[linux.git] / drivers / uwb / allocator.c

/*
 * UWB reservation management.
 *
 * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
 *
 * This program 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 program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/uwb.h>

#include "uwb-internal.h"

static void uwb_rsv_fill_column_alloc(struct uwb_rsv_alloc_info *ai)
{
	int col, mas, safe_mas, unsafe_mas;
	unsigned char *bm = ai->bm;
	struct uwb_rsv_col_info *ci = ai->ci;
	unsigned char c;

	for (col = ci->csi.start_col; col < UWB_NUM_ZONES; col += ci->csi.interval) {
    
		safe_mas   = ci->csi.safe_mas_per_col;
		unsafe_mas = ci->csi.unsafe_mas_per_col;
    
		for (mas = 0; mas < UWB_MAS_PER_ZONE; mas++ ) {
			if (bm[col * UWB_MAS_PER_ZONE + mas] == 0) {
	
				if (safe_mas > 0) {
					safe_mas--;
					c = UWB_RSV_MAS_SAFE;
				} else if (unsafe_mas > 0) {
					unsafe_mas--;
					c = UWB_RSV_MAS_UNSAFE;
				} else {
					break;
				}
				bm[col * UWB_MAS_PER_ZONE + mas] = c;
			}
		}
	}
}

static void uwb_rsv_fill_row_alloc(struct uwb_rsv_alloc_info *ai)
{
	int mas, col, rows;
	unsigned char *bm = ai->bm;
	struct uwb_rsv_row_info *ri = &ai->ri;
	unsigned char c;

	rows = 1;
	c = UWB_RSV_MAS_SAFE;
	for (mas = UWB_MAS_PER_ZONE - 1; mas >= 0; mas--) {
		if (ri->avail[mas] == 1) {
      
			if (rows > ri->used_rows) {
				break;
			} else if (rows > 7) {
				c = UWB_RSV_MAS_UNSAFE;
			}

			for (col = 0; col < UWB_NUM_ZONES; col++) {
				if (bm[col * UWB_NUM_ZONES + mas] != UWB_RSV_MAS_NOT_AVAIL) {
					bm[col * UWB_NUM_ZONES + mas] = c;
					if(c == UWB_RSV_MAS_SAFE)
						ai->safe_allocated_mases++;
					else
						ai->unsafe_allocated_mases++;
				}
			}
			rows++;
		}
	}
	ai->total_allocated_mases = ai->safe_allocated_mases + ai->unsafe_allocated_mases;
}

/*
 * Find the best column set for a given availability, interval, num safe mas and
 * num unsafe mas.
 *
 * The different sets are tried in order as shown below, depending on the interval.
 *
 * interval = 16
 *	deep = 0
 *		set 1 ->  {  8 }
 *	deep = 1
 *		set 1 ->  {  4 }
 *		set 2 ->  { 12 }
 *	deep = 2
 *		set 1 ->  {  2 }
 *		set 2 ->  {  6 }
 *		set 3 ->  { 10 }
 *		set 4 ->  { 14 }
 *	deep = 3
 *		set 1 ->  {  1 }
 *		set 2 ->  {  3 }
 *		set 3 ->  {  5 }
 *		set 4 ->  {  7 }
 *		set 5 ->  {  9 }
 *		set 6 ->  { 11 }
 *		set 7 ->  { 13 }
 *		set 8 ->  { 15 }
 *
 * interval = 8
 *	deep = 0
 *		set 1 ->  {  4  12 }
 *	deep = 1
 *		set 1 ->  {  2  10 }
 *		set 2 ->  {  6  14 }
 *	deep = 2
 *		set 1 ->  {  1   9 }
 *		set 2 ->  {  3  11 }
 *		set 3 ->  {  5  13 }
 *		set 4 ->  {  7  15 }
 *
 * interval = 4
 *	deep = 0
 *		set 1 ->  {  2   6  10  14 }
 *	deep = 1
 *		set 1 ->  {  1   5   9  13 }
 *		set 2 ->  {  3   7  11  15 }
 *
 * interval = 2
 *	deep = 0
 *		set 1 ->  {  1   3   5   7   9  11  13  15 }
 */
static int uwb_rsv_find_best_column_set(struct uwb_rsv_alloc_info *ai, int interval, 
					int num_safe_mas, int num_unsafe_mas)
{
	struct uwb_rsv_col_info *ci = ai->ci;
	struct uwb_rsv_col_set_info *csi = &ci->csi;
	struct uwb_rsv_col_set_info tmp_csi;
	int deep, set, col, start_col_deep, col_start_set;
	int start_col, max_mas_in_set, lowest_max_mas_in_deep;
	int n_mas;
	int found = UWB_RSV_ALLOC_NOT_FOUND; 

