Andy Gross | 71e8831 | 2011-12-05 19:19:21 -0600 | [diff] [blame] | 1 | /* |
| 2 | * tcm-sita.c |
| 3 | * |
| 4 | * SImple Tiler Allocator (SiTA): 2D and 1D allocation(reservation) algorithm |
| 5 | * |
| 6 | * Authors: Ravi Ramachandra <r.ramachandra@ti.com>, |
| 7 | * Lajos Molnar <molnar@ti.com> |
| 8 | * |
| 9 | * Copyright (C) 2009-2010 Texas Instruments, Inc. |
| 10 | * |
| 11 | * This package is free software; you can redistribute it and/or modify |
| 12 | * it under the terms of the GNU General Public License version 2 as |
| 13 | * published by the Free Software Foundation. |
| 14 | * |
| 15 | * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
| 16 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
| 17 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| 18 | * |
| 19 | */ |
| 20 | #include <linux/slab.h> |
| 21 | #include <linux/spinlock.h> |
| 22 | |
| 23 | #include "tcm-sita.h" |
| 24 | |
| 25 | #define ALIGN_DOWN(value, align) ((value) & ~((align) - 1)) |
| 26 | |
| 27 | /* Individual selection criteria for different scan areas */ |
| 28 | static s32 CR_L2R_T2B = CR_BIAS_HORIZONTAL; |
| 29 | static s32 CR_R2L_T2B = CR_DIAGONAL_BALANCE; |
| 30 | |
| 31 | /********************************************* |
| 32 | * TCM API - Sita Implementation |
| 33 | *********************************************/ |
| 34 | static s32 sita_reserve_2d(struct tcm *tcm, u16 h, u16 w, u8 align, |
| 35 | struct tcm_area *area); |
| 36 | static s32 sita_reserve_1d(struct tcm *tcm, u32 slots, struct tcm_area *area); |
| 37 | static s32 sita_free(struct tcm *tcm, struct tcm_area *area); |
| 38 | static void sita_deinit(struct tcm *tcm); |
| 39 | |
| 40 | /********************************************* |
| 41 | * Main Scanner functions |
| 42 | *********************************************/ |
| 43 | static s32 scan_areas_and_find_fit(struct tcm *tcm, u16 w, u16 h, u16 align, |
| 44 | struct tcm_area *area); |
| 45 | |
| 46 | static s32 scan_l2r_t2b(struct tcm *tcm, u16 w, u16 h, u16 align, |
| 47 | struct tcm_area *field, struct tcm_area *area); |
| 48 | |
| 49 | static s32 scan_r2l_t2b(struct tcm *tcm, u16 w, u16 h, u16 align, |
| 50 | struct tcm_area *field, struct tcm_area *area); |
| 51 | |
| 52 | static s32 scan_r2l_b2t_one_dim(struct tcm *tcm, u32 num_slots, |
| 53 | struct tcm_area *field, struct tcm_area *area); |
| 54 | |
| 55 | /********************************************* |
| 56 | * Support Infrastructure Methods |
| 57 | *********************************************/ |
| 58 | static s32 is_area_free(struct tcm_area ***map, u16 x0, u16 y0, u16 w, u16 h); |
| 59 | |
| 60 | static s32 update_candidate(struct tcm *tcm, u16 x0, u16 y0, u16 w, u16 h, |
| 61 | struct tcm_area *field, s32 criteria, |
| 62 | struct score *best); |
| 63 | |
| 64 | static void get_nearness_factor(struct tcm_area *field, |
| 65 | struct tcm_area *candidate, |
| 66 | struct nearness_factor *nf); |
| 67 | |
| 68 | static void get_neighbor_stats(struct tcm *tcm, struct tcm_area *area, |
| 69 | struct neighbor_stats *stat); |
| 70 | |
| 71 | static void fill_area(struct tcm *tcm, |
