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// SPDX-License-Identifier: GPL-2.0
/*
* GXP ranged resource allocator.
*
* Copyright (C) 2021 Google LLC
*/
#include "gxp-range-alloc.h"
struct range_alloc *range_alloc_create(int start, int end)
{
struct range_alloc *ra;
int count;
int size;
count = end - start;
if (count <= 0)
return ERR_PTR(-EINVAL);
size = sizeof(struct range_alloc) + count * sizeof(int);
ra = kzalloc(size, GFP_KERNEL);
if (!ra)
return ERR_PTR(-ENOMEM);
ra->total_count = count;
ra->free_count = count;
ra->start_index = start;
mutex_init(&ra->lock);
return ra;
}
int range_alloc_get(struct range_alloc *r, int element)
{
int index = element - r->start_index;
mutex_lock(&r->lock);
if (index < 0 || index >= r->total_count) {
mutex_unlock(&r->lock);
return -EINVAL;
}
if (r->elements[index]) {
mutex_unlock(&r->lock);
return -EBUSY;
}
r->elements[index] = 1;
r->free_count--;
mutex_unlock(&r->lock);
return 0;
}
int range_alloc_get_any(struct range_alloc *r, int *element)
{
int i;
mutex_lock(&r->lock);
if (!r->free_count) {
mutex_unlock(&r->lock);
return -ENOMEM;
}
for (i = 0; i < r->total_count; i++) {
if (r->elements[i] == 0) {
r->elements[i] = 1;
r->free_count--;
*element = i + r->start_index;
mutex_unlock(&r->lock);
return 0;
}
}
mutex_unlock(&r->lock);
return -ENOMEM;
}
int range_alloc_put(struct range_alloc *r, int element)
{
int index = element - r->start_index;
mutex_lock(&r->lock);
if (index < 0 || index >= r->total_count) {
mutex_unlock(&r->lock);
return -EINVAL;
}
if (r->elements[index] == 0) {
mutex_unlock(&r->lock);
return -EBUSY;
}
r->elements[index] = 0;
r->free_count++;
mutex_unlock(&r->lock);
return 0;
}
int range_alloc_num_free(struct range_alloc *r)
{
int free_count;
mutex_lock(&r->lock);
free_count = r->free_count;
mutex_unlock(&r->lock);
return free_count;
}
int range_alloc_destroy(struct range_alloc *r)
{
if (!r)
return -EFAULT;
kfree(r);
return 0;
}
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