diff options
Diffstat (limited to 'kernel/drivers/gpu/drm/omapdrm/tcm-sita.c')
| -rw-r--r-- | kernel/drivers/gpu/drm/omapdrm/tcm-sita.c | 703 |
1 files changed, 703 insertions, 0 deletions
diff --git a/kernel/drivers/gpu/drm/omapdrm/tcm-sita.c b/kernel/drivers/gpu/drm/omapdrm/tcm-sita.c new file mode 100644 index 000000000..efb609510 --- /dev/null +++ b/kernel/drivers/gpu/drm/omapdrm/tcm-sita.c @@ -0,0 +1,703 @@ +/* + * tcm-sita.c + * + * SImple Tiler Allocator (SiTA): 2D and 1D allocation(reservation) algorithm + * + * Authors: Ravi Ramachandra <r.ramachandra@ti.com>, + * Lajos Molnar <molnar@ti.com> + * + * Copyright (C) 2009-2010 Texas Instruments, Inc. + * + * This package is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. + * + */ +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include "tcm-sita.h" + +#define ALIGN_DOWN(value, align) ((value) & ~((align) - 1)) + +/* Individual selection criteria for different scan areas */ +static s32 CR_L2R_T2B = CR_BIAS_HORIZONTAL; +static s32 CR_R2L_T2B = CR_DIAGONAL_BALANCE; + +/********************************************* + * TCM API - Sita Implementation + *********************************************/ +static s32 sita_reserve_2d(struct tcm *tcm, u16 h, u16 w, u8 align, + struct tcm_area *area); +static s32 sita_reserve_1d(struct tcm *tcm, u32 slots, struct tcm_area *area); +static s32 sita_free(struct tcm *tcm, struct tcm_area *area); +static void sita_deinit(struct tcm *tcm); + +/********************************************* + * Main Scanner functions + *********************************************/ +static s32 scan_areas_and_find_fit(struct tcm *tcm, u16 w, u16 h, u16 align, + struct tcm_area *area); + +static s32 scan_l2r_t2b(struct tcm *tcm, u16 w, u16 h, u16 align, + struct tcm_area *field, struct tcm_area *area); + +static s32 scan_r2l_t2b(struct tcm *tcm, u16 w, u16 h, u16 align, + struct tcm_area *field, struct tcm_area *area); + +static s32 scan_r2l_b2t_one_dim(struct tcm *tcm, u32 num_slots, + struct tcm_area *field, struct tcm_area *area); + +/********************************************* + * Support Infrastructure Methods + *********************************************/ +static s32 is_area_free(struct tcm_area ***map, u16 x0, u16 y0, u16 w, u16 h); + +static s32 update_candidate(struct tcm *tcm, u16 x0, u16 y0, u16 w, u16 h, + struct tcm_area *field, s32 criteria, + struct score *best); + +static void get_nearness_factor(struct tcm_area *field, + struct tcm_area *candidate, + struct nearness_factor *nf); + +static void get_neighbor_stats(struct tcm *tcm, struct tcm_area *area, + struct neighbor_stats *stat); + +static void fill_area(struct tcm *tcm, + struct tcm_area *area, struct tcm_area *parent); + + +/*********************************************/ + +/********************************************* + * Utility Methods + *********************************************/ +struct tcm *sita_init(u16 width, u16 height, struct tcm_pt *attr) +{ + struct tcm *tcm; + struct sita_pvt *pvt; + struct tcm_area area = {0}; + s32 i; + + if (width == 0 || height == 0) + return NULL; + + tcm = kmalloc(sizeof(*tcm), GFP_KERNEL); + pvt = kmalloc(sizeof(*pvt), GFP_KERNEL); + if (!tcm || !pvt) + goto error; + + memset(tcm, 0, sizeof(*tcm)); + memset(pvt, 0, sizeof(*pvt)); + + /* Updating the pointers to SiTA implementation APIs */ + tcm->height = height; + tcm->width = width; + tcm->reserve_2d = sita_reserve_2d; + tcm->reserve_1d = sita_reserve_1d; + tcm->free = sita_free; + tcm->deinit = sita_deinit; + tcm->pvt = (void *)pvt; + + spin_lock_init(&(pvt->lock)); + + /* Creating tam map */ + pvt->map = kmalloc(sizeof(*pvt->map) * tcm->width, GFP_KERNEL); + if (!pvt->map) + goto error; + + for (i = 0; i < tcm->width; i++) { + pvt->map[i] = + kmalloc(sizeof(**pvt->map) * tcm->height, + GFP_KERNEL); + if (pvt->map[i] == NULL) { + while (i--) + kfree(pvt->map[i]); + kfree(pvt->map); + goto error; + } + } + + if (attr && attr->x <= tcm->width && attr->y <= tcm->height) { + pvt->div_pt.x = attr->x; + pvt->div_pt.y = attr->y; + + } else { + /* Defaulting to 3:1 ratio on width for 2D area split */ + /* Defaulting to 3:1 ratio on height for 2D and 1D split */ + pvt->div_pt.x = (tcm->width * 3) / 4; + pvt->div_pt.y = (tcm->height * 3) / 4; + } + + spin_lock(&(pvt->lock)); + assign(&area, 0, 0, width - 1, height - 1); + fill_area(tcm, &area, NULL); + spin_unlock(&(pvt->lock)); + return tcm; + +error: + kfree(tcm); + kfree(pvt); + return NULL; +} + +static void sita_deinit(struct tcm *tcm) +{ + struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; + struct tcm_area area = {0}; + s32 i; + + area.p1.x = tcm->width - 1; + area.p1.y = tcm->height - 1; + + spin_lock(&(pvt->lock)); + fill_area(tcm, &area, NULL); + spin_unlock(&(pvt->lock)); + + for (i = 0; i < tcm->height; i++) + kfree(pvt->map[i]); + kfree(pvt->map); + kfree(pvt); +} + +/** + * Reserve a 1D area in the container + * + * @param num_slots size of 1D area + * @param area pointer to the area that will be populated with the + * reserved area + * + * @return 0 on success, non-0 error value on failure. + */ +static s32 sita_reserve_1d(struct tcm *tcm, u32 num_slots, + struct tcm_area *area) +{ + s32 ret; + struct tcm_area field = {0}; + struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; + + spin_lock(&(pvt->lock)); + + /* Scanning entire container */ + assign(&field, tcm->width - 1, tcm->height - 1, 0, 0); + + ret = scan_r2l_b2t_one_dim(tcm, num_slots, &field, area); + if (!ret) + /* update map */ + fill_area(tcm, area, area); + + spin_unlock(&(pvt->lock)); + return ret; +} + +/** + * Reserve a 2D area in the container + * + * @param w width + * @param h height + * @param area pointer to the area that will be populated with the reserved + * area + * + * @return 0 on success, non-0 error value on failure. + */ +static s32 sita_reserve_2d(struct tcm *tcm, u16 h, u16 w, u8 align, + struct tcm_area *area) +{ + s32 ret; + struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; + + /* not supporting more than 64 as alignment */ + if (align > 64) + return -EINVAL; + + /* we prefer 1, 32 and 64 as alignment */ + align = align <= 1 ? 1 : align <= 32 ? 32 : 64; + + spin_lock(&(pvt->lock)); + ret = scan_areas_and_find_fit(tcm, w, h, align, area); + if (!ret) + /* update map */ + fill_area(tcm, area, area); + + spin_unlock(&(pvt->lock)); + return ret; +} + +/** + * Unreserve a previously allocated 2D or 1D area + * @param area area to be freed + * @return 0 - success + */ +static s32 sita_free(struct tcm *tcm, struct tcm_area *area) +{ + struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; + + spin_lock(&(pvt->lock)); + + /* check that this is in fact an existing area */ + WARN_ON(pvt->map[area->p0.x][area->p0.y] != area || + pvt->map[area->p1.x][area->p1.y] != area); + + /* Clear the contents of the associated tiles in the map */ + fill_area(tcm, area, NULL); + + spin_unlock(&(pvt->lock)); + + return 0; +} + +/** + * Note: In general the cordinates in the scan field area relevant to the can + * sweep directions. The scan origin (e.g. top-left corner) will always be + * the p0 member of the field. Therfore, for a scan from top-left p0.x <= p1.x + * and p0.y <= p1.y; whereas, for a scan from bottom-right p1.x <= p0.x and p1.y + * <= p0.y + */ + +/** + * Raster scan horizontally right to left from top to bottom to find a place for + * a 2D area of given size inside a scan field. + * + * @param w width of desired area + * @param h height of desired area + * @param align desired area alignment + * @param area pointer to the area that will be set to the best position + * @param field area to scan (inclusive) + * + * @return 0 on success, non-0 error value on failure. + */ +static s32 scan_r2l_t2b(struct tcm *tcm, u16 w, u16 h, u16 align, + struct tcm_area *field, struct tcm_area *area) +{ + s32 x, y; + s16 start_x, end_x, start_y, end_y, found_x = -1; + struct tcm_area ***map = ((struct sita_pvt *)tcm->pvt)->map; + struct score best = {{0}, {0}, {0}, 0}; + + start_x = field->p0.x; + end_x = field->p1.x; + start_y = field->p0.y; + end_y = field->p1.y; + + /* check scan area co-ordinates */ + if (field->p0.x < field->p1.x || + field->p1.y < field->p0.y) + return -EINVAL; + + /* check if allocation would fit in scan area */ + if (w > LEN(start_x, end_x) || h > LEN(end_y, start_y)) + return -ENOSPC; + + /* adjust start_x and end_y, as allocation would not fit beyond */ + start_x = ALIGN_DOWN(start_x - w + 1, align); /* - 1 to be inclusive */ + end_y = end_y - h + 1; + + /* check if allocation would still fit in scan area */ + if (start_x < end_x) + return -ENOSPC; + + /* scan field top-to-bottom, right-to-left */ + for (y = start_y; y <= end_y; y++) { + for (x = start_x; x >= end_x; x -= align) { + if (is_area_free(map, x, y, w, h)) { + found_x = x; + + /* update best candidate */ + if (update_candidate(tcm, x, y, w, h, field, + CR_R2L_T2B, &best)) + goto done; + + /* change upper x bound */ + end_x = x + 1; + break; + } else if (map[x][y] && map[x][y]->is2d) { + /* step over 2D areas */ + x = ALIGN(map[x][y]->p0.x - w + 1, align); + } + } + + /* break if you find a free area shouldering the scan field */ + if (found_x == start_x) + break; + } + + if (!best.a.tcm) + return -ENOSPC; +done: + assign(area, best.a.p0.x, best.a.p0.y, best.a.p1.x, best.a.p1.y); + return 0; +} + +/** + * Raster scan horizontally left to right from top to bottom to find a place for + * a 2D area of given size inside a scan field. + * + * @param w width of desired area + * @param h height of desired area + * @param align desired area alignment + * @param area pointer to the area that will be set to the best position + * @param field area to scan (inclusive) + * + * @return 0 on success, non-0 error value on failure. + */ +static s32 scan_l2r_t2b(struct tcm *tcm, u16 w, u16 h, u16 align, + struct tcm_area *field, struct tcm_area *area) +{ + s32 x, y; + s16 start_x, end_x, start_y, end_y, found_x = -1; + struct tcm_area ***map = ((struct sita_pvt *)tcm->pvt)->map; + struct score best = {{0}, {0}, {0}, 0}; + + start_x = field->p0.x; + end_x = field->p1.x; + start_y = field->p0.y; + end_y = field->p1.y; + + /* check scan area co-ordinates */ + if (field->p1.x < field->p0.x || + field->p1.y < field->p0.y) + return -EINVAL; + + /* check if allocation would fit in scan area */ + if (w > LEN(end_x, start_x) || h > LEN(end_y, start_y)) + return -ENOSPC; + + start_x = ALIGN(start_x, align); + + /* check if allocation would still fit in scan area */ + if (w > LEN(end_x, start_x)) + return -ENOSPC; + + /* adjust end_x and end_y, as allocation would not fit beyond */ + end_x = end_x - w + 1; /* + 1 to be inclusive */ + end_y = end_y - h + 1; + + /* scan field top-to-bottom, left-to-right */ + for (y = start_y; y <= end_y; y++) { + for (x = start_x; x <= end_x; x += align) { + if (is_area_free(map, x, y, w, h)) { + found_x = x; + + /* update best candidate */ + if (update_candidate(tcm, x, y, w, h, field, + CR_L2R_T2B, &best)) + goto done; + /* change upper x bound */ + end_x = x - 1; + + break; + } else if (map[x][y] && map[x][y]->is2d) { + /* step over 2D areas */ + x = ALIGN_DOWN(map[x][y]->p1.x, align); + } + } + + /* break if you find a free area shouldering the scan field */ + if (found_x == start_x) + break; + } + + if (!best.a.tcm) + return -ENOSPC; +done: + assign(area, best.a.p0.x, best.a.p0.y, best.a.p1.x, best.a.p1.y); + return 0; +} + +/** + * Raster scan horizontally right to left