Merge git://git.infradead.org/users/willy/linux-nvme

* git://git.infradead.org/users/willy/linux-nvme: (105 commits)
  NVMe: Set number of queues correctly
  NVMe: Version 0.8
  NVMe: Set queue flags correctly
  NVMe: Simplify nvme_unmap_user_pages
  NVMe: Mark the end of the sg list
  NVMe: Fix DMA mapping for admin commands
  NVMe: Rename IO_TIMEOUT to NVME_IO_TIMEOUT
  NVMe: Merge the nvme_bio and nvme_prp data structures
  NVMe: Change nvme_completion_fn to take a dev
  NVMe: Change get_nvmeq to take a dev instead of a namespace
  NVMe: Simplify completion handling
  NVMe: Update Identify Controller data structure
  NVMe: Implement doorbell stride capability
  NVMe: Version 0.7
  NVMe: Don't probe namespace 0
  Fix calculation of number of pages in a PRP List
  NVMe: Create nvme_identify and nvme_get_features functions
  NVMe: Fix memory leak in nvme_dev_add()
  NVMe: Fix calls to dma_unmap_sg
  NVMe: Correct sg list setup in nvme_map_user_pages
  ...

3 files changed, 1757 insertions, 0 deletions

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index a30aa103f95b..4e4c8a4a5fd3 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -317,6 +317,17 @@ config BLK_DEV_NBD
 
 	  If unsure, say N.
 
+config BLK_DEV_NVME
+	tristate "NVM Express block device"
+	depends on PCI
+	---help---
+	  The NVM Express driver is for solid state drives directly
+	  connected to the PCI or PCI Express bus.  If you know you
+	  don't have one of these, it is safe to answer N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called nvme.
+
 config BLK_DEV_OSD
 	tristate "OSD object-as-blkdev support"
 	depends on SCSI_OSD_ULD
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index ad7b74a44ef3..5b795059f8fb 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_XILINX_SYSACE)	+= xsysace.o
 obj-$(CONFIG_CDROM_PKTCDVD)	+= pktcdvd.o
 obj-$(CONFIG_MG_DISK)		+= mg_disk.o
 obj-$(CONFIG_SUNVDC)		+= sunvdc.o
+obj-$(CONFIG_BLK_DEV_NVME)	+= nvme.o
 obj-$(CONFIG_BLK_DEV_OSD)	+= osdblk.o
 
 obj-$(CONFIG_BLK_DEV_UMEM)	+= umem.o
diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c
new file mode 100644
index 000000000000..f4996b0e4b1a
--- /dev/null
+++ b/drivers/block/nvme.c
@@ -0,0 +1,1745 @@
+/*
+ * NVM Express device driver
+ * Copyright (c) 2011, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#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>
+#include <linux/moduleparam.h>
+#include <linux/pci.h>
+#include <linux/poison.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/version.h>
+
+#define NVME_Q_DEPTH 1024
+#define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
+#define CQ_SIZE(depth)		(depth * sizeof(struct nvme_completion))
+#define NVME_MINORS 64
+#define NVME_IO_TIMEOUT	(5 * HZ)
+#define ADMIN_TIMEOUT	(60 * HZ)
+
+static int nvme_major;
+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;
+	struct list_head namespaces;
+	char serial[20];
+	char model[40];
+	char firmware_rev[8];
+};
+
+/*
+ * An NVM Express namespace is equivalent to a SCSI LUN
+ */
+struct nvme_ns {
+	struct list_head list;
+
+	struct nvme_dev *dev;
+	struct request_queue *queue;
+	struct gendisk *disk;
+
+	int ns_id;
+	int lba_shift;
+};
+
+/*
+ * An NVM Express queue.  Each device has at least two (one for admin
+ * commands and one for I/O commands).
+ */
+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;
+	u16 cq_vector;
+	u16 sq_head;
+	u16 sq_tail;
+	u16 cq_head;
+	u16 cq_phase;
+	unsigned long cmdid_data[];
+};
+
+/*
+ * Check we didin't inadvertently grow the command struct
+ */
+static inline void _nvme_check_size(void)
+{
+	BUILD_BUG_ON(sizeof(struct nvme_rw_command) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_create_cq) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_create_sq) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_delete_queue) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_features) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_command) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_id_ctrl) != 4096);
+	BUILD_BUG_ON(sizeof(struct nvme_id_ns) != 4096);
+	BUILD_BUG_ON(sizeof(struct nvme_lba_range_type) != 64);
