CAM Transport Layer (XPT).

Submitted by:	The CAM Team

1 files changed, 441 insertions, 0 deletions

diff --git a/sys/cam/cam_queue.c b/sys/cam/cam_queue.c
new file mode 100644
index 0000000..809955e
--- /dev/null
+++ b/sys/cam/cam_queue.c
@@ -0,0 +1,441 @@
+/*
+ * CAM request queue management functions.
+ *
+ * Copyright (c) 1997 Justin T. Gibbs.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification, immediately at the beginning of the file.
+ * 2. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *      $Id$
+ */
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/types.h>
+#include <sys/malloc.h>
+
+#include <cam/cam.h>
+#include <cam/cam_ccb.h>
+#include <cam/cam_queue.h>
+#include <cam/cam_debug.h>
+
+static __inline int
+		queue_cmp(cam_pinfo **queue_array, int i, int j);
+static __inline void
+		swap(cam_pinfo **queue_array, int i, int j);
+static void	heap_up(cam_pinfo **queue_array, int new_index);
+static void	heap_down(cam_pinfo **queue_array, int index,
+			  int last_index);
+
+struct camq *
+camq_alloc(int size)
+{
+	struct camq *camq;
+
+	camq = (struct camq *)malloc(sizeof(*camq), M_DEVBUF, M_NOWAIT);
+	if (camq != NULL) {
+		if (camq_init(camq, size) != 0) {
+			free(camq, M_DEVBUF);
+			camq = NULL;
+		}
+	}
+	return (camq);
+}
+	
+int
+camq_init(struct camq *camq, int size)
+{
+	bzero(camq, sizeof(*camq));
+	camq->array_size = size;
+	if (camq->array_size != 0) {
+		camq->queue_array = (cam_pinfo**)malloc(size*sizeof(cam_pinfo*),
+							M_DEVBUF, M_NOWAIT);
+		if (camq->queue_array == NULL) {
+			printf("camq_init: - cannot malloc array!\n");
+			return (1);
+		}
+	}
+	return (0);
+}
+
+/*
+ * Free a camq structure.  This should only be called if a controller
+ * driver failes somehow during its attach routine or is unloaded and has
+ * obtained a camq structure.  The XPT should ensure that the queue
+ * is empty before calling this routine.
+ */
+void
+camq_free(struct camq *queue)
+{
+	if (queue != NULL) {
+		camq_fini(queue);
+		free(queue, M_DEVBUF);
+	}
+}
+
+void
+camq_fini(struct camq *queue)
+{
+	if (queue->queue_array != NULL) {
+		free(queue->queue_array, M_DEVBUF);
+	}
+}
+
+u_int32_t
+camq_resize(struct camq *queue, int new_size)
+{
+	cam_pinfo **new_array;
+
+#ifdef DIAGNOSTIC
+	if (new_size < queue->entries)
+		panic("camq_resize: New queue size can't accomodate "
+		      "queued entries.");
+#endif
+	new_array = (cam_pinfo **)malloc(new_size * sizeof(cam_pinfo *),
+					 M_DEVBUF, M_NOWAIT);
+	if (new_array == NULL) {
+		/* Couldn't satisfy request */
+		return (CAM_RESRC_UNAVAIL);
+	}
+	if (queue->queue_array != NULL) {
+		bcopy(queue->queue_array, new_array,
+		      queue->entries * sizeof(cam_pinfo *));
+		free(queue->queue_array, M_DEVBUF);
+	}
+	queue->queue_array = new_array;
+	queue->array_size = new_size;
+	return (CAM_REQ_CMP);
+}
+
+/*
+ * 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.
+ */
+void
+camq_insert(struct camq *queue, cam_pinfo *new_entry)
+{
+#ifdef DIAGNOSTIC
+	if (queue->entries >= queue->array_size)
+		panic("camq_insert: Attempt to insert into a full queue");
+#endif
+	queue->queue_array[queue->entries] = new_entry;
+	new_entry->index = queue->entries;
+	if (queue->entries != 0)
+		heap_up(queue->queue_array, queue->entries);
+	queue->entries++;
+}
+
+/*
+ * camq_remove:  Given an array of cam_pinfo* elevements with the
+ * Heap(0, num_elements) property and an index such that 0 <= index <=
+ * num_elements, remove that entry and restore the Heap(0, num_elements-1)
+ * property.