| 72 | struct tcm_area *area, struct tcm_area *parent); |
| 73 | |
| 74 | |
| 75 | /*********************************************/ |
| 76 | |
| 77 | /********************************************* |
| 78 | * Utility Methods |
| 79 | *********************************************/ |
| 80 | struct tcm *sita_init(u16 width, u16 height, struct tcm_pt *attr) |
| 81 | { |
| 82 | struct tcm *tcm; |
| 83 | struct sita_pvt *pvt; |
| 84 | struct tcm_area area = {0}; |
| 85 | s32 i; |
| 86 | |
| 87 | if (width == 0 || height == 0) |
| 88 | return NULL; |
| 89 | |
| 90 | tcm = kmalloc(sizeof(*tcm), GFP_KERNEL); |
| 91 | pvt = kmalloc(sizeof(*pvt), GFP_KERNEL); |
| 92 | if (!tcm || !pvt) |
| 93 | goto error; |
| 94 | |
| 95 | memset(tcm, 0, sizeof(*tcm)); |
| 96 | memset(pvt, 0, sizeof(*pvt)); |
| 97 | |
| 98 | /* Updating the pointers to SiTA implementation APIs */ |
| 99 | tcm->height = height; |
| 100 | tcm->width = width; |
| 101 | tcm->reserve_2d = sita_reserve_2d; |
| 102 | tcm->reserve_1d = sita_reserve_1d; |
| 103 | tcm->free = sita_free; |
| 104 | tcm->deinit = sita_deinit; |
| 105 | tcm->pvt = (void *)pvt; |
| 106 | |
| 107 | spin_lock_init(&(pvt->lock)); |
| 108 | |
| 109 | /* Creating tam map */ |
| 110 | pvt->map = kmalloc(sizeof(*pvt->map) * tcm->width, GFP_KERNEL); |
| 111 | if (!pvt->map) |
| 112 | goto error; |
| 113 | |
| 114 | for (i = 0; i < tcm->width; i++) { |
| 115 | pvt->map[i] = |
| 116 | kmalloc(sizeof(**pvt->map) * tcm->height, |
| 117 | GFP_KERNEL); |
| 118 | if (pvt->map[i] == NULL) { |
| 119 | while (i--) |
| 120 | kfree(pvt->map[i]); |
| 121 | kfree(pvt->map); |
| 122 | goto error; |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | if (attr && attr->x <= tcm->width && attr->y <= tcm->height) { |
| 127 | pvt->div_pt.x = attr->x; |
| 128 | pvt->div_pt.y = attr->y; |
| 129 | |
| 130 | } else { |
| 131 | /* Defaulting to 3:1 ratio on width for 2D area split */ |
| 132 | /* Defaulting to 3:1 ratio on height for 2D and 1D split */ |
| 133 | pvt->div_pt.x = (tcm->width * 3) / 4; |
| 134 | pvt->div_pt.y = (tcm->height * 3) / 4; |
| 135 | } |
| 136 | |
| 137 | spin_lock(&(pvt->lock)); |
| 138 | assign(&area, 0, 0, width - 1, height - 1); |
| 139 | fill_area(tcm, &area, NULL); |
| 140 | spin_unlock(&(pvt->lock)); |
| 141 | return tcm; |
| 142 | |
| 143 | error: |
| 144 | kfree(tcm); |
| 145 | kfree(pvt); |
| 146 | return NULL; |
| 147 | } |
| 148 | |
| 149 | static void sita_deinit(struct tcm *tcm) |
| 150 | { |
| 151 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; |
| 152 | struct tcm_area area = {0}; |
| 153 | s32 i; |
| 154 | |
| 155 | area.p1.x = tcm->width - 1; |
| 156 | area.p1.y = tcm->height - 1; |
| 157 | |
| 158 | spin_lock(&(pvt->lock)); |
| 159 | fill_area(tcm, &area, NULL); |
| 160 | spin_unlock(&(pvt->lock)); |
| 161 | |
| 162 | for (i = 0; i < tcm->height; i++) |
| 163 | kfree(pvt->map[i]); |
| 164 | kfree(pvt->map); |
| 165 | kfree(pvt); |
| 166 | } |
| 167 | |
| 168 | /** |
| 169 | * Reserve a 1D area in the container |
| 170 | * |
| 171 | * @param num_slots size of 1D area |
