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