[linux-2.6-block.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/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);
	
	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 (bit_index = 0; bit_index < UWB_NUM_MAS; bit_index++) {
		if (!test_bit(bit_index, available->bm))
			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 SP	18	#include <linux/kernel.h>
	19	#include <linux/uwb.h>
	20
	21	#include "uwb-internal.h"
	22
	23	static void uwb_rsv_fill_column_alloc(struct uwb_rsv_alloc_info *ai)
	24	{
	25	int col, mas, safe_mas, unsafe_mas;
	26	unsigned char *bm = ai->bm;
	27	struct uwb_rsv_col_info *ci = ai->ci;
	28	unsigned char c;
	29
	30	for (col = ci->csi.start_col; col < UWB_NUM_ZONES; col += ci->csi.interval) {
	31
	32	safe_mas = ci->csi.safe_mas_per_col;
	33	unsafe_mas = ci->csi.unsafe_mas_per_col;
	34
	35	for (mas = 0; mas < UWB_MAS_PER_ZONE; mas++ ) {
	36	if (bm[col * UWB_MAS_PER_ZONE + mas] == 0) {
	37
	38	if (safe_mas > 0) {
	39	safe_mas--;
	40	c = UWB_RSV_MAS_SAFE;
	41	} else if (unsafe_mas > 0) {
	42	unsafe_mas--;
	43	c = UWB_RSV_MAS_UNSAFE;
	44	} else {
	45	break;
	46	}
	47	bm[col * UWB_MAS_PER_ZONE + mas] = c;
	48	}
	49	}
	50	}
	51	}
	52
	53	static void uwb_rsv_fill_row_alloc(struct uwb_rsv_alloc_info *ai)
	54	{
	55	int mas, col, rows;
	56	unsigned char *bm = ai->bm;
	57	struct uwb_rsv_row_info *ri = &ai->ri;
	58	unsigned char c;
	59
	60	rows = 1;
	61	c = UWB_RSV_MAS_SAFE;
	62	for (mas = UWB_MAS_PER_ZONE - 1; mas >= 0; mas--) {
	63	if (ri->avail[mas] == 1) {
	64
	65	if (rows > ri->used_rows) {
	66	break;
	67	} else if (rows > 7) {
	68	c = UWB_RSV_MAS_UNSAFE;
	69	}
	70
	71	for (col = 0; col < UWB_NUM_ZONES; col++) {
	72	if (bm[col * UWB_NUM_ZONES + mas] != UWB_RSV_MAS_NOT_AVAIL) {
	73	bm[col * UWB_NUM_ZONES + mas] = c;
	74	if(c == UWB_RSV_MAS_SAFE)
	75	ai->safe_allocated_mases++;
	76	else
	77	ai->unsafe_allocated_mases++;
	78	}
	79	}
	80	rows++;
	81	}
82	}
83	ai->total_allocated_mases = ai->safe_allocated_mases + ai->unsafe_allocated_mases;
84	}
85
86	/*
87	* Find the best column set for a given availability, interval, num safe mas and
88	* num unsafe mas.
89	*
90	* The different sets are tried in order as shown below, depending on the interval.