| 172 | * @param area pointer to the area that will be populated with the |
| 173 | * reserved area |
| 174 | * |
| 175 | * @return 0 on success, non-0 error value on failure. |
| 176 | */ |
| 177 | static s32 sita_reserve_1d(struct tcm *tcm, u32 num_slots, |
| 178 | struct tcm_area *area) |
| 179 | { |
| 180 | s32 ret; |
| 181 | struct tcm_area field = {0}; |
| 182 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; |
| 183 | |
| 184 | spin_lock(&(pvt->lock)); |
| 185 | |
| 186 | /* Scanning entire container */ |
| 187 | assign(&field, tcm->width - 1, tcm->height - 1, 0, 0); |
| 188 | |
| 189 | ret = scan_r2l_b2t_one_dim(tcm, num_slots, &field, area); |
| 190 | if (!ret) |
| 191 | /* update map */ |
| 192 | fill_area(tcm, area, area); |
| 193 | |
| 194 | spin_unlock(&(pvt->lock)); |
| 195 | return ret; |
| 196 | } |
| 197 | |
| 198 | /** |
| 199 | * Reserve a 2D area in the container |
| 200 | * |
| 201 | * @param w width |
| 202 | * @param h height |
Justin P. Mattock | 6354eb8 | 2012-04-02 07:25:19 -0700 | [diff] [blame] | 203 | * @param area pointer to the area that will be populated with the reserved |
Andy Gross | 71e8831 | 2011-12-05 19:19:21 -0600 | [diff] [blame] | 204 | * area |
| 205 | * |
| 206 | * @return 0 on success, non-0 error value on failure. |
| 207 | */ |
| 208 | static s32 sita_reserve_2d(struct tcm *tcm, u16 h, u16 w, u8 align, |
| 209 | struct tcm_area *area) |
| 210 | { |
| 211 | s32 ret; |
| 212 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; |
| 213 | |
| 214 | /* not supporting more than 64 as alignment */ |
| 215 | if (align > 64) |
| 216 | return -EINVAL; |
| 217 | |
| 218 | /* we prefer 1, 32 and 64 as alignment */ |
| 219 | align = align <= 1 ? 1 : align <= 32 ? 32 : 64; |
| 220 | |
| 221 | spin_lock(&(pvt->lock)); |
| 222 | ret = scan_areas_and_find_fit(tcm, w, h, align, area); |
| 223 | if (!ret) |
| 224 | /* update map */ |
| 225 | fill_area(tcm, area, area); |
| 226 | |
| 227 | spin_unlock(&(pvt->lock)); |
| 228 | return ret; |
| 229 | } |
| 230 | |
| 231 | /** |
| 232 | * Unreserve a previously allocated 2D or 1D area |
| 233 | * @param area area to be freed |
| 234 | * @return 0 - success |
| 235 | */ |
| 236 | static s32 sita_free(struct tcm *tcm, struct tcm_area *area) |
| 237 | { |
| 238 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; |
| 239 | |
| 240 | spin_lock(&(pvt->lock)); |
| 241 | |
| 242 | /* check that this is in fact an existing area */ |
| 243 | WARN_ON(pvt->map[area->p0.x][area->p0.y] != area || |
| 244 | pvt->map[area->p1.x][area->p1.y] != area); |
| 245 | |
| 246 | /* Clear the contents of the associated tiles in the map */ |
| 247 | fill_area(tcm, area, NULL); |
| 248 | |
| 249 | spin_unlock(&(pvt->lock)); |
| 250 | |
| 251 | return 0; |
| 252 | } |
| 253 | |
| 254 | /** |
| 255 | * Note: In general the cordinates in the scan field area relevant to the can |
| 256 | * sweep directions. The scan origin (e.g. top-left corner) will always be |
| 257 | * the p0 member of the field. Therfore, for a scan from top-left p0.x <= p1.x |
| 258 | * and p0.y <= p1.y; whereas, for a scan from bottom-right p1.x <= p0.x and p1.y |