+}
+
+typedef void (*nvme_completion_fn)(struct nvme_dev *, void *,
+						struct nvme_completion *);
+
+struct nvme_cmd_info {
+	nvme_completion_fn fn;
+	void *ctx;
+	unsigned long timeout;
+};
+
+static struct nvme_cmd_info *nvme_cmd_info(struct nvme_queue *nvmeq)
+{
+	return (void *)&nvmeq->cmdid_data[BITS_TO_LONGS(nvmeq->q_depth)];
+}
+
+/**
+ * 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 function to call on completion
+ *
+ * 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,
+				nvme_completion_fn handler, unsigned timeout)
+{
+	int depth = nvmeq->q_depth - 1;
+	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
+	int cmdid;
+
+	do {
+		cmdid = find_first_zero_bit(nvmeq->cmdid_data, depth);
+		if (cmdid >= depth)
+			return -EBUSY;
+	} while (test_and_set_bit(cmdid, nvmeq->cmdid_data));
+
+	info[cmdid].fn = handler;
+	info[cmdid].ctx = ctx;
+	info[cmdid].timeout = jiffies + timeout;
+	return cmdid;
+}
+
+static int alloc_cmdid_killable(struct nvme_queue *nvmeq, void *ctx,
+				nvme_completion_fn handler, unsigned timeout)
+{
+	int cmdid;
+	wait_event_killable(nvmeq->sq_full,
+		(cmdid = alloc_cmdid(nvmeq, ctx, handler, timeout)) >= 0);
+	return (cmdid < 0) ? -EINTR : cmdid;
+}
+
+/* Special values must be less than 0x1000 */
+#define CMD_CTX_BASE		((void *)POISON_POINTER_DELTA)
+#define CMD_CTX_CANCELLED	(0x30C + CMD_CTX_BASE)
+#define CMD_CTX_COMPLETED	(0x310 + CMD_CTX_BASE)
+#define CMD_CTX_INVALID		(0x314 + CMD_CTX_BASE)
+#define CMD_CTX_FLUSH		(0x318 + CMD_CTX_BASE)
+
+static void special_completion(struct nvme_dev *dev, void *ctx,
+						struct nvme_completion *cqe)
+{
+	if (ctx == CMD_CTX_CANCELLED)
+		return;
+	if (ctx == CMD_CTX_FLUSH)
+		return;
+	if (ctx == CMD_CTX_COMPLETED) {
+		dev_warn(&dev->pci_dev->dev,
+				"completed id %d twice on queue %d\n",
+				cqe->command_id, le16_to_cpup(&cqe->sq_id));
+		return;
+	}
+	if (ctx == CMD_CTX_INVALID) {
+		dev_warn(&dev->pci_dev->dev,
+				"invalid id %d completed on queue %d\n",
+				cqe->command_id, le16_to_cpup(&cqe->sq_id));
+		return;
+	}
+
+	dev_warn(&dev->pci_dev->dev, "Unknown special completion %p\n", ctx);
+}
+
+/*
+ * Called with local interrupts disabled and the q_lock held.  May not sleep.
+ */
+static void *free_cmdid(struct nvme_queue *nvmeq, int cmdid,
+						nvme_completion_fn *fn)
+{
+	void *ctx;
+	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
+
+	if (cmdid >= nvmeq->q_depth) {
+		*fn = special_completion;
+		return CMD_CTX_INVALID;
+	}
+	*fn = info[cmdid].fn;
+	ctx = info[cmdid].ctx;
+	info[cmdid].fn = special_completion;
+	info[cmdid].ctx = CMD_CTX_COMPLETED;
+	clear_bit(cmdid, nvmeq->cmdid_data);
+	wake_up(&nvmeq->sq_full);
+	return ctx;
+}
+
+static void *cancel_cmdid(struct nvme_queue *nvmeq, int cmdid,
+						nvme_completion_fn *fn)
+{
+	void *ctx;
+	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
+	if (fn)
+		*fn = info[cmdid].fn;
+	ctx = info[cmdid].ctx;
+	info[cmdid].fn = special_completion;
+	info[cmdid].ctx = CMD_CTX_CANCELLED;
+	return ctx;
+}
+
+static struct nvme_queue *get_nvmeq(struct nvme_dev *dev)
+{
+	return dev->queues[get_cpu() + 1];
+}
+
+static void put_nvmeq(struct nvme_queue *nvmeq)
+{
+	put_cpu();
+}
+
+/**
+ * nvme_submit_cmd() - Copy a command into a queue and ring the doorbell
+ * @nvmeq: The queue to use
+ * @cmd: The command to send
+ *
+ * Safe to use from interrupt context
+ */
+static int nvme_submit_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd)
+{
+	unsigned long flags;
+	u16 tail;
+	spin_lock_irqsave(&nvmeq->q_lock, flags);
+	tail = nvmeq->sq_tail;
+	memcpy(&nvmeq->sq_cmds[tail], cmd, sizeof(*cmd));
+	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;
+}
+
+/*
+ * 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 {
+	void *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 sg[0];
+};
+
+static __le64 **iod_list(struct nvme_iod *iod)
+{
+	return ((void *)iod) + iod->offset;
+}
+
+/*
+ * Will slightly overestimate the number of pages needed.  This is OK
+ * as it only leads to a small amount of wasted memory for the lifetime of
+ * the I/O.
