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linux/drivers/uwb/allocator.c
Thomas Gleixner caab277b1d treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:07 +02:00

375 lines
9.4 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
/*
* UWB reservation management.
*
* Copyright (C) 2008 Cambridge Silicon Radio Ltd.
*/
#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;
}
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