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	Use for_each_clear_bit() to iterate over all the cleared bit in a memory region. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Stefano Panella <stefano.panella@csr.com> Cc: David Vrabel <david.vrabel@csr.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			386 lines
		
	
	
		
			9.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			386 lines
		
	
	
		
			9.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * UWB reservation management.
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 *
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 * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public License version
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 * 2 as published by the Free Software Foundation.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
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 */
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/uwb.h>
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#include "uwb-internal.h"
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static void uwb_rsv_fill_column_alloc(struct uwb_rsv_alloc_info *ai)
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{
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	int col, mas, safe_mas, unsafe_mas;
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	unsigned char *bm = ai->bm;
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	struct uwb_rsv_col_info *ci = ai->ci;
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	unsigned char c;
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	for (col = ci->csi.start_col; col < UWB_NUM_ZONES; col += ci->csi.interval) {
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		safe_mas   = ci->csi.safe_mas_per_col;
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		unsafe_mas = ci->csi.unsafe_mas_per_col;
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		for (mas = 0; mas < UWB_MAS_PER_ZONE; mas++ ) {
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			if (bm[col * UWB_MAS_PER_ZONE + mas] == 0) {
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				if (safe_mas > 0) {
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					safe_mas--;
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					c = UWB_RSV_MAS_SAFE;
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				} else if (unsafe_mas > 0) {
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					unsafe_mas--;
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					c = UWB_RSV_MAS_UNSAFE;
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				} else {
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					break;
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				}
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				bm[col * UWB_MAS_PER_ZONE + mas] = c;
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			}
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		}
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	}
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}
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static void uwb_rsv_fill_row_alloc(struct uwb_rsv_alloc_info *ai)
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{
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	int mas, col, rows;
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	unsigned char *bm = ai->bm;
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	struct uwb_rsv_row_info *ri = &ai->ri;
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	unsigned char c;
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	rows = 1;
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	c = UWB_RSV_MAS_SAFE;
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	for (mas = UWB_MAS_PER_ZONE - 1; mas >= 0; mas--) {
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		if (ri->avail[mas] == 1) {
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			if (rows > ri->used_rows) {
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				break;
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			} else if (rows > 7) {
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				c = UWB_RSV_MAS_UNSAFE;
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			}
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			for (col = 0; col < UWB_NUM_ZONES; col++) {
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				if (bm[col * UWB_NUM_ZONES + mas] != UWB_RSV_MAS_NOT_AVAIL) {
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					bm[col * UWB_NUM_ZONES + mas] = c;
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					if(c == UWB_RSV_MAS_SAFE)
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						ai->safe_allocated_mases++;
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					else
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						ai->unsafe_allocated_mases++;
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				}
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			}
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			rows++;
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		}
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	}
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	ai->total_allocated_mases = ai->safe_allocated_mases + ai->unsafe_allocated_mases;
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}
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/*
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 * Find the best column set for a given availability, interval, num safe mas and
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 * num unsafe mas.
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 *
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 * The different sets are tried in order as shown below, depending on the interval.
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 *
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 * interval = 16
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 *	deep = 0
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 *		set 1 ->  {  8 }
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 *	deep = 1
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 *		set 1 ->  {  4 }
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 *		set 2 ->  { 12 }
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 *	deep = 2
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 *		set 1 ->  {  2 }
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 *		set 2 ->  {  6 }
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 *		set 3 ->  { 10 }
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 *		set 4 ->  { 14 }
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 *	deep = 3
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 *		set 1 ->  {  1 }
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 *		set 2 ->  {  3 }
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 *		set 3 ->  {  5 }
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 *		set 4 ->  {  7 }
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 *		set 5 ->  {  9 }
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 *		set 6 ->  { 11 }
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 *		set 7 ->  { 13 }
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 *		set 8 ->  { 15 }
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 *
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 * interval = 8
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 *	deep = 0
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 *		set 1 ->  {  4  12 }
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 *	deep = 1
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 *		set 1 ->  {  2  10 }
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 *		set 2 ->  {  6  14 }
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 *	deep = 2
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 *		set 1 ->  {  1   9 }
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 *		set 2 ->  {  3  11 }
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 *		set 3 ->  {  5  13 }
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 *		set 4 ->  {  7  15 }
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 *
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 * interval = 4
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 *	deep = 0
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 *		set 1 ->  {  2   6  10  14 }
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 *	deep = 1
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 *		set 1 ->  {  1   5   9  13 }
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 *		set 2 ->  {  3   7  11  15 }
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 *
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 * interval = 2
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 *	deep = 0
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 *		set 1 ->  {  1   3   5   7   9  11  13  15 }
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 */
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static int uwb_rsv_find_best_column_set(struct uwb_rsv_alloc_info *ai, int interval, 
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					int num_safe_mas, int num_unsafe_mas)
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{
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	struct uwb_rsv_col_info *ci = ai->ci;
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	struct uwb_rsv_col_set_info *csi = &ci->csi;
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	struct uwb_rsv_col_set_info tmp_csi;
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	int deep, set, col, start_col_deep, col_start_set;
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	int start_col, max_mas_in_set, lowest_max_mas_in_deep;
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	int n_mas;
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	int found = UWB_RSV_ALLOC_NOT_FOUND; 
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	tmp_csi.start_col = 0;
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	start_col_deep = interval;
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	n_mas = num_unsafe_mas + num_safe_mas;
