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71e8831f AG |
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 | ||
07a6dc19 RV |
90 | tcm = kzalloc(sizeof(*tcm), GFP_KERNEL); |
91 | pvt = kzalloc(sizeof(*pvt), GFP_KERNEL); | |
71e8831f AG |
92 | if (!tcm || !pvt) |
93 | goto error; | |
94 | ||
71e8831f AG |
95 | /* Updating the pointers to SiTA implementation APIs */ |
96 | tcm->height = height; | |
97 | tcm->width = width; | |
98 | tcm->reserve_2d = sita_reserve_2d; | |
99 | tcm->reserve_1d = sita_reserve_1d; | |
100 | tcm->free = sita_free; | |
101 | tcm->deinit = sita_deinit; | |
102 | tcm->pvt = (void *)pvt; | |
103 | ||
104 | spin_lock_init(&(pvt->lock)); | |
105 | ||
106 | /* Creating tam map */ | |
107 | pvt->map = kmalloc(sizeof(*pvt->map) * tcm->width, GFP_KERNEL); | |
108 | if (!pvt->map) | |
109 | goto error; | |
110 | ||
111 | for (i = 0; i < tcm->width; i++) { | |
112 | pvt->map[i] = | |
113 | kmalloc(sizeof(**pvt->map) * tcm->height, | |
114 | GFP_KERNEL); | |
115 | if (pvt->map[i] == NULL) { | |
116 | while (i--) | |
117 | kfree(pvt->map[i]); | |
118 | kfree(pvt->map); | |
119 | goto error; | |
120 | } | |
121 | } | |
122 | ||
123 | if (attr && attr->x <= tcm->width && attr->y <= tcm->height) { | |
124 | pvt->div_pt.x = attr->x; | |
125 | pvt->div_pt.y = attr->y; | |
126 | ||
127 | } else { | |
128 | /* Defaulting to 3:1 ratio on width for 2D area split */ | |
129 | /* Defaulting to 3:1 ratio on height for 2D and 1D split */ | |
130 | pvt->div_pt.x = (tcm->width * 3) / 4; | |
131 | pvt->div_pt.y = (tcm->height * 3) / 4; | |
132 | } | |
133 | ||
134 | spin_lock(&(pvt->lock)); | |
135 | assign(&area, 0, 0, width - 1, height - 1); | |
136 | fill_area(tcm, &area, NULL); | |
137 | spin_unlock(&(pvt->lock)); | |
138 | return tcm; | |
139 | ||
140 | error: | |
141 | kfree(tcm); | |
142 | kfree(pvt); | |
143 | return NULL; | |
144 | } | |
145 | ||
146 | static void sita_deinit(struct tcm *tcm) | |
147 | { | |
148 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; | |
149 | struct tcm_area area = {0}; | |
150 | s32 i; | |
151 | ||
152 | area.p1.x = tcm->width - 1; | |
153 | area.p1.y = tcm->height - 1; | |
154 | ||
155 | spin_lock(&(pvt->lock)); | |
156 | fill_area(tcm, &area, NULL); | |
157 | spin_unlock(&(pvt->lock)); | |
158 | ||
159 | for (i = 0; i < tcm->height; i++) | |
160 | kfree(pvt->map[i]); | |
161 | kfree(pvt->map); | |
162 | kfree(pvt); | |
163 | } | |
164 | ||
165 | /** | |
166 | * Reserve a 1D area in the container | |
167 | * | |
168 | * @param num_slots size of 1D area | |
169 | * @param area pointer to the area that will be populated with the | |
170 | * reserved area | |
171 | * | |
172 | * @return 0 on success, non-0 error value on failure. | |
173 | */ | |
174 | static s32 sita_reserve_1d(struct tcm *tcm, u32 num_slots, | |
175 | struct tcm_area *area) | |
176 | { | |
177 | s32 ret; | |
178 | struct tcm_area field = {0}; | |
179 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; | |
180 | ||
181 | spin_lock(&(pvt->lock)); | |
182 | ||
183 | /* Scanning entire container */ | |
184 | assign(&field, tcm->width - 1, tcm->height - 1, 0, 0); | |
185 | ||
186 | ret = scan_r2l_b2t_one_dim(tcm, num_slots, &field, area); | |
187 | if (!ret) | |
188 | /* update map */ | |
189 | fill_area(tcm, area, area); | |
190 | ||
191 | spin_unlock(&(pvt->lock)); | |
192 | return ret; | |
193 | } | |
194 | ||
195 | /** | |
196 | * Reserve a 2D area in the container | |
197 | * | |
198 | * @param w width | |