	tmp_csi.start_col = 0;
	start_col_deep = interval;
	n_mas = num_unsafe_mas + num_safe_mas;

	for (deep = 0; ((interval >> deep) & 0x1) == 0; deep++) {
		start_col_deep /= 2;
		col_start_set = 0;
		lowest_max_mas_in_deep = UWB_MAS_PER_ZONE;

		for (set = 1; set <= (1 << deep); set++) {
			max_mas_in_set = 0;
			start_col = start_col_deep + col_start_set;
			for (col = start_col; col < UWB_NUM_ZONES; col += interval) {
                
				if (ci[col].max_avail_safe >= num_safe_mas &&
				    ci[col].max_avail_unsafe >= n_mas) {
					if (ci[col].highest_mas[n_mas] > max_mas_in_set)
						max_mas_in_set = ci[col].highest_mas[n_mas];
				} else {
					max_mas_in_set = 0;
					break;
				}
			}
			if ((lowest_max_mas_in_deep > max_mas_in_set) && max_mas_in_set) {
				lowest_max_mas_in_deep = max_mas_in_set;

				tmp_csi.start_col = start_col;
			}
			col_start_set += (interval >> deep);
		}

		if (lowest_max_mas_in_deep < 8) {
			csi->start_col = tmp_csi.start_col;
			found = UWB_RSV_ALLOC_FOUND;
			break;
		} else if ((lowest_max_mas_in_deep > 8) && 
			   (lowest_max_mas_in_deep != UWB_MAS_PER_ZONE) &&
			   (found == UWB_RSV_ALLOC_NOT_FOUND)) {
			csi->start_col = tmp_csi.start_col;
			found = UWB_RSV_ALLOC_FOUND;
		}
	}

	if (found == UWB_RSV_ALLOC_FOUND) {
		csi->interval = interval;
		csi->safe_mas_per_col = num_safe_mas;
		csi->unsafe_mas_per_col = num_unsafe_mas;

		ai->safe_allocated_mases = (UWB_NUM_ZONES / interval) * num_safe_mas;
		ai->unsafe_allocated_mases = (UWB_NUM_ZONES / interval) * num_unsafe_mas;
		ai->total_allocated_mases = ai->safe_allocated_mases + ai->unsafe_allocated_mases;
		ai->interval = interval;		
	}
	return found;
}

static void get_row_descriptors(struct uwb_rsv_alloc_info *ai)
{
	unsigned char *bm = ai->bm;
	struct uwb_rsv_row_info *ri = &ai->ri;
	int col, mas;
  
	ri->free_rows = 16;
	for (mas = 0; mas < UWB_MAS_PER_ZONE; mas ++) {
		ri->avail[mas] = 1;
		for (col = 1; col < UWB_NUM_ZONES; col++) {
			if (bm[col * UWB_NUM_ZONES + mas] == UWB_RSV_MAS_NOT_AVAIL) {
				ri->free_rows--;
				ri->avail[mas]=0;
				break;
			}
		}
	}
}

static void uwb_rsv_fill_column_info(unsigned char *bm, int column, struct uwb_rsv_col_info *rci)
{
	int mas;
	int block_count = 0, start_block = 0; 
	int previous_avail = 0;
	int available = 0;
	int safe_mas_in_row[UWB_MAS_PER_ZONE] = {
		8, 7, 6, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 3, 2, 1,
	};

	rci->max_avail_safe = 0;

	for (mas = 0; mas < UWB_MAS_PER_ZONE; mas ++) {
		if (!bm[column * UWB_NUM_ZONES + mas]) {
			available++;
			rci->max_avail_unsafe = available;

			rci->highest_mas[available] = mas;

