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 accomodate 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 return (NULL); 181 removed_entry = queue->queue_array[index]; 182 if (queue->entries != index) { 183 queue->queue_array[index] = queue->queue_array[queue->entries]; 184 queue->queue_array[index]->index = index; 185 heap_down(queue->queue_array, index, queue->entries - 1); 186 } 187 removed_entry->index = CAM_UNQUEUED_INDEX; 188 queue->entries--; 189 return (removed_entry); 190 } 191 192 /* 193 * camq_change_priority: Given an array of cam_pinfo* elements with the 194 * Heap(1, num_entries) property, an index such that 1 <= index <= num_elements, 195 * and a new priority for the element at index, change the priority of 196 * element index and restore the Heap(0, num_elements) property. 197 */ 198 void 199 camq_change_priority(struct camq *queue, int index, u_int32_t new_priority) 200 { 201 if (new_priority > queue->queue_array[index]->priority) { 202 queue->queue_array[index]->priority = new_priority; 203 heap_down(queue->queue_array, index, queue->entries); 204 } else { 205 /* new_priority <= old_priority */ 206 queue->queue_array[index]->priority = new_priority; 207 heap_up(queue->queue_array, index); 208 } 209 } 210 211 struct cam_devq * 212 cam_devq_alloc(int devices, int openings) 213 { 214 struct cam_devq *devq; 215 216 devq = (struct cam_devq *)malloc(sizeof(*devq), M_CAMDEVQ, M_NOWAIT); 217 if (devq == NULL) { 218 printf("cam_devq_alloc: - cannot malloc!\n"); 219 return (NULL); 220 } 221 if (cam_devq_init(devq, devices, openings) != 0) { 222 free(devq, M_CAMDEVQ); 223 return (NULL); 224 } 225 226 return (devq); 227 } 228 229 int 230 cam_devq_init(struct cam_devq *devq, int devices, int openings) 231 { 232 bzero(devq, sizeof(*devq)); 233 if (camq_init(&devq->send_queue, devices) != 0) 234 return (1); 235 devq->send_openings = openings; 236 devq->send_active = 0; 237 return (0); 238 } 239 240 void 241 cam_devq_free(struct cam_devq *devq) 242 { 243 camq_fini(&devq->send_queue); 244 free(devq, M_CAMDEVQ); 245 } 246 247 u_int32_t 248 cam_devq_resize(struct cam_devq *camq, int devices) 249 { 250 u_int32_t retval; 251 252 retval = camq_resize(&camq->send_queue, devices); 253 return (retval); 254 } 255 256 struct cam_ccbq * 257 cam_ccbq_alloc(int openings) 258 { 259 struct cam_ccbq *ccbq; 260 261 ccbq = (struct cam_ccbq *)malloc(sizeof(*ccbq), M_CAMCCBQ, M_NOWAIT); 262 if (ccbq == NULL) { 263 printf("cam_ccbq_alloc: - cannot malloc!\n"); 264 return (NULL); 265 } 266 if (cam_ccbq_init(ccbq, openings) != 0) { 267 free(ccbq, M_CAMCCBQ); 268 return (NULL); 269 } 270 271 return (ccbq); 272 } 273 274 void 275 cam_ccbq_free(struct cam_ccbq *ccbq) 276 { 277 if (ccbq) { 278 cam_ccbq_fini(ccbq); 279 free(ccbq, M_CAMCCBQ); 280 } 281 } 282 283 u_int32_t 284 cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size) 285 { 286 int delta; 287 int space_left; 288 289 delta = new_size - (ccbq->dev_active + ccbq->dev_openings); 290 space_left = new_size 291 - ccbq->queue.entries 292 - ccbq->held 293 - ccbq->dev_active; 294 295 /* 296 * Only attempt to change the underlying queue size if we are 297 * shrinking it and there is space for all outstanding entries 298 * in the new array or we have been requested to grow the array. 299 * We don't fail in the case where we can't reduce the array size, 300 * but clients that care that the queue be "garbage collected" 301 * should detect this condition and call us again with the 302 * same size once the outstanding entries have been processed. 303 */ 304 if (space_left < 0 305 || camq_resize(&ccbq->queue, new_size + (CAM_RL_VALUES - 1)) == 306 CAM_REQ_CMP) { 307 ccbq->devq_openings += delta; 308 ccbq->dev_openings += delta; 309 return (CAM_REQ_CMP); 310 } else { 311 return (CAM_RESRC_UNAVAIL); 312 } 313 } 314 315 int 316 cam_ccbq_init(struct cam_ccbq *ccbq, int openings) 317 { 318 bzero(ccbq, sizeof(*ccbq)); 319 if (camq_init(&ccbq->queue, openings + (CAM_RL_VALUES - 1)) != 0) 320 return (1); 321 ccbq->devq_openings = openings; 322 ccbq->dev_openings = openings; 323 return (0); 324 } 325 326 void 327 cam_ccbq_fini(struct cam_ccbq *ccbq) 328 { 329 330 camq_fini(&ccbq->queue); 331 } 332 333 /* 334 * Heap routines for manipulating CAM queues. 335 */ 336 /* 337 * queue_cmp: Given an array of cam_pinfo* elements and indexes i 338 * and j, return less than 0, 0, or greater than 0 if i is less than, 339 * equal too, or greater than j respectively. 340 */ 341 static __inline int 342 queue_cmp(cam_pinfo **queue_array, int i, int j) 343 { 344 if (queue_array[i]->priority == queue_array[j]->priority) 345 return ( queue_array[i]->generation 346 - queue_array[j]->generation ); 347 else 348 return ( queue_array[i]->priority 349 - queue_array[j]->priority ); 350 } 351 352 /* 353 * swap: Given an array of cam_pinfo* elements and indexes i and j, 354 * exchange elements i and j. 355 */ 356 static __inline void 357 swap(cam_pinfo **queue_array, int i, int j) 358 { 359 cam_pinfo *temp_qentry; 360 361 temp_qentry = queue_array[j]; 362 queue_array[j] = queue_array[i]; 363 queue_array[i] = temp_qentry; 364 queue_array[j]->index = j; 365 queue_array[i]->index = i; 366 } 367 368 /* 369 * heap_up: Given an array of cam_pinfo* elements with the 370 * Heap(1, new_index-1) property and a new element in location 371 * new_index, output Heap(1, new_index). 372 */ 373 static void 374 heap_up(cam_pinfo **queue_array, int new_index) 375 { 376 int child; 377 int parent; 378 379 child = new_index; 380 381 while (child != 1) { 382 383 parent = child >> 1; 384 if (queue_cmp(queue_array, parent, child) <= 0) 385 break; 386 swap(queue_array, parent, child); 387 child = parent; 388 } 389 } 390 391 /* 392 * heap_down: Given an array of cam_pinfo* elements with the 393 * Heap(index + 1, num_entries) property with index containing 394 * an unsorted entry, output Heap(index, num_entries). 395 */ 396 static void 397 heap_down(cam_pinfo **queue_array, int index, int num_entries) 398 { 399 int child; 400 int parent; 401 402 parent = index; 403 child = parent << 1; 404 for (; child <= num_entries; child = parent << 1) { 405 406 if (child < num_entries) { 407 /* child+1 is the right child of parent */ 408 if (queue_cmp(queue_array, child + 1, child) < 0) 409 child++; 410 } 411 /* child is now the least child of parent */ 412 if (queue_cmp(queue_array, parent, child) <= 0) 413 break; 414 swap(queue_array, child, parent); 415 parent = child; 416 } 417 } 418