phase = phase;
 
@@ -529,7 +702,7 @@ static irqreturn_t nvme_irq_check(int irq, void *data)
 static void nvme_abort_command(struct nvme_queue *nvmeq, int cmdid)
 {
        spin_lock_irq(&nvmeq->q_lock);
-       cancel_cmdid_data(nvmeq, cmdid);
+       cancel_cmdid(nvmeq, cmdid);
        spin_unlock_irq(&nvmeq->q_lock);
 }
 
@@ -640,11 +813,41 @@ static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
        return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
 }
 
+static int nvme_identify(struct nvme_dev *dev, unsigned nsid, unsigned cns,
+                                                       dma_addr_t dma_addr)
+{
+       struct nvme_command c;
+
+       memset(&c, 0, sizeof(c));
+       c.identify.opcode = nvme_admin_identify;
+       c.identify.nsid = cpu_to_le32(nsid);
+       c.identify.prp1 = cpu_to_le64(dma_addr);
+       c.identify.cns = cpu_to_le32(cns);
+
+       return nvme_submit_admin_cmd(dev, &c, NULL);
+}
+
+static int nvme_get_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_get_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_admin_cmd(dev, &c, result);
+}
+
 static void nvme_free_queue(struct nvme_dev *dev, int qid)
 {
        struct nvme_queue *nvmeq = dev->queues[qid];
+       int vector = dev->entry[nvmeq->cq_vector].vector;
 
-       free_irq(dev->entry[nvmeq->cq_vector].vector, nvmeq);
+       irq_set_affinity_hint(vector, NULL);
+       free_irq(vector, nvmeq);
 
        /* Don't tell the adapter to delete the admin queue */
        if (qid) {
@@ -680,12 +883,14 @@ static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
                goto free_cqdma;
 
        nvmeq->q_dmadev = dmadev;
+       nvmeq->dev = dev;
        spin_lock_init(&nvmeq->q_lock);
        nvmeq->cq_head = 0;
        nvmeq->cq_phase = 1;
        init_waitqueue_head(&nvmeq->sq_full);
+       init_waitqueue_entry(&nvmeq->sq_cong_wait, nvme_thread);
        bio_list_init(&nvmeq->sq_cong);
-       nvmeq->q_db = &dev->dbs[qid * 2];
+       nvmeq->q_db = &dev->dbs[qid << (dev->db_stride + 1)];
        nvmeq->q_depth = depth;
        nvmeq->cq_vector = vector;
 
@@ -718,7 +923,7 @@ static __devinit struct nvme_queue *nvme_create_queue(struct nvme_dev *dev,
        struct nvme_queue *nvmeq = nvme_alloc_queue(dev, qid, cq_size, vector);
 
        if (!nvmeq)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        result = adapter_alloc_cq(dev, qid, nvmeq);
        if (result < 0)
@@ -744,13 +949,15 @@ static __devinit struct nvme_queue *nvme_create_queue(struct nvme_dev *dev,
        dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
                                        nvmeq->sq_cmds, nvmeq->sq_dma_addr);
        kfree(nvmeq);
-       return NULL;
+       return ERR_PTR(result);
 }
 
 static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev)
 {
        int result;
        u32 aqa;
+       u64 cap;
+       unsigned long timeout;
        struct nvme_queue *nvmeq;
 
        dev->dbs = ((void __iomem *)dev->bar) + 4096;
@@ -765,6 +972,7 @@ static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev)
        dev->ctrl_config = NVME_CC_ENABLE | 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(0, &dev->bar->cc);
        writel(aqa, &dev->bar->aqa);
@@ -772,10 +980,19 @@ static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev)
        writeq(nvmeq->cq_dma_addr, &dev->bar->acq);
        writel(dev->ctrl_config, &dev->bar->cc);
 
