Remove camq_regen(). We already perform modular comparisons

for generation counts, so no further steps to deal with generation
count wrap are required.

Fix an off by one problem in the camq heap code.

4 files changed, 39 insertions, 72 deletions

diff --git a/sys/cam/cam.h b/sys/cam/cam.h
index 21aea02..c182fd6 100644
--- a/sys/cam/cam.h
+++ b/sys/cam/cam.h
@@ -25,7 +25,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *      $Id$
+ *      $Id: cam.h,v 1.1 1998/09/15 06:33:23 gibbs Exp $
  */
 
 #ifndef _CAM_CAM_H
@@ -74,6 +74,17 @@ typedef struct {
 #define CAM_DONEQ_INDEX		-3	
 } cam_pinfo;
 
+/*
+ * Macro to compare two generation numbers.  It is used like this:  
+ *
+ *	if (GENERATIONCMP(a, >=, b))
+ *		...;
+ *
+ * GERERATIONCMP uses modular arithmetic to guard against wraps
+ * wraps in the generation number.
+ */
+#define GENERATIONCMP(x, op, y) ((int32_t)((x) - (y)) op 0)
+
 /* CAM flags */
 typedef enum {
 	CAM_FLAG_NONE		= 0x00,
diff --git a/sys/cam/cam_queue.c b/sys/cam/cam_queue.c
index 809955e..edebfd5 100644
--- a/sys/cam/cam_queue.c
+++ b/sys/cam/cam_queue.c
@@ -25,7 +25,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *      $Id$
+ *      $Id: cam_queue.c,v 1.1 1998/09/15 06:33:23 gibbs Exp $
  */
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -126,27 +126,6 @@ camq_resize(struct camq *queue, int new_size)
 }
 
 /*
- * camq_regen: Given an array of cam_pinfo* elements with the
- * Heap(0, num_elements) property, perform the second half of
- * a heap sort, and assign new generation numbers to all entries.
- * It is assumed that the starting generation number plus the
- * number of entries in the queue is smaller than the wrap point
- * of the generation number.
- */
-void
-camq_regen(struct camq *queue)
-{
-	int index;
-
-	for (index = 0; index < queue->entries; index++) {
-
-		heap_down(queue->queue_array, index, queue->entries);
-		queue->queue_array[index]->generation = queue->generation++;
-	}
-	/* A sorted array is still a heap, so we are done */
-}
-
-/*
  * camq_insert: Given an array of cam_pinfo* elememnts with
  * the Heap(0, num_elements) property and array_size - num_elements >= 1,
  * output Heap(0, num_elements+1) including new_entry in the array.
@@ -336,23 +315,6 @@ cam_ccbq_init(struct cam_ccbq *ccbq, int openings)
 	return (0);
 }
 
-void
-cam_ccbq_regen(struct cam_ccbq *ccbq)
-{
-	struct ccb_hdr *ccbh;
-
-	/* First get all of the guys down at a device */
-	ccbh = ccbq->active_ccbs.tqh_first;
-
-	while (ccbh != NULL) {
-		ccbh->pinfo.generation = ccbq->queue.generation++;
-		ccbh = ccbh->xpt_links.tqe.tqe_next;
-	}
-
-	/* Now get everyone in our CAM queue */
-	camq_regen(&ccbq->queue);
-}
-
 /*
  * Heap routines for manipulating CAM queues.
  */
@@ -403,7 +365,7 @@ heap_up(cam_pinfo **queue_array, int new_index)
 
 	while (child != 0) {
 
-		parent = child >> 1;
+		parent = (child - 1) >> 1;
 		if (queue_cmp(queue_array, parent, child) <= 0)
 			break;
 		swap(queue_array, parent, child);
@@ -413,8 +375,8 @@ heap_up(cam_pinfo **queue_array, int new_index)
 
 /*
  * heap_down:  Given an array of cam_pinfo* elements with the
- * Heap(1, num_entries - 1) property with index 0 containing an unsorted
- * entry, output Heap(0, num_entries - 1).
+ * Heap(index + 1, num_entries - 1) property with index containing
+ * an unsorted entry, output Heap(0, num_entries - 1).
  */
 static void
 heap_down(cam_pinfo **queue_array, int index, int num_entries)
@@ -423,8 +385,8 @@ heap_down(cam_pinfo **queue_array, int index, int num_entries)
 	int parent;
 	
 	parent = index;
-	child = parent == 0 ? 1 : parent << 1;
-	for (; child < num_entries; child = parent << 1) {
+	child = (parent << 1) + 1;
+	for (; child < num_entries; child = (parent << 1) + 1) {
 
 		if (child + 1 < num_entries) {
 			/* child+1 is the right child of parent */
diff --git a/sys/cam/cam_queue.h b/sys/cam/cam_queue.h
index 7e3d0df..c9135b7 100644
--- a/sys/cam/cam_queue.h
+++ b/sys/cam/cam_queue.h
@@ -25,7 +25,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *      $Id: cam_queue.h,v 1.1 1998/09/15 06:33:23 gibbs Exp $
+ *      $Id: cam_queue.h,v 1.2 1998/12/15 08:12:03 gibbs Exp $
  */
 
