NVMe: New driver

This driver is for devices that follow the NVM Express standard

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>

3 files changed, 1055 insertions, 0 deletions

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 6f07ec1c2f58..35e56e1c948f 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -315,6 +315,17 @@ 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 76646e9a1c91..349539ad3ad9 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..ef66eccc2aa2
--- /dev/null
+++ b/drivers/block/nvme.c
@@ -0,0 +1,1043 @@
+/*
+ * 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/blkdev.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/genhd.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kdev_t.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/pci.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
+
+static int nvme_major;
+module_param(nvme_major, int, 0);
+
+/*
+ * 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;
+	int instance;
+	int queue_count;
+	u32 ctrl_config;
+	struct msix_entry *entry;
+	struct nvme_bar __iomem *bar;
+	struct list_head namespaces;
+};
+
+/*
+ * 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;
+	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;
+	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_cycle;
+	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);
+}
+
+/**
+ * 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
+ *
+ * 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.
+ */
+static int alloc_cmdid(struct nvme_queue *nvmeq, void *ctx, int handler)
+{
+	int depth = nvmeq->q_depth;
+	unsigned long data = (unsigned long)ctx | handler;
+	int cmdid;
+
+	BUG_ON((unsigned long)ctx & 3);
+
+	do {
+		cmdid = find_first_zero_bit(nvmeq->cmdid_data, depth);
+		if (cmdid >= depth)
+			return -EBUSY;
+	} while (test_and_set_bit(cmdid, nvmeq->cmdid_data));
+
+	nvmeq->cmdid_data[cmdid + BITS_TO_LONGS(depth)] = data;
+	return cmdid;
+}
+
+static int alloc_cmdid_killable(struct nvme_queue *nvmeq, void *ctx,
+								int handler)
+{
+	int cmdid;
+	wait_event_killable(nvmeq->sq_full,
+			(cmdid = alloc_cmdid(nvmeq, ctx, handler)) >= 0);
+	return (cmdid < 0) ? -EINTR : cmdid;
+}
+
+/* If you need more than four handlers, you'll need to change how
+ * alloc_cmdid and nvme_process_cq work
+ */
+enum {
+	sync_completion_id = 0,
+	bio_completion_id,
+};
+
+static unsigned long free_cmdid(struct nvme_queue *nvmeq, int cmdid)
+{
+	unsigned long data;
+
+	data = nvmeq->cmdid_data[cmdid + BITS_TO_LONGS(nvmeq->q_depth)];
+	clear_bit(cmdid, nvmeq->cmdid_data);
+	wake_up(&nvmeq->sq_full);
+	return data;
+}
+
+static struct nvme_queue *get_nvmeq(struct nvme_ns *ns)
+{
+	return ns->dev->queues[1];
+}
+
+static void put_nvmeq(struct nvme_queue *nvmeq)
+{
+}
+
+/**
+ * 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;
+	/* 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;
+	nvmeq->sq_tail = tail;
+	spin_unlock_irqrestore(&nvmeq->q_lock, flags);
+
+	return 0;
+}
+
+struct nvme_req_info {
+	struct bio *bio;
+	int nents;
+	struct scatterlist sg[0];
+};
+
+/* XXX: use a mempool */
+static struct nvme_req_info *alloc_info(unsigned nseg, gfp_t gfp)
+{
+	return kmalloc(sizeof(struct nvme_req_info) +
+			sizeof(struct scatterlist) * nseg, gfp);
+}
+
+static void free_info(struct nvme_req_info *info)
+{
+	kfree(info);
+}
+
+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;
+	u16 status = le16_to_cpup(&cqe->status) >> 1;
+
+	dma_unmap_sg(nvmeq->q_dmadev, info->sg, info->nents,
+			bio_data_dir(bio) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+	free_info(info);
+	bio_endio(bio, status ? -EIO : 0);
+}
+
