1 /*- 2 * CAM request queue management functions. 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 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/types.h> 35 #include <sys/malloc.h> 36 #include <sys/kernel.h> 37 38 #include <cam/cam.h> 39 #include <cam/cam_ccb.h> 40 #include <cam/cam_queue.h> 41 #include <cam/cam_debug.h> 42 43 static MALLOC_DEFINE(M_CAMQ, "CAM queue", "CAM queue buffers"); 44 static MALLOC_DEFINE(M_CAMDEVQ, "CAM dev queue", "CAM dev queue buffers"); 45 static MALLOC_DEFINE(M_CAMCCBQ, "CAM ccb queue", "CAM ccb queue buffers"); 46 47 static __inline int 48 queue_cmp(cam_pinfo **queue_array, int i, int j); 49 static __inline void 50 swap(cam_pinfo **queue_array, int i, int j); 51 static void heap_up(cam_pinfo **queue_array, int new_index); 52 static void heap_down(cam_pinfo **queue_array, int index, 53 int last_index); 54 55 struct camq * 56 camq_alloc(int size) 57 { 58 struct camq *camq; 59 60 camq = (struct camq *)malloc(sizeof(*camq), M_CAMQ, M_NOWAIT); 61 if (camq != NULL) { 62 if (camq_init(camq, size) != 0) { 63 free(camq, M_CAMQ); 64 camq = NULL; 65 } 66 } 67 return (camq); 68 } 69 70 int 71 camq_init(struct camq *camq, int size) 72 { 73 bzero(camq, sizeof(*camq)); 74 camq->array_size = size; 75 if (camq->array_size != 0) { 76 camq->queue_array = (cam_pinfo**)malloc(size*sizeof(cam_pinfo*), 77 M_CAMQ, M_NOWAIT); 78 if (camq->queue_array == NULL) { 79 printf("camq_init: - cannot malloc array!\n"); 80 return (1); 81 } 82 /* 83 * Heap algorithms like everything numbered from 1, so 84 * offset our pointer into the heap array by one element. 85 */ 86 camq->queue_array--; 87 } 88 return (0); 89 } 90 91 /* 92 * Free a camq structure. This should only be called if a controller 93 * driver failes somehow during its attach routine or is unloaded and has 94 * obtained a camq structure. The XPT should ensure that the queue 95 * is empty before calling this routine. 96 */ 97 void 98 camq_free(struct camq *queue) 99 { 100 if (queue != NULL) { 101 camq_fini(queue); 102 free(queue, M_CAMQ); 103 } 104 } 105 106 void 107 camq_fini(struct camq *queue) 108 { 109 if (queue->queue_array != NULL) { 110 /* 111 * Heap algorithms like everything numbered from 1, so 112 * our pointer into the heap array is offset by one element. 113 */ 114 queue->queue_array++; 115 free(queue->queue_array, M_CAMQ); 116 } 117 } 118 119 u_int32_t 120 camq_resize(struct camq *queue, int new_size) 121 { 122 cam_pinfo **new_array; 123 124 KASSERT(new_size >= queue->entries, ("camq_resize: " 125 "New queue size can't accommodate queued entries (%d < %d).", 126 new_size, queue->entries)); 127 new_array = (cam_pinfo **)malloc(new_size * sizeof(cam_pinfo *), 128 M_CAMQ, M_NOWAIT); 129 if (new_array == NULL) { 130 /* Couldn't satisfy request */ 131 return (CAM_RESRC_UNAVAIL); 132 } 133 /* 134 * Heap algorithms like everything numbered from 1, so 135 * remember that our pointer into the heap array is offset 136 * by one element. 137 */ 138 if (queue->queue_array != NULL) { 139 queue->queue_array++; 140 bcopy(queue->queue_array, new_array, 141 queue->entries * sizeof(cam_pinfo *)); 142 free(queue->queue_array, M_CAMQ); 143 } 144 queue->queue_array = new_array-1; 145 queue->array_size = new_size; 146 return (CAM_REQ_CMP); 147 } 148 149 /* 150 * camq_insert: Given an array of cam_pinfo* elememnts with 151 * the Heap(1, num_elements) property and array_size - num_elements >= 1, 152 * output Heap(1, num_elements+1) including new_entry in the array. 