120 lines
3.1 KiB
C
Executable File
120 lines
3.1 KiB
C
Executable File
/* drivers/gud/sec-os-ctrl/sec_os_ctrl.c
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*
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* Secure OS control driver for Samsung Exynos
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*
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* Copyright (c) 2014 Samsung Electronics
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* http://www.samsungsemi.com/
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/sysfs.h>
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#include <linux/device.h>
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#include <linux/mutex.h>
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#define DEFAULT_LITTLE_CORE 1
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#define DEFAULT_BIG_CORE 6
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#define ASCII_TO_DIGIT_NUM(ascii) (ascii - '0')
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static unsigned int current_core, new_core;
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static DEFINE_MUTEX(sec_os_ctrl_lock);
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int nq_switch_core(uint32_t cpu);
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uint32_t mc_active_core(void);
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static struct bus_type sec_os_ctrl_subsys = {
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.name = "sec_os_ctrl",
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.dev_name = "sec_os_ctrl",
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};
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/* Migrate Secure OS */
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static ssize_t migrate_os_store(struct kobject *kobj,
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struct kobj_attribute *attr, const char *buf, size_t count)
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{
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int ret = 0;
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unsigned int core_num = 0;
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/* Select only big or LITTLE */
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if ((buf[0] != 'L') && (buf[0] != 'b')) {
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pr_err("Invalid core number\n");
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return count;
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}
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/* Derive core number */
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core_num = ASCII_TO_DIGIT_NUM(buf[1]);
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if (buf[0] == 'L') {
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if ((buf[1] == 0xA) || (buf[1] == 0x0)) { /* if LF(Line Feed, 0xA) or NULL(0x0) */
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new_core = DEFAULT_LITTLE_CORE;
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} else if (core_num < 4) { /* From core 0 to core 3 */
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new_core = core_num;
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} else {
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pr_err("[LITTLE] Enter correct core number(0~3)\n");
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return count;
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}
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} else if (buf[0] == 'b') {
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if ((buf[1] == 0xA) || (buf[1] == 0x0)) { /* if LF(Line Feed, 0xA) or NULL(0x0) */
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new_core = DEFAULT_BIG_CORE;
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} else if (core_num < 4) { /* From core 0 to core 3 */
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new_core = core_num + 4;
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} else {
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pr_err("[big] Enter correct core number(0~3)\n");
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return count;
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}
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}
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pr_info("Secure OS will be migrated into core [%d]\n", new_core);
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if (mutex_lock_interruptible(&sec_os_ctrl_lock)) {
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pr_err("Fail to get lock\n");
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return count;
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}
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ret = nq_switch_core(new_core);
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mutex_unlock(&sec_os_ctrl_lock);
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if (ret != 0) {
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pr_err("Secure OS migration is failed!\n");
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pr_err("Return value = %d\n", ret);
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return count;
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}
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return count;
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}
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/* The current core where Secure OS is on */
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static ssize_t current_core_show(struct kobject *kobj,
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struct kobj_attribute *attr, char *buf)
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{
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current_core = mc_active_core();
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return sprintf(buf, "Secure OS is on core [%c%d]\n",
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(current_core < 4) ? 'L' : 'b', (current_core & 3));
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}
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static struct kobj_attribute migrate_os_attr =
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__ATTR(migrate_os, 0600, NULL, migrate_os_store);
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static struct kobj_attribute current_core_attr =
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__ATTR(current_core, 0600, current_core_show, NULL);
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static struct attribute *sec_os_ctrl_sysfs_attrs[] = {
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&migrate_os_attr.attr,
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¤t_core_attr.attr,
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NULL,
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};
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static struct attribute_group sec_os_ctrl_sysfs_group = {
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.attrs = sec_os_ctrl_sysfs_attrs,
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};
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static const struct attribute_group *sec_os_ctrl_sysfs_groups[] = {
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&sec_os_ctrl_sysfs_group,
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NULL,
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};
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static int __init sec_os_ctrl_init(void)
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{
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return subsys_system_register(&sec_os_ctrl_subsys, sec_os_ctrl_sysfs_groups);
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}
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late_initcall(sec_os_ctrl_init);
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