NVMe: Rename cancel_cmdid_data to cancel_cmdid
[linux-2.6.git] / drivers / block / nvme.c
index cd7aeba..9ca9db9 100644 (file)
@@ -26,6 +26,7 @@
 #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>
@@ -50,10 +51,15 @@ 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;
@@ -97,6 +103,7 @@ struct nvme_queue {
        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;
@@ -108,8 +115,6 @@ 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
  */
@@ -137,10 +142,10 @@ 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
@@ -151,7 +156,7 @@ static struct nvme_cmd_info *nvme_cmd_info(struct nvme_queue *nvmeq)
 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;
 
@@ -177,7 +182,8 @@ 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.
  */
@@ -186,10 +192,12 @@ 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)
 
 static unsigned long free_cmdid(struct nvme_queue *nvmeq, int cmdid)
 {
@@ -205,20 +213,18 @@ 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)
@@ -227,7 +233,7 @@ 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
  *
@@ -237,13 +243,12 @@ 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);
 
@@ -256,10 +261,9 @@ struct nvme_prps {
        __le64 *list[0];
 };
 
-static void nvme_free_prps(struct nvme_queue *nvmeq, struct nvme_prps *prps)
+static void nvme_free_prps(struct nvme_dev *dev, struct nvme_prps *prps)
 {
        const int last_prp = PAGE_SIZE / 8 - 1;
-       struct nvme_dev *dev = nvmeq->dev;
        int i;
        dma_addr_t prp_dma;
 
@@ -295,7 +299,7 @@ static struct nvme_bio *alloc_nbio(unsigned nseg, gfp_t gfp)
 
 static void free_nbio(struct nvme_queue *nvmeq, struct nvme_bio *nbio)
 {
-       nvme_free_prps(nvmeq, nbio->prps);
+       nvme_free_prps(nvmeq->dev, nbio->prps);
        kfree(nbio);
 }
 
@@ -309,18 +313,21 @@ static void bio_completion(struct nvme_queue *nvmeq, void *ctx,
        dma_unmap_sg(nvmeq->q_dmadev, nbio->sg, nbio->nents,
                        bio_data_dir(bio) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
        free_nbio(nvmeq, nbio);
-       bio_endio(bio, status ? -EIO : 0);
-       bio = bio_list_pop(&nvmeq->sq_cong);
-       if (bio)
-               nvme_resubmit_bio(nvmeq, bio);
+       if (status) {
+               bio_endio(bio, -EIO);
+       } else if (bio->bi_vcnt > bio->bi_idx) {
+               bio_list_add(&nvmeq->sq_cong, bio);
+               wake_up_process(nvme_thread);
+       } else {
+               bio_endio(bio, 0);
+       }
 }
 
 /* length is in bytes */
-static struct nvme_prps *nvme_setup_prps(struct nvme_queue *nvmeq,
+static struct nvme_prps *nvme_setup_prps(struct nvme_dev *dev,
                                        struct nvme_common_command *cmd,
                                        struct scatterlist *sg, int length)
 {
-       struct nvme_dev *dev = nvmeq->dev;
        struct dma_pool *pool;
        int dma_len = sg_dma_len(sg);
        u64 dma_addr = sg_dma_address(sg);
@@ -367,12 +374,13 @@ static struct nvme_prps *nvme_setup_prps(struct nvme_queue *nvmeq,
        cmd->prp2 = cpu_to_le64(prp_dma);
        i = 0;
        for (;;) {
-               if (i == PAGE_SIZE / 8 - 1) {
+               if (i == PAGE_SIZE / 8) {
                        __le64 *old_prp_list = prp_list;
                        prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
                        prps->list[prp_page++] = prp_list;
-                       old_prp_list[i] = cpu_to_le64(prp_dma);
-                       i = 0;
+                       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;
@@ -391,23 +399,68 @@ static struct nvme_prps *nvme_setup_prps(struct nvme_queue *nvmeq,
        return prps;
 }
 
+/* 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 = nbio->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;
+       }
+       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, nbio->sg, nbio->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);
 }
 
 static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
@@ -416,21 +469,30 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
        struct nvme_command *cmnd;
        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);
 
-       nbio = alloc_nbio(psegs, GFP_NOIO);
+       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 congestion;
+               goto nomem;
        nbio->bio = bio;
 
