1 /*- 2 * CAM request queue management definitions. 3 * 4 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 5 * 6 * Copyright (c) 1997 Justin T. Gibbs. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions, and the following disclaimer, 14 * without modification, immediately at the beginning of the file. 15 * 2. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 22 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * $FreeBSD$ 31 */ 32 33 #ifndef _CAM_CAM_QUEUE_H 34 #define _CAM_CAM_QUEUE_H 1 35 36 #ifdef _KERNEL 37 38 #include <sys/lock.h> 39 #include <sys/mutex.h> 40 #include <sys/queue.h> 41 #include <cam/cam.h> 42 43 /* 44 * This structure implements a heap based priority queue. The queue 45 * assumes that the objects stored in it begin with a cam_qentry 46 * structure holding the priority information used to sort the objects. 47 * This structure is opaque to clients (outside of the XPT layer) to allow 48 * the implementation to change without affecting them. 49 */ 50 struct camq { 51 cam_pinfo **queue_array; 52 int array_size; 53 int entries; 54 u_int32_t generation; 55 u_int32_t qfrozen_cnt; 56 }; 57 58 TAILQ_HEAD(ccb_hdr_tailq, ccb_hdr); 59 LIST_HEAD(ccb_hdr_list, ccb_hdr); 60 SLIST_HEAD(ccb_hdr_slist, ccb_hdr); 61 62 struct cam_ccbq { 63 struct camq queue; 64 struct ccb_hdr_tailq queue_extra_head; 65 int queue_extra_entries; 66 int total_openings; 67 int allocated; 68 int dev_openings; 69 int dev_active; 70 }; 71 72 struct cam_ed; 73 74 struct cam_devq { 75 struct mtx send_mtx; 76 struct camq send_queue; 77 int send_openings; 78 int send_active; 79 }; 80 81 82 struct cam_devq *cam_devq_alloc(int devices, int openings); 83 84 int cam_devq_init(struct cam_devq *devq, int devices, 85 int openings); 86 87 void cam_devq_free(struct cam_devq *devq); 88 89 u_int32_t cam_devq_resize(struct cam_devq *camq, int openings); 90 91 /* 92 * Allocate a cam_ccb_queue structure and initialize it. 93 */ 94 struct cam_ccbq *cam_ccbq_alloc(int openings); 95 96 u_int32_t cam_ccbq_resize(struct cam_ccbq *ccbq, int devices); 97 98 int cam_ccbq_init(struct cam_ccbq *ccbq, int openings); 99 100 void cam_ccbq_free(struct cam_ccbq *ccbq); 101 102 void cam_ccbq_fini(struct cam_ccbq *ccbq); 103 104 /* 105 * Resize a cam queue 106 */ 107 u_int32_t camq_resize(struct camq *queue, int new_size); 108 109 /* 110 * Initialize a camq structure. Return 0 on success, 1 on failure. 111 */ 112 int camq_init(struct camq *camq, int size); 113 114 /* 115 * Finialize any internal storage or state of a cam_queue. 116 */ 117 void camq_fini(struct camq *queue); 118 119 /* 120 * cam_queue_insert: Given a CAM queue with at least one open spot, 121 * insert the new entry maintaining order. 122 */ 123 void camq_insert(struct camq *queue, cam_pinfo *new_entry); 124 125 /* 126 * camq_remove: Remove and arbitrary entry from the queue maintaining 127 * queue order. 128 */ 129 cam_pinfo *camq_remove(struct camq *queue, int index); 130 #define CAMQ_HEAD 1 /* Head of queue index */ 131 132 /* Index the first element in the heap */ 133 #define CAMQ_GET_HEAD(camq) ((camq)->queue_array[CAMQ_HEAD]) 134 135 /* Get the first element priority. */ 136 #define CAMQ_GET_PRIO(camq) (((camq)->entries > 0) ? \ 137 ((camq)->queue_array[CAMQ_HEAD]->priority) : 0) 138 139 /* 140 * camq_change_priority: Raise or lower the priority of an entry 141 * maintaining queue order. 