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 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 * Resize a cam queue 105 */ 106 u_int32_t camq_resize(struct camq *queue, int new_size); 107 108 /* 109 * Initialize a camq structure. Return 0 on success, 1 on failure. 110 */ 111 int camq_init(struct camq *camq, int size); 112 113 /* 114 * Finialize any internal storage or state of a cam_queue. 115 */ 116 void camq_fini(struct camq *queue); 117 118 /* 119 * cam_queue_insert: Given a CAM queue with at least one open spot, 120 * insert the new entry maintaining order. 121 */ 122 void camq_insert(struct camq *queue, cam_pinfo *new_entry); 123 124 /* 125 * camq_remove: Remove and arbitrary entry from the queue maintaining 126 * queue order. 127 */ 128 cam_pinfo *camq_remove(struct camq *queue, int index); 129 #define CAMQ_HEAD 1 /* Head of queue index */ 130 131 /* Index the first element in the heap */ 132 #define CAMQ_GET_HEAD(camq) ((camq)->queue_array[CAMQ_HEAD]) 133 134 /* Get the first element priority. */ 135 #define CAMQ_GET_PRIO(camq) (((camq)->entries > 0) ? \ 136 ((camq)->queue_array[CAMQ_HEAD]->priority) : 0) 137 138 /* 139 * camq_change_priority: Raise or lower the priority of an entry 140 * maintaining queue order. 141 */ 142 void camq_change_priority(struct camq *queue, int index, 143 u_int32_t new_priority); 144 145 static __inline int 146 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq); 147 148 static __inline void 149 cam_ccbq_take_opening(struct cam_ccbq *ccbq); 150 151 static __inline void 152 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb); 153 154 static __inline void 155 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb); 156 157 static __inline union ccb * 158 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index); 159 160 static __inline void 161 cam_ccbq_send_ccb(struct cam_ccbq *queue, union ccb *send_ccb); 162 163 static __inline void 164 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb); 165 166 static __inline void 167 cam_ccbq_release_opening(struct cam_ccbq *ccbq); 168 169 static __inline int 170 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq) 171 { 172 return (ccbq->queue.entries + ccbq->queue_extra_entries); 173 } 174 175 static __inline void 176 cam_ccbq_take_opening(struct cam_ccbq *ccbq) 177 { 178 179 ccbq->allocated++; 180 } 181 182 static __inline void 183 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb) 184 { 185 struct ccb_hdr *old_ccb; 186 struct camq *queue = &ccbq->queue; 187 188 KASSERT((new_ccb->ccb_h.func_code & XPT_FC_QUEUED) != 0 && 189 (new_ccb->ccb_h.func_code & XPT_FC_USER_CCB) == 0, 190 ("%s: Cannot queue ccb %p func_code %#x", __func__, new_ccb, 191 new_ccb->ccb_h.func_code)); 192 193 /* 194 * If queue is already full, try to resize. 195 * If resize fail, push CCB with lowest priority out to the TAILQ. 196 */ 197 if (queue->entries == queue->array_size && 198 camq_resize(&ccbq->queue, queue->array_size * 2) != CAM_REQ_CMP) { 199 old_ccb = (struct ccb_hdr *)camq_remove(queue, queue->entries); 200 TAILQ_INSERT_HEAD(&ccbq->queue_extra_head, old_ccb, 201 xpt_links.tqe); 202 old_ccb->pinfo.index = CAM_EXTRAQ_INDEX; 203 ccbq->queue_extra_entries++; 204 } 205 206 camq_insert(queue, &new_ccb->ccb_h.pinfo); 207 } 208 209 static __inline void 210 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb) 211 { 212 struct ccb_hdr *cccb, *bccb; 213 struct camq *queue = &ccbq->queue; 214 cam_pinfo *removed_entry __unused; 215 216 /* If the CCB is on the TAILQ, remove it from there. */ 217 if (ccb->ccb_h.pinfo.index == CAM_EXTRAQ_INDEX) { 218 TAILQ_REMOVE(&ccbq->queue_extra_head, &ccb->ccb_h, 219 xpt_links.tqe); 220 ccb->ccb_h.pinfo.index = CAM_UNQUEUED_INDEX; 221 ccbq->queue_extra_entries--; 222 return; 223 } 224 225 removed_entry = camq_remove(queue, ccb->ccb_h.pinfo.index); 226 KASSERT(removed_entry == &ccb->ccb_h.pinfo, 227 ("%s: Removed wrong entry from queue (%p != %p)", __func__, 228 removed_entry, &ccb->ccb_h.pinfo)); 229 230 /* 231 * If there are some CCBs on TAILQ, find the best one and move it 232 * to the emptied space in the queue. 233 */ 234 bccb = TAILQ_FIRST(&ccbq->queue_extra_head); 235 if (bccb == NULL) 236 return; 237 TAILQ_FOREACH(cccb, &ccbq->queue_extra_head, xpt_links.tqe) { 238 if (bccb->pinfo.priority > cccb->pinfo.priority || 239 (bccb->pinfo.priority == cccb->pinfo.priority && 240 GENERATIONCMP(bccb->pinfo.generation, >, 241 cccb->pinfo.generation))) 242 bccb = cccb; 243 } 244 TAILQ_REMOVE(&ccbq->queue_extra_head, bccb, xpt_links.tqe); 245 ccbq->queue_extra_entries--; 246 camq_insert(queue, &bccb->pinfo); 247 } 248 249 static __inline union ccb * 250 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index) 251 { 252 return((union ccb *)ccbq->queue.queue_array[index]); 253 } 254 255 static __inline void 256 cam_ccbq_send_ccb(struct cam_ccbq *ccbq, union ccb *send_ccb) 257 { 258 259 send_ccb->ccb_h.pinfo.index = CAM_ACTIVE_INDEX; 260 ccbq->dev_active++; 261 ccbq->dev_openings--; 262 } 263 264 static __inline void 265 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb) 266 { 267 268 ccbq->dev_active--; 269 ccbq->dev_openings++; 270 } 271 272 static __inline void 273 cam_ccbq_release_opening(struct cam_ccbq *ccbq) 274 { 275 276 ccbq->allocated--; 277 } 278 279 #endif /* _KERNEL */ 280 #endif /* _CAM_CAM_QUEUE_H */ 281