1 files changed, 384 insertions, 0 deletions
diff --git a/sys/cam/cam_queue.c b/sys/cam/cam_queue.c
new file mode 100644
index 000000000000..074b0545a1fd
--- /dev/null
+++ b/sys/cam/cam_queue.c
@@ -0,0 +1,384 @@
+/*-
+ * CAM request queue management functions.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/types.h>
+#include <sys/malloc.h>
+#include <sys/kernel.h>
+
+#include <cam/cam.h>
+#include <cam/cam_ccb.h>
+#include <cam/cam_queue.h>
+#include <cam/cam_debug.h>
+
+static MALLOC_DEFINE(M_CAMQ, "CAM queue", "CAM queue buffers");
+static MALLOC_DEFINE(M_CAMDEVQ, "CAM dev queue", "CAM dev queue buffers");
+static MALLOC_DEFINE(M_CAMCCBQ, "CAM ccb queue", "CAM ccb queue buffers");
+
+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);
+
+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_CAMQ, M_NOWAIT);
+		if (camq->queue_array == NULL) {
+			printf("camq_init: - cannot malloc array!\n");
+			return (1);
+		}
+		/*
+		 * Heap algorithms like everything numbered from 1, so
+		 * offset our pointer into the heap array by one element.
+		 */
+		camq->queue_array--;
+	}
+	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_fini(struct camq *queue)
+{
+	if (queue->queue_array != NULL) {
+		/*
+		 * Heap algorithms like everything numbered from 1, so
+		 * our pointer into the heap array is offset by one element.
+		 */
+		queue->queue_array++;
+		free(queue->queue_array, M_CAMQ);
+	}
+}
+
+u_int32_t
+camq_resize(struct camq *queue, int new_size)
+{
+	cam_pinfo **new_array;
+
+	KASSERT(new_size >= queue->entries, ("camq_resize: "
+	    "New queue size can't accommodate queued entries (%d < %d).",
+	    new_size, queue->entries));
+	new_array = (cam_pinfo **)malloc(new_size * sizeof(cam_pinfo *),
+					 M_CAMQ, M_NOWAIT);
+	if (new_array == NULL) {
+		/* Couldn't satisfy request */
+		return (CAM_RESRC_UNAVAIL);
+	}
+	/*
+	 * Heap algorithms like everything numbered from 1, so
+	 * remember that our pointer into the heap array is offset
+	 * by one element.
+	 */
+	if (queue->queue_array != NULL) {
+		queue->queue_array++;
+		bcopy(queue->queue_array, new_array,
+		      queue->entries * sizeof(cam_pinfo *));
+		free(queue->queue_array, M_CAMQ);
+	}
+	queue->queue_array = new_array-1;
+	queue->array_size = new_size;
+	return (CAM_REQ_CMP);
+}
+
+/*
+ * camq_insert: Given an array of cam_pinfo* elememnts with
+ * the Heap(1, num_elements) property and array_size - num_elements >= 1,
+ * output Heap(1, num_elements+1) including new_entry in the array.
+ */
+void
+camq_insert(struct camq *queue, cam_pinfo *new_entry)
+{
+
+	KASSERT(queue->entries < queue->array_size,
+	    ("camq_insert: Attempt to insert into a full queue (%d >= %d)",
+	    queue->entries, queue->array_size));
+	queue->entries++;
+	queue->queue_array[queue->entries] = new_entry;
+	new_entry->index = queue->entries;
+	if (queue->entries != 0)
+		heap_up(queue->queue_array, queue->entries);
+}
+
+/*
+ * camq_remove:  Given an array of cam_pinfo* elevements with the
+ * Heap(1, num_elements) property and an index such that 1 <= index <=
+ * num_elements, remove that entry and restore the Heap(1, num_elements-1)
+ * property.
