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 devq_openings; 66 int dev_openings; 67 int dev_active; 68 int held; 69 }; 70 71 struct cam_ed; 72 73 struct cam_devq { 74 struct mtx send_mtx; 75 struct camq send_queue; 76 int send_openings; 77 int send_active; 78 }; 79 80 81 struct cam_devq *cam_devq_alloc(int devices, int openings); 82 83 int cam_devq_init(struct cam_devq *devq, int devices, 84 int openings); 85 86 void cam_devq_free(struct cam_devq *devq); 87 88 u_int32_t cam_devq_resize(struct cam_devq *camq, int openings); 89 90 /* 91 * Allocate a cam_ccb_queue structure and initialize it. 92 */ 93 struct cam_ccbq *cam_ccbq_alloc(int openings); 94 95 u_int32_t cam_ccbq_resize(struct cam_ccbq *ccbq, int devices); 96 97 int cam_ccbq_init(struct cam_ccbq *ccbq, int openings); 98 99 void cam_ccbq_free(struct cam_ccbq *ccbq); 100 101 void cam_ccbq_fini(struct cam_ccbq *ccbq); 102 103 /* 104 * Allocate and initialize a cam_queue structure. 105 */ 106 struct camq *camq_alloc(int size); 107 108 /* 109 * Resize a cam queue 110 */ 111 u_int32_t camq_resize(struct camq *queue, int new_size); 112 113 /* 114 * Initialize a camq structure. Return 0 on success, 1 on failure. 115 */ 116 int camq_init(struct camq *camq, int size); 117 118 /* 119 * Free a cam_queue structure. This should only be called if a controller 120 * driver failes somehow during its attach routine or is unloaded and has 121 * obtained a cam_queue structure. 122 */ 123 void camq_free(struct camq *queue); 124 125 /* 126 * Finialize any internal storage or state of a cam_queue. 127 */ 128 void camq_fini(struct camq *queue); 129 130 /* 131 * cam_queue_insert: Given a CAM queue with at least one open spot, 132 * insert the new entry maintaining order. 133 */ 134 void camq_insert(struct camq *queue, cam_pinfo *new_entry); 135 136 /* 137 * camq_remove: Remove and arbitrary entry from the queue maintaining 138 * queue order. 139 */ 140 cam_pinfo *camq_remove(struct camq *queue, int index); 141 #define CAMQ_HEAD 1 /* Head of queue index */ 142 143 /* Index the first element in the heap */ 144 #define CAMQ_GET_HEAD(camq) ((camq)->queue_array[CAMQ_HEAD]) 145 146 /* Get the first element priority. */ 147 #define CAMQ_GET_PRIO(camq) (((camq)->entries > 0) ? \ 148 ((camq)->queue_array[CAMQ_HEAD]->priority) : 0) 149 150 /* 151 * camq_change_priority: Raise or lower the priority of an entry 152 * maintaining queue order. 153 */ 154 void camq_change_priority(struct camq *queue, int index, 155 u_int32_t new_priority); 156 157 static __inline int 158 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq); 159 160 static __inline void 161 cam_ccbq_take_opening(struct cam_ccbq *ccbq); 162 163 static __inline void 164 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb); 165 166 static __inline void 167 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb); 168 169 static __inline union ccb * 170 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index); 171 172 static __inline void 173 cam_ccbq_send_ccb(struct cam_ccbq *queue, union ccb *send_ccb); 174 175 static __inline void 176 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb); 177 178 static __inline void 179 cam_ccbq_release_opening(struct cam_ccbq *ccbq); 180 181 182 static __inline int 183 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq) 184 { 185 return (ccbq->queue.entries + ccbq->queue_extra_entries); 186 } 187 188 static __inline void 189 cam_ccbq_take_opening(struct cam_ccbq *ccbq) 190 { 191 ccbq->devq_openings--; 192 ccbq->held++; 193 } 194 195 static __inline void 196 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb) 197 { 198 struct ccb_hdr *old_ccb; 199 struct camq *queue = &ccbq->queue; 200 201 ccbq->held--; 202 203 /* 204 * If queue is already full, try to resize. 205 * If resize fail, push CCB with lowest priority out to the TAILQ. 206 */ 207 if (queue->entries == queue->array_size && 208 camq_resize(&ccbq->queue, queue->array_size * 2) != CAM_REQ_CMP) { 209 old_ccb = (struct ccb_hdr *)camq_remove(queue, queue->entries); 210 TAILQ_INSERT_HEAD(&ccbq->queue_extra_head, old_ccb, 211 xpt_links.tqe); 212 old_ccb->pinfo.index = CAM_EXTRAQ_INDEX; 213 ccbq->queue_extra_entries++; 214 } 215 216 camq_insert(queue, &new_ccb->ccb_h.pinfo); 217 } 218 219 static __inline void 220 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb) 221 { 222 struct ccb_hdr *cccb, *bccb; 223 struct camq *queue = &ccbq->queue; 224 225 /* If the CCB is on the TAILQ, remove it from there. */ 226 if (ccb->ccb_h.pinfo.index == CAM_EXTRAQ_INDEX) { 227 TAILQ_REMOVE(&ccbq->queue_extra_head, &ccb->ccb_h, 228 xpt_links.tqe); 229 ccb->ccb_h.pinfo.index = CAM_UNQUEUED_INDEX; 230 ccbq->queue_extra_entries--; 231 return; 232 } 233 234 camq_remove(queue, ccb->ccb_h.pinfo.index); 235 236 /* 237 * If there are some CCBs on TAILQ, find the best one and move it 238 * to the emptied space in the queue. 239 */ 240 bccb = TAILQ_FIRST(&ccbq->queue_extra_head); 241 if (bccb == NULL) 242 return; 243 TAILQ_FOREACH(cccb, &ccbq->queue_extra_head, xpt_links.tqe) { 244 if (bccb->pinfo.priority > cccb->pinfo.priority || 245 (bccb->pinfo.priority == cccb->pinfo.priority && 246 GENERATIONCMP(bccb->pinfo.generation, >, 247 cccb->pinfo.generation))) 248 bccb = cccb; 249 } 250 TAILQ_REMOVE(&ccbq->queue_extra_head, bccb, xpt_links.tqe); 251 ccbq->queue_extra_entries--; 252 camq_insert(queue, &bccb->pinfo); 253 } 254 255 static __inline union ccb * 256 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index) 257 { 258 return((union ccb *)ccbq->queue.queue_array[index]); 259 } 260 261 static __inline void 262 cam_ccbq_send_ccb(struct cam_ccbq *ccbq, union ccb *send_ccb) 263 { 264 265 send_ccb->ccb_h.pinfo.index = CAM_ACTIVE_INDEX; 266 ccbq->dev_active++; 267 ccbq->dev_openings--; 268 } 269 270 static __inline void 271 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb) 272 { 273 274 ccbq->dev_active--; 275 ccbq->dev_openings++; 276 ccbq->held++; 277 } 278 279 static __inline void 280 cam_ccbq_release_opening(struct cam_ccbq *ccbq) 281 { 282 ccbq->held--; 283 ccbq->devq_openings++; 284 } 285 286 #endif /* _KERNEL */ 287 #endif /* _CAM_CAM_QUEUE_H */ 288