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/* * 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;}