			if (previous_avail) {
				block_count++;
				if ((block_count > safe_mas_in_row[start_block]) &&
				    (!rci->max_avail_safe))
					rci->max_avail_safe = available - 1;
			} else {
				previous_avail = 1;
				start_block = mas;
				block_count = 1;
			}
		} else {
			previous_avail = 0;
		}
	}
	if (!rci->max_avail_safe)
		rci->max_avail_safe = rci->max_avail_unsafe;
}

static void get_column_descriptors(struct uwb_rsv_alloc_info *ai)
{
	unsigned char *bm = ai->bm;
	struct uwb_rsv_col_info *ci = ai->ci;
	int col;

	for (col = 1; col < UWB_NUM_ZONES; col++) {
		uwb_rsv_fill_column_info(bm, col, &ci[col]);
	}
}

static int uwb_rsv_find_best_row_alloc(struct uwb_rsv_alloc_info *ai)
{
	int n_rows;
	int max_rows = ai->max_mas / UWB_USABLE_MAS_PER_ROW;
	int min_rows = ai->min_mas / UWB_USABLE_MAS_PER_ROW;
	if (ai->min_mas % UWB_USABLE_MAS_PER_ROW)
		min_rows++;
	for (n_rows = max_rows; n_rows >= min_rows; n_rows--) {
		if (n_rows <= ai->ri.free_rows) {
			ai->ri.used_rows = n_rows;
			ai->interval = 1; /* row reservation */
			uwb_rsv_fill_row_alloc(ai);
			return UWB_RSV_ALLOC_FOUND;
		}
	}  
	return UWB_RSV_ALLOC_NOT_FOUND;
}

static int uwb_rsv_find_best_col_alloc(struct uwb_rsv_alloc_info *ai, int interval)
{
	int n_safe, n_unsafe, n_mas;  
	int n_column = UWB_NUM_ZONES / interval;
	int max_per_zone = ai->max_mas / n_column;
	int min_per_zone = ai->min_mas / n_column;

	if (ai->min_mas % n_column)
		min_per_zone++;

	if (min_per_zone > UWB_MAS_PER_ZONE) {
		return UWB_RSV_ALLOC_NOT_FOUND;
	}
    
	if (max_per_zone > UWB_MAS_PER_ZONE) {
		max_per_zone = UWB_MAS_PER_ZONE;
	}
    
	for (n_mas = max_per_zone; n_mas >= min_per_zone; n_mas--) {
		if (uwb_rsv_find_best_column_set(ai, interval, 0, n_mas) == UWB_RSV_ALLOC_NOT_FOUND)
			continue;
		for (n_safe = n_mas; n_safe >= 0; n_safe--) {
			n_unsafe = n_mas - n_safe;
			if (uwb_rsv_find_best_column_set(ai, interval, n_safe, n_unsafe) == UWB_RSV_ALLOC_FOUND) {
				uwb_rsv_fill_column_alloc(ai);
				return UWB_RSV_ALLOC_FOUND;
			}
		}
	}
	return UWB_RSV_ALLOC_NOT_FOUND;
}

int uwb_rsv_find_best_allocation(struct uwb_rsv *rsv, struct uwb_mas_bm *available, 
				 struct uwb_mas_bm *result)
{
	struct uwb_rsv_alloc_info *ai;
	int interval;
	int bit_index;

	ai = kzalloc(sizeof(struct uwb_rsv_alloc_info), GFP_KERNEL);
	if (!ai)
		return UWB_RSV_ALLOC_NOT_FOUND;
	ai->min_mas = rsv->min_mas;
	ai->max_mas = rsv->max_mas;
	ai->max_interval = rsv->max_interval;


	/* fill the not available vector from the available bm */
	for_each_clear_bit(bit_index, available->bm, UWB_NUM_MAS)
		ai->bm[bit_index] = UWB_RSV_MAS_NOT_AVAIL;

	if (ai->max_interval == 1) {
		get_row_descriptors(ai);
		if (uwb_rsv_find_best_row_alloc(ai) == UWB_RSV_ALLOC_FOUND)
			goto alloc_found;
		else
			goto alloc_not_found;
	}

	get_column_descriptors(ai);
        
	for (interval = 16; interval >= 2; interval>>=1) {
		if (interval > ai->max_interval)
			continue;
		if (uwb_rsv_find_best_col_alloc(ai, interval) == UWB_RSV_ALLOC_FOUND)
			goto alloc_found;
	}

