This patch adds implementation of rand library based on hardware random number generator of security subsystem in Exynos SOC.
This library includes: - srand() - used for seed hardware block - rand() - returns random number - rand_r() - the same as above with given seed
which depends on CONFIG_EXYNOS_ACE_SHA and CONFIG_LIB_HW_RAND.
Change-Id: Ie0b44a7fcc375dd733329b04183559f376a4e25c Signed-off-by: Przemyslaw Marczak p.marczak@samsung.com cc: Akshay Saraswat akshay.s@samsung.com cc: ARUN MANKUZHI arun.m@samsung.com cc: Minkyu Kang mk7.kang@samsung.com
--- Changes v2: - none
Changes v3: - add implementation of rand library to ace_sha - add proper ifdef for ace_sha SHA functions - move cpu refer change to new commit
drivers/crypto/ace_sha.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++- drivers/crypto/ace_sha.h | 8 +++-- 2 files changed, 80 insertions(+), 4 deletions(-)
diff --git a/drivers/crypto/ace_sha.c b/drivers/crypto/ace_sha.c index acbafde..51fb92c 100644 --- a/drivers/crypto/ace_sha.c +++ b/drivers/crypto/ace_sha.c @@ -5,10 +5,12 @@ * SPDX-License-Identifier: GPL-2.0+ */ #include <common.h> +#include "ace_sha.h" + +#ifdef CONFIG_SHA_HW_ACCEL #include <sha256.h> #include <sha1.h> #include <asm/errno.h> -#include "ace_sha.h"
/* SHA1 value for the message of zero length */ static const unsigned char sha1_digest_emptymsg[SHA1_SUM_LEN] = { @@ -111,3 +113,75 @@ void hw_sha1(const unsigned char *pbuf, unsigned int buf_len, if (ace_sha_hash_digest(pbuf, buf_len, pout, ACE_SHA_TYPE_SHA1)) debug("ACE was not setup properly or it is faulty\n"); } +#endif /* CONFIG_SHA_HW_ACCEL */ + +#ifdef CONFIG_LIB_HW_RAND +static unsigned int seed_done; + +void srand(unsigned int seed) +{ + struct exynos_ace_sfr *reg = + (struct exynos_ace_sfr *)samsung_get_base_ace_sfr(); + int i; + + /* Seed data */ + for (i = 0; i < ACE_HASH_PRNG_REG_NUM; i++) + writel(seed << i, ®->hash_seed[i]); + + /* Wait for seed setup done */ + while (1) { + status = readl(®->hash_status); + if ((status & ACE_HASH_SEEDSETTING_MASK) || + (status & ACE_HASH_PRNGERROR_MASK)) + break; + } + + seed_done = 1; +} + +unsigned int rand(void) +{ + struct exynos_ace_sfr *reg = + (struct exynos_ace_sfr *)samsung_get_base_ace_sfr(); + int status, i; + unsigned int seed; + unsigned int *seed_ptr; + unsigned int ret = 0; + + if (!seed_done) + srand(seed); + + /* Start PRNG */ + writel(ACE_HASH_ENGSEL_PRNG | ACE_HASH_STARTBIT_ON, ®->hash_control); + + /* Wait for PRNG done */ + while (1) { + status = readl(®->hash_status); + if (status & ACE_HASH_PRNGDONE_MASK) + break; + if (status & ACE_HASH_PRNGERROR_MASK) { + seed_done = 0; + return 0; + } + } + + /* Clear Done IRQ */ + writel(ACE_HASH_PRNGDONE_MASK, ®->hash_status); + + /* Read a PRNG result */ + for (i = 0; i < ACE_HASH_PRNG_REG_NUM; i++) + ret += readl(®->hash_prng[i]); + + seed_done = 0; + return ret; +} + +unsigned int rand_r(unsigned int *seedp) +{ + seed_done = 0; + + srand(*seedp); + + return rand(); +} +#endif /* CONFIG_LIB_HW_RAND */ diff --git a/drivers/crypto/ace_sha.h b/drivers/crypto/ace_sha.h index a426d52..f1097f7 100644 --- a/drivers/crypto/ace_sha.h +++ b/drivers/crypto/ace_sha.h @@ -72,9 +72,10 @@ struct exynos_ace_sfr { unsigned char res12[0x30]; unsigned int hash_result[8]; unsigned char res13[0x20]; - unsigned int hash_seed[8]; - unsigned int hash_prng[8]; - unsigned char res14[0x180]; + unsigned int hash_seed[5]; + unsigned char res14[12]; + unsigned int hash_prng[5]; + unsigned char res15[0x18c];
unsigned int pka_sfr[5]; /* base + 0x700 */ }; @@ -291,6 +292,7 @@ struct exynos_ace_sfr { #define ACE_HASH_PRNGERROR_MASK (1 << 7) #define ACE_HASH_PRNGERROR_OFF (0 << 7) #define ACE_HASH_PRNGERROR_ON (1 << 7) +#define ACE_HASH_PRNG_REG_NUM 5
#define ACE_SHA_TYPE_SHA1 1 #define ACE_SHA_TYPE_SHA256 2