This is the first of several commits which will add NVM Express (NVMe)

support to FreeBSD.  A full description of the overall functionality
being added is below.  nvmexpress.org defines NVM Express as "an optimized
register interface, command set and feature set fo PCI Express (PCIe)-based
Solid-State Drives (SSDs)."

This commit adds nvme(4) and nvd(4) driver source code and Makefiles
to the tree.

Full NVMe functionality description:
Add nvme(4) and nvd(4) drivers and nvmecontrol(8) for NVM Express (NVMe)
device support.

There will continue to be ongoing work on NVM Express support, but there
is more than enough to allow for evaluation of pre-production NVM Express
devices as well as soliciting feedback.  Questions and feedback are welcome.

nvme(4) implements NVMe hardware abstraction and is a provider of NVMe
namespaces.  The closest equivalent of an NVMe namespace is a SCSI LUN.
nvd(4) is an NVMe consumer, surfacing NVMe namespaces as GEOM disks.
nvmecontrol(8) is used for NVMe configuration and management.

The following are currently supported:
nvme(4)
- full mandatory NVM command set support
- per-CPU IO queues (enabled by default but configurable)
- per-queue sysctls for statistics and full command/completion queue
     dumps for debugging
- registration API for NVMe namespace consumers
- I/O error handling (except for timeoutsee below)
- compilation switches for support back to stable-7

nvd(4)
- BIO_DELETE and BIO_FLUSH (if supported by controller)
- proper BIO_ORDERED handling

nvmecontrol(8)
- devlist: list NVMe controllers and their namespaces
- identify: display controller or namespace identify data in
      human-readable or hex format
- perftest: quick and dirty performance test to measure raw
      performance of NVMe device without userspace/physio/GEOM
      overhead

The following are still work in progress and will be completed over the
next 3-6 months in rough priority order:
- complete man pages
- firmware download and activation
- asynchronous error requests
- command timeout error handling
- controller resets
- nvmecontrol(8) log page retrieval

This has been primarily tested on amd64, with light testing on i386.  I
would be happy to provide assistance to anyone interested in porting
this to other architectures, but am not currently planning to do this
work myself.  Big-endian and dmamap sync for command/completion queues
are the main areas that would need to be addressed.

The nvme(4) driver currently has references to Chatham, which is an
Intel-developed prototype board which is not fully spec compliant.
These references will all be removed over time.

Sponsored by:        Intel
Contributions from:  Joe Golio/EMC <joseph dot golio at emc dot com>