91	*
92	* interval = 16
93	* deep = 0
94	* set 1 -> { 8 }
95	* deep = 1
96	* set 1 -> { 4 }
97	* set 2 -> { 12 }
98	* deep = 2
99	* set 1 -> { 2 }
100	* set 2 -> { 6 }
101	* set 3 -> { 10 }
102	* set 4 -> { 14 }
103	* deep = 3
104	* set 1 -> { 1 }
105	* set 2 -> { 3 }
106	* set 3 -> { 5 }
107	* set 4 -> { 7 }
108	* set 5 -> { 9 }
109	* set 6 -> { 11 }
110	* set 7 -> { 13 }
111	* set 8 -> { 15 }
112	*
113	* interval = 8
114	* deep = 0
115	* set 1 -> { 4 12 }
116	* deep = 1
117	* set 1 -> { 2 10 }
118	* set 2 -> { 6 14 }
119	* deep = 2
120	* set 1 -> { 1 9 }
121	* set 2 -> { 3 11 }
122	* set 3 -> { 5 13 }
123	* set 4 -> { 7 15 }
124	*
125	* interval = 4
126	* deep = 0
127	* set 1 -> { 2 6 10 14 }
128	* deep = 1
129	* set 1 -> { 1 5 9 13 }
130	* set 2 -> { 3 7 11 15 }
131	*
132	* interval = 2
133	* deep = 0
134	* set 1 -> { 1 3 5 7 9 11 13 15 }
135	*/
136	static int uwb_rsv_find_best_column_set(struct uwb_rsv_alloc_info *ai, int interval,
137	int num_safe_mas, int num_unsafe_mas)
138	{
139	struct uwb_rsv_col_info *ci = ai->ci;
140	struct uwb_rsv_col_set_info *csi = &ci->csi;
141	struct uwb_rsv_col_set_info tmp_csi;
142	int deep, set, col, start_col_deep, col_start_set;
143	int start_col, max_mas_in_set, lowest_max_mas_in_deep;
144	int n_mas;
145	int found = UWB_RSV_ALLOC_NOT_FOUND;
146
147	tmp_csi.start_col = 0;
148	start_col_deep = interval;
149	n_mas = num_unsafe_mas + num_safe_mas;
150
151	for (deep = 0; ((interval >> deep) & 0x1) == 0; deep++) {
152	start_col_deep /= 2;
153	col_start_set = 0;
154	lowest_max_mas_in_deep = UWB_MAS_PER_ZONE;
155
156	for (set = 1; set <= (1 << deep); set++) {
157	max_mas_in_set = 0;
158	start_col = start_col_deep + col_start_set;
159	for (col = start_col; col < UWB_NUM_ZONES; col += interval) {
160
161	if (ci[col].max_avail_safe >= num_safe_mas &&
162	ci[col].max_avail_unsafe >= n_mas) {
163	if (ci[col].highest_mas[n_mas] > max_mas_in_set)
164	max_mas_in_set = ci[col].highest_mas[n_mas];
165	} else {
166	max_mas_in_set = 0;
167	break;
168	}
169	}
170	if ((lowest_max_mas_in_deep > max_mas_in_set) && max_mas_in_set) {
171	lowest_max_mas_in_deep = max_mas_in_set;
172
173	tmp_csi.start_col = start_col;
174	}
175	col_start_set += (interval >> deep);
176	}
177
178	if (lowest_max_mas_in_deep < 8) {
179	csi->start_col = tmp_csi.start_col;
180	found = UWB_RSV_ALLOC_FOUND;
181	break;
182	} else if ((lowest_max_mas_in_deep > 8) &&
183	(lowest_max_mas_in_deep != UWB_MAS_PER_ZONE) &&
184	(found == UWB_RSV_ALLOC_NOT_FOUND)) {
185	csi->start_col = tmp_csi.start_col;
186	found = UWB_RSV_ALLOC_FOUND;
187	}
188	}
189
190	if (found == UWB_RSV_ALLOC_FOUND) {
191	csi->interval = interval;
192	csi->safe_mas_per_col = num_safe_mas;
193	csi->unsafe_mas_per_col = num_unsafe_mas;
194
195	ai->safe_allocated_mases = (UWB_NUM_ZONES / interval) * num_safe_mas;
196	ai->unsafe_allocated_mases = (UWB_NUM_ZONES / interval) * num_unsafe_mas;
197	ai->total_allocated_mases = ai->safe_allocated_mases + ai->unsafe_allocated_mases;
198	ai->interval = interval;
199	}
200	return found;
201	}
202
203	static void get_row_descriptors(struct uwb_rsv_alloc_info *ai)
204	{
205	unsigned char *bm = ai->bm;
206	struct uwb_rsv_row_info *ri = &ai->ri;
207	int col, mas;
208
209	ri->free_rows = 16;
210	for (mas = 0; mas < UWB_MAS_PER_ZONE; mas ++) {
211	ri->avail[mas] = 1;
212	for (col = 1; col < UWB_NUM_ZONES; col++) {
213	if (bm[col * UWB_NUM_ZONES + mas] == UWB_RSV_MAS_NOT_AVAIL) {
214	ri->free_rows--;
215	ri->avail[mas]=0;
216	break;
217	}