	/* try row reservation if no column is found */
	get_row_descriptors(ai);
	if (uwb_rsv_find_best_row_alloc(ai) == UWB_RSV_ALLOC_FOUND)
		goto alloc_found;
	else
		goto alloc_not_found;

  alloc_found:
	bitmap_zero(result->bm, UWB_NUM_MAS);
	bitmap_zero(result->unsafe_bm, UWB_NUM_MAS);
	/* fill the safe and unsafe bitmaps */
	for (bit_index = 0; bit_index < UWB_NUM_MAS; bit_index++) {
		if (ai->bm[bit_index] == UWB_RSV_MAS_SAFE)
			set_bit(bit_index, result->bm);
		else if (ai->bm[bit_index] == UWB_RSV_MAS_UNSAFE)
			set_bit(bit_index, result->unsafe_bm);
	}
	bitmap_or(result->bm, result->bm, result->unsafe_bm, UWB_NUM_MAS);

	result->safe   = ai->safe_allocated_mases;
	result->unsafe = ai->unsafe_allocated_mases;
	
	kfree(ai);		
	return UWB_RSV_ALLOC_FOUND;
  
  alloc_not_found:
	kfree(ai);
	return UWB_RSV_ALLOC_NOT_FOUND;
}
Commit	Line	Data
5b37717a SP	1	/*
	2	* UWB reservation management.
	3	*
	4	* Copyright (C) 2008 Cambridge Silicon Radio Ltd.
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License version
	8	* 2 as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	17	*/
5b37717a	18	#include <linux/kernel.h>
5a0e3ad6	19	#include <linux/slab.h>
5b37717a SP	20	#include <linux/uwb.h>
	21
	22	#include "uwb-internal.h"
	23
	24	static void uwb_rsv_fill_column_alloc(struct uwb_rsv_alloc_info *ai)
	25	{
	26	int col, mas, safe_mas, unsafe_mas;
	27	unsigned char *bm = ai->bm;
	28	struct uwb_rsv_col_info *ci = ai->ci;
	29	unsigned char c;
	30
	31	for (col = ci->csi.start_col; col < UWB_NUM_ZONES; col += ci->csi.interval) {
	32
	33	safe_mas = ci->csi.safe_mas_per_col;
	34	unsafe_mas = ci->csi.unsafe_mas_per_col;
	35
	36	for (mas = 0; mas < UWB_MAS_PER_ZONE; mas++ ) {
	37	if (bm[col * UWB_MAS_PER_ZONE + mas] == 0) {
	38
	39	if (safe_mas > 0) {
	40	safe_mas--;
	41	c = UWB_RSV_MAS_SAFE;
	42	} else if (unsafe_mas > 0) {
	43	unsafe_mas--;
	44	c = UWB_RSV_MAS_UNSAFE;
	45	} else {
	46	break;
	47	}
	48	bm[col * UWB_MAS_PER_ZONE + mas] = c;
	49	}
	50	}
	51	}
	52	}
	53
	54	static void uwb_rsv_fill_row_alloc(struct uwb_rsv_alloc_info *ai)
	55	{
	56	int mas, col, rows;
	57	unsigned char *bm = ai->bm;
	58	struct uwb_rsv_row_info *ri = &ai->ri;
	59	unsigned char c;
	60
	61	rows = 1;
	62	c = UWB_RSV_MAS_SAFE;
	63	for (mas = UWB_MAS_PER_ZONE - 1; mas >= 0; mas--) {
	64	if (ri->avail[mas] == 1) {
	65
	66	if (rows > ri->used_rows) {
	67	break;
	68	} else if (rows > 7) {
	69	c = UWB_RSV_MAS_UNSAFE;
	70	}
	71
	72	for (col = 0; col < UWB_NUM_ZONES; col++) {
	73	if (bm[col * UWB_NUM_ZONES + mas] != UWB_RSV_MAS_NOT_AVAIL) {
	74	bm[col * UWB_NUM_ZONES + mas] = c;
	75	if(c == UWB_RSV_MAS_SAFE)
	76	ai->safe_allocated_mases++;
	77	else
	78	ai->unsafe_allocated_mases++;
	79	}
	80	}
	81	rows++;
	82	}
	83	}
84	ai->total_allocated_mases = ai->safe_allocated_mases + ai->unsafe_allocated_mases;
85	}
86
87	/*