+static int nvme_map_bio(struct device *dev, struct nvme_req_info *info,
+		struct bio *bio, enum dma_data_direction dma_dir, int psegs)
+{
+	struct bio_vec *bvec;
+	struct scatterlist *sg = info->sg;
+	int i, nsegs;
+
+	sg_init_table(sg, psegs);
+	bio_for_each_segment(bvec, bio, i) {
+		sg_set_page(sg, bvec->bv_page, bvec->bv_len, bvec->bv_offset);
+		/* XXX: handle non-mergable here */
+		nsegs++;
+	}
+	info->nents = nsegs;
+
+	return dma_map_sg(dev, info->sg, info->nents, dma_dir);
+}
+
+static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
+								struct bio *bio)
+{
+	struct nvme_rw_command *cmnd;
+	struct nvme_req_info *info;
+	enum dma_data_direction dma_dir;
+	int cmdid;
+	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;
+
+	cmdid = alloc_cmdid(nvmeq, info, bio_completion_id);
+	if (unlikely(cmdid < 0))
+		goto free_info;
+
+	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;
+
+	spin_lock_irqsave(&nvmeq->q_lock, flags);
+	cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail].rw;
+
+	if (bio_data_dir(bio)) {
+		cmnd->opcode = nvme_cmd_write;
+		dma_dir = DMA_TO_DEVICE;
+	} else {
+		cmnd->opcode = nvme_cmd_read;
+		dma_dir = DMA_FROM_DEVICE;
+	}
+
+	nvme_map_bio(nvmeq->q_dmadev, info, bio, dma_dir, psegs);
+
+	cmnd->flags = 1;
+	cmnd->command_id = cmdid;
+	cmnd->nsid = cpu_to_le32(ns->ns_id);
+	cmnd->prp1 = cpu_to_le64(sg_phys(info->sg));
+	/* XXX: Support more than one PRP */
+	cmnd->slba = cpu_to_le64(bio->bi_sector >> (ns->lba_shift - 9));
+	cmnd->length = cpu_to_le16((bio->bi_size >> ns->lba_shift) - 1);
+	cmnd->control = cpu_to_le16(control);
+	cmnd->dsmgmt = cpu_to_le32(dsmgmt);
+
+	writel(nvmeq->sq_tail, nvmeq->q_db);
+	if (++nvmeq->sq_tail == nvmeq->q_depth)
+		nvmeq->sq_tail = 0;
+
+	spin_unlock_irqrestore(&nvmeq->q_lock, flags);
+
+	return 0;
+
+ free_info:
+	free_info(info);
+ congestion:
+	return -EBUSY;
+}
+
+/*
+ * 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);
+
+	if (nvme_submit_bio_queue(nvmeq, ns, bio)) {
+		blk_set_queue_congested(q, rw_is_sync(bio->bi_rw));
+		bio_list_add(&nvmeq->sq_cong, bio);
+	}
+	put_nvmeq(nvmeq);
+
+	return 0;
+}
+
+struct sync_cmd_info {
+	struct task_struct *task;
+	u32 result;
+	int status;
+};
+
+static void sync_completion(struct nvme_queue *nvmeq, 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);
+}
+
+typedef void (*completion_fn)(struct nvme_queue *, void *,
+						struct nvme_completion *);
+
+static irqreturn_t nvme_process_cq(struct nvme_queue *nvmeq)
+{
+	u16 head, cycle;
+
+	static const completion_fn completions[4] = {
+		[sync_completion_id] = sync_completion,
+		[bio_completion_id]  = bio_completion,
+	};
+
+	head = nvmeq->cq_head;
+	cycle = nvmeq->cq_cycle;
+
+	for (;;) {
+		unsigned long data;
+		void *ptr;
+		unsigned char handler;
+		struct nvme_completion cqe = nvmeq->cqes[head];
+		if ((le16_to_cpu(cqe.status) & 1) != cycle)
+			break;
+		nvmeq->sq_head = le16_to_cpu(cqe.sq_head);
+		if (++head == nvmeq->q_depth) {
+			head = 0;
+			cycle = !cycle;
+		}
+
+		data = free_cmdid(nvmeq, cqe.command_id);
+		handler = data & 3;
+		ptr = (void *)(data & ~3UL);
+		completions[handler](nvmeq, ptr, &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 && cycle == nvmeq->cq_cycle)
+		return IRQ_NONE;
+
+	writel(head, nvmeq->q_db + 1);
+	nvmeq->cq_head = head;
+	nvmeq->cq_cycle = cycle;
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t nvme_irq(int irq, void *data)
+{
+	return nvme_process_cq(data);
+}
+
+/*
+ * 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 *q, struct nvme_command *cmd,
+								u32 *result)
+{
+	int cmdid;
+	struct sync_cmd_info cmdinfo;
+
+	cmdinfo.task = current;
+	cmdinfo.status = -EINTR;
+
