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 MALLOC_DEFINE(M_CAMQ, "CAM queue", "CAM queue buffers"); 44 MALLOC_DEFINE(M_CAMDEVQ, "CAM dev queue", "CAM dev queue buffers"); 45 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 #ifdef DIAGNOSTIC 125 if (new_size < queue->entries) 126 panic("camq_resize: New queue size can't accomodate " 127 "queued entries."); 128 #endif 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 #ifdef DIAGNOSTIC 160 if (queue->entries >= queue->array_size) 161 panic("camq_insert: Attempt to insert into a full queue"); 162 #endif 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 return (NULL); 183 removed_entry = queue->queue_array[index]; 184 if (queue->entries != index) { 185 queue->queue_array[index] = queue->queue_array[queue->entries]; 186 queue->queue_array[index]->index = index; 187 heap_down(queue->queue_array, index, queue->entries - 1); 188 } 189 removed_entry->index = CAM_UNQUEUED_INDEX; 190 queue->entries--; 191 return (removed_entry); 192 } 193 194 /* 195 * camq_change_priority: Given an array of cam_pinfo* elements with the 196 * Heap(1, num_entries) property, an index such that 1 <= index <= num_elements, 197 * and a new priority for the element at index, change the priority of 198 * element index and restore the Heap(0, num_elements) property. 199 */ 200 void 201 camq_change_priority(struct camq *queue, int index, u_int32_t new_priority) 202 { 203 if (new_priority > queue->queue_array[index]->priority) { 204 queue->queue_array[index]->priority = new_priority; 205 heap_down(queue->queue_array, index, queue->entries); 206 } else { 207 /* new_priority <= old_priority */ 208 queue->queue_array[index]->priority = new_priority; 209 heap_up(queue->queue_array, index); 210 } 211 } 212 213 struct cam_devq * 214 cam_devq_alloc(int devices, int openings) 215 { 216 struct cam_devq *devq; 217 218 devq = (struct cam_devq *)malloc(sizeof(*devq), M_CAMDEVQ, M_NOWAIT); 219 if (devq == NULL) { 220 printf("cam_devq_alloc: - cannot malloc!\n"); 221 return (NULL); 222 } 223 if (cam_devq_init(devq, devices, openings) != 0) { 224 free(devq, M_CAMDEVQ); 225 return (NULL); 226 } 227 228 return (devq); 229 } 230 231 int 232 cam_devq_init(struct cam_devq *devq, int devices, int openings) 233 { 234 bzero(devq, sizeof(*devq)); 235 if (camq_init(&devq->alloc_queue, devices) != 0) { 236 return (1); 237 } 238 if (camq_init(&devq->send_queue, devices) != 0) { 239 camq_fini(&devq->alloc_queue); 240 return (1); 241 } 242 devq->alloc_openings = openings; 243 devq->alloc_active = 0; 244 devq->send_openings = openings; 245 devq->send_active = 0; 246 return (0); 247 } 248 249 void 250 cam_devq_free(struct cam_devq *devq) 251 { 252 camq_fini(&devq->alloc_queue); 253 camq_fini(&devq->send_queue); 254 free(devq, M_CAMDEVQ); 255 } 256 257 u_int32_t 258 cam_devq_resize(struct cam_devq *camq, int devices) 259 { 260 u_int32_t retval; 261 262 retval = camq_resize(&camq->alloc_queue, devices); 263 264 if (retval == CAM_REQ_CMP) 265 retval = camq_resize(&camq->send_queue, devices); 266 267 return (retval); 268 } 269 270 struct cam_ccbq * 271 cam_ccbq_alloc(int openings) 272 { 273 struct cam_ccbq *ccbq; 274 275 ccbq = (struct cam_ccbq *)malloc(sizeof(*ccbq), M_CAMCCBQ, M_NOWAIT); 276 if (ccbq == NULL) { 277 printf("cam_ccbq_alloc: - cannot malloc!