+       cap = readq(&dev->bar->cap);
+       timeout = ((NVME_CAP_TIMEOUT(cap) + 1) * HZ / 2) + jiffies;
+       dev->db_stride = NVME_CAP_STRIDE(cap);
+
        while (!(readl(&dev->bar->csts) & NVME_CSTS_RDY)) {
                msleep(100);
                if (fatal_signal_pending(current))
                        return -EINTR;
+               if (time_after(jiffies, timeout)) {
+                       dev_err(&dev->pci_dev->dev,
+                               "Device not ready; aborting initialisation\n");
+                       return -ENODEV;
+               }
        }
 
        result = queue_request_irq(dev, nvmeq, "nvme admin");
@@ -809,11 +1026,11 @@ static int nvme_map_user_pages(struct nvme_dev *dev, int write,
 
        sg = kcalloc(count, sizeof(*sg), GFP_KERNEL);
        sg_init_table(sg, count);
-       sg_set_page(&sg[0], pages[0], PAGE_SIZE - offset, offset);
-       length -= (PAGE_SIZE - offset);
-       for (i = 1; i < count; i++) {
-               sg_set_page(&sg[i], pages[i], min_t(int, length, PAGE_SIZE), 0);
-               length -= PAGE_SIZE;
+       for (i = 0; i < count; i++) {
+               sg_set_page(&sg[i], pages[i],
+                               min_t(int, length, PAGE_SIZE - offset), offset);
+               length -= (PAGE_SIZE - offset);
+               offset = 0;
        }
 
        err = -ENOMEM;
@@ -834,58 +1051,17 @@ static int nvme_map_user_pages(struct nvme_dev *dev, int write,
 }
 
 static void nvme_unmap_user_pages(struct nvme_dev *dev, int write,
-                               unsigned long addr, int length,
-                               struct scatterlist *sg, int nents)
+                       unsigned long addr, int length, struct scatterlist *sg)
 {
        int i, count;
 
        count = DIV_ROUND_UP(offset_in_page(addr) + length, PAGE_SIZE);
-       dma_unmap_sg(&dev->pci_dev->dev, sg, nents, DMA_FROM_DEVICE);
+       dma_unmap_sg(&dev->pci_dev->dev, sg, count, DMA_FROM_DEVICE);
 
        for (i = 0; i < count; i++)
                put_page(sg_page(&sg[i]));
 }
 
-static int nvme_submit_user_admin_command(struct nvme_dev *dev,
-                                       unsigned long addr, unsigned length,
-                                       struct nvme_command *cmd)
-{
-       int err, nents;
-       struct scatterlist *sg;
-
-       nents = nvme_map_user_pages(dev, 0, addr, length, &sg);
-       if (nents < 0)
-               return nents;
-       nvme_setup_prps(&cmd->common, sg, length);
-       err = nvme_submit_admin_cmd(dev, cmd, NULL);
-       nvme_unmap_user_pages(dev, 0, addr, length, sg, nents);
-       return err ? -EIO : 0;
-}
-
-static int nvme_identify(struct nvme_ns *ns, unsigned long addr, int cns)
-{
-       struct nvme_command c;
-
-       memset(&c, 0, sizeof(c));
-       c.identify.opcode = nvme_admin_identify;
-       c.identify.nsid = cns ? 0 : cpu_to_le32(ns->ns_id);
-       c.identify.cns = cpu_to_le32(cns);
-
-       return nvme_submit_user_admin_command(ns->dev, addr, 4096, &c);
-}
-
-static int nvme_get_range_type(struct nvme_ns *ns, unsigned long addr)
-{
-       struct nvme_command c;
-
-       memset(&c, 0, sizeof(c));
-       c.features.opcode = nvme_admin_get_features;
-       c.features.nsid = cpu_to_le32(ns->ns_id);
-       c.features.fid = cpu_to_le32(NVME_FEAT_LBA_RANGE);
-
-       return nvme_submit_user_admin_command(ns->dev, addr, 4096, &c);
-}
-
 static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
 {
        struct nvme_dev *dev = ns->dev;
@@ -893,104 +1069,119 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
        struct nvme_user_io io;
        struct nvme_command c;
        unsigned length;
-       u32 result;
        int nents, status;
        struct scatterlist *sg;
+       struct nvme_prps *prps;
 