1 files changed, 318 insertions, 0 deletions

diff --git a/sys/dev/nvd/nvd.c b/sys/dev/nvd/nvd.c
new file mode 100644
index 0000000..2017d79
--- /dev/null
+++ b/sys/dev/nvd/nvd.c
@@ -0,0 +1,318 @@
+/*-
+ * Copyright (C) 2012 Intel Corporation
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/bio.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/module.h>
+#include <sys/systm.h>
+#include <sys/taskqueue.h>
+
+#include <geom/geom.h>
+#include <geom/geom_disk.h>
+
+#include <dev/nvme/nvme.h>
+
+struct nvd_disk;
+
+static disk_ioctl_t nvd_ioctl;
+static disk_strategy_t nvd_strategy;
+
+static void create_geom_disk(void *, struct nvme_namespace *ns);
+static void destroy_geom_disk(struct nvd_disk *ndisk);
+
+static int nvd_load(void);
+static void nvd_unload(void);
+
+MALLOC_DEFINE(M_NVD, "nvd", "nvd(4) allocations");
+
+struct nvme_consumer *consumer_handle;
+
+struct nvd_disk {
+
+	struct bio_queue_head	bioq;
+	struct task		bioqtask;
+	struct mtx		bioqlock;
+
+	struct disk		*disk;
+	struct taskqueue	*tq;
+	struct nvme_namespace	*ns;
+
+	uint32_t		cur_depth;
+
+	TAILQ_ENTRY(nvd_disk)	tailq;
+};
+
+TAILQ_HEAD(, nvd_disk)	nvd_head;
+
+static int nvd_modevent(module_t mod, int type, void *arg)
+{
+	int error = 0;
+
+	switch (type) {
+	case MOD_LOAD:
+		error = nvd_load();
+		break;
+	case MOD_UNLOAD:
+		nvd_unload();
+		break;
+	default:
+		break;
+	}
+
+	return (error);
+}
+
+moduledata_t nvd_mod = {
+	"nvd",
+	(modeventhand_t)nvd_modevent,
+	0
+};
+
+DECLARE_MODULE(nvd, nvd_mod, SI_SUB_DRIVERS, SI_ORDER_ANY);
+MODULE_VERSION(nvd, 1);
+MODULE_DEPEND(nvd, nvme, 1, 1, 1);
+
+static int
+nvd_load()
+{
+
+	TAILQ_INIT(&nvd_head);
+	consumer_handle = nvme_register_consumer(create_geom_disk, NULL);
+
+	return (consumer_handle != NULL ? 0 : -1);
+}
+
+static void
+nvd_unload()
+{
+	struct nvd_disk *nvd;
+
+	while (!TAILQ_EMPTY(&nvd_head)) {
+		nvd = TAILQ_FIRST(&nvd_head);
+		TAILQ_REMOVE(&nvd_head, nvd, tailq);
+		destroy_geom_disk(nvd);
+		free(nvd, M_NVD);
+	}
+
+	nvme_unregister_consumer(consumer_handle);
+}
+
+static void
+nvd_strategy(struct bio *bp)
+{
+	struct nvd_disk *ndisk;
+
+	ndisk = (struct nvd_disk *)bp->bio_disk->d_drv1;
+
+	mtx_lock(&ndisk->bioqlock);
+	bioq_insert_tail(&ndisk->bioq, bp);
+	mtx_unlock(&ndisk->bioqlock);
+	taskqueue_enqueue(ndisk->tq, &ndisk->bioqtask);
+}
+
+static int
+nvd_ioctl(struct disk *ndisk, u_long cmd, void *data, int fflag,
+    struct thread *td)
+{
+	int ret = 0;
+
+	switch (cmd) {
+	default:
+		ret = EIO;
+	}
+
+	return (ret);
+}
+
+static void
+nvd_done(void *arg, const struct nvme_completion *status)
+{
+	struct bio *bp;
+	struct nvd_disk *ndisk;
+
+	bp = (struct bio *)arg;
+
+	ndisk = bp->bio_disk->d_drv1;
+
+	if (atomic_fetchadd_int(&ndisk->cur_depth, -1) == NVME_QD)
+		taskqueue_enqueue(ndisk->tq, &ndisk->bioqtask);
+
+	/*
+	 * TODO: add more extensive translation of NVMe status codes
+	 *  to different bio error codes (i.e. EIO, EINVAL, etc.)
+	 */
+	if (status->sf_sc || status->sf_sct) {
+		bp->bio_error = EIO;
+		bp->bio_flags |= BIO_ERROR;
+		bp->bio_resid = bp->bio_bcount;
+	} else
+		bp->bio_resid = 0;
+
+	biodone(bp);
+}
+
+static void
+nvd_bioq_process(void *arg, int pending)