199 | * @param h height | |
6354eb81 | 200 | * @param area pointer to the area that will be populated with the reserved |
71e8831f AG |
201 | * area |
202 | * | |
203 | * @return 0 on success, non-0 error value on failure. | |
204 | */ | |
205 | static s32 sita_reserve_2d(struct tcm *tcm, u16 h, u16 w, u8 align, | |
206 | struct tcm_area *area) | |
207 | { | |
208 | s32 ret; | |
209 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; | |
210 | ||
211 | /* not supporting more than 64 as alignment */ | |
212 | if (align > 64) | |
213 | return -EINVAL; | |
214 | ||
215 | /* we prefer 1, 32 and 64 as alignment */ | |
216 | align = align <= 1 ? 1 : align <= 32 ? 32 : 64; | |
217 | ||
218 | spin_lock(&(pvt->lock)); | |
219 | ret = scan_areas_and_find_fit(tcm, w, h, align, area); | |
220 | if (!ret) | |
221 | /* update map */ | |
222 | fill_area(tcm, area, area); | |
223 | ||
224 | spin_unlock(&(pvt->lock)); | |
225 | return ret; | |
226 | } | |
227 | ||
228 | /** | |
229 | * Unreserve a previously allocated 2D or 1D area | |
230 | * @param area area to be freed | |
231 | * @return 0 - success | |
232 | */ | |
233 | static s32 sita_free(struct tcm *tcm, struct tcm_area *area) | |
234 | { | |
235 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; | |
236 | ||
237 | spin_lock(&(pvt->lock)); | |
238 | ||
239 | /* check that this is in fact an existing area */ | |
240 | WARN_ON(pvt->map[area->p0.x][area->p0.y] != area || | |
241 | pvt->map[area->p1.x][area->p1.y] != area); | |
242 | ||
243 | /* Clear the contents of the associated tiles in the map */ | |
244 | fill_area(tcm, area, NULL); | |
245 | ||
246 | spin_unlock(&(pvt->lock)); | |
247 | ||
248 | return 0; | |
249 | } | |
250 | ||
251 | /** | |
252 | * Note: In general the cordinates in the scan field area relevant to the can | |
253 | * sweep directions. The scan origin (e.g. top-left corner) will always be | |
254 | * the p0 member of the field. Therfore, for a scan from top-left p0.x <= p1.x | |
255 | * and p0.y <= p1.y; whereas, for a scan from bottom-right p1.x <= p0.x and p1.y | |
256 | * <= p0.y | |
257 | */ | |
258 | ||
259 | /** | |
260 | * Raster scan horizontally right to left from top to bottom to find a place for | |
261 | * a 2D area of given size inside a scan field. | |
262 | * | |
263 | * @param w width of desired area | |
264 | * @param h height of desired area | |
265 | * @param align desired area alignment | |
266 | * @param area pointer to the area that will be set to the best position | |
267 | * @param field area to scan (inclusive) | |
268 | * | |
269 | * @return 0 on success, non-0 error value on failure. | |
270 | */ | |
271 | static s32 scan_r2l_t2b(struct tcm *tcm, u16 w, u16 h, u16 align, | |
272 | struct tcm_area *field, struct tcm_area *area) | |
273 | { | |
274 | s32 x, y; | |
275 | s16 start_x, end_x, start_y, end_y, found_x = -1; | |
276 | struct tcm_area ***map = ((struct sita_pvt *)tcm->pvt)->map; | |
277 | struct score best = {{0}, {0}, {0}, 0}; | |
278 | ||
279 | start_x = field->p0.x; | |
280 | end_x = field->p1.x; | |
281 | start_y = field->p0.y; | |
282 | end_y = field->p1.y; | |
283 | ||
284 | /* check scan area co-ordinates */ | |
285 | if (field->p0.x < field->p1.x || | |
286 | field->p1.y < field->p0.y) | |
287 | return -EINVAL; | |
288 | ||
289 | /* check if allocation would fit in scan area */ | |
290 | if (w > LEN(start_x, end_x) || h > LEN(end_y, start_y)) | |
291 | return -ENOSPC; | |
292 | ||
