u-boot/arch/arm/cpu/armv8/sec_firmware.c
Ruchika Gupta a797f274d7 ARMv8/sec_firmware : Update chosen/kaslr-seed with random number
kASLR support in kernel requires a random number to be passed via
chosen/kaslr-seed propert. sec_firmware generates this random seed
which can then be passed in the device tree node.

sec_firmware reserves JR3 for it's own usage. Node for JR3 is
removed from device-tree.

Signed-off-by: Ruchika Gupta <ruchika.gupta@nxp.com>
2017-08-26 14:56:11 -04:00

379 lines
9 KiB
C

/*
* Copyright 2016 NXP Semiconductor, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <errno.h>
#include <linux/kernel.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/types.h>
#include <asm/macro.h>
#include <asm/armv8/sec_firmware.h>
DECLARE_GLOBAL_DATA_PTR;
extern void c_runtime_cpu_setup(void);
#define SEC_FIRMWARE_LOADED 0x1
#define SEC_FIRMWARE_RUNNING 0x2
#define SEC_FIRMWARE_ADDR_MASK (~0x3)
/*
* Secure firmware load addr
* Flags used: 0x1 secure firmware has been loaded to secure memory
* 0x2 secure firmware is running
*/
phys_addr_t sec_firmware_addr;
#ifndef SEC_FIRMWARE_FIT_IMAGE
#define SEC_FIRMWARE_FIT_IMAGE "firmware"
#endif
#ifndef SEC_FIRMEWARE_FIT_CNF_NAME
#define SEC_FIRMEWARE_FIT_CNF_NAME "config@1"
#endif
#ifndef SEC_FIRMWARE_TARGET_EL
#define SEC_FIRMWARE_TARGET_EL 2
#endif
static int sec_firmware_get_data(const void *sec_firmware_img,
const void **data, size_t *size)
{
int conf_node_off, fw_node_off;
char *conf_node_name = NULL;
char *desc;
int ret;
conf_node_name = SEC_FIRMEWARE_FIT_CNF_NAME;
conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
if (conf_node_off < 0) {
printf("SEC Firmware: %s: no such config\n", conf_node_name);
return -ENOENT;
}
fw_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
SEC_FIRMWARE_FIT_IMAGE);
if (fw_node_off < 0) {
printf("SEC Firmware: No '%s' in config\n",
SEC_FIRMWARE_FIT_IMAGE);
return -ENOLINK;
}
/* Verify secure firmware image */
if (!(fit_image_verify(sec_firmware_img, fw_node_off))) {
printf("SEC Firmware: Bad firmware image (bad CRC)\n");
return -EINVAL;
}
if (fit_image_get_data(sec_firmware_img, fw_node_off, data, size)) {
printf("SEC Firmware: Can't get %s subimage data/size",
SEC_FIRMWARE_FIT_IMAGE);
return -ENOENT;
}
ret = fit_get_desc(sec_firmware_img, fw_node_off, &desc);
if (ret)
printf("SEC Firmware: Can't get description\n");
else
printf("%s\n", desc);
return ret;
}
/*
* SEC Firmware FIT image parser checks if the image is in FIT
* format, verifies integrity of the image and calculates raw
* image address and size values.
*
* Returns 0 on success and a negative errno on error task fail.
*/
static int sec_firmware_parse_image(const void *sec_firmware_img,
const void **raw_image_addr,
size_t *raw_image_size)
{
int ret;
ret = sec_firmware_get_data(sec_firmware_img, raw_image_addr,
raw_image_size);
if (ret)
return ret;
debug("SEC Firmware: raw_image_addr = 0x%p, raw_image_size = 0x%lx\n",
*raw_image_addr, *raw_image_size);
return 0;
}
static int sec_firmware_copy_image(const char *title,
u64 image_addr, u32 image_size, u64 sec_firmware)
{
debug("%s copied to address 0x%p\n", title, (void *)sec_firmware);
memcpy((void *)sec_firmware, (void *)image_addr, image_size);
flush_dcache_range(sec_firmware, sec_firmware + image_size);
return 0;
}
/*
* This function will parse the SEC Firmware image, and then load it
* to secure memory.
*/
static int sec_firmware_load_image(const void *sec_firmware_img)
{
const void *raw_image_addr;
size_t raw_image_size = 0;
int ret;
/*
* The Excetpion Level must be EL3 to load and initialize
* the SEC Firmware.
*/
if (current_el() != 3) {
ret = -EACCES;
goto out;
}
#ifdef CONFIG_SYS_MEM_RESERVE_SECURE
/*
* The SEC Firmware must be stored in secure memory.
* Append SEC Firmware to secure mmu table.
*/
if (!(gd->arch.secure_ram & MEM_RESERVE_SECURE_MAINTAINED)) {
ret = -ENXIO;
goto out;
}
sec_firmware_addr = (gd->arch.secure_ram & MEM_RESERVE_SECURE_ADDR_MASK) +
gd->arch.tlb_size;
#else
#error "The CONFIG_SYS_MEM_RESERVE_SECURE must be defined when enabled SEC Firmware support"
#endif
/* Align SEC Firmware base address to 4K */
sec_firmware_addr = (sec_firmware_addr + 0xfff) & ~0xfff;
debug("SEC Firmware: Load address: 0x%llx\n",
sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
ret = sec_firmware_parse_image(sec_firmware_img, &raw_image_addr,
&raw_image_size);
if (ret)
goto out;
/* TODO:
* Check if the end addr of SEC Firmware has been extend the secure
* memory.
*/
/* Copy the secure firmware to secure memory */
ret = sec_firmware_copy_image("SEC Firmware", (u64)raw_image_addr,
raw_image_size, sec_firmware_addr &
