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/queue.h> 37 #include <cam/cam.h> 38 39 /* 40 * This structure implements a heap based priority queue. The queue 41 * assumes that the objects stored in it begin with a cam_qentry 42 * structure holding the priority information used to sort the objects. 43 * This structure is opaque to clients (outside of the XPT layer) to allow 44 * the implementation to change without affecting them. 45 */ 46 struct camq { 47 cam_pinfo **queue_array; 48 int array_size; 49 int entries; 50 u_int32_t generation; 51 u_int32_t qfrozen_cnt[CAM_RL_VALUES]; 52 }; 53 54 TAILQ_HEAD(ccb_hdr_tailq, ccb_hdr); 55 LIST_HEAD(ccb_hdr_list, ccb_hdr); 56 SLIST_HEAD(ccb_hdr_slist, ccb_hdr); 57 58 struct cam_ccbq { 59 struct camq queue; 60 int devq_openings; 61 int dev_openings; 62 int dev_active; 63 int held; 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 /* Get the first element priority. */ 145 #define CAMQ_GET_PRIO(camq) (((camq)->entries > 0) ? \ 146 ((camq)->queue_array[CAMQ_HEAD]->priority) : 0) 147 148 /* 149 * camq_change_priority: Raise or lower the priority of an entry 150 * maintaining queue order. 151 */ 152 void camq_change_priority(struct camq *queue, int index, 153 u_int32_t new_priority); 154 155 static __inline int 156 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq); 157 158 static __inline void 159 cam_ccbq_take_opening(struct cam_ccbq *ccbq); 160 161 static __inline int 162 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb); 163 164 static __inline int 165 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb); 166 167 static __inline union ccb * 168 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index); 169 170 static __inline void 171 cam_ccbq_send_ccb(struct cam_ccbq *queue, union ccb *send_ccb); 172 173 static __inline void 174 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb); 175 176 static __inline void 177 cam_ccbq_release_opening(struct cam_ccbq *ccbq); 178 179 180 static __inline int 181 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq) 182 { 183 return (ccbq->queue.entries); 184 } 185 186 static __inline void 187 cam_ccbq_take_opening(struct cam_ccbq *ccbq) 188 { 189 ccbq->devq_openings--; 190 ccbq->held++; 191 } 192 193 static __inline int 194 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb) 195 { 196 ccbq->held--; 197 camq_insert(&ccbq->queue, &new_ccb->ccb_h.pinfo); 198 if (ccbq->queue.qfrozen_cnt[CAM_PRIORITY_TO_RL( 199 new_ccb->ccb_h.pinfo.priority)] > 0) { 200 ccbq->devq_openings++; 201 ccbq->held++; 202 return (1); 203 } else 204 return (0); 205 } 206 207 static __inline int 208 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb) 209 { 210 camq_remove(&ccbq->queue, ccb->ccb_h.pinfo.index); 211 if (ccbq->queue.qfrozen_cnt[CAM_PRIORITY_TO_RL( 212 ccb->ccb_h.pinfo.priority)] > 0) { 213 ccbq->devq_openings--; 214 ccbq->held--; 215 return (1); 216 } else 217 return (0); 218 } 219 220 static __inline union ccb * 221 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index) 222 { 223 return((union ccb *)ccbq->queue.queue_array[index]); 224 } 225 226 static __inline void 227 cam_ccbq_send_ccb(struct cam_ccbq *ccbq, union ccb *send_ccb) 228 { 229 230 send_ccb->ccb_h.pinfo.index = CAM_ACTIVE_INDEX; 231 ccbq->dev_active++; 232 ccbq->dev_openings--; 233 } 234 235 static __inline void 236 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb) 237 { 238 239 ccbq->dev_active--; 240 ccbq->dev_openings++; 241 ccbq->held++; 242 } 243 244 static __inline void 245 cam_ccbq_release_opening(struct cam_ccbq *ccbq) 246 { 247 ccbq->held--; 248 ccbq->devq_openings++; 249 } 250 251 static __inline int 252 cam_ccbq_freeze(struct cam_ccbq *ccbq, cam_rl rl, u_int32_t cnt) 253 { 254 int i, frozen = 0; 255 cam_rl p, n; 256 257 /* Find pevious run level. */ 258 for (p = 0; p < CAM_RL_VALUES && ccbq->queue.qfrozen_cnt[p] == 0; p++); 259 /* Find new run level. */ 260 n = min(rl, p); 261 /* Apply new run level. */ 262 for (i = rl; i < CAM_RL_VALUES; i++) 263 ccbq->queue.qfrozen_cnt[i] += cnt; 264 /* Update ccbq statistics. */ 265 if (n == p) 266 return (0); 267 for (i = CAMQ_HEAD; i <= ccbq->queue.entries; i++) { 268 cam_rl rrl = 269 CAM_PRIORITY_TO_RL(ccbq->queue.queue_array[i]->priority); 270 if (rrl < n) 271 continue; 272 if (rrl >= p) 273 break; 274 ccbq->devq_openings++; 275 ccbq->held++; 276 frozen++; 277 } 278 return (frozen); 279 } 280 281 static __inline int 282 cam_ccbq_release(struct cam_ccbq *ccbq, cam_rl rl, u_int32_t cnt) 283 { 284 int i, released = 0; 285 cam_rl p, n; 286 287 /* Apply new run level. */ 288 for (i = rl; i < CAM_RL_VALUES; i++) 289 ccbq->queue.qfrozen_cnt[i] -= cnt; 290 /* Find new run level. */ 291 for (n = 0; n < CAM_RL_VALUES && ccbq->queue.qfrozen_cnt[n] == 0; n++); 292 /* Find previous run level. */ 293 p = min(rl, n); 294 /* Update ccbq statistics. */ 295 if (n == p) 296 return (0); 297 for (i = CAMQ_HEAD; i <= ccbq->queue.entries; i++) { 298 cam_rl rrl = 299 CAM_PRIORITY_TO_RL(ccbq->queue.queue_array[i]->priority); 300 if (rrl < p) 301 continue; 302 if (rrl >= n) 303 break; 304 ccbq->devq_openings--; 305 ccbq->held--; 306 released++; 307 } 308 return (released); 309 } 310 311 static __inline u_int32_t 312 cam_ccbq_frozen(struct cam_ccbq *ccbq, cam_rl rl) 313 { 314 315 return (ccbq->queue.qfrozen_cnt[rl]); 316 } 317 318 static __inline u_int32_t 319 cam_ccbq_frozen_top(struct cam_ccbq *ccbq) 320 { 321 cam_rl rl; 322 323 rl = CAM_PRIORITY_TO_RL(CAMQ_GET_PRIO(&ccbq->queue)); 324 return (ccbq->queue.qfrozen_cnt[rl]); 325 } 326 327 #endif /* _KERNEL */ 328 #endif /* _CAM_CAM_QUEUE_H */ 329