+ */
+cam_pinfo *
+camq_remove(struct camq *queue, int index)
+{
+	cam_pinfo *removed_entry;
+
+	if (index <= 0 || index > queue->entries)
+		panic("%s: Attempt to remove out-of-bounds index %d "
+		    "from queue %p of size %d", __func__, index, queue,
+		    queue->entries);
+
+	removed_entry = queue->queue_array[index];
+	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 - 1);
+	}
+	removed_entry->index = CAM_UNQUEUED_INDEX;
+	queue->entries--;
+	return (removed_entry);
+}
+
+/*
+ * camq_change_priority:  Given an array of cam_pinfo* elements with the
+ * Heap(1, num_entries) property, an index such that 1 <= index <= num_elements,
+ * and a 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_CAMDEVQ, 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_CAMDEVQ);
+		return (NULL);
+	}
+	return (devq);
+}
+
+int
+cam_devq_init(struct cam_devq *devq, int devices, int openings)
+{
+
+	bzero(devq, sizeof(*devq));
+	mtx_init(&devq->send_mtx, "CAM queue lock", NULL, MTX_DEF);
+	if (camq_init(&devq->send_queue, devices) != 0)
+		return (1);
+	devq->send_openings = openings;
+	devq->send_active = 0;
+	return (0);
+}
+
+void
+cam_devq_free(struct cam_devq *devq)
+{
+
+	camq_fini(&devq->send_queue);
+	mtx_destroy(&devq->send_mtx);
+	free(devq, M_CAMDEVQ);
+}
+
+u_int32_t
+cam_devq_resize(struct cam_devq *camq, int devices)
+{
+	u_int32_t retval;
+
+	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_CAMCCBQ, M_NOWAIT);
+	if (ccbq == NULL) {
+		printf("cam_ccbq_alloc: - cannot malloc!\n");
+		return (NULL);
+	}
+	if (cam_ccbq_init(ccbq, openings) != 0) {
+		free(ccbq, M_CAMCCBQ);
+		return (NULL);		
+	}
+
+	return (ccbq);
+}
+
+void
+cam_ccbq_free(struct cam_ccbq *ccbq)
+{
+	if (ccbq) {
+		cam_ccbq_fini(ccbq);
+		free(ccbq, M_CAMCCBQ);
+	}
+}
+
+u_int32_t
+cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size)
+{
+	int delta;
+
+	delta = new_size - (ccbq->dev_active + ccbq->dev_openings);
+	ccbq->total_openings += delta;
+	ccbq->dev_openings += delta;
+
+	new_size = imax(64, 1 << fls(new_size + new_size / 2));
+	if (new_size > ccbq->queue.array_size)
+		return (camq_resize(&ccbq->queue, new_size));
+	else
+		return (CAM_REQ_CMP);
+}
+
+int
+cam_ccbq_init(struct cam_ccbq *ccbq, int openings)
+{
+	bzero(ccbq, sizeof(*ccbq));
+	if (camq_init(&ccbq->queue,
+	    imax(64, 1 << fls(openings + openings / 2))) != 0)
+		return (1);
+	ccbq->total_openings = openings;
+	ccbq->dev_openings = openings;
+	return (0);
+}
+
+void
+cam_ccbq_fini(struct cam_ccbq *ccbq)
+{
+
+	camq_fini(&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(1, new_index-1) property and a new element in location
+ * new_index, output Heap(1, new_index).
+ */
+static void
+heap_up(cam_pinfo **queue_array, int new_index)
+{
+	int child;
+	int parent;
+
+	child = new_index;
+
+	while (child != 1) {
+		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(index + 1, num_entries) property with index containing
+ * an unsorted entry, output Heap(index, num_entries).
+ */
+static void
+heap_down(cam_pinfo **queue_array, int index, int num_entries)
+{
+	int child;
+	int parent;
+
+	parent = index;
+	child = parent << 1;
+	for (; child <= num_entries; child = parent << 1) {
+		if (child < 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;
+	}
+}