        if (copy_from_user(&io, uio, sizeof(io)))
                return -EFAULT;
-       length = io.nblocks << io.block_shift;
-       nents = nvme_map_user_pages(dev, io.opcode & 1, io.addr, length, &sg);
+       length = (io.nblocks + 1) << ns->lba_shift;
+
+       switch (io.opcode) {
+       case nvme_cmd_write:
+       case nvme_cmd_read:
+       case nvme_cmd_compare:
+               nents = nvme_map_user_pages(dev, io.opcode & 1, io.addr,
+                                                               length, &sg);
+               break;
+       default:
+               return -EINVAL;
+       }
+
        if (nents < 0)
                return nents;
 
        memset(&c, 0, sizeof(c));
        c.rw.opcode = io.opcode;
        c.rw.flags = io.flags;
-       c.rw.nsid = cpu_to_le32(io.nsid);
+       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 - 1);
+       c.rw.length = cpu_to_le16(io.nblocks);
        c.rw.control = cpu_to_le16(io.control);
        c.rw.dsmgmt = cpu_to_le16(io.dsmgmt);
-       c.rw.reftag = cpu_to_le32(io.reftag);   /* XXX: endian? */
-       c.rw.apptag = cpu_to_le16(io.apptag);
-       c.rw.appmask = cpu_to_le16(io.appmask);
+       c.rw.reftag = io.reftag;
+       c.rw.apptag = io.apptag;
+       c.rw.appmask = io.appmask;
        /* XXX: metadata */
-       nvme_setup_prps(&c.common, sg, length);
+       prps = nvme_setup_prps(dev, &c.common, sg, &length, GFP_KERNEL);
 
        nvmeq = get_nvmeq(ns);
-       /* Since nvme_submit_sync_cmd sleeps, we can't keep preemption
+       /*
+        * Since nvme_submit_sync_cmd sleeps, we can't keep preemption
         * disabled.  We may be preempted at any point, and be rescheduled
         * to a different CPU.  That will cause cacheline bouncing, but no
         * additional races since q_lock already protects against other CPUs.
         */
        put_nvmeq(nvmeq);
-       status = nvme_submit_sync_cmd(nvmeq, &c, &result, IO_TIMEOUT);
+       if (length != (io.nblocks + 1) << ns->lba_shift)
+               status = -ENOMEM;
+       else
+               status = nvme_submit_sync_cmd(nvmeq, &c, NULL, IO_TIMEOUT);
 
-       nvme_unmap_user_pages(dev, io.opcode & 1, io.addr, length, sg, nents);
-       put_user(result, &uio->result);
+       nvme_unmap_user_pages(dev, io.opcode & 1, io.addr, length, sg);
+       nvme_free_prps(dev, prps);
        return status;
 }
 
-static int nvme_download_firmware(struct nvme_ns *ns,
-                                               struct nvme_dlfw __user *udlfw)
+static int nvme_user_admin_cmd(struct nvme_ns *ns,
+                                       struct nvme_admin_cmd __user *ucmd)
 {
        struct nvme_dev *dev = ns->dev;
-       struct nvme_dlfw dlfw;
+       struct nvme_admin_cmd cmd;
        struct nvme_command c;
-       int nents, status;
+       int status, length, nents = 0;
        struct scatterlist *sg;
+       struct nvme_prps *prps = NULL;
 