+ */
+cam_pinfo *
+camq_remove(struct camq *queue, int index)
+{
+	cam_pinfo *removed_entry;
+
+	if ((queue->entries - index) <= 0)
+		return (NULL);
+	removed_entry = queue->queue_array[index];
+	queue->entries--;
+	if (queue->entries != index) {
+		queue->queue_array[index] = queue->queue_array[queue->entries];
+		queue->queue_array[index]->index = index;
+		heap_down(queue->queue_array, index, queue->entries);
+	}
+	removed_entry->index = CAM_UNQUEUED_INDEX;
+	return (removed_entry);
+}
+
+/*
+ * camq_change_priority:  Given an array of cam_pinfo* elements with the
+ * Heap(0, num_entries) property, an index such that 0 <= index <= num_elements,
+ * and an new priority for the element at index, change the priority of
+ * element index and restore the Heap(0, num_elements) property.
+ */
+void
+camq_change_priority(struct camq *queue, int index, u_int32_t new_priority)
+{
+	if (new_priority > queue->queue_array[index]->priority) {
+		queue->queue_array[index]->priority = new_priority;
+		heap_down(queue->queue_array, index, queue->entries);
+	} else {
+		/* new_priority <= old_priority */
+		queue->queue_array[index]->priority = new_priority;
+		heap_up(queue->queue_array, index);
+	}
+}
+
+struct cam_devq *
+cam_devq_alloc(int devices, int openings)
+{
+	struct cam_devq *devq;
+
+	devq = (struct cam_devq *)malloc(sizeof(*devq), M_DEVBUF, M_NOWAIT);
+	if (devq == NULL) {
+		printf("cam_devq_alloc: - cannot malloc!\n");
+		return (NULL);
+	}
+	if (cam_devq_init(devq, devices, openings) != 0) {
+		free(devq, M_DEVBUF);
+		return (NULL);		
+	}
+	
+	return (devq);
+}
+
+int
+cam_devq_init(struct cam_devq *devq, int devices, int openings)
+{
+	bzero(devq, sizeof(*devq));
+	if (camq_init(&devq->alloc_queue, devices) != 0) {
+		return (1);
+	}
+	if (camq_init(&devq->send_queue, devices) != 0) {
+		camq_fini(&devq->alloc_queue);
+		return (1);
+	}
+	devq->alloc_openings = openings;
+	devq->alloc_active = 0;
+	devq->send_openings = openings;
+	devq->send_active = 0;	
+	return (0);	
+}
+
+void
+cam_devq_free(struct cam_devq *devq)
+{
+	camq_free(&devq->alloc_queue);
+	camq_free(&devq->send_queue);
+	free(devq, M_DEVBUF);
+}
+
+u_int32_t
+cam_devq_resize(struct cam_devq *camq, int devices)
+{
+	u_int32_t retval;
+
+	retval = camq_resize(&camq->alloc_queue, devices);
+
+	if (retval == CAM_REQ_CMP)
+		retval = camq_resize(&camq->send_queue, devices);
+
+	return (retval);
+}
+
+struct cam_ccbq *
+cam_ccbq_alloc(int openings)
+{
+	struct cam_ccbq *ccbq;
+
+	ccbq = (struct cam_ccbq *)malloc(sizeof(*ccbq), M_DEVBUF, M_NOWAIT);
+	if (ccbq == NULL) {
+		printf("cam_ccbq_alloc: - cannot malloc!\n");
+		return (NULL);
+	}
+	if (cam_ccbq_init(ccbq, openings) != 0) {
+		free(ccbq, M_DEVBUF);
+		return (NULL);		
+	}
+	
+	return (ccbq);
+}
+
+void
+cam_ccbq_free(struct cam_ccbq *ccbq)
+{
+	if (ccbq) {
+		camq_fini(&ccbq->queue);
+		free(ccbq, M_DEVBUF);
+	}
+}
+
+u_int32_t
+cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size)
+{
+	int delta;
+	int space_left;
+
+	delta = new_size - (ccbq->dev_active + ccbq->dev_openings);
+	space_left = new_size
+	    - ccbq->queue.entries
+	    - ccbq->held
+	    - ccbq->dev_active;
+
+	/*
+	 * Only attempt to change the underlying queue size if we are
+	 * shrinking it and there is space for all outstanding entries
+	 * in the new array or we have been requested to grow the array.
