blob: 3157f69e389bc7b968dec27c9f1418c7494016db [file] [log] [blame]
/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
/* Shared memory module for Chrome EC */
#include "common.h"
#include "console.h"
#include "link_defs.h"
#include "shared_mem.h"
#include "system.h"
#include "util.h"
static int buf_in_use;
static int max_used;
int shared_mem_size(void)
* Use all the RAM we can. The shared memory buffer is the last thing
* allocated from the start of RAM, so we can use everything up to the
* jump data at the end of RAM.
return system_usable_ram_end() - (uintptr_t)__shared_mem_buf;
int shared_mem_acquire(int size, char **dest_ptr)
if (size > shared_mem_size() || size <= 0)
if (buf_in_use)
* We could guard buf_in_use with a mutex, but since shared memory is
* currently only used by debug commands, that's overkill.
buf_in_use = size;
*dest_ptr = __shared_mem_buf;
if (max_used < size)
max_used = size;
return EC_SUCCESS;
void shared_mem_release(void *ptr)
buf_in_use = 0;
static int command_shmem(int argc, char **argv)
ccprintf("Size:%6d\n", shared_mem_size());
ccprintf("Used:%6d\n", buf_in_use);
ccprintf("Max: %6d\n", max_used);
return EC_SUCCESS;
DECLARE_SAFE_CONSOLE_COMMAND(shmem, command_shmem,
"Print shared memory stats");