-       if (copy_from_user(&dlfw, udlfw, sizeof(dlfw)))
+       if (!capable(CAP_SYS_ADMIN))
+               return -EACCES;
+       if (copy_from_user(&cmd, ucmd, sizeof(cmd)))
                return -EFAULT;
-       if (dlfw.length >= (1 << 30))
-               return -EINVAL;
-
-       nents = nvme_map_user_pages(dev, 1, dlfw.addr, dlfw.length * 4, &sg);
-       if (nents < 0)
-               return nents;
 
        memset(&c, 0, sizeof(c));
-       c.dlfw.opcode = nvme_admin_download_fw;
-       c.dlfw.numd = cpu_to_le32(dlfw.length);
-       c.dlfw.offset = cpu_to_le32(dlfw.offset);
-       nvme_setup_prps(&c.common, sg, dlfw.length * 4);
+       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);
+
+       length = cmd.data_len;
+       if (cmd.data_len) {
+               nents = nvme_map_user_pages(dev, 1, cmd.addr, length, &sg);
+               if (nents < 0)
+                       return nents;
+               prps = nvme_setup_prps(dev, &c.common, sg, &length, GFP_KERNEL);
+       }
 
-       status = nvme_submit_admin_cmd(dev, &c, NULL);
-       nvme_unmap_user_pages(dev, 0, dlfw.addr, dlfw.length * 4, sg, nents);
+       if (length != cmd.data_len)
+               status = -ENOMEM;
+       else
+               status = nvme_submit_admin_cmd(dev, &c, NULL);
+       if (cmd.data_len) {
+               nvme_unmap_user_pages(dev, 0, cmd.addr, cmd.data_len, sg);
+               nvme_free_prps(dev, prps);
+       }
        return status;
 }
 
-static int nvme_activate_firmware(struct nvme_ns *ns, unsigned long arg)
-{
-       struct nvme_dev *dev = ns->dev;
-       struct nvme_command c;
-
-       memset(&c, 0, sizeof(c));
-       c.common.opcode = nvme_admin_activate_fw;
-       c.common.rsvd10[0] = cpu_to_le32(arg);
-
-       return nvme_submit_admin_cmd(dev, &c, NULL);
-}
-
 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_IDENTIFY_NS:
-               return nvme_identify(ns, arg, 0);
-       case NVME_IOCTL_IDENTIFY_CTRL:
-               return nvme_identify(ns, arg, 1);
-       case NVME_IOCTL_GET_RANGE_TYPE:
-               return nvme_get_range_type(ns, arg);
+       case NVME_IOCTL_ID:
+               return ns->ns_id;
+       case NVME_IOCTL_ADMIN_CMD:
+               return nvme_user_admin_cmd(ns, (void __user *)arg);
        case NVME_IOCTL_SUBMIT_IO:
                return nvme_submit_io(ns, (void __user *)arg);
-       case NVME_IOCTL_DOWNLOAD_FW:
-               return nvme_download_firmware(ns, (void __user *)arg);
-       case NVME_IOCTL_ACTIVATE_FW:
-               return nvme_activate_firmware(ns, arg);
        default:
                return -ENOTTY;
        }
@@ -999,9 +1190,103 @@ static int nvme_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
 static const struct block_device_operations nvme_fops = {
        .owner          = THIS_MODULE,
        .ioctl          = nvme_ioctl,
+       .compat_ioctl   = nvme_ioctl,
 };
 
