FreeBSD/Linux Kernel Cross Reference
sys/cam/cam_queue.h
1 /*-
2 * CAM request queue management definitions.
3 *
4 * Copyright (c) 1997 Justin T. Gibbs.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions, and the following disclaimer,
12 * without modification, immediately at the beginning of the file.
13 * 2. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD: src/sys/cam/cam_queue.h,v 1.9 2005/01/05 22:34:34 imp Exp $
29 */
30
31 #ifndef _CAM_CAM_QUEUE_H
32 #define _CAM_CAM_QUEUE_H 1
33
34 #ifdef _KERNEL
35
36 #include <sys/queue.h>
37
38 /*
39 * This structure implements a heap based priority queue. The queue
40 * assumes that the objects stored in it begin with a cam_qentry
41 * structure holding the priority information used to sort the objects.
42 * This structure is opaque to clients (outside of the XPT layer) to allow
43 * the implementation to change without affecting them.
44 */
45 struct camq {
46 cam_pinfo **queue_array;
47 int array_size;
48 int entries;
49 u_int32_t generation;
50 u_int32_t qfrozen_cnt;
51 };
52
53 TAILQ_HEAD(ccb_hdr_tailq, ccb_hdr);
54 LIST_HEAD(ccb_hdr_list, ccb_hdr);
55 SLIST_HEAD(ccb_hdr_slist, ccb_hdr);
56
57 struct cam_ccbq {
58 struct camq queue;
59 int devq_openings;
60 int dev_openings;
61 int dev_active;
62 int held;
63 struct ccb_hdr_tailq active_ccbs;
64 };
65
66 struct cam_ed;
67
68 struct cam_devq {
69 struct camq alloc_queue;
70 struct camq send_queue;
71 struct cam_ed *active_dev;
72 int alloc_openings;
73 int alloc_active;
74 int send_openings;
75 int send_active;
76 };
77
78
79 struct cam_devq *cam_devq_alloc(int devices, int openings);
80
81 int cam_devq_init(struct cam_devq *devq, int devices,
82 int openings);
83
84 void cam_devq_free(struct cam_devq *devq);
85
86 u_int32_t cam_devq_resize(struct cam_devq *camq, int openings);
87
88 /*
89 * Allocate a cam_ccb_queue structure and initialize it.
90 */
91 struct cam_ccbq *cam_ccbq_alloc(int openings);
92
93 u_int32_t cam_ccbq_resize(struct cam_ccbq *ccbq, int devices);
94
95 int cam_ccbq_init(struct cam_ccbq *ccbq, int openings);
96
97 void cam_ccbq_free(struct cam_ccbq *ccbq);
98
99 void cam_ccbq_fini(struct cam_ccbq *ccbq);
100
101 /*
102 * Allocate and initialize a cam_queue structure.
103 */
104 struct camq *camq_alloc(int size);
105
106 /*
107 * Resize a cam queue
108 */
109 u_int32_t camq_resize(struct camq *queue, int new_size);
110
111 /*
112 * Initialize a camq structure. Return 0 on success, 1 on failure.
113 */
114 int camq_init(struct camq *camq, int size);
115
116 /*
117 * Free a cam_queue structure. This should only be called if a controller
118 * driver failes somehow during its attach routine or is unloaded and has
119 * obtained a cam_queue structure.
120 */
121 void camq_free(struct camq *queue);
122
123 /*
124 * Finialize any internal storage or state of a cam_queue.
125 */
126 void camq_fini(struct camq *queue);
127
128 /*
129 * cam_queue_insert: Given a CAM queue with at least one open spot,
130 * insert the new entry maintaining order.
131 */
132 void camq_insert(struct camq *queue, cam_pinfo *new_entry);
133
134 /*
135 * camq_remove: Remove and arbitrary entry from the queue maintaining
136 * queue order.
137 */
138 cam_pinfo *camq_remove(struct camq *queue, int index);
139 #define CAMQ_HEAD 1 /* Head of queue index */
140
141 /* Index the first element in the heap */
142 #define CAMQ_GET_HEAD(camq) ((camq)->queue_array[CAMQ_HEAD])
143
144 /*
145 * camq_change_priority: Raise or lower the priority of an entry
146 * maintaining queue order.
147 */
148 void camq_change_priority(struct camq *queue, int index,
149 u_int32_t new_priority);
150
151 static __inline int
152 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq);
153
154 static __inline void
155 cam_ccbq_take_opening(struct cam_ccbq *ccbq);
156
157 static __inline void
158 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb);
159
160 static __inline void
161 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb);
162
163 static __inline union ccb *
164 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index);
165
166 static __inline void
167 cam_ccbq_send_ccb(struct cam_ccbq *queue, union ccb *send_ccb);
168
169 static __inline void
170 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb);
171
172 static __inline void
173 cam_ccbq_release_opening(struct cam_ccbq *ccbq);
174
175
176 static __inline int
177 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq)
178 {
179 return (ccbq->queue.entries);
180 }
181
182 static __inline void
183 cam_ccbq_take_opening(struct cam_ccbq *ccbq)
184 {
185 ccbq->devq_openings--;
186 ccbq->held++;
187 }
188
189 static __inline void
190 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb)
191 {
192 ccbq->held--;
193 camq_insert(&ccbq->queue, &new_ccb->ccb_h.pinfo);
194 }
195
196 static __inline void
197 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb)
198 {
199 camq_remove(&ccbq->queue, ccb->ccb_h.pinfo.index);
200 }
201
202 static __inline union ccb *
203 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index)
204 {
205 return((union ccb *)ccbq->queue.queue_array[index]);
206 }
207
208 static __inline void
209 cam_ccbq_send_ccb(struct cam_ccbq *ccbq, union ccb *send_ccb)
210 {
211
212 TAILQ_INSERT_TAIL(&ccbq->active_ccbs,
213 &(send_ccb->ccb_h),
214 xpt_links.tqe);
215 send_ccb->ccb_h.pinfo.index = CAM_ACTIVE_INDEX;
216 ccbq->dev_active++;
217 ccbq->dev_openings--;
218 }
219
220 static __inline void
221 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb)
222 {
223 TAILQ_REMOVE(&ccbq->active_ccbs, &done_ccb->ccb_h,
224 xpt_links.tqe);
225 ccbq->dev_active--;
226 ccbq->dev_openings++;
227 ccbq->held++;
228 }
229
230 static __inline void
231 cam_ccbq_release_opening(struct cam_ccbq *ccbq)
232 {
233 ccbq->held--;
234 ccbq->devq_openings++;
235 }
236
237 #endif /* _KERNEL */
238 #endif /* _CAM_CAM_QUEUE_H */
239
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