from bottom to top to find a place + * for a 1D area of given size inside a scan field. + * + * @param num_slots size of desired area + * @param align desired area alignment + * @param area pointer to the area that will be set to the best + * position + * @param field area to scan (inclusive) + * + * @return 0 on success, non-0 error value on failure. + */ +static s32 scan_r2l_b2t_one_dim(struct tcm *tcm, u32 num_slots, + struct tcm_area *field, struct tcm_area *area) +{ + s32 found = 0; + s16 x, y; + struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; + struct tcm_area *p; + + /* check scan area co-ordinates */ + if (field->p0.y < field->p1.y) + return -EINVAL; + + /** + * Currently we only support full width 1D scan field, which makes sense + * since 1D slot-ordering spans the full container width. + */ + if (tcm->width != field->p0.x - field->p1.x + 1) + return -EINVAL; + + /* check if allocation would fit in scan area */ + if (num_slots > tcm->width * LEN(field->p0.y, field->p1.y)) + return -ENOSPC; + + x = field->p0.x; + y = field->p0.y; + + /* find num_slots consecutive free slots to the left */ + while (found < num_slots) { + if (y < 0) + return -ENOSPC; + + /* remember bottom-right corner */ + if (found == 0) { + area->p1.x = x; + area->p1.y = y; + } + + /* skip busy regions */ + p = pvt->map[x][y]; + if (p) { + /* move to left of 2D areas, top left of 1D */ + x = p->p0.x; + if (!p->is2d) + y = p->p0.y; + + /* start over */ + found = 0; + } else { + /* count consecutive free slots */ + found++; + if (found == num_slots) + break; + } + + /* move to the left */ + if (x == 0) + y--; + x = (x ? : tcm->width) - 1; + + } + + /* set top-left corner */ + area->p0.x = x; + area->p0.y = y; + return 0; +} + +/** + * Find a place for a 2D area of given size inside a scan field based on its + * alignment needs. + * + * @param w width of desired area + * @param h height of desired area + * @param align desired area alignment + * @param area pointer to the area that will be set to the best position + * + * @return 0 on success, non-0 error value on failure. + */ +static s32 scan_areas_and_find_fit(struct tcm *tcm, u16 w, u16 h, u16 align, + struct tcm_area *area) +{ + s32 ret = 0; + struct tcm_area field = {0}; + u16 boundary_x, boundary_y; + struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; + + if (align > 1) { + /* prefer top-left corner */ + boundary_x = pvt->div_pt.x - 1; + boundary_y = pvt->div_pt.y - 1; + + /* expand width and height if needed */ + if (w > pvt->div_pt.x) + boundary_x = tcm->width - 1; + if (h > pvt->div_pt.y) + boundary_y = tcm->height - 1; + + assign(&field, 0, 0, boundary_x, boundary_y); + ret = scan_l2r_t2b(tcm, w, h, align, &field, area); + + /* scan whole container if failed, but do not scan 2x */ + if (ret != 0 && (boundary_x != tcm->width - 1 || + boundary_y != tcm->height - 1)) { + /* scan the entire container if nothing found */ + assign(&field, 0, 0, tcm->width - 1, tcm->height - 1); + ret = scan_l2r_t2b(tcm, w, h, align, &field, area); + } + } else if (align == 1) { + /* prefer top-right corner */ + boundary_x = pvt->div_pt.x; + boundary_y = pvt->div_pt.y - 1; + + /* expand width and height if needed */ + if (w > (tcm->width - pvt->div_pt.x)) + boundary_x = 0; + if (h > pvt->div_pt.y) + boundary_y = tcm->height - 1; + + assign(&field, tcm->width - 1, 0, boundary_x, boundary_y); + ret = scan_r2l_t2b(tcm, w, h, align, &field, area); + + /* scan whole container if failed, but do not scan 2x */ + if (ret != 0 && (boundary_x != 0 || + boundary_y != tcm->height - 1)) { + /* scan the entire container if nothing found */ + assign(&field, tcm->width - 1, 0, 0, tcm->height - 1); + ret = scan_r2l_t2b(tcm, w, h, align, &field, + area); + } + } + + return ret; +} + +/* check if an entire area is free */ +static s32 