| 259 | * <= p0.y |
| 260 | */ |
| 261 | |
| 262 | /** |
| 263 | * Raster scan horizontally right to left from top to bottom to find a place for |
| 264 | * a 2D area of given size inside a scan field. |
| 265 | * |
| 266 | * @param w width of desired area |
| 267 | * @param h height of desired area |
| 268 | * @param align desired area alignment |
| 269 | * @param area pointer to the area that will be set to the best position |
| 270 | * @param field area to scan (inclusive) |
| 271 | * |
| 272 | * @return 0 on success, non-0 error value on failure. |
| 273 | */ |
| 274 | static s32 scan_r2l_t2b(struct tcm *tcm, u16 w, u16 h, u16 align, |
| 275 | struct tcm_area *field, struct tcm_area *area) |
| 276 | { |
| 277 | s32 x, y; |
| 278 | s16 start_x, end_x, start_y, end_y, found_x = -1; |
| 279 | struct tcm_area ***map = ((struct sita_pvt *)tcm->pvt)->map; |
| 280 | struct score best = {{0}, {0}, {0}, 0}; |
| 281 | |
| 282 | start_x = field->p0.x; |
| 283 | end_x = field->p1.x; |
| 284 | start_y = field->p0.y; |
| 285 | end_y = field->p1.y; |
| 286 | |
| 287 | /* check scan area co-ordinates */ |
| 288 | if (field->p0.x < field->p1.x || |
| 289 | field->p1.y < field->p0.y) |
| 290 | return -EINVAL; |
| 291 | |
| 292 | /* check if allocation would fit in scan area */ |
| 293 | if (w > LEN(start_x, end_x) || h > LEN(end_y, start_y)) |
| 294 | return -ENOSPC; |
| 295 | |
| 296 | /* adjust start_x and end_y, as allocation would not fit beyond */ |
| 297 | start_x = ALIGN_DOWN(start_x - w + 1, align); /* - 1 to be inclusive */ |
| 298 | end_y = end_y - h + 1; |
| 299 | |
| 300 | /* check if allocation would still fit in scan area */ |
| 301 | if (start_x < end_x) |
| 302 | return -ENOSPC; |
| 303 | |
| 304 | /* scan field top-to-bottom, right-to-left */ |
| 305 | for (y = start_y; y <= end_y; y++) { |
| 306 | for (x = start_x; x >= end_x; x -= align) { |
| 307 | if (is_area_free(map, x, y, w, h)) { |
| 308 | found_x = x; |
| 309 | |
| 310 | /* update best candidate */ |
| 311 | if (update_candidate(tcm, x, y, w, h, field, |
| 312 | CR_R2L_T2B, &best)) |
| 313 | goto done; |
| 314 | |
| 315 | /* change upper x bound */ |
| 316 | end_x = x + 1; |
| 317 | break; |
| 318 | } else if (map[x][y] && map[x][y]->is2d) { |
| 319 | /* step over 2D areas */ |
| 320 | x = ALIGN(map[x][y]->p0.x - w + 1, align); |
| 321 | } |
| 322 | } |
| 323 | |
| 324 | /* break if you find a free area shouldering the scan field */ |
| 325 | if (found_x == start_x) |
| 326 | break; |
| 327 | } |
| 328 | |
| 329 | if (!best.a.tcm) |
| 330 | return -ENOSPC; |
| 331 | done: |
| 332 | assign(area, best.a.p0.x, best.a.p0.y, best.a.p1.x, best.a.p1.y); |
| 333 | return 0; |
| 334 | } |
| 335 | |
| 336 | /** |
| 337 | * Raster scan horizontally left to right from top to bottom to find a place for |
| 338 | * a 2D area of given size inside a scan field. |
| 339 | * |
| 340 | * @param w width of desired area |
| 341 | * @param h height of desired area |
| 342 | * @param align desired area alignment |
| 343 | * @param area pointer to the area that will be set to the best position |