 #ifndef _CAM_CAM_QUEUE_H
@@ -98,8 +98,6 @@ void		cam_ccbq_free(struct cam_ccbq *ccbq);
 
 void		cam_ccbq_fini(struct cam_ccbq *ccbq);
 
-void		cam_ccbq_regen(struct cam_ccbq *ccbq);
-
 /*
  * Allocate and initialize a cam_queue structure.
  */
@@ -146,8 +144,6 @@ cam_pinfo	*camq_remove(struct camq *queue, int index);
 void		camq_change_priority(struct camq *queue, int index,
 				     u_int32_t new_priority);
 
-void		camq_regen(struct camq *queue);
-
 static __inline int
 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq);
 
diff --git a/sys/cam/cam_xpt.c b/sys/cam/cam_xpt.c
index dcdc663..e44d6b2 100644
--- a/sys/cam/cam_xpt.c
+++ b/sys/cam/cam_xpt.c
@@ -26,7 +26,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *      $Id: cam_xpt.c,v 1.48 1999/03/11 10:48:02 jkh Exp $
+ *      $Id: cam_xpt.c,v 1.49 1999/03/14 05:15:38 ken Exp $
  */
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -3292,12 +3292,8 @@ xpt_schedule(struct cam_periph *perph, u_int32_t new_priority)
 		/* New entry on the queue */
 		CAM_DEBUG(perph->path, CAM_DEBUG_SUBTRACE,
 			  ("   added periph to queue\n"));
-		if (device->drvq.generation++ == 0) {
-			/* Generation wrap, regen all entries */
-			camq_regen(&device->drvq);
-		}
 		perph->pinfo.priority = new_priority;
-		perph->pinfo.generation = device->drvq.generation;
+		perph->pinfo.generation = ++device->drvq.generation;
 		camq_insert(&device->drvq, &perph->pinfo);
 		runq = xpt_schedule_dev_allocq(perph->path->bus, device);
 	}
@@ -3350,11 +3346,7 @@ xpt_schedule_dev(struct camq *queue, cam_pinfo *pinfo,
 
 		CAM_DEBUG_PRINT(CAM_DEBUG_XPT,
 				("Inserting onto queue\n"));
-		if (queue->generation++ == 0) {
-			/* Generation wrap, regen all entries */
-			camq_regen(queue);
-		}
-		pinfo->generation = queue->generation;
+		pinfo->generation = ++queue->generation;
 		camq_insert(queue, pinfo);
 		retval = 1;
 	}
@@ -3611,12 +3603,8 @@ xpt_setup_ccb(struct ccb_hdr *ccb_h, struct cam_path *path, u_int32_t priority)
 	else
 		ccb_h->target_id = CAM_TARGET_WILDCARD;
 	if (path->device) {
-		if (path->device->ccbq.queue.generation++ == 0) {
-			/* Generation wrap, regen all entries */
-			cam_ccbq_regen(&path->device->ccbq);
-		}
 		ccb_h->target_lun = path->device->lun_id;
-		ccb_h->pinfo.generation = path->device->ccbq.queue.generation;
+		ccb_h->pinfo.generation = ++path->device->ccbq.queue.generation;
 	} else {
 		ccb_h->target_lun = CAM_TARGET_WILDCARD;
 	}
@@ -5588,7 +5576,8 @@ xpt_set_transfer_settings(struct ccb_trans_settings *cts, struct cam_ed *device,
 	}
 
 	qfrozen = FALSE;
-	if ((cts->valid & CCB_TRANS_TQ_VALID) != 0) {
+	if ((cts->valid & CCB_TRANS_TQ_VALID) != 0
+	 && (async_update == FALSE)) {
 		int device_tagenb;
 
 		/*
@@ -5629,15 +5618,24 @@ xpt_set_transfer_settings(struct ccb_trans_settings *cts, struct cam_ed *device,
 				device->flags &= ~CAM_DEV_TAG_AFTER_COUNT;
 				device->tag_delay_count = 0;
 			}
-		} else if ((cts->flags & (CCB_TRANS_SYNC_RATE_VALID|
-					  CCB_TRANS_SYNC_OFFSET_VALID|
-					  CCB_TRANS_BUS_WIDTH_VALID)) != 0) {
-			xpt_toggle_tags(cts->ccb_h.path);
 		}
 	}
 
-	if (async_update == FALSE)
+	if (async_update == FALSE) {
+		/*
+		 * If we are currently performing tagged transactions to
+		 * this device and want to change its negotiation parameters,
+		 * go non-tagged for a bit to give the controller a chance to
+		 * negotiate unhampered by tag messages.
+		 */
+		if ((device->inq_flags & SID_CmdQue) != 0
+		 && (cts->flags & (CCB_TRANS_SYNC_RATE_VALID|
+				   CCB_TRANS_SYNC_OFFSET_VALID|
+				   CCB_TRANS_BUS_WIDTH_VALID)) != 0)
+			xpt_toggle_tags(cts->ccb_h.path);
+
 		(*(sim->sim_action))(sim, (union ccb *)cts);
+	}
 
 	if (qfrozen) {
 		struct ccb_relsim crs;