\n"); 278 return (NULL); 279 } 280 if (cam_ccbq_init(ccbq, openings) != 0) { 281 free(ccbq, M_CAMCCBQ); 282 return (NULL); 283 } 284 285 return (ccbq); 286 } 287 288 void 289 cam_ccbq_free(struct cam_ccbq *ccbq) 290 { 291 if (ccbq) { 292 cam_ccbq_fini(ccbq); 293 free(ccbq, M_CAMCCBQ); 294 } 295 } 296 297 u_int32_t 298 cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size) 299 { 300 int delta; 301 int space_left; 302 303 delta = new_size - (ccbq->dev_active + ccbq->dev_openings); 304 space_left = new_size 305 - ccbq->queue.entries 306 - ccbq->held 307 - ccbq->dev_active; 308 309 /* 310 * Only attempt to change the underlying queue size if we are 311 * shrinking it and there is space for all outstanding entries 312 * in the new array or we have been requested to grow the array. 313 * We don't fail in the case where we can't reduce the array size, 314 * but clients that care that the queue be "garbage collected" 315 * should detect this condition and call us again with the 316 * same size once the outstanding entries have been processed. 317 */ 318 if (space_left < 0 319 || camq_resize(&ccbq->queue, new_size) == CAM_REQ_CMP) { 320 ccbq->devq_openings += delta; 321 ccbq->dev_openings += delta; 322 return (CAM_REQ_CMP); 323 } else { 324 return (CAM_RESRC_UNAVAIL); 325 } 326 } 327 328 int 329 cam_ccbq_init(struct cam_ccbq *ccbq, int openings) 330 { 331 bzero(ccbq, sizeof(*ccbq)); 332 if (camq_init(&ccbq->queue, openings) != 0) { 333 return (1); 334 } 335 ccbq->devq_openings = openings; 336 ccbq->dev_openings = openings; 337 return (0); 338 } 339 340 void 341 cam_ccbq_fini(struct cam_ccbq *ccbq) 342 { 343 344 camq_fini(&ccbq->queue); 345 } 346 347 /* 348 * Heap routines for manipulating CAM queues. 349 */ 350 /* 351 * queue_cmp: Given an array of cam_pinfo* elements and indexes i 352 * and j, return less than 0, 0, or greater than 0 if i is less than, 353 * equal too, or greater than j respectively. 354 */ 355 static __inline int 356 queue_cmp(cam_pinfo **queue_array, int i, int j) 357 { 358 if (queue_array[i]->priority == queue_array[j]->priority) 359 return ( queue_array[i]->generation 360 - queue_array[j]->generation ); 361 else 362 return ( queue_array[i]->priority 363 - queue_array[j]->priority ); 364 } 365 366 /* 367 * swap: Given an array of cam_pinfo* elements and indexes i and j, 368 * exchange elements i and j. 369 */ 370 static __inline void 371 swap(cam_pinfo **queue_array, int i, int j) 372 { 373 cam_pinfo *temp_qentry; 374 375 temp_qentry = queue_array[j]; 376 queue_array[j] = queue_array[i]; 377 queue_array[i] = temp_qentry; 378 queue_array[j]->index = j; 379 queue_array[i]->index = i; 380 } 381 382 /* 383 * heap_up: Given an array of cam_pinfo* elements with the 384 * Heap(1, new_index-1) property and a new element in location 385 * new_index, output Heap(1, new_index). 386 */ 387 static void 388 heap_up(cam_pinfo **queue_array, int new_index) 389 { 390 int child; 391 int parent; 392 393 child = new_index; 394 395 while (child != 1) { 396 397 parent = child >> 1; 398 if (queue_cmp(queue_array, parent, child) <= 0) 399 break; 400 swap(queue_array, parent, child); 401 child = parent; 402 } 403 } 404 405 /* 406 * heap_down: Given an array of cam_pinfo* elements with the 407 * Heap(index + 1, num_entries) property with index containing 408 * an unsorted entry, output Heap(index, num_entries). 409 */ 410 static void 411 heap_down(cam_pinfo **queue_array, int index, int num_entries) 412 { 413 int child; 414 int parent; 415 416 parent = index; 417 child = parent << 1; 418 for (; child <= num_entries; child = parent << 1) { 419 420 if (child < num_entries) { 421 /* child+1 is the right child of parent */ 422 if (queue_cmp(queue_array, child + 1, child) < 0) 423 child++; 424 } 425 /* child is now the least child of parent */ 426 if (queue_cmp(queue_array, parent, child) <= 0) 427 break; 428 swap(queue_array, child, parent); 429 parent = child; 430 } 431 } 432