-static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int index,
+static void nvme_timeout_ios(struct nvme_queue *nvmeq)
+{
+       int depth = nvmeq->q_depth - 1;
+       struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
+       unsigned long now = jiffies;
+       int cmdid;
+
+       for_each_set_bit(cmdid, nvmeq->cmdid_data, depth) {
+               unsigned long data;
+               void *ptr;
+               unsigned char handler;
+               static struct nvme_completion cqe = { .status = cpu_to_le16(NVME_SC_ABORT_REQ) << 1, };
+
+               if (!time_after(now, info[cmdid].timeout))
+                       continue;
+               dev_warn(nvmeq->q_dmadev, "Timing out I/O %d\n", cmdid);
+               data = cancel_cmdid(nvmeq, cmdid);
+               handler = data & 3;
+               ptr = (void *)(data & ~3UL);
+               nvme_completions[handler](nvmeq, ptr, &cqe);
+       }
+}
+
+static void nvme_resubmit_bios(struct nvme_queue *nvmeq)
+{
+       while (bio_list_peek(&nvmeq->sq_cong)) {
+               struct bio *bio = bio_list_pop(&nvmeq->sq_cong);
+               struct nvme_ns *ns = bio->bi_bdev->bd_disk->private_data;
+               if (nvme_submit_bio_queue(nvmeq, ns, bio)) {
+                       bio_list_add_head(&nvmeq->sq_cong, bio);
+                       break;
+               }
+               if (bio_list_empty(&nvmeq->sq_cong))
+                       remove_wait_queue(&nvmeq->sq_full,
+                                                       &nvmeq->sq_cong_wait);
+       }
+}
+
+static int nvme_kthread(void *data)
+{
+       struct nvme_dev *dev;
+
+       while (!kthread_should_stop()) {
+               __set_current_state(TASK_RUNNING);
+               spin_lock(&dev_list_lock);
+               list_for_each_entry(dev, &dev_list, node) {
+                       int i;
+                       for (i = 0; i < dev->queue_count; i++) {
+                               struct nvme_queue *nvmeq = dev->queues[i];
+                               if (!nvmeq)
+                                       continue;
+                               spin_lock_irq(&nvmeq->q_lock);
+                               if (nvme_process_cq(nvmeq))
+                                       printk("process_cq did something\n");
+                               nvme_timeout_ios(nvmeq);
+                               nvme_resubmit_bios(nvmeq);
+                               spin_unlock_irq(&nvmeq->q_lock);
+                       }
+               }
+               spin_unlock(&dev_list_lock);
+               set_current_state(TASK_INTERRUPTIBLE);
+               schedule_timeout(HZ);
+       }
+       return 0;
+}
+
+static DEFINE_IDA(nvme_index_ida);
+
+static int nvme_get_ns_idx(void)
+{
+       int index, error;
+
+       do {
+               if (!ida_pre_get(&nvme_index_ida, GFP_KERNEL))
+                       return -1;
+
+               spin_lock(&dev_list_lock);
+               error = ida_get_new(&nvme_index_ida, &index);
+               spin_unlock(&dev_list_lock);
+       } while (error == -EAGAIN);
+
+       if (error)
+               index = -1;
+       return index;
+}
+
+static void nvme_put_ns_idx(int index)
+{
+       spin_lock(&dev_list_lock);
+       ida_remove(&nvme_index_ida, index);
+       spin_unlock(&dev_list_lock);
+}
+
+static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int nsid,
                        struct nvme_id_ns *id, struct nvme_lba_range_type *rt)
 {
        struct nvme_ns *ns;
@@ -1026,19 +1311,19 @@ static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int index,
        disk = alloc_disk(NVME_MINORS);
        if (!disk)
                goto out_free_queue;
-       ns->ns_id = index;
+       ns->ns_id = nsid;
        ns->disk = disk;
        lbaf = id->flbas & 0xf;
        ns->lba_shift = id->lbaf[lbaf].ds;
 
        disk->major = nvme_major;
        disk->minors = NVME_MINORS;
-       disk->first_minor = NVME_MINORS * index;
+       disk->first_minor = NVME_MINORS * nvme_get_ns_idx();
        disk->fops = &nvme_fops;
        disk->private_data = ns;
        disk->queue = ns->queue;
        disk->driverfs_dev = &dev->pci_dev->dev;
-       sprintf(disk->disk_name, "nvme%dn%d", dev->instance, index);
+       sprintf(disk->disk_name, "nvme%dn%d", dev->instance, nsid);
        set_capacity(disk, le64_to_cpup(&id->nsze) << (ns->lba_shift - 9));
 
        return ns;
@@ -1052,7 +1337,9 @@ static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int index,
 
 static void nvme_ns_free(struct nvme_ns *ns)
 {
+       int index = ns->disk->first_minor / NVME_MINORS;
        put_disk(ns->disk);
+       nvme_put_ns_idx(index);
        blk_cleanup_queue(ns->queue);
        kfree(ns);
 }
@@ -1061,15 +1348,10 @@ static int set_queue_count(struct nvme_dev *dev, int count)
 {
        int status;
        u32 result;
-       struct nvme_command c;
        u32 q_count = (count - 1) | ((count - 1) << 16);
 