293 | /* adjust start_x and end_y, as allocation would not fit beyond */ | |
294 | start_x = ALIGN_DOWN(start_x - w + 1, align); /* - 1 to be inclusive */ | |
295 | end_y = end_y - h + 1; | |
296 | ||
297 | /* check if allocation would still fit in scan area */ | |
298 | if (start_x < end_x) | |
299 | return -ENOSPC; | |
300 | ||
301 | /* scan field top-to-bottom, right-to-left */ | |
302 | for (y = start_y; y <= end_y; y++) { | |
303 | for (x = start_x; x >= end_x; x -= align) { | |
304 | if (is_area_free(map, x, y, w, h)) { | |
305 | found_x = x; | |
306 | ||
307 | /* update best candidate */ | |
308 | if (update_candidate(tcm, x, y, w, h, field, | |
309 | CR_R2L_T2B, &best)) | |
310 | goto done; | |
311 | ||
312 | /* change upper x bound */ | |
313 | end_x = x + 1; | |
314 | break; | |
315 | } else if (map[x][y] && map[x][y]->is2d) { | |
316 | /* step over 2D areas */ | |
317 | x = ALIGN(map[x][y]->p0.x - w + 1, align); | |
318 | } | |
319 | } | |
320 | ||
321 | /* break if you find a free area shouldering the scan field */ | |
322 | if (found_x == start_x) | |
323 | break; | |
324 | } | |
325 | ||
326 | if (!best.a.tcm) | |
327 | return -ENOSPC; | |
328 | done: | |
329 | assign(area, best.a.p0.x, best.a.p0.y, best.a.p1.x, best.a.p1.y); | |
330 | return 0; | |
331 | } | |
332 | ||
333 | /** | |
334 | * Raster scan horizontally left to right from top to bottom to find a place for | |
335 | * a 2D area of given size inside a scan field. | |
336 | * | |
337 | * @param w width of desired area | |
338 | * @param h height of desired area | |
339 | * @param align desired area alignment | |
340 | * @param area pointer to the area that will be set to the best position | |
341 | * @param field area to scan (inclusive) | |
342 | * | |
343 | * @return 0 on success, non-0 error value on failure. | |
344 | */ | |
345 | static s32 scan_l2r_t2b(struct tcm *tcm, u16 w, u16 h, u16 align, | |
346 | struct tcm_area *field, struct tcm_area *area) | |
347 | { | |
348 | s32 x, y; | |
349 | s16 start_x, end_x, start_y, end_y, found_x = -1; | |
350 | struct tcm_area ***map = ((struct sita_pvt *)tcm->pvt)->map; | |
351 | struct score best = {{0}, {0}, {0}, 0}; | |
352 | ||
353 | start_x = field->p0.x; | |
354 | end_x = field->p1.x; | |
355 | start_y = field->p0.y; | |
356 | end_y = field->p1.y; | |
357 | ||
358 | /* check scan area co-ordinates */ | |
359 | if (field->p1.x < field->p0.x || | |
360 | field->p1.y < field->p0.y) | |
361 | return -EINVAL; | |
362 | ||
363 | /* check if allocation would fit in scan area */ | |
364 | if (w > LEN(end_x, start_x) || h > LEN(end_y, start_y)) | |
365 | return -ENOSPC; | |
366 | ||
367 | start_x = ALIGN(start_x, align); | |
368 | ||
369 | /* check if allocation would still fit in scan area */ | |
370 | if (w > LEN(end_x, start_x)) | |
371 | return -ENOSPC; | |
372 | ||
373 | /* adjust end_x and end_y, as allocation would not fit beyond */ | |
374 | end_x = end_x - w + 1; /* + 1 to be inclusive */ | |
375 | end_y = end_y - h + 1; | |
376 | ||
377 | /* scan field top-to-bottom, left-to-right */ | |
378 | for (y = start_y; y <= end_y; y++) { | |
379 | for (x = start_x; x <= end_x; x += align) { | |
380 | if (is_area_free(map, x, y, w, h)) { | |
381 | found_x = x; | |
382 | ||
383 | /* update best candidate */ | |
384 | if (update_candidate(tcm, x, y, w, h, field, | |
385 | CR_L2R_T2B, &best)) | |
386 | goto done; | |
387 | /* change upper x bound */ | |
388 | end_x = x - 1; | |
389 | ||
390 | break; | |
391 | } else if (map[x][y] && map[x][y]->is2d) { | |