153 */ 154 void 155 camq_insert(struct camq *queue, cam_pinfo *new_entry) 156 { 157 158 KASSERT(queue->entries < queue->array_size, 159 ("camq_insert: Attempt to insert into a full queue (%d >= %d)", 160 queue->entries, queue->array_size)); 161 queue->entries++; 162 queue->queue_array[queue->entries] = new_entry; 163 new_entry->index = queue->entries; 164 if (queue->entries != 0) 165 heap_up(queue->queue_array, queue->entries); 166 } 167 168 /* 169 * camq_remove: Given an array of cam_pinfo* elevements with the 170 * Heap(1, num_elements) property and an index such that 1 <= index <= 171 * num_elements, remove that entry and restore the Heap(1, num_elements-1) 172 * property. 173 */ 174 cam_pinfo * 175 camq_remove(struct camq *queue, int index) 176 { 177 cam_pinfo *removed_entry; 178 179 if (index <= 0 || index > queue->entries) 180 panic("%s: Attempt to remove out-of-bounds index %d " 181 "from queue %p of size %d", __func__, index, queue, 182 queue->entries); 183 184 removed_entry = queue->queue_array[index]; 185 if (queue->entries != index) { 186 queue->queue_array[index] = queue->queue_array[queue->entries]; 187 queue->queue_array[index]->index = index; 188 heap_down(queue->queue_array, index, queue->entries - 1); 189 } 190 removed_entry->index = CAM_UNQUEUED_INDEX; 191 queue->entries--; 192 return (removed_entry); 193 } 194 195 /* 196 * camq_change_priority: Given an array of cam_pinfo* elements with the 197 * Heap(1, num_entries) property, an index such that 1 <= index <= num_elements, 198 * and a new priority for the element at index, change the priority of 199 * element index and restore the Heap(0, num_elements) property. 200 */ 201 void 202 camq_change_priority(struct camq *queue, int index, u_int32_t new_priority) 203 { 204 if (new_priority > queue->queue_array[index]->priority) { 205 queue->queue_array[index]->priority = new_priority; 206 heap_down(queue->queue_array, index, queue->entries); 207 } else { 208 /* new_priority <= old_priority */ 209 queue->queue_array[index]->priority = new_priority; 210 heap_up(queue->queue_array, index); 211 } 212 } 213 214 struct cam_devq * 215 cam_devq_alloc(int devices, int openings) 216 { 217 struct cam_devq *devq; 218 219 devq = (struct cam_devq *)malloc(sizeof(*devq), M_CAMDEVQ, M_NOWAIT); 220 if (devq == NULL) { 221 printf("cam_devq_alloc: - cannot malloc!\n"); 222 return (NULL); 223 } 224 if (cam_devq_init(devq, devices, openings) != 0) { 225 free(devq, M_CAMDEVQ); 226 return (NULL); 227 } 228 return (devq); 229 } 230 231 int 232 cam_devq_init(struct cam_devq *devq, int devices, int openings) 233 { 234 235 bzero(devq, sizeof(*devq)); 236 mtx_init(&devq->send_mtx, "CAM queue lock", NULL, MTX_DEF); 237 if (camq_init(&devq->send_queue, devices) != 0) 238 return (1); 239 devq->send_openings = openings; 240 devq->send_active = 0; 241 return (0); 242 } 243 244 void 245 cam_devq_free(struct cam_devq *devq) 246 { 247 248 camq_fini(&devq->send_queue); 249 mtx_destroy(&devq->send_mtx); 250 free(devq, M_CAMDEVQ); 251 } 252 253 u_int32_t 254 cam_devq_resize(struct cam_devq *camq, int devices) 255 { 256 u_int32_t retval; 257 258 retval = camq_resize(&camq->send_queue, devices); 259 return (retval); 260 } 261 262 struct cam_ccbq * 263 cam_ccbq_alloc(int openings) 264 { 265 struct cam_ccbq *ccbq; 266 267 ccbq = (struct cam_ccbq *)malloc(sizeof(*ccbq), M_CAMCCBQ, M_NOWAIT); 268 if (ccbq == NULL) { 269 printf("cam_ccbq_alloc: - cannot malloc!