-       memset(&c, 0, sizeof(c));
-       c.features.opcode = nvme_admin_get_features;
-       c.features.fid = cpu_to_le32(NVME_FEAT_NUM_QUEUES);
-       c.features.dword11 = cpu_to_le32(q_count);
-
-       status = nvme_submit_admin_cmd(dev, &c, &result);
+       status = nvme_get_features(dev, NVME_FEAT_NUM_QUEUES, q_count, 0,
+                                                               &result);
        if (status)
                return -EIO;
        return min(result & 0xffff, result >> 16) + 1;
@@ -1077,29 +1359,39 @@ static int set_queue_count(struct nvme_dev *dev, int count)
 
 static int __devinit nvme_setup_io_queues(struct nvme_dev *dev)
 {
-       int result, cpu, i, nr_queues;
+       int result, cpu, i, nr_io_queues, db_bar_size;
 
-       nr_queues = num_online_cpus();
-       result = set_queue_count(dev, nr_queues);
+       nr_io_queues = num_online_cpus();
+       result = set_queue_count(dev, nr_io_queues);
        if (result < 0)
                return result;
-       if (result < nr_queues)
-               nr_queues = result;
+       if (result < nr_io_queues)
+               nr_io_queues = result;
 
        /* Deregister the admin queue's interrupt */
        free_irq(dev->entry[0].vector, dev->queues[0]);
 
-       for (i = 0; i < nr_queues; i++)
+       db_bar_size = 4096 + ((nr_io_queues + 1) << (dev->db_stride + 3));
+       if (db_bar_size > 8192) {
+               iounmap(dev->bar);
+               dev->bar = ioremap(pci_resource_start(dev->pci_dev, 0),
+                                                               db_bar_size);
+               dev->dbs = ((void __iomem *)dev->bar) + 4096;
+               dev->queues[0]->q_db = dev->dbs;
+       }
+
+       for (i = 0; i < nr_io_queues; i++)
                dev->entry[i].entry = i;
        for (;;) {
-               result = pci_enable_msix(dev->pci_dev, dev->entry, nr_queues);
+               result = pci_enable_msix(dev->pci_dev, dev->entry,
+                                                               nr_io_queues);
                if (result == 0) {
                        break;
                } else if (result > 0) {
-                       nr_queues = result;
+                       nr_io_queues = result;
                        continue;
                } else {
-                       nr_queues = 1;
+                       nr_io_queues = 1;
                        break;
                }
        }
@@ -1108,19 +1400,24 @@ static int __devinit nvme_setup_io_queues(struct nvme_dev *dev)
        /* XXX: handle failure here */
 
        cpu = cpumask_first(cpu_online_mask);
-       for (i = 0; i < nr_queues; i++) {
+       for (i = 0; i < nr_io_queues; i++) {
                irq_set_affinity_hint(dev->entry[i].vector, get_cpu_mask(cpu));
                cpu = cpumask_next(cpu, cpu_online_mask);
        }
 
-       for (i = 0; i < nr_queues; i++) {
+       for (i = 0; i < nr_io_queues; i++) {
                dev->queues[i + 1] = nvme_create_queue(dev, i + 1,
                                                        NVME_Q_DEPTH, i);
-               if (!dev->queues[i + 1])
-                       return -ENOMEM;
+               if (IS_ERR(dev->queues[i + 1]))
+                       return PTR_ERR(dev->queues[i + 1]);
                dev->queue_count++;
        }
 
+       for (; i < num_possible_cpus(); i++) {
+               int target = i % rounddown_pow_of_two(dev->queue_count - 1);
+               dev->queues[i + 1] = dev->queues[target + 1];
+       }
+
        return 0;
 }
 