+       result = -EBUSY;
        cmdid = alloc_cmdid(nvmeq, nbio, bio_completion_id, IO_TIMEOUT);
        if (unlikely(cmdid < 0))
                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)
                control |= NVME_RW_FUA;
@@ -441,7 +503,6 @@ 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));
@@ -453,40 +514,32 @@ 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, nbio, 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);
-       nbio->prps = nvme_setup_prps(nvmeq, &cmnd->common, nbio->sg,
-                                                               bio->bi_size);
+       nbio->prps = nvme_setup_prps(nvmeq->dev, &cmnd->common, nbio->sg,
+                                                               length);
        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_nbio:
        free_nbio(nvmeq, nbio);
- 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 */
+ nomem:
+       return result;
 }
 
 /*
@@ -497,13 +550,18 @@ 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;
@@ -519,7 +577,9 @@ 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,
@@ -610,7 +670,7 @@ 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);
 }
 
@@ -724,8 +784,10 @@ static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
 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) {
@@ -766,6 +828,7 @@ static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
        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_depth = depth;
@@ -833,6 +896,8 @@ 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;
@@ -847,6 +912,7 @@ 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);
@@ -854,10 +920,18 @@ 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;
+
        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");
@@ -939,10 +1013,10 @@ static int nvme_submit_user_admin_command(struct nvme_dev *dev,
        nents = nvme_map_user_pages(dev, 0, addr, length, &sg);
        if (nents < 0)
                return nents;
-       prps = nvme_setup_prps(dev->queues[0], &cmd->common, sg, length);
+       prps = nvme_setup_prps(dev, &cmd->common, sg, length);
        err = nvme_submit_admin_cmd(dev, cmd, NULL);
        nvme_unmap_user_pages(dev, 0, addr, length, sg, nents);
-       nvme_free_prps(dev->queues[0], prps);
+       nvme_free_prps(dev, prps);
        return err ? -EIO : 0;
 }
 
@@ -977,44 +1051,52 @@ 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:
+               nents = nvme_map_user_pages(dev, io.opcode & 1, io.addr,
+                                                               length, &sg);
+       default:
+               return -EFAULT;
+       }
+
        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);
-       nvmeq = get_nvmeq(ns);
+       c.rw.reftag = io.reftag;
+       c.rw.apptag = io.apptag;
+       c.rw.appmask = io.appmask;
        /* XXX: metadata */
-       prps = nvme_setup_prps(nvmeq, &c.common, sg, length);
+       prps = nvme_setup_prps(dev, &c.common, sg, length);
 
-       /* Since nvme_submit_sync_cmd sleeps, we can't keep preemption
+       nvmeq = get_nvmeq(ns);
+       /*
+        * 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);
+       status = nvme_submit_sync_cmd(nvmeq, &c, NULL, IO_TIMEOUT);
 
        nvme_unmap_user_pages(dev, io.opcode & 1, io.addr, length, sg, nents);
-       nvme_free_prps(nvmeq, prps);
-       put_user(result, &uio->result);
+       nvme_free_prps(dev, prps);
        return status;
 }
 
@@ -1041,11 +1123,11 @@ static int nvme_download_firmware(struct nvme_ns *ns,
        c.dlfw.opcode = nvme_admin_download_fw;
        c.dlfw.numd = cpu_to_le32(dlfw.length);
        c.dlfw.offset = cpu_to_le32(dlfw.offset);
-       prps = nvme_setup_prps(dev->queues[0], &c.common, sg, dlfw.length * 4);
+       prps = nvme_setup_prps(dev, &c.common, sg, dlfw.length * 4);
 
        status = nvme_submit_admin_cmd(dev, &c, NULL);
        nvme_unmap_user_pages(dev, 0, dlfw.addr, dlfw.length * 4, sg, nents);
-       nvme_free_prps(dev->queues[0], prps);
+       nvme_free_prps(dev, prps);
        return status;
 }
 
@@ -1087,8 +1169,51 @@ 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 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_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 struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int index,
                        struct nvme_id_ns *id, struct nvme_lba_range_type *rt)
 {
@@ -1165,29 +1290,30 @@ 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;
 
-       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++)
+       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;
                }
        }
@@ -1196,12 +1322,12 @@ 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])
@@ -1209,6 +1335,11 @@ static int __devinit nvme_setup_io_queues(struct nvme_dev *dev)
                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;
 }
 
@@ -1261,7 +1392,7 @@ static int __devinit nvme_dev_add(struct nvme_dev *dev)
        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++) {
+       for (i = 0; i <= nn; i++) {
                cid.identify.nsid = cpu_to_le32(i);
                res = nvme_submit_admin_cmd(dev, &cid, NULL);
                if (res)
@@ -1299,6 +1430,10 @@ 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) {
@@ -1395,12 +1530,21 @@ 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);
@@ -1471,17 +1615,25 @@ 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;
 }
 
@@ -1489,10 +1641,11 @@ 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("0.5");
 module_init(nvme_init);
 module_exit(nvme_exit);