1 /*- 2 * CAM request queue management functions. 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 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/types.h> 37 #include <sys/malloc.h> 38 #include <sys/kernel.h> 39 40 #include <cam/cam.h> 41 #include <cam/cam_ccb.h> 42 #include <cam/cam_queue.h> 43 #include <cam/cam_debug.h> 44 45 static MALLOC_DEFINE(M_CAMQ, "CAM queue", "CAM queue buffers"); 46 static MALLOC_DEFINE(M_CAMDEVQ, "CAM dev queue", "CAM dev queue buffers"); 47 static MALLOC_DEFINE(M_CAMCCBQ, "CAM ccb queue", "CAM ccb queue buffers"); 48 49 static __inline int 50 queue_cmp(cam_pinfo **queue_array, int i, int j); 51 static __inline void 52 swap(cam_pinfo **queue_array, int i, int j); 53 static void heap_up(cam_pinfo **queue_array, int new_index); 54 static void heap_down(cam_pinfo **queue_array, int index, 55 int last_index); 56 57 struct camq * 58 camq_alloc(int size) 59 { 60 struct camq *camq; 61 62 camq = (struct camq *)malloc(sizeof(*camq), M_CAMQ, M_NOWAIT); 63 if (camq != NULL) { 64 if (camq_init(camq, size) != 0) { 65 free(camq, M_CAMQ); 66 camq = NULL; 67 } 68 } 69 return (camq); 70 } 71 72 int 73 camq_init(struct camq *camq, int size) 74 { 75 bzero(camq, sizeof(*camq)); 76 camq->array_size = size; 77 if (camq->array_size != 0) { 78 camq->queue_array = (cam_pinfo**)malloc(size*sizeof(cam_pinfo*), 79 M_CAMQ, M_NOWAIT); 80 if (camq->queue_array == NULL) { 81 printf("camq_init: - cannot malloc array!\n"); 82 return (1); 83 } 84 /* 85 * Heap algorithms like everything numbered from 1, so 86 * offset our pointer into the heap array by one element. 87 */ 88 camq->queue_array--; 89 } 90 return (0); 91 } 92 93 /* 94 * Free a camq structure. This should only be called if a controller 95 * driver failes somehow during its attach routine or is unloaded and has 96 * obtained a camq structure. The XPT should ensure that the queue 97 * is empty before calling this routine. 98 */ 99 void 100 camq_free(struct camq *queue) 101 { 102 if (queue != NULL) { 103 camq_fini(queue); 104 free(queue, M_CAMQ); 105 } 106 } 107 108 void 109 camq_fini(struct camq *queue) 110 { 111 if (queue->queue_array != NULL) { 112 /* 113 * Heap algorithms like everything numbered from 1, so 114 * our pointer into the heap array is offset by one element. 115 */ 116 queue->queue_array++; 117 free(queue->queue_array, M_CAMQ); 118 } 119 } 120 121 u_int32_t 122 camq_resize(struct camq *queue, int new_size) 123 { 124 cam_pinfo **new_array; 125 126 KASSERT(new_size >= queue->entries, ("camq_resize: " 127 "New queue size can't accommodate queued entries (%d < %d).", 128 new_size, queue->entries)); 129 new_array = (cam_pinfo **)malloc(new_size * sizeof(cam_pinfo *), 130 M_CAMQ, M_NOWAIT); 131 if (new_array == NULL) { 132 /* Couldn't satisfy request */ 133 return (CAM_RESRC_UNAVAIL); 134 } 135 /* 136 * Heap algorithms like everything numbered from 1, so 137 * remember that our pointer into the heap array is offset 138 * by one element. 139 */ 140 if (queue->queue_array != NULL) { 141 queue->queue_array++; 142 bcopy(queue->queue_array, new_array, 143 queue->entries * sizeof(cam_pinfo *)); 144 free(queue->queue_array, M_CAMQ); 145 } 146 queue->queue_array = new_array-1; 147 queue->array_size = new_size; 148 return (CAM_REQ_CMP); 149 } 150 151 /* 152 * camq_insert: Given an array of cam_pinfo* elememnts with 153 * the Heap(1, num_elements) property and array_size - num_elements >= 1, 154 * output Heap(1, num_elements+1) including new_entry in the array. 