88	* Find the best column set for a given availability, interval, num safe mas and
89	* num unsafe mas.
90	*
91	* The different sets are tried in order as shown below, depending on the interval.
92	*
93	* interval = 16
94	* deep = 0
95	* set 1 -> { 8 }
96	* deep = 1
97	* set 1 -> { 4 }
98	* set 2 -> { 12 }
99	* deep = 2
100	* set 1 -> { 2 }
101	* set 2 -> { 6 }
102	* set 3 -> { 10 }
103	* set 4 -> { 14 }
104	* deep = 3
105	* set 1 -> { 1 }
106	* set 2 -> { 3 }
107	* set 3 -> { 5 }
108	* set 4 -> { 7 }
109	* set 5 -> { 9 }
110	* set 6 -> { 11 }
111	* set 7 -> { 13 }
112	* set 8 -> { 15 }
113	*
114	* interval = 8
115	* deep = 0
116	* set 1 -> { 4 12 }
117	* deep = 1
118	* set 1 -> { 2 10 }
119	* set 2 -> { 6 14 }
120	* deep = 2
121	* set 1 -> { 1 9 }
122	* set 2 -> { 3 11 }
123	* set 3 -> { 5 13 }
124	* set 4 -> { 7 15 }
125	*
126	* interval = 4
127	* deep = 0
128	* set 1 -> { 2 6 10 14 }
129	* deep = 1
130	* set 1 -> { 1 5 9 13 }
131	* set 2 -> { 3 7 11 15 }
132	*
133	* interval = 2
134	* deep = 0
135	* set 1 -> { 1 3 5 7 9 11 13 15 }
136	*/
137	static int uwb_rsv_find_best_column_set(struct uwb_rsv_alloc_info *ai, int interval,
138	int num_safe_mas, int num_unsafe_mas)
139	{
140	struct uwb_rsv_col_info *ci = ai->ci;
141	struct uwb_rsv_col_set_info *csi = &ci->csi;
142	struct uwb_rsv_col_set_info tmp_csi;
143	int deep, set, col, start_col_deep, col_start_set;
144	int start_col, max_mas_in_set, lowest_max_mas_in_deep;
145	int n_mas;
146	int found = UWB_RSV_ALLOC_NOT_FOUND;
147
148	tmp_csi.start_col = 0;
149	start_col_deep = interval;
150	n_mas = num_unsafe_mas + num_safe_mas;
151
152	for (deep = 0; ((interval >> deep) & 0x1) == 0; deep++) {
153	start_col_deep /= 2;
154	col_start_set = 0;
155	lowest_max_mas_in_deep = UWB_MAS_PER_ZONE;
156
157	for (set = 1; set <= (1 << deep); set++) {
158	max_mas_in_set = 0;
159	start_col = start_col_deep + col_start_set;
160	for (col = start_col; col < UWB_NUM_ZONES; col += interval) {
161
162	if (ci[col].max_avail_safe >= num_safe_mas &&
163	ci[col].max_avail_unsafe >= n_mas) {
164	if (ci[col].highest_mas[n_mas] > max_mas_in_set)
165	max_mas_in_set = ci[col].highest_mas[n_mas];
166	} else {
167	max_mas_in_set = 0;
168	break;
169	}
170	}
171	if ((lowest_max_mas_in_deep > max_mas_in_set) && max_mas_in_set) {
172	lowest_max_mas_in_deep = max_mas_in_set;
173
174	tmp_csi.start_col = start_col;
175	}
176	col_start_set += (interval >> deep);
177	}
178
179	if (lowest_max_mas_in_deep < 8) {
180	csi->start_col = tmp_csi.start_col;
181	found = UWB_RSV_ALLOC_FOUND;
182	break;
183	} else if ((lowest_max_mas_in_deep > 8) &&
184	(lowest_max_mas_in_deep != UWB_MAS_PER_ZONE) &&
185	(found == UWB_RSV_ALLOC_NOT_FOUND)) {
186	csi->start_col = tmp_csi.start_col;
187	found = UWB_RSV_ALLOC_FOUND;
188	}
189	}
190
191	if (found == UWB_RSV_ALLOC_FOUND) {
192	csi->interval = interval;
193	csi->safe_mas_per_col = num_safe_mas;