@@ -1137,65 +1434,51 @@ static int __devinit nvme_dev_add(struct nvme_dev *dev)
        int res, nn, i;
        struct nvme_ns *ns, *next;
        struct nvme_id_ctrl *ctrl;
-       void *id;
+       struct nvme_id_ns *id_ns;
+       void *mem;
        dma_addr_t dma_addr;
-       struct nvme_command cid, crt;
 
        res = nvme_setup_io_queues(dev);
        if (res)
                return res;
 
-       /* XXX: Switch to a SG list once prp2 works */
-       id = dma_alloc_coherent(&dev->pci_dev->dev, 8192, &dma_addr,
+       mem = dma_alloc_coherent(&dev->pci_dev->dev, 8192, &dma_addr,
                                                                GFP_KERNEL);
 
-       memset(&cid, 0, sizeof(cid));
-       cid.identify.opcode = nvme_admin_identify;
-       cid.identify.nsid = 0;
-       cid.identify.prp1 = cpu_to_le64(dma_addr);
-       cid.identify.cns = cpu_to_le32(1);
-
-       res = nvme_submit_admin_cmd(dev, &cid, NULL);
+       res = nvme_identify(dev, 0, 1, dma_addr);
        if (res) {
                res = -EIO;
                goto out_free;
        }
 
-       ctrl = id;
+       ctrl = mem;
        nn = le32_to_cpup(&ctrl->nn);
        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));
 
-       cid.identify.cns = 0;
-       memset(&crt, 0, sizeof(crt));
-       crt.features.opcode = nvme_admin_get_features;
-       crt.features.prp1 = cpu_to_le64(dma_addr + 4096);
-       crt.features.fid = cpu_to_le32(NVME_FEAT_LBA_RANGE);
-
-       for (i = 0; i < nn; i++) {
-               cid.identify.nsid = cpu_to_le32(i);
-               res = nvme_submit_admin_cmd(dev, &cid, NULL);
+       id_ns = mem;
+       for (i = 1; i <= nn; i++) {
+               res = nvme_identify(dev, i, 0, dma_addr);
                if (res)
                        continue;
 
-               if (((struct nvme_id_ns *)id)->ncap == 0)
+               if (id_ns->ncap == 0)
                        continue;
 
-               crt.features.nsid = cpu_to_le32(i);
-               res = nvme_submit_admin_cmd(dev, &crt, NULL);
+               res = nvme_get_features(dev, NVME_FEAT_LBA_RANGE, i,
+                                                       dma_addr + 4096, NULL);
                if (res)
                        continue;
 
-               ns = nvme_alloc_ns(dev, i, id, id + 4096);
+               ns = nvme_alloc_ns(dev, i, mem, mem + 4096);
                if (ns)
                        list_add_tail(&ns->list, &dev->namespaces);
        }
        list_for_each_entry(ns, &dev->namespaces, list)
                add_disk(ns->disk);
 
-       dma_free_coherent(&dev->pci_dev->dev, 4096, id, dma_addr);
-       return 0;
+       goto out;
 
  out_free:
        list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
@@ -1203,7 +1486,8 @@ static int __devinit nvme_dev_add(struct nvme_dev *dev)
                nvme_ns_free(ns);
        }
 
-       dma_free_coherent(&dev->pci_dev->dev, 4096, id, dma_addr);
+ out:
+       dma_free_coherent(&dev->pci_dev->dev, 8192, mem, dma_addr);
        return res;
 }
 
@@ -1211,6 +1495,10 @@ static int nvme_dev_remove(struct nvme_dev *dev)
 {
        struct nvme_ns *ns, *next;
 
+       spin_lock(&dev_list_lock);
+       list_del(&dev->node);
+       spin_unlock(&dev_list_lock);
+
        /* TODO: wait all I/O finished or cancel them */
 
        list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
@@ -1224,6 +1512,30 @@ static int nvme_dev_remove(struct nvme_dev *dev)
        return 0;
 }
 