+ */
+static int nvme_npages(unsigned size)
+{
+	unsigned nprps = DIV_ROUND_UP(size + PAGE_SIZE, PAGE_SIZE);
+	return DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
+}
+
+static struct nvme_iod *
+nvme_alloc_iod(unsigned nseg, unsigned nbytes, gfp_t gfp)
+{
+	struct nvme_iod *iod = kmalloc(sizeof(struct nvme_iod) +
+				sizeof(__le64 *) * nvme_npages(nbytes) +
+				sizeof(struct scatterlist) * nseg, gfp);
+
+	if (iod) {
+		iod->offset = offsetof(struct nvme_iod, sg[nseg]);
+		iod->npages = -1;
+		iod->length = nbytes;
+	}
+
+	return iod;
+}
+
+static void nvme_free_iod(struct nvme_dev *dev, struct nvme_iod *iod)
+{
+	const int last_prp = PAGE_SIZE / 8 - 1;
+	int i;
+	__le64 **list = iod_list(iod);
+	dma_addr_t prp_dma = iod->first_dma;
+
+	if (iod->npages == 0)
+		dma_pool_free(dev->prp_small_pool, list[0], prp_dma);
+	for (i = 0; i < iod->npages; i++) {
+		__le64 *prp_list = 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(iod);
+}
+
+static void requeue_bio(struct nvme_dev *dev, struct bio *bio)
+{
+	struct nvme_queue *nvmeq = get_nvmeq(dev);
+	if (bio_list_empty(&nvmeq->sq_cong))
+		add_wait_queue(&nvmeq->sq_full, &nvmeq->sq_cong_wait);
+	bio_list_add(&nvmeq->sq_cong, bio);
+	put_nvmeq(nvmeq);
+	wake_up_process(nvme_thread);
+}
+
+static void bio_completion(struct nvme_dev *dev, void *ctx,
+						struct nvme_completion *cqe)
+{
+	struct nvme_iod *iod = ctx;
+	struct bio *bio = iod->private;
+	u16 status = le16_to_cpup(&cqe->status) >> 1;
+
+	dma_unmap_sg(&dev->pci_dev->dev, iod->sg, iod->nents,
+			bio_data_dir(bio) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+	nvme_free_iod(dev, iod);
+	if (status) {
+		bio_endio(bio, -EIO);
+	} else if (bio->bi_vcnt > bio->bi_idx) {
+		requeue_bio(dev, bio);
+	} else {
+		bio_endio(bio, 0);
+	}
+}
+
+/* length is in bytes.  gfp flags indicates whether we may sleep. */
+static int nvme_setup_prps(struct nvme_dev *dev,
+			struct nvme_common_command *cmd, struct nvme_iod *iod,
+			int total_len, gfp_t gfp)
+{
+	struct dma_pool *pool;
+	int length = total_len;
+	struct scatterlist *sg = iod->sg;
+	int dma_len = sg_dma_len(sg);
+	u64 dma_addr = sg_dma_address(sg);
+	int offset = offset_in_page(dma_addr);
+	__le64 *prp_list;
+	__le64 **list = iod_list(iod);
+	dma_addr_t prp_dma;
+	int nprps, i;
+
+	cmd->prp1 = cpu_to_le64(dma_addr);
+	length -= (PAGE_SIZE - offset);
+	if (length <= 0)
+		return total_len;
+
+	dma_len -= (PAGE_SIZE - offset);
+	if (dma_len) {
+		dma_addr += (PAGE_SIZE - offset);
+	} else {
+		sg = sg_next(sg);
+		dma_addr = sg_dma_address(sg);
+		dma_len = sg_dma_len(sg);
+	}
+
+	if (length <= PAGE_SIZE) {
+		cmd->prp2 = cpu_to_le64(dma_addr);
+		return total_len;
+	}
+
+	nprps = DIV_ROUND_UP(length, PAGE_SIZE);
+	if (nprps <= (256 / 8)) {
+		pool = dev->prp_small_pool;
+		iod->npages = 0;
+	} else {
+		pool = dev->prp_page_pool;
+		iod->npages = 1;
+	}
+
+	prp_list = dma_pool_alloc(pool, gfp, &prp_dma);
+	if (!prp_list) {
+		cmd->prp2 = cpu_to_le64(dma_addr);
+		iod->npages = -1;
+		return (total_len - length) + PAGE_SIZE;
+	}
+	list[0] = prp_list;
+	iod->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)
+				return total_len - length;
+			list[iod->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);
+	}
+
+	return total_len;
+}
+
+/* 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_iod *iod,
+		struct bio *bio, enum dma_data_direction dma_dir, int psegs)
+{
+	struct bio_vec *bvec, *bvprv = NULL;
+	struct scatterlist *sg = NULL;
+	int i, old_idx, length = 0, nsegs = 0;
+
+	sg_init_table(iod->sg, psegs);
+	old_idx = bio->bi_idx;
+	bio_for_each_segment(bvec, bio, i) {
+		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 : iod->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;
+	iod->nents = nsegs;
+	sg_mark_end(sg);
+	if (dma_map_sg(dev, iod->sg, iod->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 0;
+}
+
+static int nvme_submit_flush_data(struct nvme_queue *nvmeq, struct nvme_ns *ns)
+{
+	int cmdid = alloc_cmdid(nvmeq, (void *)CMD_CTX_FLUSH,
+					special_completion, NVME_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_iod *iod;
+	enum dma_data_direction dma_dir;
+	int cmdid, length, result = -ENOMEM;
+	u16 control;
+	u32 dsmgmt;
+	int psegs = bio_phys_segments(ns->queue, bio);