194	csi->unsafe_mas_per_col = num_unsafe_mas;
195
196	ai->safe_allocated_mases = (UWB_NUM_ZONES / interval) * num_safe_mas;
197	ai->unsafe_allocated_mases = (UWB_NUM_ZONES / interval) * num_unsafe_mas;
198	ai->total_allocated_mases = ai->safe_allocated_mases + ai->unsafe_allocated_mases;
199	ai->interval = interval;
200	}
201	return found;
202	}
203
204	static void get_row_descriptors(struct uwb_rsv_alloc_info *ai)
205	{
206	unsigned char *bm = ai->bm;
207	struct uwb_rsv_row_info *ri = &ai->ri;
208	int col, mas;
209
210	ri->free_rows = 16;
211	for (mas = 0; mas < UWB_MAS_PER_ZONE; mas ++) {
212	ri->avail[mas] = 1;
213	for (col = 1; col < UWB_NUM_ZONES; col++) {
214	if (bm[col * UWB_NUM_ZONES + mas] == UWB_RSV_MAS_NOT_AVAIL) {
215	ri->free_rows--;
216	ri->avail[mas]=0;
217	break;
218	}
219	}
220	}
221	}
222
223	static void uwb_rsv_fill_column_info(unsigned char bm, int column, struct uwb_rsv_col_info rci)
224	{
225	int mas;
226	int block_count = 0, start_block = 0;
227	int previous_avail = 0;
228	int available = 0;
229	int safe_mas_in_row[UWB_MAS_PER_ZONE] = {
230	8, 7, 6, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 3, 2, 1,
231	};
232
233	rci->max_avail_safe = 0;
234
235	for (mas = 0; mas < UWB_MAS_PER_ZONE; mas ++) {
236	if (!bm[column * UWB_NUM_ZONES + mas]) {
237	available++;
238	rci->max_avail_unsafe = available;
239
240	rci->highest_mas[available] = mas;
241
242	if (previous_avail) {
243	block_count++;
244	if ((block_count > safe_mas_in_row[start_block]) &&
245	(!rci->max_avail_safe))
246	rci->max_avail_safe = available - 1;
247	} else {
248	previous_avail = 1;
249	start_block = mas;
250	block_count = 1;
251	}
252	} else {
253	previous_avail = 0;
254	}
255	}
256	if (!rci->max_avail_safe)
257	rci->max_avail_safe = rci->max_avail_unsafe;
258	}
259
260	static void get_column_descriptors(struct uwb_rsv_alloc_info *ai)
261	{
262	unsigned char *bm = ai->bm;
263	struct uwb_rsv_col_info *ci = ai->ci;
264	int col;
265
266	for (col = 1; col < UWB_NUM_ZONES; col++) {
267	uwb_rsv_fill_column_info(bm, col, &ci[col]);
268	}
269	}
270
271	static int uwb_rsv_find_best_row_alloc(struct uwb_rsv_alloc_info *ai)
272	{
273	int n_rows;
274	int max_rows = ai->max_mas / UWB_USABLE_MAS_PER_ROW;
275	int min_rows = ai->min_mas / UWB_USABLE_MAS_PER_ROW;
276	if (ai->min_mas % UWB_USABLE_MAS_PER_ROW)
277	min_rows++;
278	for (n_rows = max_rows; n_rows >= min_rows; n_rows--) {
279	if (n_rows <= ai->ri.free_rows) {
280	ai->ri.used_rows = n_rows;
281	ai->interval = 1; /* row reservation */
282	uwb_rsv_fill_row_alloc(ai);
283	return UWB_RSV_ALLOC_FOUND;
284	}
285	}
286	return UWB_RSV_ALLOC_NOT_FOUND;
287	}
288
289	static int uwb_rsv_find_best_col_alloc(struct uwb_rsv_alloc_info *ai, int interval)
290	{
291	int n_safe, n_unsafe, n_mas;
292	int n_column = UWB_NUM_ZONES / interval;
293	int max_per_zone = ai->max_mas / n_column;
