Move the CAM passthrough code into a true module so that it doesn't have to be

compiled into the main AMR driver.  It's code that is nice to have but not
required for normal operation, and it is reported to cause problems for some
people.

3 files changed, 58 insertions, 33 deletions

diff --git a/sys/dev/amr/amr.c b/sys/dev/amr/amr.c
index 192f128..6b75ebb 100644
--- a/sys/dev/amr/amr.c
+++ b/sys/dev/amr/amr.c
@@ -88,13 +88,6 @@ __FBSDID("$FreeBSD$");
 #define AMR_DEFINE_TABLES
 #include <dev/amr/amr_tables.h>
 
-/*
- * The CAM interface appears to be completely broken.  Disable it.
- */
-#ifndef AMR_ENABLE_CAM
-#define AMR_ENABLE_CAM 1
-#endif
-
 SYSCTL_NODE(_hw, OID_AUTO, amr, CTLFLAG_RD, 0, "AMR driver parameters");
 
 static d_open_t         amr_open;
@@ -202,6 +195,7 @@ MALLOC_DEFINE(M_AMR, "amr", "AMR memory");
 int
 amr_attach(struct amr_softc *sc)
 {
+    device_t child;
 
     debug_called(1);
 
@@ -259,14 +253,16 @@ amr_attach(struct amr_softc *sc)
      */
     amr_init_sysctl(sc);
 
-#if AMR_ENABLE_CAM != 0
     /*
      * Attach our 'real' SCSI channels to CAM.
      */
-    if (amr_cam_attach(sc))
-	return(ENXIO);
-    debug(2, "CAM attach done");
-#endif
+    child = device_add_child(sc->amr_dev, "amrp", -1);
+    sc->amr_pass = child;
+    if (child != NULL) {
+	device_set_softc(child, sc);
+	device_set_desc(child, "SCSI Passthrough Bus");
+	bus_generic_attach(sc->amr_dev);
+    }
 
     /*
      * Create the control device.
@@ -391,10 +387,9 @@ amr_free(struct amr_softc *sc)
 {
     struct amr_command_cluster	*acc;
 
-#if AMR_ENABLE_CAM != 0
     /* detach from CAM */
-    amr_cam_detach(sc); 
-#endif
+    if (sc->amr_pass != NULL)
+	device_delete_child(sc->amr_dev, sc->amr_pass);
 
     /* cancel status timeout */
     untimeout(amr_periodic, sc, sc->amr_timeout);
@@ -1240,11 +1235,9 @@ amr_startio(struct amr_softc *sc)
 	if (ac == NULL)
 	    (void)amr_bio_command(sc, &ac);
 
-#if AMR_ENABLE_CAM != 0
 	/* if that failed, build a command from a ccb */
-	if (ac == NULL)
-	    (void)amr_cam_command(sc, &ac);
-#endif
+	if ((ac == NULL) && (sc->amr_cam_command != NULL))
+	    sc->amr_cam_command(sc, &ac);
 
 	/* if we don't have anything to do, give up */
 	if (ac == NULL)
diff --git a/sys/dev/amr/amr_cam.c b/sys/dev/amr/amr_cam.c
index 65913d1..bcd036e 100644
--- a/sys/dev/amr/amr_cam.c
+++ b/sys/dev/amr/amr_cam.c
@@ -61,6 +61,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/systm.h>
 #include <sys/malloc.h>
 #include <sys/kernel.h>
+#include <sys/module.h>
 
 #include <sys/bio.h>
 #include <sys/bus.h>
@@ -82,9 +83,31 @@ __FBSDID("$FreeBSD$");
 #include <dev/amr/amrreg.h>
 #include <dev/amr/amrvar.h>
 
+static int	amr_cam_probe(device_t dev);
+static int	amr_cam_attach(device_t dev);
+static int	amr_cam_detach(device_t dev);
 static void	amr_cam_action(struct cam_sim *sim, union ccb *ccb);
 static void	amr_cam_poll(struct cam_sim *sim);
 static void	amr_cam_complete(struct amr_command *ac);
+static int	amr_cam_command(struct amr_softc *sc, struct amr_command **acp);
+
+static devclass_t	amr_pass_devclass;
+
+static device_method_t	amr_pass_methods[] = {
+	DEVMETHOD(device_probe,		amr_cam_probe),
+	DEVMETHOD(device_attach,	amr_cam_attach),
+	DEVMETHOD(device_detach,	amr_cam_detach),
+	{ 0, 0 }
+};
+
+static driver_t	amr_pass_driver = {
+	"amrp",
+	amr_pass_methods,
+	0
+};
+
+DRIVER_MODULE(amrp, amr, amr_pass_driver, amr_pass_devclass, 0, 0);
+MODULE_DEPEND(amrp, cam, 1, 1, 1);
 