| 344 | * @param field area to scan (inclusive) |
| 345 | * |
| 346 | * @return 0 on success, non-0 error value on failure. |
| 347 | */ |
| 348 | static s32 scan_l2r_t2b(struct tcm *tcm, u16 w, u16 h, u16 align, |
| 349 | struct tcm_area *field, struct tcm_area *area) |
| 350 | { |
| 351 | s32 x, y; |
| 352 | s16 start_x, end_x, start_y, end_y, found_x = -1; |
| 353 | struct tcm_area ***map = ((struct sita_pvt *)tcm->pvt)->map; |
| 354 | struct score best = {{0}, {0}, {0}, 0}; |
| 355 | |
| 356 | start_x = field->p0.x; |
| 357 | end_x = field->p1.x; |
| 358 | start_y = field->p0.y; |
| 359 | end_y = field->p1.y; |
| 360 | |
| 361 | /* check scan area co-ordinates */ |
| 362 | if (field->p1.x < field->p0.x || |
| 363 | field->p1.y < field->p0.y) |
| 364 | return -EINVAL; |
| 365 | |
| 366 | /* check if allocation would fit in scan area */ |
| 367 | if (w > LEN(end_x, start_x) || h > LEN(end_y, start_y)) |
| 368 | return -ENOSPC; |
| 369 | |
| 370 | start_x = ALIGN(start_x, align); |
| 371 | |
| 372 | /* check if allocation would still fit in scan area */ |
| 373 | if (w > LEN(end_x, start_x)) |
| 374 | return -ENOSPC; |
| 375 | |
| 376 | /* adjust end_x and end_y, as allocation would not fit beyond */ |
| 377 | end_x = end_x - w + 1; /* + 1 to be inclusive */ |
| 378 | end_y = end_y - h + 1; |
| 379 | |
| 380 | /* scan field top-to-bottom, left-to-right */ |
| 381 | for (y = start_y; y <= end_y; y++) { |
| 382 | for (x = start_x; x <= end_x; x += align) { |
| 383 | if (is_area_free(map, x, y, w, h)) { |
| 384 | found_x = x; |
| 385 | |
| 386 | /* update best candidate */ |
| 387 | if (update_candidate(tcm, x, y, w, h, field, |
| 388 | CR_L2R_T2B, &best)) |
| 389 | goto done; |
| 390 | /* change upper x bound */ |
| 391 | end_x = x - 1; |
| 392 | |
| 393 | break; |
| 394 | } else if (map[x][y] && map[x][y]->is2d) { |
| 395 | /* step over 2D areas */ |
| 396 | x = ALIGN_DOWN(map[x][y]->p1.x, align); |
| 397 | } |
| 398 | } |
| 399 | |
| 400 | /* break if you find a free area shouldering the scan field */ |
| 401 | if (found_x == start_x) |
| 402 | break; |
| 403 | } |
| 404 | |
| 405 | if (!best.a.tcm) |
| 406 | return -ENOSPC; |
| 407 | done: |
| 408 | assign(area, best.a.p0.x, best.a.p0.y, best.a.p1.x, best.a.p1.y); |
| 409 | return 0; |
| 410 | } |
| 411 | |
| 412 | /** |
| 413 | * Raster scan horizontally right to left from bottom to top to find a place |
| 414 | * for a 1D area of given size inside a scan field. |
| 415 | * |
| 416 | * @param num_slots size of desired area |
| 417 | * @param align desired area alignment |
| 418 | * @param area pointer to the area that will be set to the best |
| 419 | * position |
| 420 | * @param field area to scan (inclusive) |
| 421 | * |
| 422 | * @return 0 on success, non-0 error value on failure. |
| 423 | */ |
| 424 | static s32 scan_r2l_b2t_one_dim(struct tcm *tcm, u32 num_slots, |
| 425 | struct tcm_area *field, struct tcm_area *area) |
| 426 | { |
| 427 | s32 found = 0; |
| 428 | s16 x, y; |
| 429 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; |