SEC_FIRMWARE_ADDR_MASK);
if (ret)
goto out;
sec_firmware_addr |= SEC_FIRMWARE_LOADED;
debug("SEC Firmware: Entry point: 0x%llx\n",
sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
return 0;
out:
printf("SEC Firmware: error (%d)\n", ret);
sec_firmware_addr = 0;
return ret;
}
static int sec_firmware_entry(u32 *eret_hold_l, u32 *eret_hold_h)
{
const void *entry = (void *)(sec_firmware_addr &
SEC_FIRMWARE_ADDR_MASK);
return _sec_firmware_entry(entry, eret_hold_l, eret_hold_h);
}
/* Check the secure firmware FIT image */
__weak bool sec_firmware_is_valid(const void *sec_firmware_img)
{
if (fdt_check_header(sec_firmware_img)) {
printf("SEC Firmware: Bad firmware image (not a FIT image)\n");
return false;
}
if (!fit_check_format(sec_firmware_img)) {
printf("SEC Firmware: Bad firmware image (bad FIT header)\n");
return false;
}
return true;
}
#ifdef CONFIG_SEC_FIRMWARE_ARMV8_PSCI
/*
* The PSCI_VERSION function is added from PSCI v0.2. When the PSCI
* v0.1 received this function, the NOT_SUPPORTED (0xffff_ffff) error
* number will be returned according to SMC Calling Conventions. But
* when getting the NOT_SUPPORTED error number, we cannot ensure if
* the PSCI version is v0.1 or other error occurred. So, PSCI v0.1
* won't be supported by this framework.
* And if the secure firmware isn't running, return NOT_SUPPORTED.
*
* The return value on success is PSCI version in format
* major[31:16]:minor[15:0].
*/
unsigned int sec_firmware_support_psci_version(void)
{
if (current_el() == SEC_FIRMWARE_TARGET_EL)
return _sec_firmware_support_psci_version();
return PSCI_INVALID_VER;
}
#endif
/*
* Check with sec_firmware if it supports random number generation
* via HW RNG
*
* The return value will be true if it is supported
*/
bool sec_firmware_support_hwrng(void)
{
uint8_t rand[8];
if (sec_firmware_addr & SEC_FIRMWARE_RUNNING) {
if (!sec_firmware_get_random(rand, 8))
return true;
}
return false;
}
/*
* sec_firmware_get_random - Get a random number from SEC Firmware
* @rand: random number buffer to be filled
* @bytes: Number of bytes of random number to be supported
* @eret: -1 in case of error, 0 for success
*/
int sec_firmware_get_random(uint8_t *rand, int bytes)
{
unsigned long long num;
struct pt_regs regs;
int param1;
if (!bytes || bytes > 8) {
printf("Max Random bytes genration supported is 8\n");
return -1;
}
#define SIP_RNG_64 0xC200FF11
regs.regs[0] = SIP_RNG_64;
if (bytes <= 4)
param1 = 0;
else
param1 = 1;
regs.regs[1] = param1;
smc_call(&regs);
if (regs.regs[0])
return -1;
num = regs.regs[1];
memcpy(rand, &num, bytes);
return 0;
}
/*
* sec_firmware_init - Initialize the SEC Firmware
* @sec_firmware_img: the SEC Firmware image address
* @eret_hold_l: the address to hold exception return address low
* @eret_hold_h: the address to hold exception return address high
*/
int sec_firmware_init(const void *sec_firmware_img,
u32 *eret_hold_l,
u32 *eret_hold_h)
{
int ret;
if (!sec_firmware_is_valid(sec_firmware_img))
return -EINVAL;
ret = sec_firmware_load_image(sec_firmware_img);
if (ret) {
printf("SEC Firmware: Failed to load image\n");
return ret;
} else if (sec_firmware_addr & SEC_FIRMWARE_LOADED) {
ret = sec_firmware_entry(eret_hold_l, eret_hold_h);
if (ret) {
printf("SEC Firmware: Failed to initialize\n");
return ret;
}
}
debug("SEC Firmware: Return from SEC Firmware: current_el = %d\n",
current_el());
/*
* The PE will be turned into target EL when returned from
* SEC Firmware.
*/
if (current_el() != SEC_FIRMWARE_TARGET_EL)
return -EACCES;
sec_firmware_addr |= SEC_FIRMWARE_RUNNING;
/* Set exception table and enable caches if it isn't EL3 */
if (current_el() != 3) {
c_runtime_cpu_setup();
enable_caches();
}
return 0;
}
/*
* fdt_fix_kaslr - Add kalsr-seed node in Device tree
* @fdt: Device tree
* @eret: 0 in case of error, 1 for success
*/
int fdt_fixup_kaslr(void *fdt)
{
int nodeoffset;
int err, ret = 0;
u8 rand[8];
#if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT)
/* Check if random seed generation is supported */
if (sec_firmware_support_hwrng() == false)
return 0;
ret = sec_firmware_get_random(rand, 8);
if (ret < 0) {
printf("WARNING: No random number to set kaslr-seed\n");
return 0;
}
err = fdt_check_header(fdt);
if (err < 0) {
printf("fdt_chosen: %s\n", fdt_strerror(err));
return 0;
}
/* find or create "/chosen" node. */
nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
if (nodeoffset < 0)
return 0;
err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand,
sizeof(rand));
if (err < 0) {
printf("WARNING: can't set kaslr-seed %s.\n",
fdt_strerror(err));
return 0;
}
ret = 1;
#endif
return ret;
}