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