155 */ 156 void 157 camq_insert(struct camq *queue, cam_pinfo *new_entry) 158 { 159 160 KASSERT(queue->entries < queue->array_size, 161 ("camq_insert: Attempt to insert into a full queue (%d >= %d)", 162 queue->entries, queue->array_size)); 163 queue->entries++; 164 queue->queue_array[queue->entries] = new_entry; 165 new_entry->index = queue->entries; 166 if (queue->entries != 0) 167 heap_up(queue->queue_array, queue->entries); 168 } 169 170 /* 171 * camq_remove: Given an array of cam_pinfo* elevements with the 172 * Heap(1, num_elements) property and an index such that 1 <= index <= 173 * num_elements, remove that entry and restore the Heap(1, num_elements-1) 174 * property. 175 */ 176 cam_pinfo * 177 camq_remove(struct camq *queue, int index) 178 { 179 cam_pinfo *removed_entry; 180 181 if (index <= 0 || index > queue->entries) 182 panic("%s: Attempt to remove out-of-bounds index %d " 183 "from queue %p of size %d", __func__, index, queue, 184 queue->entries); 185 186 removed_entry = queue->queue_array[index]; 187 if (queue->entries != index) { 188 queue->queue_array[index] = queue->queue_array[queue->entries]; 189 queue->queue_array[index]->index = index; 190 heap_down(queue->queue_array, index, queue->entries - 1); 191 } 192 removed_entry->index = CAM_UNQUEUED_INDEX; 193 queue->entries--; 194 return (removed_entry); 195 } 196 197 /* 198 * camq_change_priority: Given an array of cam_pinfo* elements with the 199 * Heap(1, num_entries) property, an index such that 1 <= index <= num_elements, 200 * and a new priority for the element at index, change the priority of 201 * element index and restore the Heap(0, num_elements) property. 202 */ 203 void 204 camq_change_priority(struct camq *queue, int index, u_int32_t new_priority) 205 { 206 if (new_priority > queue->queue_array[index]->priority) { 207 queue->queue_array[index]->priority = new_priority; 208 heap_down(queue->queue_array, index, queue->entries); 209 } else { 210 /* new_priority <= old_priority */ 211 queue->queue_array[index]->priority = new_priority; 212 heap_up(queue->queue_array, index); 213 } 214 } 215 216 struct cam_devq * 217 cam_devq_alloc(int devices, int openings) 218 { 219 struct cam_devq *devq; 220 221 devq = (struct cam_devq *)malloc(sizeof(*devq), M_CAMDEVQ, M_NOWAIT); 222 if (devq == NULL) { 223 printf("cam_devq_alloc: - cannot malloc!\n"); 224 return (NULL); 225 } 226 if (cam_devq_init(devq, devices, openings) != 0) { 227 free(devq, M_CAMDEVQ); 228 return (NULL); 229 } 230 return (devq); 231 } 232 233 int 234 cam_devq_init(struct cam_devq *devq, int devices, int openings) 235 { 236 237 bzero(devq, sizeof(*devq)); 238 mtx_init(&devq->send_mtx, "CAM queue lock", NULL, MTX_DEF); 239 if (camq_init(&devq->send_queue, devices) != 0) 240 return (1); 241 devq->send_openings = openings; 242 devq->send_active = 0; 243 return (0); 244 } 245 246 void 247 cam_devq_free(struct cam_devq *devq) 248 { 249 250 camq_fini(&devq->send_queue); 251 mtx_destroy(&devq->send_mtx); 252 free(devq, M_CAMDEVQ); 253 } 254 255 u_int32_t 256 cam_devq_resize(struct cam_devq *camq, int devices) 257 { 258 u_int32_t retval; 259 260 retval = camq_resize(&camq->send_queue, devices); 261 return (retval); 262 } 263 264 struct cam_ccbq * 265 cam_ccbq_alloc(int openings) 266 { 267 struct cam_ccbq *ccbq; 268 269 ccbq = (struct cam_ccbq *)malloc(sizeof(*ccbq), M_CAMCCBQ, M_NOWAIT); 270 if (ccbq == NULL) { 271 printf("cam_ccbq_alloc: - cannot malloc!