u-boot/arch/arm/mach-meson/sm.c
Neil Armstrong b1dd7debea arm: meson: add sm command to retrieve the reboot reason
The Secure Monitor offers multiple services, like returning the
SoC unique serial number, and can provide the "reboot reason" as
set by the previous booted system.

This extends the Amlogic specific "sm" cmd with a "reboot_reason" subcommand
to print or set a specified environment variable with the reboot reason in
human readable format.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
2019-08-12 10:02:30 +02:00

212 lines
4.6 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2016 Beniamino Galvani <b.galvani@gmail.com>
*
* Secure monitor calls.
*/
#include <common.h>
#include <asm/arch/sm.h>
#include <linux/kernel.h>
#include <dm.h>
#include <linux/bitfield.h>
#include <regmap.h>
#include <syscon.h>
#define FN_GET_SHARE_MEM_INPUT_BASE 0x82000020
#define FN_GET_SHARE_MEM_OUTPUT_BASE 0x82000021
#define FN_EFUSE_READ 0x82000030
#define FN_EFUSE_WRITE 0x82000031
#define FN_CHIP_ID 0x82000044
static void *shmem_input;
static void *shmem_output;
static void meson_init_shmem(void)
{
struct pt_regs regs;
if (shmem_input && shmem_output)
return;
regs.regs[0] = FN_GET_SHARE_MEM_INPUT_BASE;
smc_call(&regs);
shmem_input = (void *)regs.regs[0];
regs.regs[0] = FN_GET_SHARE_MEM_OUTPUT_BASE;
smc_call(&regs);
shmem_output = (void *)regs.regs[0];
debug("Secure Monitor shmem: 0x%p 0x%p\n", shmem_input, shmem_output);
}
ssize_t meson_sm_read_efuse(uintptr_t offset, void *buffer, size_t size)
{
struct pt_regs regs;
meson_init_shmem();
regs.regs[0] = FN_EFUSE_READ;
regs.regs[1] = offset;
regs.regs[2] = size;
smc_call(&regs);
if (regs.regs[0] == 0)
return -1;
memcpy(buffer, shmem_output, min(size, regs.regs[0]));
return regs.regs[0];
}
#define SM_CHIP_ID_LENGTH 119
#define SM_CHIP_ID_OFFSET 4
#define SM_CHIP_ID_SIZE 12
int meson_sm_get_serial(void *buffer, size_t size)
{
struct pt_regs regs;
meson_init_shmem();
regs.regs[0] = FN_CHIP_ID;
regs.regs[1] = 0;
regs.regs[2] = 0;
smc_call(&regs);
memcpy(buffer, shmem_output + SM_CHIP_ID_OFFSET,
min_t(size_t, size, SM_CHIP_ID_SIZE));
return 0;
}
#define AO_SEC_SD_CFG15 0xfc
#define REBOOT_REASON_MASK GENMASK(15, 12)
int meson_sm_get_reboot_reason(void)
{
struct regmap *regmap;
int nodeoffset;
ofnode node;
unsigned int reason;
/* find the offset of compatible node */
nodeoffset = fdt_node_offset_by_compatible(gd->fdt_blob, -1,
"amlogic,meson-gx-ao-secure");
if (nodeoffset < 0) {
printf("%s: failed to get amlogic,meson-gx-ao-secure\n",
__func__);
return -ENODEV;
}
/* get regmap from the syscon node */
node = offset_to_ofnode(nodeoffset);
regmap = syscon_node_to_regmap(node);
if (IS_ERR(regmap)) {
printf("%s: failed to get regmap\n", __func__);
return -EINVAL;
}
regmap_read(regmap, AO_SEC_SD_CFG15, &reason);
/* The SMC call is not used, we directly use AO_SEC_SD_CFG15 */
return FIELD_GET(REBOOT_REASON_MASK, reason);
}
static int do_sm_serial(cmd_tbl_t *cmdtp, int flag, int argc,
char *const argv[])
{
ulong address;
int ret;
if (argc < 2)
return CMD_RET_USAGE;
address = simple_strtoul(argv[1], NULL, 0);
ret = meson_sm_get_serial((void *)address, SM_CHIP_ID_SIZE);
if (ret)
return CMD_RET_FAILURE;
return CMD_RET_SUCCESS;
}
#define MAX_REBOOT_REASONS 14
static const char *reboot_reasons[MAX_REBOOT_REASONS] = {
[REBOOT_REASON_COLD] = "cold_boot",
[REBOOT_REASON_NORMAL] = "normal",
[REBOOT_REASON_RECOVERY] = "recovery",
[REBOOT_REASON_UPDATE] = "update",
[REBOOT_REASON_FASTBOOT] = "fastboot",
[REBOOT_REASON_SUSPEND_OFF] = "suspend_off",
[REBOOT_REASON_HIBERNATE] = "hibernate",
[REBOOT_REASON_BOOTLOADER] = "bootloader",
[REBOOT_REASON_SHUTDOWN_REBOOT] = "shutdown_reboot",
[REBOOT_REASON_RPMBP] = "rpmbp",
[REBOOT_REASON_CRASH_DUMP] = "crash_dump",
[REBOOT_REASON_KERNEL_PANIC] = "kernel_panic",
[REBOOT_REASON_WATCHDOG_REBOOT] = "watchdog_reboot",
};
static int do_sm_reboot_reason(cmd_tbl_t *cmdtp, int flag, int argc,
char *const argv[])
{
const char *reason_str;
char *destarg = NULL;
int reason;
if (argc > 1)
destarg = argv[1];
reason = meson_sm_get_reboot_reason();
if (reason < 0)
return CMD_RET_FAILURE;
if (reason >= MAX_REBOOT_REASONS ||
!reboot_reasons[reason])
reason_str = "unknown";
else
reason_str = reboot_reasons[reason];
if (destarg)
env_set(destarg, reason_str);
else
printf("reboot reason: %s (%x)\n", reason_str, reason);
return CMD_RET_SUCCESS;
}
static cmd_tbl_t cmd_sm_sub[] = {
U_BOOT_CMD_MKENT(serial, 2, 1, do_sm_serial, "", ""),
U_BOOT_CMD_MKENT(reboot_reason, 1, 1, do_sm_reboot_reason, "", ""),
};
static int do_sm(cmd_tbl_t *cmdtp, int flag, int argc,
char *const argv[])
{
cmd_tbl_t *c;
if (argc < 2)
return CMD_RET_USAGE;
/* Strip off leading 'sm' command argument */
argc--;
argv++;
c = find_cmd_tbl(argv[0], &cmd_sm_sub[0], ARRAY_SIZE(cmd_sm_sub));
if (c)
return c->cmd(cmdtp, flag, argc, argv);
else
return CMD_RET_USAGE;
}
U_BOOT_CMD(
sm, 5, 0, do_sm,
"Secure Monitor Control",
"serial <address> - read chip unique id to memory address\n"
"sm reboot_reason [name] - get reboot reason and store to to environment"
);