| 430 | struct tcm_area *p; |
| 431 | |
| 432 | /* check scan area co-ordinates */ |
| 433 | if (field->p0.y < field->p1.y) |
| 434 | return -EINVAL; |
| 435 | |
| 436 | /** |
| 437 | * Currently we only support full width 1D scan field, which makes sense |
| 438 | * since 1D slot-ordering spans the full container width. |
| 439 | */ |
| 440 | if (tcm->width != field->p0.x - field->p1.x + 1) |
| 441 | return -EINVAL; |
| 442 | |
| 443 | /* check if allocation would fit in scan area */ |
| 444 | if (num_slots > tcm->width * LEN(field->p0.y, field->p1.y)) |
| 445 | return -ENOSPC; |
| 446 | |
| 447 | x = field->p0.x; |
| 448 | y = field->p0.y; |
| 449 | |
| 450 | /* find num_slots consecutive free slots to the left */ |
| 451 | while (found < num_slots) { |
| 452 | if (y < 0) |
| 453 | return -ENOSPC; |
| 454 | |
| 455 | /* remember bottom-right corner */ |
| 456 | if (found == 0) { |
| 457 | area->p1.x = x; |
| 458 | area->p1.y = y; |
| 459 | } |
| 460 | |
| 461 | /* skip busy regions */ |
| 462 | p = pvt->map[x][y]; |
| 463 | if (p) { |
| 464 | /* move to left of 2D areas, top left of 1D */ |
| 465 | x = p->p0.x; |
| 466 | if (!p->is2d) |
| 467 | y = p->p0.y; |
| 468 | |
| 469 | /* start over */ |
| 470 | found = 0; |
| 471 | } else { |
| 472 | /* count consecutive free slots */ |
| 473 | found++; |
| 474 | if (found == num_slots) |
| 475 | break; |
| 476 | } |
| 477 | |
| 478 | /* move to the left */ |
| 479 | if (x == 0) |
| 480 | y--; |
| 481 | x = (x ? : tcm->width) - 1; |
| 482 | |
| 483 | } |
| 484 | |
| 485 | /* set top-left corner */ |
| 486 | area->p0.x = x; |
| 487 | area->p0.y = y; |
| 488 | return 0; |
| 489 | } |
| 490 | |
| 491 | /** |
| 492 | * Find a place for a 2D area of given size inside a scan field based on its |
| 493 | * alignment needs. |
| 494 | * |
| 495 | * @param w width of desired area |
| 496 | * @param h height of desired area |
| 497 | * @param align desired area alignment |
| 498 | * @param area pointer to the area that will be set to the best position |
| 499 | * |
| 500 | * @return 0 on success, non-0 error value on failure. |
| 501 | */ |
| 502 | static s32 scan_areas_and_find_fit(struct tcm *tcm, u16 w, u16 h, u16 align, |
| 503 | struct tcm_area *area) |
| 504 | { |
| 505 | s32 ret = 0; |
| 506 | struct tcm_area field = {0}; |
| 507 | u16 boundary_x, boundary_y; |
| 508 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; |
| 509 | |
| 510 | if (align > 1) { |
| 511 | /* prefer top-left corner */ |
| 512 | boundary_x = pvt->div_pt.x - 1; |
| 513 | boundary_y = pvt->div_pt.y - 1; |
| 514 | |
| 515 | /* expand width and height if needed */ |
| 516 | if (w > pvt->div_pt.x) |
| 517 | boundary_x = tcm->width - 1; |
| 518 | if (h > pvt->div_pt.y) |
| 519 | boundary_y = tcm->height - 1; |
| 520 | |
| 521 | assign(&field, 0, 0, boundary_x, boundary_y); |
| 522 | ret = scan_l2r_t2b(tcm, w, h, align, &field, area); |
| 523 | |
| 524 | /* scan whole container if failed, but do not scan 2x */ |
| 525 | if (ret != 0 && (boundary_x != tcm->width - 1 || |
| 526 | boundary_y != tcm->height - 1)) { |
