kernel_samsung_sm7125/drivers/char/knox_kap.c

/*
*/
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/mman.h>
#include <linux/random.h>
#include <linux/init.h>
#include <linux/raw.h>
#include <linux/tty.h>
#include <linux/capability.h>
#include <linux/ptrace.h>
#include <linux/device.h>
#include <linux/highmem.h>
#include <linux/crash_dump.h>
#include <linux/backing-dev.h>
#include <linux/bootmem.h>
#include <linux/splice.h>
#include <linux/pfn.h>
#include <linux/export.h>
#include <linux/seq_file.h>
#include <linux/knox_kap.h>

#include <linux/uaccess.h>
#include <linux/io.h>

#include "../misc/qseecom_kernel.h"

#define SMC_CMD_KAP_CALL                (0x83000009)
#define SMC_CMD_KAP_STATUS                (0x8300000A)

unsigned int kap_on_reboot;  // 1: turn on kap after reboot; 0: no pending ON action
unsigned int kap_off_reboot; // 1: turn off kap after reboot; 0: no pending OFF action

u64 exynos_smc64(u64 cmd, u64 arg1, u64 arg2, u64 arg3)
{
	register u64 reg0 __asm__("x0") = cmd;
	register u64 reg1 __asm__("x1") = arg1;
	register u64 reg2 __asm__("x2") = arg2;
	register u64 reg3 __asm__("x3") = arg3;
	__asm__ volatile (
			"dsb    sy\n"
			"smc    0\n"
			: "+r"(reg0), "+r"(reg1), "+r"(reg2), "+r"(reg3)
			);

	return reg0;
}

static int get_kap_bksecapp_call(void)
{
	int ret = -1;
	int dmv_req_len = 0;
	int dmv_rsp_len = 0;
	struct dmv_req_t *dmv_req = NULL;
	struct dmv_rsp_t *dmv_rsp = NULL;
	struct qseecom_handle *qhandle_kap = NULL;

	pr_err(" %s -> qhandle address : %p\n", __func__, qhandle_kap);
	ret = qseecom_start_app((&qhandle_kap), "bksecapp", QSEECOM_SBUFF_SIZE);
	if (ret) {
		pr_err(" %s -> qseecom_start_app failed %d\n", __func__, ret);
		goto err_ret;
	}
	pr_err(" %s -> qseecom_start_app succeeded. %d\n", __func__, ret);
	dmv_req = (struct dmv_req_t *)qhandle_kap->sbuf;
	pr_err(" %s -> dmv_req address : %p .\n", __func__, dmv_req);
	dmv_req_len = sizeof(struct dmv_req_t);

	dmv_req->cmd_id = SEC_BOOT_CMD101_GET_DMV_DATA;

	dmv_rsp = (struct dmv_rsp_t *)(qhandle_kap->sbuf + dmv_req_len);
	dmv_rsp_len = sizeof(struct dmv_rsp_t);

	ret = qseecom_send_command(qhandle_kap, dmv_req, dmv_req_len, dmv_rsp, dmv_rsp_len);

	pr_err(" %s -> read KAP status %d\n", __func__, dmv_req->data.dmv_bl_status.security_mode);
	if (ret) {
		pr_err(" %s -> Failed to send command : %d\n", __func__, ret);
		pr_err("%s -> sending command to tz app failed with error %d\n", __func__, ret);
		goto err_ret;
	}

	ret = dmv_req->data.dmv_bl_status.security_mode;

err_ret:
	pr_err("shutting down %s\n", "bksecapp");
	qseecom_shutdown_app(&(qhandle_kap));
	return ret;
}

static void turn_off_kap(void)
{
	kap_on_reboot = 0;
	kap_off_reboot = 1;
	pr_err("%s -> Turn off kap mode\n", __func__);
	//exynos_smc64(SMC_CMD_KAP_CALL, 0x51, 0, 0);
}

static void turn_on_kap(void)
{
	kap_off_reboot = 0;
	kap_on_reboot = 1;
	pr_err("%s -> Turn on kap mode\n", __func__);
}

#define KAP_RET_SIZE	5
#define KAP_MAGIC	0x5afe0000
#define KAP_MAGIC_MASK	0xffff0000
static int knox_kap_read(struct seq_file *m, void *v)
{
	unsigned long tz_ret = 0;
	unsigned char ret_buffer[KAP_RET_SIZE];

	unsigned int ret_val;

	// ????? //
	//clean_dcache_area(&tz_ret, 8);
	//tima_send_cmd(__pa(&tz_ret), 0x3f850221);
	//tz_ret = exynos_smc_kap(SMC_CMD_KAP_CALL, 0x50, 0, 0);
	tz_ret =   get_kap_bksecapp_call();
	//tz_ret = KAP_MAGIC | 1;

	pr_err("KAP Read STATUS val = %lx\n", tz_ret);

	if (tz_ret == (KAP_MAGIC | 0x01)) {
		ret_val = 0x03;		//RKP and/or DMVerity says device is tampered
	} else if (tz_ret == (KAP_MAGIC | 0x11)) {
		/* KAP is ON*/
		if (kap_off_reboot == 1)
			ret_val = 0x10;//KAP is ON and will turn OFF upon next reboot
		else
			ret_val = 0x11;//KAP is ON and will stay ON
	} else if (tz_ret == (KAP_MAGIC)) {
		/* KAP is OFF*/
		if (kap_on_reboot == 1)
			ret_val = 0x01;		//KAP is OFF but will turn on upon next reboot
		else
			ret_val = 0;		//KAP is OFF and will stay OFF upon next reboot

	} else {
		ret_val = 0x04;		//The magic string is not there. KAP mode not implemented
	}
	memset(ret_buffer, 0, KAP_RET_SIZE);
	snprintf(ret_buffer, sizeof(ret_buffer), "%02x\n", ret_val);
	seq_write(m, ret_buffer, sizeof(ret_buffer));

	return 0;
}
static int knox_kap_open(struct inode *inode, struct file *filp)
{
	return single_open(filp, knox_kap_read, NULL);
}

long knox_kap_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	//Switch according to the ioctl called
	switch (cmd) {
	case 0:
		turn_off_kap();
		break;
	case 1:
		turn_on_kap();
		break;
	default:
		pr_err("%s -> Invalid kap mode operations\n", __func__);
		return -1;
	}
	return 0;
}

const struct file_operations knox_kap_fops = {
	.open	= knox_kap_open,
	.release	= single_release,
	.read	= seq_read,
	.unlocked_ioctl  = knox_kap_ioctl,
};