Add controller reset capability to nvme(4) and ability to explicitly

invoke it from nvmecontrol(8).

Controller reset will be performed in cases where I/O are repeatedly
timing out, the controller reports an unrecoverable condition, or
when explicitly requested via IOCTL or an nvme consumer.  Since the
controller may be in such a state where it cannot even process queue
deletion requests, we will perform a controller reset without trying
to clean up anything on the controller first.

Sponsored by:	Intel
Reviewed by:	carl

2 files changed, 51 insertions, 2 deletions

diff --git a/sbin/nvmecontrol/nvmecontrol.8 b/sbin/nvmecontrol/nvmecontrol.8
index e726cbc..7e26240 100644
--- a/sbin/nvmecontrol/nvmecontrol.8
+++ b/sbin/nvmecontrol/nvmecontrol.8
@@ -33,7 +33,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd September 17, 2012
+.Dd March 26, 2013
 .Dt NVMECONTROL 8
 .Os
 .Sh NAME
@@ -54,7 +54,10 @@
 .Op Fl p
 .Aq Fl s Ar size_in_bytes
 .Aq Fl t Ar time_in_sec
-.Aq device id
+.Aq namespace id
+.Nm
+.Ic reset
+.Aq controller id
 .Sh DESCRIPTION
 NVM Express (NVMe) is a storage protocol standard, for SSDs and other
 high-speed storage devices over PCI Express.
@@ -62,6 +65,7 @@ high-speed storage devices over PCI Express.
 .Dl nvmecontrol devlist
 .Pp
 Display a list of NVMe controllers and namespaces along with their device nodes.
+.Pp
 .Dl nvmecontrol identify nvme0
 .Pp
 Display a human-readable summary of the nvme0 IDENTIFY_CONTROLLER data.
@@ -76,6 +80,10 @@ Display a hexadecimal dump of the nvme0 IDENTIFY_NAMESPACE data for namespace
 Run a performance test on nvme0ns1 using 32 kernel threads for 30 seconds.  Each
 thread will issue a single 512 byte read command.  Results are printed to
 stdout when 30 seconds expires.
+.Pp
+.Dl nvmecontrol reset nvme0
+.Pp
+Perform a controller-level reset of the nvme0 controller.
 .Sh AUTHORS
 .An -nosplit
 .Nm
diff --git a/sbin/nvmecontrol/nvmecontrol.c b/sbin/nvmecontrol/nvmecontrol.c
index 6abd3f5..b6b6908 100644
--- a/sbin/nvmecontrol/nvmecontrol.c
+++ b/sbin/nvmecontrol/nvmecontrol.c
@@ -56,6 +56,9 @@ __FBSDID("$FreeBSD$");
 "                            <-i intr|wait> [-f refthread] [-p]\n"	       \
 "                            <namespace id>\n"
 
+#define RESET_USAGE							       \
+"       nvmecontrol reset <controller id>\n"
+
 static void perftest_usage(void);
 
 static void
@@ -64,6 +67,7 @@ usage(void)
 	fprintf(stderr, "usage:\n");
 	fprintf(stderr, DEVLIST_USAGE);
 	fprintf(stderr, IDENTIFY_USAGE);
+	fprintf(stderr, RESET_USAGE);
 	fprintf(stderr, PERFTEST_USAGE);
 	exit(EX_USAGE);
 }
@@ -580,6 +584,41 @@ perftest(int argc, char *argv[])
 	exit(EX_OK);
 }
 
+static void
+reset_ctrlr(int argc, char *argv[])
+{
+	struct stat			devstat;
+	char				path[64];
+	int				ch, fd;
+
+	while ((ch = getopt(argc, argv, "")) != -1) {
+		switch ((char)ch) {
+		default:
+			usage();
+		}
+	}
+
+	sprintf(path, "/dev/%s", argv[optind]);
+
+	if (stat(path, &devstat) != 0) {
+		printf("Invalid device node '%s'.\n", path);
+		exit(EX_IOERR);
+	}
+
+	fd = open(path, O_RDWR);
+	if (fd < 0) {
+		printf("Could not open %s.\n", path);
+		exit(EX_NOPERM);
+	}
+
+	if (ioctl(fd, NVME_RESET_CONTROLLER) == -1) {
+		printf("ioctl to %s failed.\n", path);
+		exit(EX_IOERR);
+	}
+
+	exit(EX_OK);
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -593,6 +632,8 @@ main(int argc, char *argv[])
 		identify(argc-1, &argv[1]);
 	else if (strcmp(argv[1], "perftest") == 0)
 		perftest(argc-1, &argv[1]);
+	else if (strcmp(argv[1], "reset") == 0)
+		reset_ctrlr(argc-1, &argv[1]);
 
 	usage();