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// SPDX-License-Identifier: BSD-2-Clause
/*
* Copyright (c) 2016, Linaro Limited
*/
/* Driver for the internal Random Number Generator of HiSilicon P660/Hi16xx */
#include <initcall.h>
#include <io.h>
#include <kernel/spinlock.h>
#include <kernel/tee_time.h>
#include <mm/core_memprot.h>
#include <mm/core_mmu.h>
#include <platform_config.h>
#include <rng_support.h>
#include <trace.h>
#include <types_ext.h>
#include <util.h>
/* ALG sub-controller registers */
#define ALG_SC_RNG_RESET_DREQ 0xAB4 /* RNG reset cancel */
# define ALG_SC_SRST_DREQ_RNG BIT(0)
/* RNG registers */
#define RNG_SEED 0x0 /* Initial seed */
#define RNG_CTRL 0x4 /* Control register */
# define RNG_SEED_SEL BIT(2) /* Re-seed source: 1: ring osc., 0: LFSR */
# define RNG_RING_EN BIT(1) /* Enable ring oscillator */
# define RNG_EN BIT(0) /* Enable RNG */
#define RNG_NUM 0x10 /* Random number output */
#define RNG_PHY_SEED 0x14 /* Ring oscillator output */
register_phys_mem_pgdir(MEM_AREA_IO_SEC, ALG_SC_BASE, ALG_SC_REG_SIZE);
register_phys_mem_pgdir(MEM_AREA_IO_SEC, RNG_BASE, RNG_REG_SIZE);
static unsigned int rng_lock = SPINLOCK_UNLOCK;
static TEE_Result hi16xx_rng_init(void)
{
vaddr_t alg = (vaddr_t)phys_to_virt(ALG_SC_BASE, MEM_AREA_IO_SEC);
vaddr_t rng = (vaddr_t)phys_to_virt(RNG_BASE, MEM_AREA_IO_SEC);
TEE_Time time;
/* ALG sub-controller must allow RNG out of reset */
io_write32(alg + ALG_SC_RNG_RESET_DREQ, ALG_SC_SRST_DREQ_RNG);
/* Set initial seed */
tee_time_get_sys_time(&time);
io_write32(rng + RNG_SEED, time.seconds * 1000 + time.millis);
/*
* Enable RNG and configure it to re-seed automatically from the
* internal ring oscillator
*/
io_write32(rng + RNG_CTRL, RNG_EN | RNG_RING_EN | RNG_SEED_SEL);
IMSG("Hi16xx RNG initialized");
return TEE_SUCCESS;
}
uint8_t hw_get_random_byte(void)
{
static vaddr_t r;
static int pos;
static union {
uint32_t val;
uint8_t byte[4];
} random;
uint8_t ret;
uint32_t exceptions;
exceptions = cpu_spin_lock_xsave(&rng_lock);
if (!r)
r = (vaddr_t)phys_to_virt(RNG_BASE, MEM_AREA_IO_SEC) + RNG_NUM;
if (!pos)
random.val = io_read32(r);
ret = random.byte[pos++];
if (pos == 4)
pos = 0;
cpu_spin_unlock_xrestore(&rng_lock, exceptions);
return ret;
}
driver_init(hi16xx_rng_init);
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