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 * $FreeBSD$ 29 */ 30 31 #ifndef _CAM_CAM_QUEUE_H 32 #define _CAM_CAM_QUEUE_H 1 33 34 #ifdef _KERNEL 35 36 #include <sys/lock.h> 37 #include <sys/mutex.h> 38 #include <sys/queue.h> 39 #include <cam/cam.h> 40 41 /* 42 * This structure implements a heap based priority queue. The queue 43 * assumes that the objects stored in it begin with a cam_qentry 44 * structure holding the priority information used to sort the objects. 45 * This structure is opaque to clients (outside of the XPT layer) to allow 46 * the implementation to change without affecting them. 47 */ 48 struct camq { 49 cam_pinfo **queue_array; 50 int array_size; 51 int entries; 52 u_int32_t generation; 53 u_int32_t qfrozen_cnt; 54 }; 55 56 TAILQ_HEAD(ccb_hdr_tailq, ccb_hdr); 57 LIST_HEAD(ccb_hdr_list, ccb_hdr); 58 SLIST_HEAD(ccb_hdr_slist, ccb_hdr); 59 60 struct cam_ccbq { 61 struct camq queue; 62 struct ccb_hdr_tailq queue_extra_head; 63 int queue_extra_entries; 64 int total_openings; 65 int allocated; 66 int dev_openings; 67 int dev_active; 68 }; 69 70 struct cam_ed; 71 72 struct cam_devq { 73 struct mtx send_mtx; 74 struct camq send_queue; 75 int send_openings; 76 int send_active; 77 }; 78 79 80 struct cam_devq *cam_devq_alloc(int devices, int openings); 81 82 int cam_devq_init(struct cam_devq *devq, int devices, 83 int openings); 84 85 void cam_devq_free(struct cam_devq *devq); 86 87 u_int32_t cam_devq_resize(struct cam_devq *camq, int openings); 88 89 /* 90 * Allocate a cam_ccb_queue structure and initialize it. 91 */ 92 struct cam_ccbq *cam_ccbq_alloc(int openings); 93 94 u_int32_t cam_ccbq_resize(struct cam_ccbq *ccbq, int devices); 95 96 int cam_ccbq_init(struct cam_ccbq *ccbq, int openings); 97 98 void cam_ccbq_free(struct cam_ccbq *ccbq); 99 100 void cam_ccbq_fini(struct cam_ccbq *ccbq); 101 102 /* 103 * Allocate and initialize a cam_queue structure. 104 */ 105 struct camq *camq_alloc(int size); 106 107 /* 108 * Resize a cam queue 109 */ 110 u_int32_t camq_resize(struct camq *queue, int new_size); 111 112 /* 113 * Initialize a camq structure. Return 0 on success, 1 on failure. 114 */ 115 int camq_init(struct camq *camq, int size); 116 117 /* 118 * Free a cam_queue structure. This should only be called if a controller 119 * driver failes somehow during its attach routine or is unloaded and has 120 * obtained a cam_queue structure. 121 */ 122 void camq_free(struct camq *queue); 123 124 /* 125 * Finialize any internal storage or state of a cam_queue. 126 */ 127 void camq_fini(struct camq *queue); 128 129 /* 130 * cam_queue_insert: Given a CAM queue with at least one open spot, 131 * insert the new entry maintaining order. 132 */ 133 void camq_insert(struct camq *queue, cam_pinfo *new_entry); 134 135 /* 136 * camq_remove: Remove and arbitrary entry from the queue maintaining 137 * queue order. 138 */ 139 cam_pinfo *camq_remove(struct camq *queue, int index); 140 #define CAMQ_HEAD 1 /* Head of queue index */ 141 142 /* Index the first element in the heap */ 143 #define CAMQ_GET_HEAD(camq) ((camq)->queue_array[CAMQ_HEAD]) 144 145 /* Get the first element priority. */ 146 #define CAMQ_GET_PRIO(camq) (((camq)->entries > 0) ? \ 147 ((camq)->queue_array[CAMQ_HEAD]->priority) : 0) 148 149 /* 150 * camq_change_priority: Raise or lower the priority of an entry 151 * maintaining queue order. 