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-rw-r--r--drivers/block/nvme.c1739
1 files changed, 1739 insertions, 0 deletions
diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c
new file mode 100644
index 000000000000..c1dc4d86c221
--- /dev/null
+++ b/drivers/block/nvme.c
@@ -0,0 +1,1739 @@
+/*
+ * 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;
+}
+
+static void 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);
+}
+
+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);