+	cmdid = alloc_cmdid_killable(q, &cmdinfo, sync_completion_id);
+	if (cmdid < 0)
+		return cmdid;
+	cmd->common.command_id = cmdid;
+
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	nvme_submit_cmd(q, cmd);
+	schedule();
+
+	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);
+}
+
+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 void nvme_free_queue(struct nvme_dev *dev, int qid)
+{
+	struct nvme_queue *nvmeq = dev->queues[qid];
+
+	free_irq(dev->entry[nvmeq->cq_vector].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 + BITS_TO_LONGS(depth)) * sizeof(long);
+	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;
+	spin_lock_init(&nvmeq->q_lock);
+	nvmeq->cq_head = 0;
+	nvmeq->cq_cycle = 1;
+	init_waitqueue_head(&nvmeq->sq_full);
+	bio_list_init(&nvmeq->sq_cong);
+	nvmeq->q_db = &dev->dbs[qid * 2];
+	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 __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);
+
+	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 = request_irq(dev->entry[vector].vector, nvme_irq,
+				IRQF_DISABLED | IRQF_SHARED, "nvme", nvmeq);
+	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 NULL;
+}
+
+static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev)
+{
+	int result;
+	u32 aqa;
+	struct nvme_queue *nvmeq;
+
+	dev->dbs = ((void __iomem *)dev->bar) + 4096;
+
+	nvmeq = nvme_alloc_queue(dev, 0, 64, 0);
+
+	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;
+
+	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);
+
+	while (!(readl(&dev->bar->csts) & NVME_CSTS_RDY)) {
+		msleep(100);
+		if (fatal_signal_pending(current))
+			return -EINTR;
+	}
+
+	result = request_irq(dev->entry[0].vector, nvme_irq,
+			IRQF_DISABLED | IRQF_SHARED, "nvme admin", nvmeq);
+	dev->queues[0] = nvmeq;
+	return result;
+}
+
+static int nvme_identify(struct nvme_ns *ns, void __user *addr, int cns)
+{
+	struct nvme_dev *dev = ns->dev;
+	int status;
+	struct nvme_command c;
+	void *page;
+	dma_addr_t dma_addr;
+
+	page = dma_alloc_coherent(&dev->pci_dev->dev, 4096, &dma_addr,
+								GFP_KERNEL);
+
+	memset(&c, 0, sizeof(c));
+	c.identify.opcode = nvme_admin_identify;
+	c.identify.nsid = cns ? 0 : cpu_to_le32(ns->ns_id);
+	c.identify.prp1 = cpu_to_le64(dma_addr);
+	c.identify.cns = cpu_to_le32(cns);
+
+	status = nvme_submit_admin_cmd(dev, &c, NULL);
+
+	if (status)
+		status = -EIO;
+	else if (copy_to_user(addr, page, 4096))
+		status = -EFAULT;
+
+	dma_free_coherent(&dev->pci_dev->dev, 4096, page, dma_addr);
+
+	return status;
+}
+
+static int nvme_get_range_type(struct nvme_ns *ns, void __user *addr)
+{
+	struct nvme_dev *dev = ns->dev;
+	int status;
+	struct nvme_command c;
+	void *page;
+	dma_addr_t dma_addr;
+
+	page = dma_alloc_coherent(&dev->pci_dev->dev, 4096, &dma_addr,
+								GFP_KERNEL);
+
+	memset(&c, 0, sizeof(c));
+	c.features.opcode = nvme_admin_get_features;
+	c.features.nsid = cpu_to_le32(ns->ns_id);
+	c.features.prp1 = cpu_to_le64(dma_addr);
+	c.features.fid = cpu_to_le32(NVME_FEAT_LBA_RANGE);
+
+	status = nvme_submit_admin_cmd(dev, &c, NULL);
+
+	/* XXX: Assuming first range for now */
+	if (status)
+		status = -EIO;
+	else if (copy_to_user(addr, page, 64))
+		status = -EFAULT;
+
+	dma_free_coherent(&dev->pci_dev->dev, 4096, page, dma_addr);
+
+	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_IDENTIFY_NS:
+		return nvme_identify(ns, (void __user *)arg, 0);
+	case NVME_IOCTL_IDENTIFY_CTRL:
+		return nvme_identify(ns, (void __user *)arg, 1);
+	case NVME_IOCTL_GET_RANGE_TYPE:
+		return nvme_get_range_type(ns, (void __user *)arg);
+	default:
+		return -ENOTTY;
+	}
+}
+
+static const struct block_device_operations nvme_fops = {
+	.owner		= THIS_MODULE,