\n"); 272 return (NULL); 273 } 274 if (cam_ccbq_init(ccbq, openings) != 0) { 275 free(ccbq, M_CAMCCBQ); 276 return (NULL); 277 } 278 279 return (ccbq); 280 } 281 282 void 283 cam_ccbq_free(struct cam_ccbq *ccbq) 284 { 285 if (ccbq) { 286 cam_ccbq_fini(ccbq); 287 free(ccbq, M_CAMCCBQ); 288 } 289 } 290 291 u_int32_t 292 cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size) 293 { 294 int delta; 295 296 delta = new_size - (ccbq->dev_active + ccbq->dev_openings); 297 ccbq->total_openings += delta; 298 ccbq->dev_openings += delta; 299 300 new_size = imax(64, 1 << fls(new_size + new_size / 2)); 301 if (new_size > ccbq->queue.array_size) 302 return (camq_resize(&ccbq->queue, new_size)); 303 else 304 return (CAM_REQ_CMP); 305 } 306 307 int 308 cam_ccbq_init(struct cam_ccbq *ccbq, int openings) 309 { 310 bzero(ccbq, sizeof(*ccbq)); 311 if (camq_init(&ccbq->queue, 312 imax(64, 1 << fls(openings + openings / 2))) != 0) 313 return (1); 314 ccbq->total_openings = openings; 315 ccbq->dev_openings = openings; 316 return (0); 317 } 318 319 void 320 cam_ccbq_fini(struct cam_ccbq *ccbq) 321 { 322 323 camq_fini(&ccbq->queue); 324 } 325 326 /* 327 * Heap routines for manipulating CAM queues. 328 */ 329 /* 330 * queue_cmp: Given an array of cam_pinfo* elements and indexes i 331 * and j, return less than 0, 0, or greater than 0 if i is less than, 332 * equal too, or greater than j respectively. 333 */ 334 static __inline int 335 queue_cmp(cam_pinfo **queue_array, int i, int j) 336 { 337 if (queue_array[i]->priority == queue_array[j]->priority) 338 return ( queue_array[i]->generation 339 - queue_array[j]->generation ); 340 else 341 return ( queue_array[i]->priority 342 - queue_array[j]->priority ); 343 } 344 345 /* 346 * swap: Given an array of cam_pinfo* elements and indexes i and j, 347 * exchange elements i and j. 348 */ 349 static __inline void 350 swap(cam_pinfo **queue_array, int i, int j) 351 { 352 cam_pinfo *temp_qentry; 353 354 temp_qentry = queue_array[j]; 355 queue_array[j] = queue_array[i]; 356 queue_array[i] = temp_qentry; 357 queue_array[j]->index = j; 358 queue_array[i]->index = i; 359 } 360 361 /* 362 * heap_up: Given an array of cam_pinfo* elements with the 363 * Heap(1, new_index-1) property and a new element in location 364 * new_index, output Heap(1, new_index). 365 */ 366 static void 367 heap_up(cam_pinfo **queue_array, int new_index) 368 { 369 int child; 370 int parent; 371 372 child = new_index; 373 374 while (child != 1) { 375 376 parent = child >> 1; 377 if (queue_cmp(queue_array, parent, child) <= 0) 378 break; 379 swap(queue_array, parent, child); 380 child = parent; 381 } 382 } 383 384 /* 385 * heap_down: Given an array of cam_pinfo* elements with the 386 * Heap(index + 1, num_entries) property with index containing 387 * an unsorted entry, output Heap(index, num_entries). 388 */ 389 static void 390 heap_down(cam_pinfo **queue_array, int index, int num_entries) 391 { 392 int child; 393 int parent; 394 395 parent = index; 396 child = parent << 1; 397 for (; child <= num_entries; child = parent << 1) { 398 399 if (child < num_entries) { 400 /* child+1 is the right child of parent */ 401 if (queue_cmp(queue_array, child + 1, child) < 0) 402 child++; 403 } 404 /* child is now the least child of parent */ 405 if (queue_cmp(queue_array, parent, child) <= 0) 406 break; 407 swap(queue_array, child, parent); 408 parent = child; 409 } 410 } 411