+
+	if ((bio->bi_rw & REQ_FLUSH) && psegs) {
+		result = nvme_submit_flush_data(nvmeq, ns);
+		if (result)
+			return result;
+	}
+
+	iod = nvme_alloc_iod(psegs, bio->bi_size, GFP_ATOMIC);
+	if (!iod)
+		goto nomem;
+	iod->private = bio;
+
+	result = -EBUSY;
+	cmdid = alloc_cmdid(nvmeq, iod, bio_completion, NVME_IO_TIMEOUT);
+	if (unlikely(cmdid < 0))
+		goto free_iod;
+
+	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;
+	if (bio->bi_rw & (REQ_FAILFAST_DEV | REQ_RAHEAD))
+		control |= NVME_RW_LR;
+
+	dsmgmt = 0;
+	if (bio->bi_rw & REQ_RAHEAD)
+		dsmgmt |= NVME_RW_DSM_FREQ_PREFETCH;
+
+	cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail];
+
+	memset(cmnd, 0, sizeof(*cmnd));
+	if (bio_data_dir(bio)) {
+		cmnd->rw.opcode = nvme_cmd_write;
+		dma_dir = DMA_TO_DEVICE;
+	} else {
+		cmnd->rw.opcode = nvme_cmd_read;
+		dma_dir = DMA_FROM_DEVICE;
+	}
+
+	result = nvme_map_bio(nvmeq->q_dmadev, iod, bio, dma_dir, psegs);
+	if (result < 0)
+		goto free_iod;
+	length = result;
+
+	cmnd->rw.command_id = cmdid;
+	cmnd->rw.nsid = cpu_to_le32(ns->ns_id);
+	length = nvme_setup_prps(nvmeq->dev, &cmnd->common, iod, length,
+								GFP_ATOMIC);
+	cmnd->rw.slba = cpu_to_le64(bio->bi_sector >> (ns->lba_shift - 9));
+	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);
+
+	bio->bi_sector += length >> 9;
+
+	if (++nvmeq->sq_tail == nvmeq->q_depth)
+		nvmeq->sq_tail = 0;
+	writel(nvmeq->sq_tail, nvmeq->q_db);
+
+	return 0;
+
+ free_iod:
+	nvme_free_iod(nvmeq->dev, iod);
+ nomem:
+	return result;
+}
+
+/*
+ * NB: return value of non-zero would mean that we were a stacking driver.
+ * make_request must always succeed.
+ */
+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->dev);
+	int result = -EBUSY;
+
+	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);
+	put_nvmeq(nvmeq);
+
+	return 0;
+}
+
+static irqreturn_t nvme_process_cq(struct nvme_queue *nvmeq)
+{
+	u16 head, phase;
+
+	head = nvmeq->cq_head;
+	phase = nvmeq->cq_phase;
+
+	for (;;) {
+		void *ctx;
+		nvme_completion_fn fn;
+		struct nvme_completion cqe = nvmeq->cqes[head];
+		if ((le16_to_cpu(cqe.status) & 1) != phase)
+			break;
+		nvmeq->sq_head = le16_to_cpu(cqe.sq_head);
+		if (++head == nvmeq->q_depth) {
+			head = 0;
+			phase = !phase;
+		}
+
+		ctx = free_cmdid(nvmeq, cqe.command_id, &fn);
+		fn(nvmeq->dev, ctx, &cqe);
+	}
+
+	/* If the controller ignores the cq head doorbell and continuously
+	 * writes to the queue, it is theoretically possible to wrap around
+	 * the queue twice and mistakenly return IRQ_NONE.  Linux only
+	 * requires that 0.1% of your interrupts are handled, so this isn't
+	 * a big problem.
+	 */
+	if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
+		return IRQ_NONE;
+
+	writel(head, nvmeq->q_db + (1 << nvmeq->dev->db_stride));
+	nvmeq->cq_head = head;
+	nvmeq->cq_phase = phase;
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t nvme_irq(int irq, void *data)
+{
+	irqreturn_t result;
+	struct nvme_queue *nvmeq = data;
+	spin_lock(&nvmeq->q_lock);
+	result = nvme_process_cq(nvmeq);
+	spin_unlock(&nvmeq->q_lock);
+	return result;
+}
+
+static irqreturn_t nvme_irq_check(int irq, void *data)
+{
+	struct nvme_queue *nvmeq = data;
+	struct nvme_completion cqe = nvmeq->cqes[nvmeq->cq_head];
+	if ((le16_to_cpu(cqe.status) & 1) != nvmeq->cq_phase)
+		return IRQ_NONE;
+	return IRQ_WAKE_THREAD;
+}
+
+static void nvme_abort_command(struct nvme_queue *nvmeq, int cmdid)
+{
+	spin_lock_irq(&nvmeq->q_lock);
+	cancel_cmdid(nvmeq, cmdid, NULL);
+	spin_unlock_irq(&nvmeq->q_lock);
+}
+
+struct sync_cmd_info {
+	struct task_struct *task;
+	u32 result;
+	int status;
+};
+
+static void sync_completion(struct nvme_dev *dev, void *ctx,
+						struct nvme_completion *cqe)
+{
+	struct sync_cmd_info *cmdinfo = ctx;
+	cmdinfo->result = le32_to_cpup(&cqe->result);
+	cmdinfo->status = le16_to_cpup(&cqe->status) >> 1;
+	wake_up_process(cmdinfo->task);
+}
+
+/*
+ * 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
+ */
+static int nvme_submit_sync_cmd(struct nvme_queue *nvmeq,
+			struct nvme_command *cmd, u32 *result, unsigned timeout)
+{
+	int cmdid;
+	struct sync_cmd_info cmdinfo;
+
+	cmdinfo.task = current;
+	cmdinfo.status = -EINTR;
+
+	cmdid = alloc_cmdid_killable(nvmeq, &cmdinfo, sync_completion,