| 527 | /* scan the entire container if nothing found */ |
| 528 | assign(&field, 0, 0, tcm->width - 1, tcm->height - 1); |
| 529 | ret = scan_l2r_t2b(tcm, w, h, align, &field, area); |
| 530 | } |
| 531 | } else if (align == 1) { |
| 532 | /* prefer top-right corner */ |
| 533 | boundary_x = pvt->div_pt.x; |
| 534 | boundary_y = pvt->div_pt.y - 1; |
| 535 | |
| 536 | /* expand width and height if needed */ |
| 537 | if (w > (tcm->width - pvt->div_pt.x)) |
| 538 | boundary_x = 0; |
| 539 | if (h > pvt->div_pt.y) |
| 540 | boundary_y = tcm->height - 1; |
| 541 | |
| 542 | assign(&field, tcm->width - 1, 0, boundary_x, boundary_y); |
| 543 | ret = scan_r2l_t2b(tcm, w, h, align, &field, area); |
| 544 | |
| 545 | /* scan whole container if failed, but do not scan 2x */ |
| 546 | if (ret != 0 && (boundary_x != 0 || |
| 547 | boundary_y != tcm->height - 1)) { |
| 548 | /* scan the entire container if nothing found */ |
| 549 | assign(&field, tcm->width - 1, 0, 0, tcm->height - 1); |
| 550 | ret = scan_r2l_t2b(tcm, w, h, align, &field, |
| 551 | area); |
| 552 | } |
| 553 | } |
| 554 | |
| 555 | return ret; |
| 556 | } |
| 557 | |
| 558 | /* check if an entire area is free */ |
| 559 | static s32 is_area_free(struct tcm_area ***map, u16 x0, u16 y0, u16 w, u16 h) |
| 560 | { |
| 561 | u16 x = 0, y = 0; |
| 562 | for (y = y0; y < y0 + h; y++) { |
| 563 | for (x = x0; x < x0 + w; x++) { |
| 564 | if (map[x][y]) |
| 565 | return false; |
| 566 | } |
| 567 | } |
| 568 | return true; |
| 569 | } |
| 570 | |
| 571 | /* fills an area with a parent tcm_area */ |
| 572 | static void fill_area(struct tcm *tcm, struct tcm_area *area, |
| 573 | struct tcm_area *parent) |
| 574 | { |
| 575 | s32 x, y; |
| 576 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; |
| 577 | struct tcm_area a, a_; |
| 578 | |
| 579 | /* set area's tcm; otherwise, enumerator considers it invalid */ |
| 580 | area->tcm = tcm; |
| 581 | |
| 582 | tcm_for_each_slice(a, *area, a_) { |
| 583 | for (x = a.p0.x; x <= a.p1.x; ++x) |
| 584 | for (y = a.p0.y; y <= a.p1.y; ++y) |
| 585 | pvt->map[x][y] = parent; |
| 586 | |
| 587 | } |
| 588 | } |
| 589 | |
| 590 | /** |
| 591 | * Compares a candidate area to the current best area, and if it is a better |
| 592 | * fit, it updates the best to this one. |
| 593 | * |
| 594 | * @param x0, y0, w, h top, left, width, height of candidate area |
| 595 | * @param field scan field |
| 596 | * @param criteria scan criteria |
| 597 | * @param best best candidate and its scores |
| 598 | * |
| 599 | * @return 1 (true) if the candidate area is known to be the final best, so no |
| 600 | * more searching should be performed |
| 601 | */ |
| 602 | static s32 update_candidate(struct tcm *tcm, u16 x0, u16 y0, u16 w, u16 h, |
| 603 | struct tcm_area *field, s32 criteria, |
| 604 | struct score *best) |
| 605 | { |
| 606 | struct score me; /* score for area */ |
| 607 | |
| 608 | /* |
| 609 | * NOTE: For horizontal bias we always give the first found, because our |
| 610 | * scan is horizontal-raster-based and the first candidate will always |
| 611 | * have the horizontal bias. |