 MALLOC_DEFINE(M_AMRCAM, "amrcam", "AMR CAM memory");
 
@@ -115,14 +138,23 @@ amr_dequeue_ccb(struct amr_softc *sc)
 	return(ccb);
 }
 
+static int
+amr_cam_probe(device_t dev)
+{
+	return (0);
+}
+
 /********************************************************************************
  * Attach our 'real' SCSI channels to CAM
  */
-int
-amr_cam_attach(struct amr_softc *sc)
+static int
+amr_cam_attach(device_t dev)
 {
+	struct amr_softc *sc;
 	struct cam_devq	*devq;
-	int			chn, error;
+	int chn, error;
+
+	sc = device_get_softc(dev);
 
 	/* initialise the ccb queue */
 	TAILQ_INIT(&sc->amr_cam_ccbq);
@@ -134,7 +166,7 @@ amr_cam_attach(struct amr_softc *sc)
 	 * during detach.
 	 */
 	if ((devq = cam_simq_alloc(AMR_MAX_SCSI_CMDS)) == NULL)
-	return(ENOMEM);
+		return(ENOMEM);
 	sc->amr_cam_devq = devq;
 
 	/*
@@ -165,17 +197,20 @@ amr_cam_attach(struct amr_softc *sc)
 	 * XXX we should scan the config and work out which devices are
 	 * actually protected.
 	 */
+	sc->amr_cam_command = amr_cam_command;
 	return(0);
 }
 
 /********************************************************************************
  * Disconnect ourselves from CAM
  */
-void
-amr_cam_detach(struct amr_softc *sc)
+static int
+amr_cam_detach(device_t dev)
 {
+	struct amr_softc *sc;
 	int		chn;
 
+	sc = device_get_softc(dev);
 	mtx_lock(&sc->amr_list_lock);
 	for (chn = 0; chn < sc->amr_maxchan; chn++) {
 		/*
@@ -191,6 +226,8 @@ amr_cam_detach(struct amr_softc *sc)
 	/* Now free the devq */
 	if (sc->amr_cam_devq != NULL)
 		cam_simq_free(sc->amr_cam_devq);
+
+	return (0);
 }
 
 /***********************************************************************
@@ -379,7 +416,7 @@ amr_cam_action(struct cam_sim *sim, union ccb *ccb)
  * Convert a CAM CCB off the top of the CCB queue to a passthrough SCSI
  * command.
  */
-int
+static int
 amr_cam_command(struct amr_softc *sc, struct amr_command **acp)
 {
 	struct amr_command		*ac;
diff --git a/sys/dev/amr/amrvar.h b/sys/dev/amr/amrvar.h
index e208c53..7dc0fb4 100644
--- a/sys/dev/amr/amrvar.h
+++ b/sys/dev/amr/amrvar.h
@@ -253,6 +253,8 @@ struct amr_softc
     int 			support_ext_cdb;	/* greater than 10 byte cdb support */
 
     /* misc glue */
+    device_t			amr_pass;
+    int				(*amr_cam_command)(struct amr_softc *sc, struct amr_command **acp);
     struct intr_config_hook	amr_ich;		/* wait-for-interrupts probe hook */
     struct callout_handle	amr_timeout;		/* periodic status check */
     int				amr_allow_vol_config;
@@ -277,13 +279,6 @@ extern struct amr_command	*amr_alloccmd(struct amr_softc *sc);
 extern void			amr_releasecmd(struct amr_command *ac);
 
 /*
- * CAM interface
- */
-extern int		amr_cam_attach(struct amr_softc *sc);
-extern void		amr_cam_detach(struct amr_softc *sc);
-extern int		amr_cam_command(struct amr_softc *sc, struct amr_command **acp);
-
-/*
  * MegaRAID logical disk driver
  */
 struct amrd_softc