218	}
219	}
220	}
221
222	static void uwb_rsv_fill_column_info(unsigned char bm, int column, struct uwb_rsv_col_info rci)
223	{
224	int mas;
225	int block_count = 0, start_block = 0;
226	int previous_avail = 0;
227	int available = 0;
228	int safe_mas_in_row[UWB_MAS_PER_ZONE] = {
229	8, 7, 6, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 3, 2, 1,
230	};
231
232	rci->max_avail_safe = 0;
233
234	for (mas = 0; mas < UWB_MAS_PER_ZONE; mas ++) {
235	if (!bm[column * UWB_NUM_ZONES + mas]) {
236	available++;
237	rci->max_avail_unsafe = available;
238
239	rci->highest_mas[available] = mas;
240
241	if (previous_avail) {
242	block_count++;
243	if ((block_count > safe_mas_in_row[start_block]) &&
244	(!rci->max_avail_safe))
245	rci->max_avail_safe = available - 1;
246	} else {
247	previous_avail = 1;
248	start_block = mas;
249	block_count = 1;
250	}
251	} else {
252	previous_avail = 0;
253	}
254	}
255	if (!rci->max_avail_safe)
256	rci->max_avail_safe = rci->max_avail_unsafe;
257	}
258
259	static void get_column_descriptors(struct uwb_rsv_alloc_info *ai)
260	{
261	unsigned char *bm = ai->bm;
262	struct uwb_rsv_col_info *ci = ai->ci;
263	int col;
264
265	for (col = 1; col < UWB_NUM_ZONES; col++) {
266	uwb_rsv_fill_column_info(bm, col, &ci[col]);
267	}
268	}
269
270	static int uwb_rsv_find_best_row_alloc(struct uwb_rsv_alloc_info *ai)
271	{
272	int n_rows;
273	int max_rows = ai->max_mas / UWB_USABLE_MAS_PER_ROW;
274	int min_rows = ai->min_mas / UWB_USABLE_MAS_PER_ROW;
275	if (ai->min_mas % UWB_USABLE_MAS_PER_ROW)
276	min_rows++;
277	for (n_rows = max_rows; n_rows >= min_rows; n_rows--) {
278	if (n_rows <= ai->ri.free_rows) {
279	ai->ri.used_rows = n_rows;
280	ai->interval = 1; /* row reservation */
281	uwb_rsv_fill_row_alloc(ai);
282	return UWB_RSV_ALLOC_FOUND;
283	}
284	}
285	return UWB_RSV_ALLOC_NOT_FOUND;
286	}
287
288	static int uwb_rsv_find_best_col_alloc(struct uwb_rsv_alloc_info *ai, int interval)
289	{
290	int n_safe, n_unsafe, n_mas;
291	int n_column = UWB_NUM_ZONES / interval;
292	int max_per_zone = ai->max_mas / n_column;
293	int min_per_zone = ai->min_mas / n_column;
294
295	if (ai->min_mas % n_column)
296	min_per_zone++;
297
298	if (min_per_zone > UWB_MAS_PER_ZONE) {
299	return UWB_RSV_ALLOC_NOT_FOUND;
300	}
301
302	if (max_per_zone > UWB_MAS_PER_ZONE) {
303	max_per_zone = UWB_MAS_PER_ZONE;
304	}
305
306	for (n_mas = max_per_zone; n_mas >= min_per_zone; n_mas--) {
307	if (uwb_rsv_find_best_column_set(ai, interval, 0, n_mas) == UWB_RSV_ALLOC_NOT_FOUND)
308	continue;
309	for (n_safe = n_mas; n_safe >= 0; n_safe--) {
310	n_unsafe = n_mas - n_safe;
311	if (uwb_rsv_find_best_column_set(ai, interval, n_safe, n_unsafe) == UWB_RSV_ALLOC_FOUND) {
312	uwb_rsv_fill_column_alloc(ai);
313	return UWB_RSV_ALLOC_FOUND;
314	}
315	}
316	}
317	return UWB_RSV_ALLOC_NOT_FOUND;
318	}
319
320	int uwb_rsv_find_best_allocation(struct uwb_rsv rsv, struct uwb_mas_bm available,
321	struct uwb_mas_bm *result)
322	{
323	struct uwb_rsv_alloc_info *ai;
324	int interval;
325	int bit_index;
326
327	ai = kzalloc(sizeof(struct uwb_rsv_alloc_info), GFP_KERNEL);
328
329	ai->min_mas = rsv->min_mas;
330	ai->max_mas = rsv->max_mas;
331	ai->max_interval = rsv->max_interval;
332
333
334	/* fill the not available vector from the available bm */
335	for (bit_index = 0; bit_index < UWB_NUM_MAS; bit_index++) {
336	if (!test_bit(bit_index, available->bm))
337	ai->bm[bit_index] = UWB_RSV_MAS_NOT_AVAIL;
338	}
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	}