+{
+	struct nvd_disk *ndisk = arg;
+	struct bio *bp;
+	int err;
+
+	for (;;) {
+		if (atomic_load_acq_int(&ndisk->cur_depth) >= NVME_QD)
+			break;
+
+		mtx_lock(&ndisk->bioqlock);
+		bp = bioq_takefirst(&ndisk->bioq);
+		mtx_unlock(&ndisk->bioqlock);
+		if (bp == NULL)
+			break;
+
+#ifdef BIO_ORDERED
+		/*
+		 * BIO_ORDERED flag dictates that all outstanding bios
+		 *  must be completed before processing the bio with
+		 *  BIO_ORDERED flag set.
+		 */
+		if (bp->bio_flags & BIO_ORDERED) {
+			while (ndisk->cur_depth > 0) {
+				pause("nvd flush", 1);
+			}
+		}
+#endif
+
+		bp->bio_driver1 = NULL;
+		atomic_add_acq_int(&ndisk->cur_depth, 1);
+
+		err = nvme_ns_bio_process(ndisk->ns, bp, nvd_done);
+
+		if (err) {
+			atomic_add_acq_int(&ndisk->cur_depth, -1);
+			bp->bio_error = EIO;
+			bp->bio_flags |= BIO_ERROR;
+			bp->bio_resid = bp->bio_bcount;
+			biodone(bp);
+		}
+
+#ifdef BIO_ORDERED
+		/*
+		 * BIO_ORDERED flag dictates that the bio with BIO_ORDERED
+		 *  flag set must be completed before proceeding with
+		 *  additional bios.
+		 */
+		if (bp->bio_flags & BIO_ORDERED) {
+			while (ndisk->cur_depth > 0) {
+				pause("nvd flush", 1);
+			}
+		}
+#endif
+	}
+}
+
+static void
+create_geom_disk(void *arg, struct nvme_namespace *ns)
+{
+	struct nvd_disk *ndisk;
+	struct disk *disk;
+
+	ndisk = malloc(sizeof(struct nvd_disk), M_NVD, M_ZERO | M_NOWAIT);
+
+	disk = disk_alloc();
+	disk->d_strategy = nvd_strategy;
+	disk->d_ioctl = nvd_ioctl;
+	disk->d_name = "nvd";
+	disk->d_drv1 = ndisk;
+
+	disk->d_maxsize = nvme_ns_get_max_io_xfer_size(ns);
+	disk->d_sectorsize = nvme_ns_get_sector_size(ns);
+	disk->d_mediasize = (off_t)nvme_ns_get_size(ns);
+
+	if (TAILQ_EMPTY(&nvd_head))
+		disk->d_unit = 0;
+	else
+		disk->d_unit = TAILQ_FIRST(&nvd_head)->disk->d_unit + 1;
+
+	disk->d_flags = 0;
+
+	if (nvme_ns_get_flags(ns) & NVME_NS_DEALLOCATE_SUPPORTED)
+		disk->d_flags |= DISKFLAG_CANDELETE;
+
+	if (nvme_ns_get_flags(ns) & NVME_NS_FLUSH_SUPPORTED)
+		disk->d_flags |= DISKFLAG_CANFLUSHCACHE;
+
+	strlcpy(disk->d_ident, nvme_ns_get_serial_number(ns),
+	    sizeof(disk->d_ident));
+
+#if __FreeBSD_version >= 900034
+	strlcpy(disk->d_descr, nvme_ns_get_model_number(ns),
+	    sizeof(disk->d_descr));
+#endif
+
+	disk_create(disk, DISK_VERSION);
+
+	ndisk->ns = ns;
+	ndisk->disk = disk;
+	ndisk->cur_depth = 0;
+
+	mtx_init(&ndisk->bioqlock, "NVD bioq lock", NULL, MTX_DEF);
+	bioq_init(&ndisk->bioq);
+
+	TASK_INIT(&ndisk->bioqtask, 0, nvd_bioq_process, ndisk);
+	ndisk->tq = taskqueue_create("nvd_taskq", M_WAITOK,
+	    taskqueue_thread_enqueue, &ndisk->tq);
+	taskqueue_start_threads(&ndisk->tq, 1, PI_DISK, "nvd taskq");
+
+	TAILQ_INSERT_HEAD(&nvd_head, ndisk, tailq);
+}
+
+static void
+destroy_geom_disk(struct nvd_disk *ndisk)
+{
+	struct bio *bp;
+
+	taskqueue_free(ndisk->tq);
+	disk_destroy(ndisk->disk);
+
+	mtx_lock(&ndisk->bioqlock);
+	for (;;) {
+		bp = bioq_takefirst(&ndisk->bioq);
+		if (bp == NULL)
+			break;
+		bp->bio_error = EIO;
+		bp->bio_flags |= BIO_ERROR;
+		bp->bio_resid = bp->bio_bcount;
+
+		biodone(bp);
+	}
+	mtx_unlock(&ndisk->bioqlock);
+
+	mtx_destroy(&ndisk->bioqlock);
+}