+	 * We don't fail in the case where we can't reduce the array size,
+	 * but clients that care that the queue be "garbage collected"
+	 * should detect this condition and call us again with the
+	 * same size once the outstanding entries have been processed.
+	 */
+	if (space_left < 0
+	 || camq_resize(&ccbq->queue, new_size) == CAM_REQ_CMP) {
+		ccbq->devq_openings += delta;
+		ccbq->dev_openings += delta;
+		return (CAM_REQ_CMP);
+	} else {
+		return (CAM_RESRC_UNAVAIL);
+	}
+}
+
+int
+cam_ccbq_init(struct cam_ccbq *ccbq, int openings)
+{
+	bzero(ccbq, sizeof(*ccbq));
+	if (camq_init(&ccbq->queue, openings) != 0) {
+		return (1);
+	}
+	ccbq->devq_openings = openings;
+	ccbq->dev_openings = openings;	
+	TAILQ_INIT(&ccbq->active_ccbs);
+	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.
+ */
+/*
+ * queue_cmp: Given an array of cam_pinfo* elements and indexes i
+ * and j, return less than 0, 0, or greater than 0 if i is less than,
+ * equal too, or greater than j respectively.
+ */
+static __inline int
+queue_cmp(cam_pinfo **queue_array, int i, int j)
+{
+	if (queue_array[i]->priority == queue_array[j]->priority)
+		return (  queue_array[i]->generation
+			- queue_array[j]->generation );
+	else
+		return (  queue_array[i]->priority
+			- queue_array[j]->priority );
+}
+
+/*
+ * swap: Given an array of cam_pinfo* elements and indexes i and j,
+ * exchange elements i and j.
+ */
+static __inline void
+swap(cam_pinfo **queue_array, int i, int j)
+{
+	cam_pinfo *temp_qentry;
+
+	temp_qentry = queue_array[j];
+	queue_array[j] = queue_array[i];
+	queue_array[i] = temp_qentry;
+	queue_array[j]->index = j;
+	queue_array[i]->index = i;
+}
+
+/*
+ * heap_up:  Given an array of cam_pinfo* elements with the
+ * Heap(0, new_index-1) property and a new element in location
+ * new_index, output Heap(0, new_index).
+ */
+static void
+heap_up(cam_pinfo **queue_array, int new_index)
+{
+	int child;
+	int parent;
+
+	child = new_index;
+
+	while (child != 0) {
+
+		parent = child >> 1;
+		if (queue_cmp(queue_array, parent, child) <= 0)
+			break;
+		swap(queue_array, parent, child);
+		child = parent;
+	}
+}
+
+/*
+ * 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).
+ */
+static void
+heap_down(cam_pinfo **queue_array, int index, int num_entries)
+{
+	int child;
+	int parent;
+	
+	parent = index;
+	child = parent == 0 ? 1 : parent << 1;
+	for (; child < num_entries; child = parent << 1) {
+
+		if (child + 1 < num_entries) {
+			/* child+1 is the right child of parent */
+			if (queue_cmp(queue_array, child + 1, child) < 0)
+				child++;
+		}
+		/* child is now the least child of parent */
+		if (queue_cmp(queue_array, parent, child) <= 0)
+			break;
+		swap(queue_array, child, parent);
+		parent = child;
+	}
+}
+