M7350/kernel/arch/arm/mach-msm/early_random.c
2024-09-09 08:52:07 +00:00

84 lines
2.0 KiB
C

/* Copyright (c) 2013, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/kernel.h>
#include <mach/scm.h>
#include <asm/io.h>
#include <asm/cacheflush.h>
#define TZ_SVC_CRYPTO 10
#define PRNG_CMD_ID 0x01
static int use_arch_random = 1;
struct tz_prng_data {
uint8_t *out_buf;
uint32_t out_buf_sz;
} __packed;
DEFINE_SCM_BUFFER(common_scm_buf)
DEFINE_MUTEX(arch_random_lock);
#define RANDOM_BUFFER_SIZE PAGE_SIZE
char random_buffer[RANDOM_BUFFER_SIZE] __aligned(PAGE_SIZE);
int arch_get_random_common(void *v, size_t size)
{
struct tz_prng_data data;
int ret;
u32 resp;
if (!use_arch_random)
return 0;
if (size > sizeof(random_buffer))
return 0;
mutex_lock(&arch_random_lock);
data.out_buf = (uint8_t *) virt_to_phys(random_buffer);
data.out_buf_sz = size;
ret = scm_call_noalloc(TZ_SVC_CRYPTO, PRNG_CMD_ID, &data,
sizeof(data), &resp, sizeof(resp),
common_scm_buf, SCM_BUFFER_SIZE(common_scm_buf));
if (!ret) {
dmac_inv_range(random_buffer, random_buffer +
RANDOM_BUFFER_SIZE);
outer_inv_range(
(unsigned long) virt_to_phys(random_buffer),
(unsigned long) virt_to_phys(random_buffer) +
RANDOM_BUFFER_SIZE);
memcpy(v, random_buffer, size);
}
mutex_unlock(&arch_random_lock);
return !ret;
}
int arch_get_random_long(unsigned long *v)
{
return arch_get_random_common(v, sizeof(unsigned long));
}
int arch_get_random_int(unsigned int *v)
{
return arch_get_random_common(v, sizeof(unsigned int));
}
int arch_random_init(void)
{
use_arch_random = 0;
return 0;
}
module_init(arch_random_init);