392 | /* step over 2D areas */ | |
393 | x = ALIGN_DOWN(map[x][y]->p1.x, align); | |
394 | } | |
395 | } | |
396 | ||
397 | /* break if you find a free area shouldering the scan field */ | |
398 | if (found_x == start_x) | |
399 | break; | |
400 | } | |
401 | ||
402 | if (!best.a.tcm) | |
403 | return -ENOSPC; | |
404 | done: | |
405 | assign(area, best.a.p0.x, best.a.p0.y, best.a.p1.x, best.a.p1.y); | |
406 | return 0; | |
407 | } | |
408 | ||
409 | /** | |
410 | * Raster scan horizontally right to left from bottom to top to find a place | |
411 | * for a 1D area of given size inside a scan field. | |
412 | * | |
413 | * @param num_slots size of desired area | |
414 | * @param align desired area alignment | |
415 | * @param area pointer to the area that will be set to the best | |
416 | * position | |
417 | * @param field area to scan (inclusive) | |
418 | * | |
419 | * @return 0 on success, non-0 error value on failure. | |
420 | */ | |
421 | static s32 scan_r2l_b2t_one_dim(struct tcm *tcm, u32 num_slots, | |
422 | struct tcm_area *field, struct tcm_area *area) | |
423 | { | |
424 | s32 found = 0; | |
425 | s16 x, y; | |
426 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; | |
427 | struct tcm_area *p; | |
428 | ||
429 | /* check scan area co-ordinates */ | |
430 | if (field->p0.y < field->p1.y) | |
431 | return -EINVAL; | |
432 | ||
433 | /** | |
434 | * Currently we only support full width 1D scan field, which makes sense | |
435 | * since 1D slot-ordering spans the full container width. | |
436 | */ | |
437 | if (tcm->width != field->p0.x - field->p1.x + 1) | |
438 | return -EINVAL; | |
439 | ||
440 | /* check if allocation would fit in scan area */ | |
441 | if (num_slots > tcm->width * LEN(field->p0.y, field->p1.y)) | |
442 | return -ENOSPC; | |
443 | ||
444 | x = field->p0.x; | |
445 | y = field->p0.y; | |
446 | ||
447 | /* find num_slots consecutive free slots to the left */ | |
448 | while (found < num_slots) { | |
449 | if (y < 0) | |
450 | return -ENOSPC; | |
451 | ||
452 | /* remember bottom-right corner */ | |
453 | if (found == 0) { | |
454 | area->p1.x = x; | |
455 | area->p1.y = y; | |
456 | } | |
457 | ||
458 | /* skip busy regions */ | |
459 | p = pvt->map[x][y]; | |
460 | if (p) { | |
461 | /* move to left of 2D areas, top left of 1D */ | |
462 | x = p->p0.x; | |
463 | if (!p->is2d) | |
464 | y = p->p0.y; | |
465 | ||
466 | /* start over */ | |
467 | found = 0; | |
468 | } else { | |
469 | /* count consecutive free slots */ | |
470 | found++; | |
471 | if (found == num_slots) | |
472 | break; | |
473 | } | |
474 | ||
475 | /* move to the left */ | |
476 | if (x == 0) | |
477 | y--; | |
478 | x = (x ? : tcm->width) - 1; | |
479 | ||
480 | } | |
481 | ||
482 | /* set top-left corner */ | |
483 | area->p0.x = x; | |
484 | area->p0.y = y; | |
485 | return 0; | |
486 | } | |
487 | ||
488 | /** | |
489 | * Find a place for a 2D area of given size inside a scan field based on its | |
490 | * alignment needs. | |
491 | * | |
492 | * @param w width of desired area | |
493 | * @param h height of desired area | |
494 | * @param align desired area alignment | |
495 | * @param area pointer to the area that will be set to the best position | |
496 | * | |
497 | * @return 0 on success, non-0 error value on failure. | |
498 | */ | |
499 | static s32 scan_areas_and_find_fit(struct tcm *tcm, u16 w, u16 h, u16 align, | |
500 | struct tcm_area *area) | |
501 | { | |
502 | s32 ret = 0; | |