+								timeout);
+	if (cmdid < 0)
+		return cmdid;
+	cmd->common.command_id = cmdid;
+
+	set_current_state(TASK_KILLABLE);
+	nvme_submit_cmd(nvmeq, cmd);
+	schedule();
+
+	if (cmdinfo.status == -EINTR) {
+		nvme_abort_command(nvmeq, cmdid);
+		return -EINTR;
+	}
+
+	if (result)
+		*result = cmdinfo.result;
+
+	return cmdinfo.status;
+}
+
+static int nvme_submit_admin_cmd(struct nvme_dev *dev, struct nvme_command *cmd,
+								u32 *result)
+{
+	return nvme_submit_sync_cmd(dev->queues[0], cmd, result, ADMIN_TIMEOUT);
+}
+
+static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
+{
+	int status;
+	struct nvme_command c;
+
+	memset(&c, 0, sizeof(c));
+	c.delete_queue.opcode = opcode;
+	c.delete_queue.qid = cpu_to_le16(id);
+
+	status = nvme_submit_admin_cmd(dev, &c, NULL);
+	if (status)
+		return -EIO;
+	return 0;
+}
+
+static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
+						struct nvme_queue *nvmeq)
+{
+	int status;
+	struct nvme_command c;
+	int flags = NVME_QUEUE_PHYS_CONTIG | NVME_CQ_IRQ_ENABLED;
+
+	memset(&c, 0, sizeof(c));
+	c.create_cq.opcode = nvme_admin_create_cq;
+	c.create_cq.prp1 = cpu_to_le64(nvmeq->cq_dma_addr);
+	c.create_cq.cqid = cpu_to_le16(qid);
+	c.create_cq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
+	c.create_cq.cq_flags = cpu_to_le16(flags);
+	c.create_cq.irq_vector = cpu_to_le16(nvmeq->cq_vector);
+
+	status = nvme_submit_admin_cmd(dev, &c, NULL);
+	if (status)
+		return -EIO;
+	return 0;
+}
+
+static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
+						struct nvme_queue *nvmeq)
+{
+	int status;
+	struct nvme_command c;
+	int flags = NVME_QUEUE_PHYS_CONTIG | NVME_SQ_PRIO_MEDIUM;
+
+	memset(&c, 0, sizeof(c));
+	c.create_sq.opcode = nvme_admin_create_sq;
+	c.create_sq.prp1 = cpu_to_le64(nvmeq->sq_dma_addr);
+	c.create_sq.sqid = cpu_to_le16(qid);
+	c.create_sq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
+	c.create_sq.sq_flags = cpu_to_le16(flags);
+	c.create_sq.cqid = cpu_to_le16(qid);
+
+	status = nvme_submit_admin_cmd(dev, &c, NULL);
+	if (status)
+		return -EIO;
+	return 0;
+}
+
+static int adapter_delete_cq(struct nvme_dev *dev, u16 cqid)
+{
+	return adapter_delete_queue(dev, nvme_admin_delete_cq, cqid);
+}
+
+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)
+{
+	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, NULL);
+}
+
+static 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_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;
+
+	irq_set_affinity_hint(vector, NULL);
+	free_irq(vector, nvmeq);
+
+	/* Don't tell the adapter to delete the admin queue */
+	if (qid) {
+		adapter_delete_sq(dev, qid);
+		adapter_delete_cq(dev, qid);
+	}
+
+	dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
+				(void *)nvmeq->cqes, nvmeq->cq_dma_addr);
+	dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
+					nvmeq->sq_cmds, nvmeq->sq_dma_addr);
+	kfree(nvmeq);
+}
+
+static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
+							int depth, int vector)
+{
+	struct device *dmadev = &dev->pci_dev->dev;
+	unsigned extra = (depth / 8) + (depth * sizeof(struct nvme_cmd_info));
+	struct nvme_queue *nvmeq = kzalloc(sizeof(*nvmeq) + extra, GFP_KERNEL);
+	if (!nvmeq)
+		return NULL;
+
+	nvmeq->cqes = dma_alloc_coherent(dmadev, CQ_SIZE(depth),
+					&nvmeq->cq_dma_addr, GFP_KERNEL);
+	if (!nvmeq->cqes)
+		goto free_nvmeq;
+	memset((void *)nvmeq->cqes, 0, CQ_SIZE(depth));
+
+	nvmeq->sq_cmds = dma_alloc_coherent(dmadev, SQ_SIZE(depth),
+					&nvmeq->sq_dma_addr, GFP_KERNEL);
+	if (!nvmeq->sq_cmds)
+		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 << (dev->db_stride + 1)];
+	nvmeq->q_depth = depth;
+	nvmeq->cq_vector = vector;
+
+	return nvmeq;
+
+ free_cqdma:
+	dma_free_coherent(dmadev, CQ_SIZE(nvmeq->q_depth), (void *)nvmeq->cqes,
+							nvmeq->cq_dma_addr);
+ free_nvmeq:
+	kfree(nvmeq);
+	return NULL;
+}
+
+static int queue_request_irq(struct nvme_dev *dev, struct nvme_queue *nvmeq,
+							const char *name)
+{
+	if (use_threaded_interrupts)
+		return request_threaded_irq(dev->entry[nvmeq->cq_vector].vector,
+					nvme_irq_check, nvme_irq,
+					IRQF_DISABLED | IRQF_SHARED,
+					name, nvmeq);
+	return request_irq(dev->entry[nvmeq->cq_vector].vector, nvme_irq,
+				IRQF_DISABLED | IRQF_SHARED, name, nvmeq);