+	.ioctl		= nvme_ioctl,
+};
+
+static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int index,
+			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_NOMERGES |
+				QUEUE_FLAG_NONROT | QUEUE_FLAG_DISCARD;
+	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 = index;
+	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->fops = &nvme_fops;
+	disk->private_data = ns;
+	disk->queue = ns->queue;
+	sprintf(disk->disk_name, "nvme%dn%d", dev->instance, index);
+	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)
+{
+	put_disk(ns->disk);
+	blk_cleanup_queue(ns->queue);
+	kfree(ns);
+}
+
+static int set_queue_count(struct nvme_dev *dev, int sq_count, int cq_count)
+{
+	int status;
+	u32 result;
+	struct nvme_command c;
+	u32 q_count = (sq_count - 1) | ((cq_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);
+	if (status)
+		return -EIO;
+	return min(result & 0xffff, result >> 16) + 1;
+}
+
+/* XXX: Create per-CPU queues */
+static int __devinit nvme_setup_io_queues(struct nvme_dev *dev)
+{
+	int this_cpu;
+
+	set_queue_count(dev, 1, 1);
+
+	this_cpu = get_cpu();
+	dev->queues[1] = nvme_create_queue(dev, 1, NVME_Q_DEPTH, this_cpu);
+	put_cpu();
+	if (!dev->queues[1])
+		return -ENOMEM;
+	dev->queue_count++;
+
+	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;
+	void *id;
+	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,
+								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);
+	if (res) {
+		res = -EIO;
+		goto out_free;
+	}
+
+	nn = le32_to_cpup(&((struct nvme_id_ctrl *)id)->nn);
+
+	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);
+		if (res)
+			continue;
+
+		if (((struct nvme_id_ns *)id)->ncap == 0)
+			continue;
+
+		crt.features.nsid = cpu_to_le32(i);
+		res = nvme_submit_admin_cmd(dev, &crt, NULL);
+		if (res)
+			continue;
+
+		ns = nvme_alloc_ns(dev, i, id, id + 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;
+
+ out_free:
+	list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
+		list_del(&ns->list);
+		nvme_ns_free(ns);
+	}
+
+	dma_free_coherent(&dev->pci_dev->dev, 4096, id, dma_addr);
+	return res;
+}
+
+static int nvme_dev_remove(struct nvme_dev *dev)
+{
+	struct nvme_ns *ns, *next;
+
+	/* 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;
+}
+
+/* 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 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(2, sizeof(void *), GFP_KERNEL);
+	if (!dev->queues)
+		goto free;
+
+	INIT_LIST_HEAD(&dev->namespaces);
+	dev->pci_dev = pdev;
+	pci_set_drvdata(pdev, dev);
+	dma_set_mask(&dev->pci_dev->dev, DMA_BIT_MASK(64));
+	nvme_set_instance(dev);
+
+	dev->bar = ioremap(pci_resource_start(pdev, 0), 8192);
+	if (!dev->bar) {
+		result = -ENOMEM;
+		goto disable;
+	}
+
+	result = nvme_configure_admin_queue(dev);
+	if (result)
+		goto unmap;
+	dev->queue_count++;
+
+	result = nvme_dev_add(dev);
+	if (result)
+		goto delete;
+	return 0;
+
+ delete:
+	nvme_free_queues(dev);
+ unmap:
+	iounmap(dev->bar);
+ disable:
+	pci_disable_msix(pdev);
+	nvme_release_instance(dev);
+ 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);
+	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;
+
+	nvme_major = register_blkdev(nvme_major, "nvme");
+	if (nvme_major <= 0)
+		return -EBUSY;
+
+	result = pci_register_driver(&nvme_driver);
+	if (!result)
+		return 0;
+
+	unregister_blkdev(nvme_major, "nvme");
+	return result;
+}
+
+static void __exit nvme_exit(void)
+{
+	pci_unregister_driver(&nvme_driver);
+	unregister_blkdev(nvme_major, "nvme");
+}
+
+MODULE_AUTHOR("Matthew Wilcox <willy@linux.intel.com>");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.1");
+module_init(nvme_init);
+module_exit(nvme_exit);