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barebox/common/resource.c

146 lines
3.5 KiB
C

/*
* resource.c - barebox resource management
*
* Copyright (c) 2011 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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.
*/
#include <common.h>
#include <malloc.h>
#include <errno.h>
#include <init.h>
#include <linux/ioport.h>
#include <asm/io.h>
static int init_resource(struct resource *res, const char *name)
{
INIT_LIST_HEAD(&res->children);
res->parent = NULL;
res->name = xstrdup(name);
return 0;
}
/*
* request a region.
* This will succedd when the requested region is completely inside
* the parent resource and does not conflict with any of the child
* resources.
*/
struct resource *__request_region(struct resource *parent,
const char *name, resource_size_t start,
resource_size_t end)
{
struct resource *r, *new;
if (end < start) {
debug("%s: request region 0x%08llx:0x%08llx: end < start\n",
__func__,
(unsigned long long)start,
(unsigned long long)end);
return NULL;
}
/* outside parent resource? */
if (start < parent->start || end > parent->end) {
debug("%s: 0x%08llx:0x%08llx outside parent resource 0x%08llx:0x%08llx\n",
__func__,
(unsigned long long)start,
(unsigned long long)end,
(unsigned long long)parent->start,
(unsigned long long)parent->end);
return NULL;
}
/*
* We keep the list of child resources ordered which helps
* us searching for conflicts here.
*/
list_for_each_entry(r, &parent->children, sibling) {
if (end < r->start)
goto ok;
if (start > r->end)
continue;
debug("%s: 0x%08llx:0x%08llx conflicts with 0x%08llx:0x%08llx\n",
__func__,
(unsigned long long)start,
(unsigned long long)end,
(unsigned long long)r->start,
(unsigned long long)r->end);
return NULL;
}
ok:
debug("%s ok: 0x%08llx:0x%08llx\n", __func__,
(unsigned long long)start,
(unsigned long long)end);
new = xzalloc(sizeof(*new));
init_resource(new, name);
new->start = start;
new->end = end;
new->parent = parent;
list_add_tail(&new->sibling, &r->sibling);
return new;
}
/*
* release a region previously requested with request_*_region
*/
int release_region(struct resource *res)
{
if (!list_empty(&res->children))
return -EBUSY;
list_del(&res->sibling);
free((char *)res->name);
free(res);
return 0;
}
/* The root resource for the whole memory-mapped io space */
struct resource iomem_resource = {
.start = 0,
.end = 0xffffffff,
.name = "iomem",
.children = LIST_HEAD_INIT(iomem_resource.children),
};
/*
* request a region inside the io space (memory)
*/
struct resource *request_iomem_region(const char *name,
resource_size_t start, resource_size_t end)
{
return __request_region(&iomem_resource, name, start, end);
}
/* The root resource for the whole io-mapped io space */
struct resource ioport_resource = {
.start = 0,
.end = IO_SPACE_LIMIT,
.name = "ioport",
.children = LIST_HEAD_INIT(ioport_resource.children),
};
/*
* request a region inside the io space (i/o port)
*/
struct resource *request_ioport_region(const char *name,
resource_size_t start, resource_size_t end)
{
return __request_region(&ioport_resource, name, start, end);
}