+}
+
+static __devinit struct nvme_queue *nvme_create_queue(struct nvme_dev *dev,
+					int qid, int cq_size, int vector)
+{
+	int result;
+	struct nvme_queue *nvmeq = nvme_alloc_queue(dev, qid, cq_size, vector);
+
+	if (!nvmeq)
+		return ERR_PTR(-ENOMEM);
+
+	result = adapter_alloc_cq(dev, qid, nvmeq);
+	if (result < 0)
+		goto free_nvmeq;
+
+	result = adapter_alloc_sq(dev, qid, nvmeq);
+	if (result < 0)
+		goto release_cq;
+
+	result = queue_request_irq(dev, nvmeq, "nvme");
+	if (result < 0)
+		goto release_sq;
+
+	return nvmeq;
+
+ release_sq:
+	adapter_delete_sq(dev, qid);
+ release_cq:
+	adapter_delete_cq(dev, qid);
+ free_nvmeq:
+	dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
+				(void *)nvmeq->cqes, nvmeq->cq_dma_addr);
+	dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
+					nvmeq->sq_cmds, nvmeq->sq_dma_addr);
+	kfree(nvmeq);
+	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;
+
+	nvmeq = nvme_alloc_queue(dev, 0, 64, 0);
+	if (!nvmeq)
+		return -ENOMEM;
+
+	aqa = nvmeq->q_depth - 1;
+	aqa |= aqa << 16;
+
+	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);
+	writeq(nvmeq->sq_dma_addr, &dev->bar->asq);
+	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");
+	dev->queues[0] = nvmeq;
+	return result;
+}
+
+static struct nvme_iod *nvme_map_user_pages(struct nvme_dev *dev, int write,
+				unsigned long addr, unsigned length)
+{
+	int i, err, count, nents, offset;
+	struct scatterlist *sg;
+	struct page **pages;
+	struct nvme_iod *iod;
+
+	if (addr & 3)
+		return ERR_PTR(-EINVAL);
+	if (!length)
+		return ERR_PTR(-EINVAL);
+
+	offset = offset_in_page(addr);
+	count = DIV_ROUND_UP(offset + length, PAGE_SIZE);
+	pages = kcalloc(count, sizeof(*pages), GFP_KERNEL);
+
+	err = get_user_pages_fast(addr, count, 1, pages);
+	if (err < count) {
+		count = err;
+		err = -EFAULT;
+		goto put_pages;
+	}
+
+	iod = nvme_alloc_iod(count, length, GFP_KERNEL);
+	sg = iod->sg;
+	sg_init_table(sg, count);
+	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;
+	}
+	sg_mark_end(&sg[i - 1]);
+	iod->nents = count;
+
+	err = -ENOMEM;
+	nents = dma_map_sg(&dev->pci_dev->dev, sg, count,
+				write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+	if (!nents)
+		goto free_iod;
+
+	kfree(pages);
+	return iod;
+
+ free_iod:
+	kfree(iod);
+ put_pages:
+	for (i = 0; i < count; i++)
+		put_page(pages[i]);
+	kfree(pages);
+	return ERR_PTR(err);
+}
+
+static void nvme_unmap_user_pages(struct nvme_dev *dev, int write,
+			struct nvme_iod *iod)
+{
+	int i;
+
+	dma_unmap_sg(&dev->pci_dev->dev, iod->sg, iod->nents,
+				write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+
+	for (i = 0; i < iod->nents; i++)
+		put_page(sg_page(&iod->sg[i]));
+}
+
+static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
+{
+	struct nvme_dev *dev = ns->dev;
+	struct nvme_queue *nvmeq;
+	struct nvme_user_io io;
+	struct nvme_command c;
+	unsigned length;
+	int status;
+	struct nvme_iod *iod;
+
+	if (copy_from_user(&io, uio, sizeof(io)))
+		return -EFAULT;
+	length = (io.nblocks + 1) << ns->lba_shift;
+
+	switch (io.opcode) {
+	case nvme_cmd_write:
+	case nvme_cmd_read:
+	case nvme_cmd_compare:
+		iod = nvme_map_user_pages(dev, io.opcode & 1, io.addr, length);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (IS_ERR(iod))
+		return PTR_ERR(iod);
+
+	memset(&c, 0, sizeof(c));
+	c.rw.opcode = io.opcode;
+	c.rw.flags = io.flags;
+	c.rw.nsid = cpu_to_le32(ns->ns_id);
+	c.rw.slba = cpu_to_le64(io.slba);
+	c.rw.length = cpu_to_le16(io.nblocks);
+	c.rw.control = cpu_to_le16(io.control);
+	c.rw.dsmgmt = cpu_to_le16(io.dsmgmt);
+	c.rw.reftag = io.reftag;
+	c.rw.apptag = io.apptag;
+	c.rw.appmask = io.appmask;
+	/* XXX: metadata */
+	length = nvme_setup_prps(dev, &c.common, iod, length, GFP_KERNEL);
+
+	nvmeq = get_nvmeq(dev);
+	/*
+	 * 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);
+	if (length != (io.nblocks + 1) << ns->lba_shift)
+		status = -ENOMEM;
+	else
+		status = nvme_submit_sync_cmd(nvmeq, &c, NULL, NVME_IO_TIMEOUT);
+
+	nvme_unmap_user_pages(dev, io.opcode & 1, iod);
+	nvme_free_iod(dev, iod);
+	return status;
+}
+
+static int nvme_user_admin_cmd(struct nvme_ns *ns,
+					struct nvme_admin_cmd __user *ucmd)
+{
+	struct nvme_dev *dev = ns->dev;
+	struct nvme_admin_cmd cmd;