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	for (deep = 0; ((interval >> deep) & 0x1) == 0; deep++) {
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		start_col_deep /= 2;
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		col_start_set = 0;
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		lowest_max_mas_in_deep = UWB_MAS_PER_ZONE;
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		for (set = 1; set <= (1 << deep); set++) {
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			max_mas_in_set = 0;
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			start_col = start_col_deep + col_start_set;
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			for (col = start_col; col < UWB_NUM_ZONES; col += interval) {
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				if (ci[col].max_avail_safe >= num_safe_mas &&
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				    ci[col].max_avail_unsafe >= n_mas) {
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					if (ci[col].highest_mas[n_mas] > max_mas_in_set)
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						max_mas_in_set = ci[col].highest_mas[n_mas];
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				} else {
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					max_mas_in_set = 0;
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					break;
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				}
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			}
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			if ((lowest_max_mas_in_deep > max_mas_in_set) && max_mas_in_set) {
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				lowest_max_mas_in_deep = max_mas_in_set;
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				tmp_csi.start_col = start_col;
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			}
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			col_start_set += (interval >> deep);
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		}
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		if (lowest_max_mas_in_deep < 8) {
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			csi->start_col = tmp_csi.start_col;
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			found = UWB_RSV_ALLOC_FOUND;
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			break;
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		} else if ((lowest_max_mas_in_deep > 8) && 
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			   (lowest_max_mas_in_deep != UWB_MAS_PER_ZONE) &&
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			   (found == UWB_RSV_ALLOC_NOT_FOUND)) {
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			csi->start_col = tmp_csi.start_col;
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			found = UWB_RSV_ALLOC_FOUND;
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		}
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	}
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	if (found == UWB_RSV_ALLOC_FOUND) {
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		csi->interval = interval;
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		csi->safe_mas_per_col = num_safe_mas;
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		csi->unsafe_mas_per_col = num_unsafe_mas;
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		ai->safe_allocated_mases = (UWB_NUM_ZONES / interval) * num_safe_mas;
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		ai->unsafe_allocated_mases = (UWB_NUM_ZONES / interval) * num_unsafe_mas;
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		ai->total_allocated_mases = ai->safe_allocated_mases + ai->unsafe_allocated_mases;
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		ai->interval = interval;		
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	}
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	return found;
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}
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static void get_row_descriptors(struct uwb_rsv_alloc_info *ai)
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{
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	unsigned char *bm = ai->bm;
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	struct uwb_rsv_row_info *ri = &ai->ri;
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	int col, mas;
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	ri->free_rows = 16;
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	for (mas = 0; mas < UWB_MAS_PER_ZONE; mas ++) {
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		ri->avail[mas] = 1;
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		for (col = 1; col < UWB_NUM_ZONES; col++) {
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			if (bm[col * UWB_NUM_ZONES + mas] == UWB_RSV_MAS_NOT_AVAIL) {
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				ri->free_rows--;
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				ri->avail[mas]=0;
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				break;
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			}
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		}
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	}
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}
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static void uwb_rsv_fill_column_info(unsigned char *bm, int column, struct uwb_rsv_col_info *rci)
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{
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	int mas;
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	int block_count = 0, start_block = 0; 
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	int previous_avail = 0;
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	int available = 0;
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	int safe_mas_in_row[UWB_MAS_PER_ZONE] = {
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		8, 7, 6, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 3, 2, 1,
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	};
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	rci->max_avail_safe = 0;
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	for (mas = 0; mas < UWB_MAS_PER_ZONE; mas ++) {
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		if (!bm[column * UWB_NUM_ZONES + mas]) {
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			available++;
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			rci->max_avail_unsafe = available;
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			rci->highest_mas[available] = mas;
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			if (previous_avail) {
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				block_count++;
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				if ((block_count > safe_mas_in_row[start_block]) &&
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				    (!rci->max_avail_safe))
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					rci->max_avail_safe = available - 1;
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			} else {
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				previous_avail = 1;
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				start_block = mas;
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				block_count = 1;
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			}
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		} else {
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			previous_avail = 0;
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		}
 | 
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	}
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	if (!rci->max_avail_safe)
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		rci->max_avail_safe = rci->max_avail_unsafe;
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}
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static void get_column_descriptors(struct uwb_rsv_alloc_info *ai)
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{
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	unsigned char *bm = ai->bm;
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	struct uwb_rsv_col_info *ci = ai->ci;
 | 
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	int col;
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 | 
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	for (col = 1; col < UWB_NUM_ZONES; col++) {
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		uwb_rsv_fill_column_info(bm, col, &ci[col]);
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	}
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}
 | 
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 | 
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static int uwb_rsv_find_best_row_alloc(struct uwb_rsv_alloc_info *ai)
 | 
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{
 | 
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	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)
 | 
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		min_rows++;
 | 
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	for (n_rows = max_rows; n_rows >= min_rows; n_rows--) {
 | 
						|
		if (n_rows <= ai->ri.free_rows) {
 | 
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			ai->ri.used_rows = n_rows;
 | 
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			ai->interval = 1; /* row reservation */
 | 
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			uwb_rsv_fill_row_alloc(ai);
 | 
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			return UWB_RSV_ALLOC_FOUND;
 | 
						|
		}
 | 
						|
	}  
 | 
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	return UWB_RSV_ALLOC_NOT_FOUND;
 | 
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}
 | 
						|
 | 
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static int uwb_rsv_find_best_col_alloc(struct uwb_rsv_alloc_info *ai, int interval)
 | 
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{
 | 
						|
	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;
 | 
						|
 | 
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	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);
 | 
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				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;
 | 
						|
}
 |