| 612 | */ |
| 613 | bool first = criteria & CR_BIAS_HORIZONTAL; |
| 614 | |
| 615 | assign(&me.a, x0, y0, x0 + w - 1, y0 + h - 1); |
| 616 | |
| 617 | /* calculate score for current candidate */ |
| 618 | if (!first) { |
| 619 | get_neighbor_stats(tcm, &me.a, &me.n); |
| 620 | me.neighs = me.n.edge + me.n.busy; |
| 621 | get_nearness_factor(field, &me.a, &me.f); |
| 622 | } |
| 623 | |
| 624 | /* the 1st candidate is always the best */ |
| 625 | if (!best->a.tcm) |
| 626 | goto better; |
| 627 | |
| 628 | BUG_ON(first); |
| 629 | |
| 630 | /* diagonal balance check */ |
| 631 | if ((criteria & CR_DIAGONAL_BALANCE) && |
| 632 | best->neighs <= me.neighs && |
| 633 | (best->neighs < me.neighs || |
| 634 | /* this implies that neighs and occupied match */ |
| 635 | best->n.busy < me.n.busy || |
| 636 | (best->n.busy == me.n.busy && |
| 637 | /* check the nearness factor */ |
| 638 | best->f.x + best->f.y > me.f.x + me.f.y))) |
| 639 | goto better; |
| 640 | |
| 641 | /* not better, keep going */ |
| 642 | return 0; |
| 643 | |
| 644 | better: |
| 645 | /* save current area as best */ |
| 646 | memcpy(best, &me, sizeof(me)); |
| 647 | best->a.tcm = tcm; |
| 648 | return first; |
| 649 | } |
| 650 | |
| 651 | /** |
| 652 | * Calculate the nearness factor of an area in a search field. The nearness |
| 653 | * factor is smaller if the area is closer to the search origin. |
| 654 | */ |
| 655 | static void get_nearness_factor(struct tcm_area *field, struct tcm_area *area, |
| 656 | struct nearness_factor *nf) |
| 657 | { |
| 658 | /** |
| 659 | * Using signed math as field coordinates may be reversed if |
| 660 | * search direction is right-to-left or bottom-to-top. |
| 661 | */ |
| 662 | nf->x = (s32)(area->p0.x - field->p0.x) * 1000 / |
| 663 | (field->p1.x - field->p0.x); |
| 664 | nf->y = (s32)(area->p0.y - field->p0.y) * 1000 / |
| 665 | (field->p1.y - field->p0.y); |
| 666 | } |
| 667 | |
| 668 | /* get neighbor statistics */ |
| 669 | static void get_neighbor_stats(struct tcm *tcm, struct tcm_area *area, |
| 670 | struct neighbor_stats *stat) |
| 671 | { |
| 672 | s16 x = 0, y = 0; |
| 673 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; |
| 674 | |
| 675 | /* Clearing any exisiting values */ |
| 676 | memset(stat, 0, sizeof(*stat)); |
| 677 | |
| 678 | /* process top & bottom edges */ |
| 679 | for (x = area->p0.x; x <= area->p1.x; x++) { |
| 680 | if (area->p0.y == 0) |
| 681 | stat->edge++; |
| 682 | else if (pvt->map[x][area->p0.y - 1]) |
| 683 | stat->busy++; |
| 684 | |
| 685 | if (area->p1.y == tcm->height - 1) |
| 686 | stat->edge++; |
| 687 | else if (pvt->map[x][area->p1.y + 1]) |
| 688 | stat->busy++; |
| 689 | } |
| 690 | |
| 691 | /* process left & right edges */ |
| 692 | for (y = area->p0.y; y <= area->p1.y; ++y) { |
| 693 | if (area->p0.x == 0) |
| 694 | stat->edge++; |
| 695 | else if (pvt->map[area->p0.x - 1][y]) |
| 696 | stat->busy++; |
| 697 | |
| 698 | if (area->p1.x == tcm->width - 1) |
| 699 | stat->edge++; |
| 700 | else if (pvt->map[area->p1.x + 1][y]) |
| 701 | stat->busy++; |
| 702 | } |
| 703 | } |