+	struct nvme_command c;
+	int status, length;
+	struct nvme_iod *iod;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+	if (copy_from_user(&cmd, ucmd, sizeof(cmd)))
+		return -EFAULT;
+
+	memset(&c, 0, sizeof(c));
+	c.common.opcode = cmd.opcode;
+	c.common.flags = cmd.flags;
+	c.common.nsid = cpu_to_le32(cmd.nsid);
+	c.common.cdw2[0] = cpu_to_le32(cmd.cdw2);
+	c.common.cdw2[1] = cpu_to_le32(cmd.cdw3);
+	c.common.cdw10[0] = cpu_to_le32(cmd.cdw10);
+	c.common.cdw10[1] = cpu_to_le32(cmd.cdw11);
+	c.common.cdw10[2] = cpu_to_le32(cmd.cdw12);
+	c.common.cdw10[3] = cpu_to_le32(cmd.cdw13);
+	c.common.cdw10[4] = cpu_to_le32(cmd.cdw14);
+	c.common.cdw10[5] = cpu_to_le32(cmd.cdw15);
+
+	length = cmd.data_len;
+	if (cmd.data_len) {
+		iod = nvme_map_user_pages(dev, cmd.opcode & 1, cmd.addr,
+								length);
+		if (IS_ERR(iod))
+			return PTR_ERR(iod);
+		length = nvme_setup_prps(dev, &c.common, iod, length,
+								GFP_KERNEL);
+	}
+
+	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, cmd.opcode & 1, iod);
+		nvme_free_iod(dev, iod);
+	}
+	return status;
+}
+
+static int nvme_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
+							unsigned long arg)
+{
+	struct nvme_ns *ns = bdev->bd_disk->private_data;
+
+	switch (cmd) {
+	case NVME_IOCTL_ID:
+		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);
+	default:
+		return -ENOTTY;
+	}
+}
+
+static const struct block_device_operations nvme_fops = {
+	.owner		= THIS_MODULE,
+	.ioctl		= nvme_ioctl,
+	.compat_ioctl	= nvme_ioctl,
+};
+
+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) {
+		void *ctx;
+		nvme_completion_fn fn;
+		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);
+		ctx = cancel_cmdid(nvmeq, cmdid, &fn);
+		fn(nvmeq->dev, ctx, &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;
+	struct gendisk *disk;
+	int lbaf;
+
+	if (rt->attributes & NVME_LBART_ATTRIB_HIDE)
+		return NULL;
+
+	ns = kzalloc(sizeof(*ns), GFP_KERNEL);
+	if (!ns)
+		return NULL;
+	ns->queue = blk_alloc_queue(GFP_KERNEL);
+	if (!ns->queue)
+		goto out_free_ns;
+	ns->queue->queue_flags = QUEUE_FLAG_DEFAULT;
+	queue_flag_set_unlocked(QUEUE_FLAG_NOMERGES, ns->queue);
+	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, ns->queue);
+/*	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, ns->queue); */
+	blk_queue_make_request(ns->queue, nvme_make_request);
+	ns->dev = dev;
+	ns->queue->queuedata = ns;
+
+	disk = alloc_disk(NVME_MINORS);
+	if (!disk)
+		goto out_free_queue;
+	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 * 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, nsid);
+	set_capacity(disk, le64_to_cpup(&id->nsze) << (ns->lba_shift - 9));
+
+	return ns;
+
+ out_free_queue:
+	blk_cleanup_queue(ns->queue);
+ out_free_ns:
+	kfree(ns);
+	return NULL;
+}
+
+static void nvme_ns_free(struct nvme_ns *ns)
+{
+	int index = ns->disk->first_minor / NVME_MINORS;
+	put_disk(ns->disk);
+	nvme_put_ns_idx(index);
+	blk_cleanup_queue(ns->queue);
+	kfree(ns);
+}
+
+static int set_queue_count(struct nvme_dev *dev, int count)
+{
+	int status;
+	u32 result;
+	u32 q_count = (count - 1) | ((count - 1) << 16);
+
+	status = nvme_set_features(dev, NVME_FEAT_NUM_QUEUES, q_count, 0,
+								&result);
+	if (status)
+		return -EIO;
+	return min(result & 0xffff, result >> 16) + 1;
+}
+
+static int __devinit nvme_setup_io_queues(struct nvme_dev *dev)
+{
+	int result, cpu, i, nr_io_queues, db_bar_size;
+
+	nr_io_queues = num_online_cpus();
+	result = set_queue_count(dev, nr_io_queues);
+	if (result < 0)
+		return 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]);
+
+	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_io_queues);
+		if (result == 0) {
+			break;
+		} else if (result > 0) {
+			nr_io_queues = result;
+			continue;
+		} else {
+			nr_io_queues = 1;
+			break;
+		}
+	}
+
+	result = queue_request_irq(dev, dev->queues[0], "nvme admin");
+	/* XXX: handle failure here */
+
+	cpu = cpumask_first(cpu_online_mask);
+	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_io_queues; i++) {
+		dev->queues[i + 1] = nvme_create_queue(dev, i + 1,
+							NVME_Q_DEPTH, i);
+		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;
+}
+
+static void nvme_free_queues(struct nvme_dev *dev)
+{
+	int i;
+
+	for (i = dev->queue_count - 1; i >= 0; i--)