+static int nvme_setup_prp_pools(struct nvme_dev *dev)
+{
+       struct device *dmadev = &dev->pci_dev->dev;
+       dev->prp_page_pool = dma_pool_create("prp list page", dmadev,
+                                               PAGE_SIZE, PAGE_SIZE, 0);
+       if (!dev->prp_page_pool)
+               return -ENOMEM;
+
+       /* Optimisation for I/Os between 4k and 128k */
+       dev->prp_small_pool = dma_pool_create("prp list 256", dmadev,
+                                               256, 256, 0);
+       if (!dev->prp_small_pool) {
+               dma_pool_destroy(dev->prp_page_pool);
+               return -ENOMEM;
+       }
+       return 0;
+}
+
+static void nvme_release_prp_pools(struct nvme_dev *dev)
+{
+       dma_pool_destroy(dev->prp_page_pool);
+       dma_pool_destroy(dev->prp_small_pool);
+}
+
 /* XXX: Use an ida or something to let remove / add work correctly */
 static void nvme_set_instance(struct nvme_dev *dev)
 {
@@ -1268,6 +1580,10 @@ static int __devinit nvme_probe(struct pci_dev *pdev,
        nvme_set_instance(dev);
        dev->entry[0].vector = pdev->irq;
 
+       result = nvme_setup_prp_pools(dev);
+       if (result)
+               goto disable_msix;
+
        dev->bar = ioremap(pci_resource_start(pdev, 0), 8192);
        if (!dev->bar) {
                result = -ENOMEM;
@@ -1279,18 +1595,28 @@ static int __devinit nvme_probe(struct pci_dev *pdev,
                goto unmap;
        dev->queue_count++;
 
+       spin_lock(&dev_list_lock);
+       list_add(&dev->node, &dev_list);
+       spin_unlock(&dev_list_lock);
+
        result = nvme_dev_add(dev);
        if (result)
                goto delete;
+
        return 0;
 
  delete:
+       spin_lock(&dev_list_lock);
+       list_del(&dev->node);
+       spin_unlock(&dev_list_lock);
+
        nvme_free_queues(dev);
  unmap:
        iounmap(dev->bar);
  disable_msix:
        pci_disable_msix(pdev);
        nvme_release_instance(dev);
+       nvme_release_prp_pools(dev);
  disable:
        pci_disable_device(pdev);
        pci_release_regions(pdev);
@@ -1308,6 +1634,7 @@ static void __devexit nvme_remove(struct pci_dev *pdev)
        pci_disable_msix(pdev);
        iounmap(dev->bar);
        nvme_release_instance(dev);
+       nvme_release_prp_pools(dev);
        pci_disable_device(pdev);
        pci_release_regions(pdev);
        kfree(dev->queues);
@@ -1353,17 +1680,25 @@ static struct pci_driver nvme_driver = {
 
 static int __init nvme_init(void)
 {
-       int result;
+       int result = -EBUSY;
+
+       nvme_thread = kthread_run(nvme_kthread, NULL, "nvme");
+       if (IS_ERR(nvme_thread))
+               return PTR_ERR(nvme_thread);
 
        nvme_major = register_blkdev(nvme_major, "nvme");
        if (nvme_major <= 0)
-               return -EBUSY;
+               goto kill_kthread;
 
        result = pci_register_driver(&nvme_driver);
-       if (!result)
-               return 0;
+       if (result)
+               goto unregister_blkdev;
+       return 0;
 
+ unregister_blkdev:
        unregister_blkdev(nvme_major, "nvme");
+ kill_kthread:
+       kthread_stop(nvme_thread);
        return result;
 }
 
@@ -1371,10 +1706,11 @@ static void __exit nvme_exit(void)
 {
        pci_unregister_driver(&nvme_driver);
        unregister_blkdev(nvme_major, "nvme");
+       kthread_stop(nvme_thread);
 }
 
 MODULE_AUTHOR("Matthew Wilcox <willy@linux.intel.com>");
 MODULE_LICENSE("GPL");
-MODULE_VERSION("0.2");
+MODULE_VERSION("0.7");
 module_init(nvme_init);
 module_exit(nvme_exit);