svn commit: r254116 - head/sys/dev/mps

[Scott Long]

Author: scottl
Date: Fri Aug  9 01:09:02 2013
New Revision: 254116
URL: http://svnweb.freebsd.org/changeset/base/254116

Log:
  Sometimes a device misbehaves so badly that it disrupts the entire system.
  Add a tunable that allows such a device to be excluded from the driver.
  The id parameter is the target id that the driver assigns to a given device.
  
  dev.mps.X.exclude_ids=<id>,<id>
  
  Obtained from:	Netflix
  MFC after:	3 days

Modified:
  head/sys/dev/mps/mps.c
  head/sys/dev/mps/mps_sas.c
  head/sys/dev/mps/mps_sas.h
  head/sys/dev/mps/mps_sas_lsi.c
  head/sys/dev/mps/mpsvar.h

Modified: head/sys/dev/mps/mps.c
==============================================================================
--- head/sys/dev/mps/mps.c	Fri Aug  9 01:04:44 2013	(r254115)
+++ head/sys/dev/mps/mps.c	Fri Aug  9 01:09:02 2013	(r254116)
@@ -1371,6 +1371,11 @@ mps_get_tunables(struct mps_softc *sc)
 	snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_chains",
 	    device_get_unit(sc->mps_dev));
 	TUNABLE_INT_FETCH(tmpstr, &sc->max_chains);
+
+	bzero(sc->exclude_ids, sizeof(sc->exclude_ids));
+	snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.exclude_ids",
+	    device_get_unit(sc->mps_dev));
+	TUNABLE_STR_FETCH(tmpstr, sc->exclude_ids, sizeof(sc->exclude_ids));
 }
 
 static void

Modified: head/sys/dev/mps/mps_sas.c
==============================================================================
--- head/sys/dev/mps/mps_sas.c	Fri Aug  9 01:04:44 2013	(r254115)
+++ head/sys/dev/mps/mps_sas.c	Fri Aug  9 01:09:02 2013	(r254116)
@@ -3553,3 +3553,20 @@ mpssas_portenable_complete(struct mps_so
 	xpt_release_simq(sassc->sim, 1);
 }
 
+int
+mpssas_check_id(struct mpssas_softc *sassc, int id)
+{
+	struct mps_softc *sc = sassc->sc;
+	char *ids;
+	char *name;
+
+	ids = &sc->exclude_ids[0];
+	while((name = strsep(&ids, ",")) != NULL) {
+		if (name[0] == '\0')
+			continue;
+		if (strtol(name, NULL, 0) == (long)id)
+			return (1);
+	}
+
+	return (0);
+}

Modified: head/sys/dev/mps/mps_sas.h
==============================================================================
--- head/sys/dev/mps/mps_sas.h	Fri Aug  9 01:04:44 2013	(r254115)
+++ head/sys/dev/mps/mps_sas.h	Fri Aug  9 01:09:02 2013	(r254116)
@@ -158,3 +158,4 @@ void mpssas_startup_decrement(struct mps
 struct mps_command * mpssas_alloc_tm(struct mps_softc *sc);
 void mpssas_free_tm(struct mps_softc *sc, struct mps_command *tm);
 void mpssas_firmware_event_work(void *arg, int pending);
+int mpssas_check_id(struct mpssas_softc *sassc, int id);

Modified: head/sys/dev/mps/mps_sas_lsi.c
==============================================================================
--- head/sys/dev/mps/mps_sas_lsi.c	Fri Aug  9 01:04:44 2013	(r254115)
+++ head/sys/dev/mps/mps_sas_lsi.c	Fri Aug  9 01:09:02 2013	(r254116)
@@ -669,6 +669,13 @@ mpssas_add_device(struct mps_softc *sc, 
 		error = ENXIO;
 		goto out;
 	}
+
+	if (mpssas_check_id(sassc, id) != 0) {
+		device_printf(sc->mps_dev, "Excluding target id %d\n", id);
+		error = ENXIO;
+		goto out;
+	}
+
 	mps_dprint(sc, MPS_MAPPING, "SAS Address from SAS device page0 = %jx\n",
 	    sas_address);
 	targ = &sassc->targets[id];

Modified: head/sys/dev/mps/mpsvar.h
==============================================================================
--- head/sys/dev/mps/mpsvar.h	Fri Aug  9 01:04:44 2013	(r254115)
+++ head/sys/dev/mps/mpsvar.h	Fri Aug  9 01:09:02 2013	(r254116)
@@ -414,6 +414,8 @@ struct mps_softc {
 	uint16_t			DD_block_exponent;
 	uint64_t			DD_max_lba;
 	struct mps_column_map		DD_column_map[MPS_MAX_DISKS_IN_VOL];
+
+	char				exclude_ids[80];
 };
 
 struct mps_config_params {