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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 | ||
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 | |
6354eb81 | 203 | * @param area pointer to the area that will be populated with the reserved |
71e8831f AG |
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 | } |