\n"); 270 return (NULL); 271 } 272 if (cam_ccbq_init(ccbq, openings) != 0) { 273 free(ccbq, M_CAMCCBQ); 274 return (NULL); 275 } 276 277 return (ccbq); 278 } 279 280 void 281 cam_ccbq_free(struct cam_ccbq *ccbq) 282 { 283 if (ccbq) { 284 cam_ccbq_fini(ccbq); 285 free(ccbq, M_CAMCCBQ); 286 } 287 } 288 289 u_int32_t 290 cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size) 291 { 292 int delta; 293 294 delta = new_size - (ccbq->dev_active + ccbq->dev_openings); 295 ccbq->total_openings += delta; 296 ccbq->dev_openings += delta; 297 298 new_size = imax(64, 1 << fls(new_size + new_size / 2)); 299 if (new_size > ccbq->queue.array_size) 300 return (camq_resize(&ccbq->queue, new_size)); 301 else 302 return (CAM_REQ_CMP); 303 } 304 305 int 306 cam_ccbq_init(struct cam_ccbq *ccbq, int openings) 307 { 308 bzero(ccbq, sizeof(*ccbq)); 309 if (camq_init(&ccbq->queue, 310 imax(64, 1 << fls(openings + openings / 2))) != 0) 311 return (1); 312 ccbq->total_openings = openings; 313 ccbq->dev_openings = openings; 314 return (0); 315 } 316 317 void 318 cam_ccbq_fini(struct cam_ccbq *ccbq) 319 { 320 321 camq_fini(&ccbq->queue); 322 } 323 324 /* 325 * Heap routines for manipulating CAM queues. 326 */ 327 /* 328 * queue_cmp: Given an array of cam_pinfo* elements and indexes i 329 * and j, return less than 0, 0, or greater than 0 if i is less than, 330 * equal too, or greater than j respectively. 331 */ 332 static __inline int 333 queue_cmp(cam_pinfo **queue_array, int i, int j) 334 { 335 if (queue_array[i]->priority == queue_array[j]->priority) 336 return ( queue_array[i]->generation 337 - queue_array[j]->generation ); 338 else 339 return ( queue_array[i]->priority 340 - queue_array[j]->priority ); 341 } 342 343 /* 344 * swap: Given an array of cam_pinfo* elements and indexes i and j, 345 * exchange elements i and j. 346 */ 347 static __inline void 348 swap(cam_pinfo **queue_array, int i, int j) 349 { 350 cam_pinfo *temp_qentry; 351 352 temp_qentry = queue_array[j]; 353 queue_array[j] = queue_array[i]; 354 queue_array[i] = temp_qentry; 355 queue_array[j]->index = j; 356 queue_array[i]->index = i; 357 } 358 359 /* 360 * heap_up: Given an array of cam_pinfo* elements with the 361 * Heap(1, new_index-1) property and a new element in location 362 * new_index, output Heap(1, new_index). 363 */ 364 static void 365 heap_up(cam_pinfo **queue_array, int new_index) 366 { 367 int child; 368 int parent; 369 370 child = new_index; 371 372 while (child != 1) { 373 374 parent = child >> 1; 375 if (queue_cmp(queue_array, parent, child) <= 0) 376 break; 377 swap(queue_array, parent, child); 378 child = parent; 379 } 380 } 381 382 /* 383 * heap_down: Given an array of cam_pinfo* elements with the 384 * Heap(index + 1, num_entries) property with index containing 385 * an unsorted entry, output Heap(index, num_entries). 386 */ 387 static void 388 heap_down(cam_pinfo **queue_array, int index, int num_entries) 389 { 390 int child; 391 int parent; 392 393 parent = index; 394 child = parent << 1; 395 for (; child <= num_entries; child = parent << 1) { 396 397 if (child < num_entries) { 398 /* child+1 is the right child of parent */ 399 if (queue_cmp(queue_array, child + 1, child) < 0) 400 child++; 401 } 402 /* child is now the least child of parent */ 403 if (queue_cmp(queue_array, parent, child) <= 0) 404 break; 405 swap(queue_array, child, parent); 406 parent = child; 407 } 408 } 409