+		nvme_free_queue(dev, i);
+}
+
+static int __devinit nvme_dev_add(struct nvme_dev *dev)
+{
+	int res, nn, i;
+	struct nvme_ns *ns, *next;
+	struct nvme_id_ctrl *ctrl;
+	struct nvme_id_ns *id_ns;
+	void *mem;
+	dma_addr_t dma_addr;
+
+	res = nvme_setup_io_queues(dev);
+	if (res)
+		return res;
+
+	mem = dma_alloc_coherent(&dev->pci_dev->dev, 8192, &dma_addr,
+								GFP_KERNEL);
+
+	res = nvme_identify(dev, 0, 1, dma_addr);
+	if (res) {
+		res = -EIO;
+		goto out_free;
+	}
+
+	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));
+
+	id_ns = mem;
+	for (i = 1; i <= nn; i++) {
+		res = nvme_identify(dev, i, 0, dma_addr);
+		if (res)
+			continue;
+
+		if (id_ns->ncap == 0)
+			continue;
+
+		res = nvme_get_features(dev, NVME_FEAT_LBA_RANGE, i,
+							dma_addr + 4096);
+		if (res)
+			continue;
+
+		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);
+
+	goto out;
+
+ out_free:
+	list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
+		list_del(&ns->list);
+		nvme_ns_free(ns);
+	}
+
+ out:
+	dma_free_coherent(&dev->pci_dev->dev, 8192, mem, dma_addr);
+	return res;
+}
+
+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) {
+		list_del(&ns->list);
+		del_gendisk(ns->disk);
+		nvme_ns_free(ns);
+	}
+
+	nvme_free_queues(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)
+{
+	static int instance;
+	dev->instance = instance++;
+}
+
+static void nvme_release_instance(struct nvme_dev *dev)
+{
+}
+
+static int __devinit nvme_probe(struct pci_dev *pdev,
+						const struct pci_device_id *id)
+{
+	int bars, result = -ENOMEM;
+	struct nvme_dev *dev;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+	dev->entry = kcalloc(num_possible_cpus(), sizeof(*dev->entry),
+								GFP_KERNEL);
+	if (!dev->entry)
+		goto free;
+	dev->queues = kcalloc(num_possible_cpus() + 1, sizeof(void *),
+								GFP_KERNEL);
+	if (!dev->queues)
+		goto free;
+
+	if (pci_enable_device_mem(pdev))
+		goto free;
+	pci_set_master(pdev);
+	bars = pci_select_bars(pdev, IORESOURCE_MEM);
+	if (pci_request_selected_regions(pdev, bars, "nvme"))
+		goto disable;
+
+	INIT_LIST_HEAD(&dev->namespaces);
+	dev->pci_dev = pdev;
+	pci_set_drvdata(pdev, dev);
+	dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
+	dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64));
+	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;
+		goto disable_msix;
+	}
+
+	result = nvme_configure_admin_queue(dev);
+	if (result)
+		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);
+ free:
+	kfree(dev->queues);
+	kfree(dev->entry);
+	kfree(dev);
+	return result;
+}
+
+static void __devexit nvme_remove(struct pci_dev *pdev)
+{
+	struct nvme_dev *dev = pci_get_drvdata(pdev);
+	nvme_dev_remove(dev);
+	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);
+	kfree(dev->entry);
+	kfree(dev);
+}
+
+/* These functions are yet to be implemented */
+#define nvme_error_detected NULL
+#define nvme_dump_registers NULL
+#define nvme_link_reset NULL
+#define nvme_slot_reset NULL
+#define nvme_error_resume NULL
+#define nvme_suspend NULL
+#define nvme_resume NULL
+
+static struct pci_error_handlers nvme_err_handler = {
+	.error_detected	= nvme_error_detected,
+	.mmio_enabled	= nvme_dump_registers,
+	.link_reset	= nvme_link_reset,
+	.slot_reset	= nvme_slot_reset,
+	.resume		= nvme_error_resume,
+};
+
+/* Move to pci_ids.h later */
+#define PCI_CLASS_STORAGE_EXPRESS	0x010802
+
+static DEFINE_PCI_DEVICE_TABLE(nvme_id_table) = {
+	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
+	{ 0, }
+};
+MODULE_DEVICE_TABLE(pci, nvme_id_table);
+
+static struct pci_driver nvme_driver = {
+	.name		= "nvme",
+	.id_table	= nvme_id_table,
+	.probe		= nvme_probe,
+	.remove		= __devexit_p(nvme_remove),
+	.suspend	= nvme_suspend,
+	.resume		= nvme_resume,
+	.err_handler	= &nvme_err_handler,
+};
+
+static int __init nvme_init(void)
+{
+	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)
+		goto kill_kthread;
+
+	result = pci_register_driver(&nvme_driver);
+	if (result)
+		goto unregister_blkdev;
+	return 0;
+
+ unregister_blkdev:
+	unregister_blkdev(nvme_major, "nvme");
+ kill_kthread:
+	kthread_stop(nvme_thread);
+	return result;
+}
+
+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("0.8");
+module_init(nvme_init);
+module_exit(nvme_exit);