MFp4: Large set of CAM inprovements.

- Unify bus reset/probe sequence. Whenever bus attached at boot or later,
CAM will automatically reset and scan it. It allows to remove duplicate
code from many drivers.
- Any bus, attached before CAM completed it's boot-time initialization,
will equally join to the process, delaying boot if needed.
- New kern.cam.boot_delay loader tunable should help controllers that
are still unable to register their buses in time (such as slow USB/
PCCard/ CardBus devices), by adding one more event to wait on boot.
- To allow synchronization between different CAM levels, concept of
requests priorities was extended. Priorities now split between several
"run levels". Device can be freezed at specified level, allowing higher
priority requests to pass. For example, no payload requests allowed,
until PMP driver enable port. ATA XPT negotiate transfer parameters,
periph driver configure caching and so on.
- Frozen requests are no more counted by request allocation scheduler.
It fixes deadlocks, when frozen low priority payload requests occupying
slots, required by higher levels to manage theit execution.
- Two last changes were holding proper ATA reinitialization and error
recovery implementation. Now it is done: SATA controllers and Port
Multipliers now implement automatic hot-plug and should correctly
recover from timeouts and bus resets.
- Improve SCSI error recovery for devices on buses without automatic sense
reporting, such as ATAPI or USB. For example, it allows CAM to wait, while
CD drive loads disk, instead of immediately return error status.
- Decapitalize diagnostic messages and make them more readable and sensible.
- Teach PMP driver to limit maximum speed on fan-out ports.
- Make boot wait for PMP scan completes, and make rescan more reliable.
- Fix pass driver, to return CCB to user level in case of error.
- Increase number of retries in cd driver, as device may return several UAs.

1 files changed, 100 insertions, 5 deletions

diff --git a/sys/cam/cam_queue.h b/sys/cam/cam_queue.h
index 31f9bc2..dd9f9a7 100644
--- a/sys/cam/cam_queue.h
+++ b/sys/cam/cam_queue.h
@@ -34,6 +34,7 @@
 #ifdef _KERNEL
 
 #include <sys/queue.h>
+#include <cam/cam.h>
 
 /*
  * This structure implements a heap based priority queue.  The queue
@@ -47,7 +48,7 @@ struct camq {
 	int	   array_size;
 	int	   entries;
 	u_int32_t  generation;
-	u_int32_t  qfrozen_cnt;
+	u_int32_t  qfrozen_cnt[CAM_RL_VALUES];
 };
 
 TAILQ_HEAD(ccb_hdr_tailq, ccb_hdr);
@@ -140,6 +141,10 @@ cam_pinfo	*camq_remove(struct camq *queue, int index);
 /* Index the first element in the heap */
 #define CAMQ_GET_HEAD(camq) ((camq)->queue_array[CAMQ_HEAD])
 
+/* Get the first element priority. */
+#define CAMQ_GET_PRIO(camq) (((camq)->entries > 0) ?			\
+			    ((camq)->queue_array[CAMQ_HEAD]->priority) : 0)
+
 /*
  * camq_change_priority: Raise or lower the priority of an entry
  * maintaining queue order.
@@ -153,10 +158,10 @@ cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq);
 static __inline void
 cam_ccbq_take_opening(struct cam_ccbq *ccbq);
 
-static __inline void
+static __inline int
 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb);
 
-static __inline void
+static __inline int
 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb);
 
 static __inline union ccb *
@@ -185,17 +190,31 @@ cam_ccbq_take_opening(struct cam_ccbq *ccbq)
 	ccbq->held++;
 }
 
-static __inline void
+static __inline int
 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb)
 {
 	ccbq->held--;
 	camq_insert(&ccbq->queue, &new_ccb->ccb_h.pinfo);
+	if (ccbq->queue.qfrozen_cnt[CAM_PRIORITY_TO_RL(
+	    new_ccb->ccb_h.pinfo.priority)] > 0) {
+		ccbq->devq_openings++;
+		ccbq->held++;
+		return (1);
+	} else
+		return (0);
 }
 
-static __inline void
+static __inline int
 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb)
 {
 	camq_remove(&ccbq->queue, ccb->ccb_h.pinfo.index);
+	if (ccbq->queue.qfrozen_cnt[CAM_PRIORITY_TO_RL(
+	    ccb->ccb_h.pinfo.priority)] > 0) {
+		ccbq->devq_openings--;
+		ccbq->held--;
+		return (1);
+	} else
+		return (0);
 }
 
 static __inline union ccb *
@@ -229,5 +248,81 @@ cam_ccbq_release_opening(struct cam_ccbq *ccbq)
 	ccbq->devq_openings++;
 }
 
+static __inline int
+cam_ccbq_freeze(struct cam_ccbq *ccbq, cam_rl rl, u_int32_t cnt)
+{
+	int i, frozen = 0;
+	cam_rl p, n;
+
+	/* Find pevious run level. */
+	for (p = 0; p < CAM_RL_VALUES && ccbq->queue.qfrozen_cnt[p] == 0; p++);
+	/* Find new run level. */
+	n = min(rl, p);
+	/* Apply new run level. */
+	for (i = rl; i < CAM_RL_VALUES; i++)
+		ccbq->queue.qfrozen_cnt[i] += cnt;
+	/* Update ccbq statistics. */
+	if (n == p)
+		return (0);
+	for (i = CAMQ_HEAD; i <= ccbq->queue.entries; i++) {
+		cam_rl rrl =
+		    CAM_PRIORITY_TO_RL(ccbq->queue.queue_array[i]->priority);
+		if (rrl < n)
+			continue;
+		if (rrl >= p)
+			break;
+		ccbq->devq_openings++;
+		ccbq->held++;
+		frozen++;
+	}
+	return (frozen);
+}
+
+static __inline int
+cam_ccbq_release(struct cam_ccbq *ccbq, cam_rl rl, u_int32_t cnt)
+{
+	int i, released = 0;
+	cam_rl p, n;
+
+	/* Apply new run level. */
+	for (i = rl; i < CAM_RL_VALUES; i++)
+		ccbq->queue.qfrozen_cnt[i] -= cnt;
+	/* Find new run level. */
+	for (n = 0; n < CAM_RL_VALUES && ccbq->queue.qfrozen_cnt[n] == 0; n++);
+	/* Find previous run level. */
+	p = min(rl, n);
+	/* Update ccbq statistics. */
+	if (n == p)
+		return (0);
+	for (i = CAMQ_HEAD; i <= ccbq->queue.entries; i++) {
+		cam_rl rrl =
+		    CAM_PRIORITY_TO_RL(ccbq->queue.queue_array[i]->priority);
+		if (rrl < p)
+			continue;
+		if (rrl >= n)
+			break;
+		ccbq->devq_openings--;
+		ccbq->held--;
+		released++;
+	}
+	return (released);
+}
+
+static __inline u_int32_t
+cam_ccbq_frozen(struct cam_ccbq *ccbq, cam_rl rl)
+{
+	
+	return (ccbq->queue.qfrozen_cnt[rl]);
+}
+
+static __inline u_int32_t
+cam_ccbq_frozen_top(struct cam_ccbq *ccbq)
+{
+	cam_rl rl;
+	
+	rl = CAM_PRIORITY_TO_RL(CAMQ_GET_PRIO(&ccbq->queue));
+	return (ccbq->queue.qfrozen_cnt[rl]);
+}
+
 #endif /* _KERNEL */
 #endif  /* _CAM_CAM_QUEUE_H */