Commit 43cbaf06 authored by Roberto Vargas's avatar Roberto Vargas
Browse files

Add mem_region utility functions



This commit introduces a new type (mem_region_t) used to describe
memory regions and it adds two utility functions:

	- clear_mem_regions: This function clears (write 0) to a set
		of regions described with an array of mem_region_t.

	- mem_region_in_array_chk This function checks if a
		region is covered by some of the regions described
		with an array of mem_region_t.

Change-Id: I12ce549f5e81dd15ac0981645f6e08ee7c120811
Signed-off-by: default avatarRoberto Vargas <roberto.vargas@arm.com>
parent d4c596be
...@@ -19,6 +19,25 @@ ...@@ -19,6 +19,25 @@
#include <types.h> #include <types.h>
typedef struct mem_region_t {
uintptr_t base;
size_t nbytes;
} mem_region_t;
/*
* zero_normalmem all the regions defined in tbl.
*/
void clear_mem_regions(mem_region_t *tbl, size_t nregions);
/*
* checks that a region (addr + nbytes-1) of memory is totally covered by
* one of the regions defined in tbl. Caller must ensure that (addr+nbytes-1)
* doesn't overflow.
*/
int mem_region_in_array_chk(mem_region_t *tbl, size_t nregions,
uintptr_t addr, size_t nbytes);
/* /*
* Fill a region of normal memory of size "length" in bytes with zero bytes. * Fill a region of normal memory of size "length" in bytes with zero bytes.
* *
......
/*
* Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <assert.h>
#include <utils.h>
/*
* All the regions defined in mem_region_t must have the following properties
*
* - Any contiguous regions must be merged into a single entry.
* - The number of bytes of each region must be greater than zero.
* - The calculation of the highest address within the region (base + nbytes-1)
* doesn't produce an overflow.
*
* These conditions must be fulfilled by the caller and they aren't checked
* at runtime.
*/
/*
* zero_normalmem all the regions defined in tbl.
* It assumes that MMU is enabled and the memory is Normal memory.
* tbl must be a valid pointer to a memory mem_region_t array,
* nregions is the size of the array.
*/
void clear_mem_regions(mem_region_t *tbl, size_t nregions)
{
size_t i;
assert(tbl);
assert(nregions > 0);
for (i = 0; i < nregions; i++) {
assert(tbl->nbytes > 0);
assert(!check_uptr_overflow(tbl->base, tbl->nbytes-1));
zero_normalmem((void *) (tbl->base), tbl->nbytes);
tbl++;
}
}
/*
* This function checks that a region (addr + nbytes-1) of memory is totally
* covered by one of the regions defined in tbl.
* tbl must be a valid pointer to a memory mem_region_t array, nregions
* is the size of the array and the region described by addr and nbytes must
* not generate an overflow.
* Returns:
* -1 means that the region is not covered by any of the regions
* described in tbl.
* 0 the region (addr + nbytes-1) is covered by one of the regions described
* in tbl
*/
int mem_region_in_array_chk(mem_region_t *tbl, size_t nregions,
uintptr_t addr, size_t nbytes)
{
uintptr_t region_start, region_end, start, end;
size_t i;
assert(tbl);
assert(nbytes > 0);
assert(!check_uptr_overflow(addr, nbytes-1));
region_start = addr;
region_end = addr + (nbytes - 1);
for (i = 0; i < nregions; i++) {
assert(tbl->nbytes > 0);
assert(!check_uptr_overflow(tbl->base, tbl->nbytes-1));
start = tbl->base;
end = start + (tbl->nbytes - 1);
if (region_start >= start && region_end <= end)
return 0;
tbl++;
}
return -1;
}
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