294	int min_per_zone = ai->min_mas / n_column;
295
296	if (ai->min_mas % n_column)
297	min_per_zone++;
298
299	if (min_per_zone > UWB_MAS_PER_ZONE) {
300	return UWB_RSV_ALLOC_NOT_FOUND;
301	}
302
303	if (max_per_zone > UWB_MAS_PER_ZONE) {
304	max_per_zone = UWB_MAS_PER_ZONE;
305	}
306
307	for (n_mas = max_per_zone; n_mas >= min_per_zone; n_mas--) {
308	if (uwb_rsv_find_best_column_set(ai, interval, 0, n_mas) == UWB_RSV_ALLOC_NOT_FOUND)
309	continue;
310	for (n_safe = n_mas; n_safe >= 0; n_safe--) {
311	n_unsafe = n_mas - n_safe;
312	if (uwb_rsv_find_best_column_set(ai, interval, n_safe, n_unsafe) == UWB_RSV_ALLOC_FOUND) {
313	uwb_rsv_fill_column_alloc(ai);
314	return UWB_RSV_ALLOC_FOUND;
315	}
316	}
317	}
318	return UWB_RSV_ALLOC_NOT_FOUND;
319	}
320
321	int uwb_rsv_find_best_allocation(struct uwb_rsv rsv, struct uwb_mas_bm available,
322	struct uwb_mas_bm *result)
323	{
324	struct uwb_rsv_alloc_info *ai;
325	int interval;
326	int bit_index;
327
328	ai = kzalloc(sizeof(struct uwb_rsv_alloc_info), GFP_KERNEL);
793b6233 JJ	329	if (!ai)
793b6233 JJ	330	return UWB_RSV_ALLOC_NOT_FOUND;
5b37717a SP	331	ai->min_mas = rsv->min_mas;
	332	ai->max_mas = rsv->max_mas;
	333	ai->max_interval = rsv->max_interval;
	334
	335
	336	/* fill the not available vector from the available bm */
1a07cbba AM	337	for_each_clear_bit(bit_index, available->bm, UWB_NUM_MAS)
1a07cbba AM	338	ai->bm[bit_index] = UWB_RSV_MAS_NOT_AVAIL;
5b37717a SP	339
	340	if (ai->max_interval == 1) {
	341	get_row_descriptors(ai);
	342	if (uwb_rsv_find_best_row_alloc(ai) == UWB_RSV_ALLOC_FOUND)
	343	goto alloc_found;
	344	else
	345	goto alloc_not_found;
	346	}
	347
	348	get_column_descriptors(ai);
	349
	350	for (interval = 16; interval >= 2; interval>>=1) {
	351	if (interval > ai->max_interval)
	352	continue;
	353	if (uwb_rsv_find_best_col_alloc(ai, interval) == UWB_RSV_ALLOC_FOUND)
	354	goto alloc_found;
	355	}
	356
	357	/* try row reservation if no column is found */
	358	get_row_descriptors(ai);
	359	if (uwb_rsv_find_best_row_alloc(ai) == UWB_RSV_ALLOC_FOUND)
	360	goto alloc_found;
	361	else
	362	goto alloc_not_found;
	363
	364	alloc_found:
	365	bitmap_zero(result->bm, UWB_NUM_MAS);
	366	bitmap_zero(result->unsafe_bm, UWB_NUM_MAS);
	367	/* fill the safe and unsafe bitmaps */
	368	for (bit_index = 0; bit_index < UWB_NUM_MAS; bit_index++) {
	369	if (ai->bm[bit_index] == UWB_RSV_MAS_SAFE)
	370	set_bit(bit_index, result->bm);
	371	else if (ai->bm[bit_index] == UWB_RSV_MAS_UNSAFE)
	372	set_bit(bit_index, result->unsafe_bm);
	373	}
	374	bitmap_or(result->bm, result->bm, result->unsafe_bm, UWB_NUM_MAS);
	375
	376	result->safe = ai->safe_allocated_mases;
	377	result->unsafe = ai->unsafe_allocated_mases;
	378
	379	kfree(ai);
	380	return UWB_RSV_ALLOC_FOUND;
	381
	382	alloc_not_found:
	383	kfree(ai);
	384	return UWB_RSV_ALLOC_NOT_FOUND;
	385	}