142 */ 143 void camq_change_priority(struct camq *queue, int index, 144 u_int32_t new_priority); 145 146 static __inline int 147 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq); 148 149 static __inline void 150 cam_ccbq_take_opening(struct cam_ccbq *ccbq); 151 152 static __inline void 153 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb); 154 155 static __inline void 156 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb); 157 158 static __inline union ccb * 159 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index); 160 161 static __inline void 162 cam_ccbq_send_ccb(struct cam_ccbq *queue, union ccb *send_ccb); 163 164 static __inline void 165 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb); 166 167 static __inline void 168 cam_ccbq_release_opening(struct cam_ccbq *ccbq); 169 170 171 static __inline int 172 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq) 173 { 174 return (ccbq->queue.entries + ccbq->queue_extra_entries); 175 } 176 177 static __inline void 178 cam_ccbq_take_opening(struct cam_ccbq *ccbq) 179 { 180 181 ccbq->allocated++; 182 } 183 184 static __inline void 185 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb) 186 { 187 struct ccb_hdr *old_ccb; 188 struct camq *queue = &ccbq->queue; 189 190 KASSERT((new_ccb->ccb_h.func_code & XPT_FC_QUEUED) != 0 && 191 (new_ccb->ccb_h.func_code & XPT_FC_USER_CCB) == 0, 192 ("%s: Cannot queue ccb %p func_code %#x", __func__, new_ccb, 193 new_ccb->ccb_h.func_code)); 194 195 /* 196 * If queue is already full, try to resize. 197 * If resize fail, push CCB with lowest priority out to the TAILQ. 198 */ 199 if (queue->entries == queue->array_size && 200 camq_resize(&ccbq->queue, queue->array_size * 2) != CAM_REQ_CMP) { 201 old_ccb = (struct ccb_hdr *)camq_remove(queue, queue->entries); 202 TAILQ_INSERT_HEAD(&ccbq->queue_extra_head, old_ccb, 203 xpt_links.tqe); 204 old_ccb->pinfo.index = CAM_EXTRAQ_INDEX; 205 ccbq->queue_extra_entries++; 206 } 207 208 camq_insert(queue, &new_ccb->ccb_h.pinfo); 209 } 210 211 static __inline void 212 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb) 213 { 214 struct ccb_hdr *cccb, *bccb; 215 struct camq *queue = &ccbq->queue; 216 cam_pinfo *removed_entry __unused; 217 218 /* If the CCB is on the TAILQ, remove it from there. */ 219 if (ccb->ccb_h.pinfo.index == CAM_EXTRAQ_INDEX) { 220 TAILQ_REMOVE(&ccbq->queue_extra_head, &ccb->ccb_h, 221 xpt_links.tqe); 222 ccb->ccb_h.pinfo.index = CAM_UNQUEUED_INDEX; 223 ccbq->queue_extra_entries--; 224 return; 225 } 226 227 removed_entry = camq_remove(queue, ccb->ccb_h.pinfo.index); 228 KASSERT(removed_entry == &ccb->ccb_h.pinfo, 229 ("%s: Removed wrong entry from queue (%p != %p)", __func__, 230 removed_entry, &ccb->ccb_h.pinfo)); 231 232 /* 233 * If there are some CCBs on TAILQ, find the best one and move it 234 * to the emptied space in the queue. 235 */ 236 bccb = TAILQ_FIRST(&ccbq->queue_extra_head); 237 if (bccb == NULL) 238 return; 239 TAILQ_FOREACH(cccb, &ccbq->queue_extra_head, xpt_links.tqe) { 240 if (bccb->pinfo.priority > cccb->pinfo.priority || 241 (bccb->pinfo.priority == cccb->pinfo.priority && 242 GENERATIONCMP(bccb->pinfo.generation, >, 243 cccb->pinfo.generation))) 244 bccb = cccb; 245 } 246 TAILQ_REMOVE(&ccbq->queue_extra_head, bccb, xpt_links.tqe); 247 ccbq->queue_extra_entries--; 248 camq_insert(queue, &bccb->pinfo); 249 } 250 251 static __inline union ccb * 252 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index) 253 { 254 return((union ccb *)ccbq->queue.queue_array[index]); 255 } 256 257 static __inline void 258 cam_ccbq_send_ccb(struct cam_ccbq *ccbq, union ccb *send_ccb) 259 { 260 261 send_ccb->ccb_h.pinfo.index = CAM_ACTIVE_INDEX; 262 ccbq->dev_active++; 263 ccbq->dev_openings--; 264 } 265 266 static __inline void 267 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb) 268 { 269 270 ccbq->dev_active--; 271 ccbq->dev_openings++; 272 } 273 274 static __inline void 275 cam_ccbq_release_opening(struct cam_ccbq *ccbq) 276 { 277 278 ccbq->allocated--; 279 } 280 281 #endif /* _KERNEL */ 282 #endif /* _CAM_CAM_QUEUE_H */ 283