152 */ 153 void camq_change_priority(struct camq *queue, int index, 154 u_int32_t new_priority); 155 156 static __inline int 157 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq); 158 159 static __inline void 160 cam_ccbq_take_opening(struct cam_ccbq *ccbq); 161 162 static __inline void 163 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb); 164 165 static __inline void 166 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb); 167 168 static __inline union ccb * 169 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index); 170 171 static __inline void 172 cam_ccbq_send_ccb(struct cam_ccbq *queue, union ccb *send_ccb); 173 174 static __inline void 175 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb); 176 177 static __inline void 178 cam_ccbq_release_opening(struct cam_ccbq *ccbq); 179 180 181 static __inline int 182 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq) 183 { 184 return (ccbq->queue.entries + ccbq->queue_extra_entries); 185 } 186 187 static __inline void 188 cam_ccbq_take_opening(struct cam_ccbq *ccbq) 189 { 190 191 ccbq->allocated++; 192 } 193 194 static __inline void 195 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb) 196 { 197 struct ccb_hdr *old_ccb; 198 struct camq *queue = &ccbq->queue; 199 200 /* 201 * If queue is already full, try to resize. 202 * If resize fail, push CCB with lowest priority out to the TAILQ. 203 */ 204 if (queue->entries == queue->array_size && 205 camq_resize(&ccbq->queue, queue->array_size * 2) != CAM_REQ_CMP) { 206 old_ccb = (struct ccb_hdr *)camq_remove(queue, queue->entries); 207 TAILQ_INSERT_HEAD(&ccbq->queue_extra_head, old_ccb, 208 xpt_links.tqe); 209 old_ccb->pinfo.index = CAM_EXTRAQ_INDEX; 210 ccbq->queue_extra_entries++; 211 } 212 213 camq_insert(queue, &new_ccb->ccb_h.pinfo); 214 } 215 216 static __inline void 217 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb) 218 { 219 struct ccb_hdr *cccb, *bccb; 220 struct camq *queue = &ccbq->queue; 221 222 /* If the CCB is on the TAILQ, remove it from there. */ 223 if (ccb->ccb_h.pinfo.index == CAM_EXTRAQ_INDEX) { 224 TAILQ_REMOVE(&ccbq->queue_extra_head, &ccb->ccb_h, 225 xpt_links.tqe); 226 ccb->ccb_h.pinfo.index = CAM_UNQUEUED_INDEX; 227 ccbq->queue_extra_entries--; 228 return; 229 } 230 231 camq_remove(queue, ccb->ccb_h.pinfo.index); 232 233 /* 234 * If there are some CCBs on TAILQ, find the best one and move it 235 * to the emptied space in the queue. 236 */ 237 bccb = TAILQ_FIRST(&ccbq->queue_extra_head); 238 if (bccb == NULL) 239 return; 240 TAILQ_FOREACH(cccb, &ccbq->queue_extra_head, xpt_links.tqe) { 241 if (bccb->pinfo.priority > cccb->pinfo.priority || 242 (bccb->pinfo.priority == cccb->pinfo.priority && 243 GENERATIONCMP(bccb->pinfo.generation, >, 244 cccb->pinfo.generation))) 245 bccb = cccb; 246 } 247 TAILQ_REMOVE(&ccbq->queue_extra_head, bccb, xpt_links.tqe); 248 ccbq->queue_extra_entries--; 249 camq_insert(queue, &bccb->pinfo); 250 } 251 252 static __inline union ccb * 253 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index) 254 { 255 return((union ccb *)ccbq->queue.queue_array[index]); 256 } 257 258 static __inline void 259 cam_ccbq_send_ccb(struct cam_ccbq *ccbq, union ccb *send_ccb) 260 { 261 262 send_ccb->ccb_h.pinfo.index = CAM_ACTIVE_INDEX; 263 ccbq->dev_active++; 264 ccbq->dev_openings--; 265 } 266 267 static __inline void 268 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb) 269 { 270 271 ccbq->dev_active--; 272 ccbq->dev_openings++; 273 } 274 275 static __inline void 276 cam_ccbq_release_opening(struct cam_ccbq *ccbq) 277 { 278 279 ccbq->allocated--; 280 } 281 282 #endif /* _KERNEL */ 283 #endif /* _CAM_CAM_QUEUE_H */ 284