503 | struct tcm_area field = {0}; | |
504 | u16 boundary_x, boundary_y; | |
505 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; | |
506 | ||
507 | if (align > 1) { | |
508 | /* prefer top-left corner */ | |
509 | boundary_x = pvt->div_pt.x - 1; | |
510 | boundary_y = pvt->div_pt.y - 1; | |
511 | ||
512 | /* expand width and height if needed */ | |
513 | if (w > pvt->div_pt.x) | |
514 | boundary_x = tcm->width - 1; | |
515 | if (h > pvt->div_pt.y) | |
516 | boundary_y = tcm->height - 1; | |
517 | ||
518 | assign(&field, 0, 0, boundary_x, boundary_y); | |
519 | ret = scan_l2r_t2b(tcm, w, h, align, &field, area); | |
520 | ||
521 | /* scan whole container if failed, but do not scan 2x */ | |
522 | if (ret != 0 && (boundary_x != tcm->width - 1 || | |
523 | boundary_y != tcm->height - 1)) { | |
524 | /* scan the entire container if nothing found */ | |
525 | assign(&field, 0, 0, tcm->width - 1, tcm->height - 1); | |
526 | ret = scan_l2r_t2b(tcm, w, h, align, &field, area); | |
527 | } | |
528 | } else if (align == 1) { | |
529 | /* prefer top-right corner */ | |
530 | boundary_x = pvt->div_pt.x; | |
531 | boundary_y = pvt->div_pt.y - 1; | |
532 | ||
533 | /* expand width and height if needed */ | |
534 | if (w > (tcm->width - pvt->div_pt.x)) | |
535 | boundary_x = 0; | |
536 | if (h > pvt->div_pt.y) | |
537 | boundary_y = tcm->height - 1; | |
538 | ||
539 | assign(&field, tcm->width - 1, 0, boundary_x, boundary_y); | |
540 | ret = scan_r2l_t2b(tcm, w, h, align, &field, area); | |
541 | ||
542 | /* scan whole container if failed, but do not scan 2x */ | |
543 | if (ret != 0 && (boundary_x != 0 || | |
544 | boundary_y != tcm->height - 1)) { | |
545 | /* scan the entire container if nothing found */ | |
546 | assign(&field, tcm->width - 1, 0, 0, tcm->height - 1); | |
547 | ret = scan_r2l_t2b(tcm, w, h, align, &field, | |
548 | area); | |
549 | } | |
550 | } | |
551 | ||
552 | return ret; | |
553 | } | |
554 | ||
555 | /* check if an entire area is free */ | |
556 | static s32 is_area_free(struct tcm_area ***map, u16 x0, u16 y0, u16 w, u16 h) | |
557 | { | |
558 | u16 x = 0, y = 0; | |
559 | for (y = y0; y < y0 + h; y++) { | |
560 | for (x = x0; x < x0 + w; x++) { | |
561 | if (map[x][y]) | |
562 | return false; | |
563 | } | |
564 | } | |
565 | return true; | |
566 | } | |
567 | ||
568 | /* fills an area with a parent tcm_area */ | |
569 | static void fill_area(struct tcm *tcm, struct tcm_area *area, | |
570 | struct tcm_area *parent) | |
571 | { | |
572 | s32 x, y; | |
573 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; | |
574 | struct tcm_area a, a_; | |
575 | ||
576 | /* set area's tcm; otherwise, enumerator considers it invalid */ | |
577 | area->tcm = tcm; | |
578 | ||
579 | tcm_for_each_slice(a, *area, a_) { | |
580 | for (x = a.p0.x; x <= a.p1.x; ++x) | |
581 | for (y = a.p0.y; y <= a.p1.y; ++y) | |
582 | pvt->map[x][y] = parent; | |
583 | ||
584 | } | |
585 | } | |
586 | ||
587 | /** | |
588 | * Compares a candidate area to the current best area, and if it is a better | |
589 | * fit, it updates the best to this one. | |
590 | * | |
591 | * @param x0, y0, w, h top, left, width, height of candidate area | |
592 | * @param field scan field | |
593 | * @param criteria scan criteria | |
594 | * @param best best candidate and its scores | |
595 | * | |
596 | * @return 1 (true) if the candidate area is known to be the final best, so no | |
597 | * more searching should be performed | |
598 | */ | |