is_area_free(struct tcm_area ***map, u16 x0, u16 y0, u16 w, u16 h) +{ + u16 x = 0, y = 0; + for (y = y0; y < y0 + h; y++) { + for (x = x0; x < x0 + w; x++) { + if (map[x][y]) + return false; + } + } + return true; +} + +/* fills an area with a parent tcm_area */ +static void fill_area(struct tcm *tcm, struct tcm_area *area, + struct tcm_area *parent) +{ + s32 x, y; + struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; + struct tcm_area a, a_; + + /* set area's tcm; otherwise, enumerator considers it invalid */ + area->tcm = tcm; + + tcm_for_each_slice(a, *area, a_) { + for (x = a.p0.x; x <= a.p1.x; ++x) + for (y = a.p0.y; y <= a.p1.y; ++y) + pvt->map[x][y] = parent; + + } +} + +/** + * Compares a candidate area to the current best area, and if it is a better + * fit, it updates the best to this one. + * + * @param x0, y0, w, h top, left, width, height of candidate area + * @param field scan field + * @param criteria scan criteria + * @param best best candidate and its scores + * + * @return 1 (true) if the candidate area is known to be the final best, so no + * more searching should be performed + */ +static s32 update_candidate(struct tcm *tcm, u16 x0, u16 y0, u16 w, u16 h, + struct tcm_area *field, s32 criteria, + struct score *best) +{ + struct score me; /* score for area */ + + /* + * NOTE: For horizontal bias we always give the first found, because our + * scan is horizontal-raster-based and the first candidate will always + * have the horizontal bias. + */ + bool first = criteria & CR_BIAS_HORIZONTAL; + + assign(&me.a, x0, y0, x0 + w - 1, y0 + h - 1); + + /* calculate score for current candidate */ + if (!first) { + get_neighbor_stats(tcm, &me.a, &me.n); + me.neighs = me.n.edge + me.n.busy; + get_nearness_factor(field, &me.a, &me.f); + } + + /* the 1st candidate is always the best */ + if (!best->a.tcm) + goto better; + + BUG_ON(first); + + /* diagonal balance check */ + if ((criteria & CR_DIAGONAL_BALANCE) && + best->neighs <= me.neighs && + (best->neighs < me.neighs || + /* this implies that neighs and occupied match */ + best->n.busy < me.n.busy || + (best->n.busy == me.n.busy && + /* check the nearness factor */ + best->f.x + best->f.y > me.f.x + me.f.y))) + goto better; + + /* not better, keep going */ + return 0; + +better: + /* save current area as best */ + memcpy(best, &me, sizeof(me)); + best->a.tcm = tcm; + return first; +} + +/** + * Calculate the nearness factor of an area in a search field. The nearness + * factor is smaller if the area is closer to the search origin. + */ +static void get_nearness_factor(struct tcm_area *field, struct tcm_area *area, + struct nearness_factor *nf) +{ + /** + * Using signed math as field coordinates may be reversed if + * search direction is right-to-left or bottom-to-top. + */ + nf->x = (s32)(area->p0.x - field->p0.x) * 1000 / + (field->p1.x - field->p0.x); + nf->y = (s32)(area->p0.y - field->p0.y) * 1000 / + (field->p1.y - field->p0.y); +} + +/* get neighbor statistics */ +static void get_neighbor_stats(struct tcm *tcm, struct tcm_area *area, + struct neighbor_stats *stat) +{ + s16 x = 0, y = 0; + struct sita_pvt *pvt = (struct sita_pvt *)tcm->pvt; + + /* Clearing any exisiting values */ + memset(stat, 0, sizeof(*stat)); + + /* process top & bottom edges */ + for (x = area->p0.x; x <= area->p1.x; x++) { + if (area->p0.y == 0) + stat->edge++; + else if (pvt->map[x][area->p0.y - 1]) + stat->busy++; + + if (area->p1.y == tcm->height - 1) + stat->edge++; + else if (pvt->map[x][area->p1.y + 1]) + stat->busy++; + } + + /* process left & right edges */ + for (y = area->p0.y; y <= area->p1.y; ++y) { + if (area->p0.x == 0) + stat->edge++; + else if (pvt->map[area->p0.x - 1][y]) + stat->busy++; + + if (area->p1.x == tcm->width - 1) + stat->edge++; + else if (pvt->map[area->p1.x + 1][y]) + stat->busy++; + } +} |