599 | static s32 update_candidate(struct tcm *tcm, u16 x0, u16 y0, u16 w, u16 h, | |
600 | struct tcm_area *field, s32 criteria, | |
601 | struct score *best) | |
602 | { | |
603 | struct score me; /* score for area */ | |
604 | ||
605 | /* | |
606 | * NOTE: For horizontal bias we always give the first found, because our | |
607 | * scan is horizontal-raster-based and the first candidate will always | |
608 | * have the horizontal bias. | |
609 | */ | |
610 | bool first = criteria & CR_BIAS_HORIZONTAL; | |
611 | ||
612 | assign(&me.a, x0, y0, x0 + w - 1, y0 + h - 1); | |
613 | ||
614 | /* calculate score for current candidate */ | |
615 | if (!first) { | |
616 | get_neighbor_stats(tcm, &me.a, &me.n); | |
617 | me.neighs = me.n.edge + me.n.busy; | |
618 | get_nearness_factor(field, &me.a, &me.f); | |
619 | } | |
620 | ||
621 | /* the 1st candidate is always the best */ | |
622 | if (!best->a.tcm) | |
623 | goto better; | |
624 | ||
625 | BUG_ON(first); | |
626 | ||
627 | /* diagonal balance check */ | |
628 | if ((criteria & CR_DIAGONAL_BALANCE) && | |
629 | best->neighs <= me.neighs && | |
630 | (best->neighs < me.neighs || | |
631 | /* this implies that neighs and occupied match */ | |
632 | best->n.busy < me.n.busy || | |
633 | (best->n.busy == me.n.busy && | |
634 | /* check the nearness factor */ | |
635 | best->f.x + best->f.y > me.f.x + me.f.y))) | |
636 | goto better; | |
637 | ||
638 | /* not better, keep going */ | |
639 | return 0; | |
640 | ||
641 | better: | |
642 | /* save current area as best */ | |
643 | memcpy(best, &me, sizeof(me)); | |
644 | best->a.tcm = tcm; | |
645 | return first; | |
646 | } | |
647 | ||
648 | /** | |
649 | * Calculate the nearness factor of an area in a search field. The nearness | |
650 | * factor is smaller if the area is closer to the search origin. | |
651 | */ | |
652 | static void get_nearness_factor(struct tcm_area *field, struct tcm_area *area, | |
653 | struct nearness_factor *nf) | |
654 | { | |
655 | /** | |
656 | * Using signed math as field coordinates may be reversed if | |
657 | * search direction is right-to-left or bottom-to-top. | |
658 | */ | |
659 | nf->x = (s32)(area->p0.x - field->p0.x) * 1000 / | |
660 | (field->p1.x - field->p0.x); | |
661 | nf->y = (s32)(area->p0.y - field->p0.y) * 1000 / | |
662 | (field->p1.y - field->p0.y); | |
663 | } | |
664 | ||
665 | /* get neighbor statistics */ | |
666 | static void get_neighbor_stats(struct tcm *tcm, struct tcm_area *area, | |
667 | struct neighbor_stats *stat) | |
668 | { | |
669 | s16 x = 0, y = 0; | |
670 | struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; | |
671 | ||
672 | /* Clearing any exisiting values */ | |
673 | memset(stat, 0, sizeof(*stat)); | |
674 | ||
675 | /* process top & bottom edges */ | |
676 | for (x = area->p0.x; x <= area->p1.x; x++) { | |
677 | if (area->p0.y == 0) | |
678 | stat->edge++; | |
679 | else if (pvt->map[x][area->p0.y - 1]) | |
680 | stat->busy++; | |
681 | ||
682 | if (area->p1.y == tcm->height - 1) | |
683 | stat->edge++; | |
684 | else if (pvt->map[x][area->p1.y + 1]) | |
685 | stat->busy++; | |
686 | } | |
687 | ||
688 | /* process left & right edges */ | |
689 | for (y = area->p0.y; y <= area->p1.y; ++y) { | |
690 | if (area->p0.x == 0) | |
691 | stat->edge++; | |
692 | else if (pvt->map[area->p0.x - 1][y]) | |
693 | stat->busy++; | |
694 | ||
695 | if (area->p1.x == tcm->width - 1) | |
696 | stat->edge++; | |
697 | else if (pvt->map[area->p1.x + 1][y]) | |
698 | stat->busy++; | |
699 | } | |
700 | } |