* [PATCH 1/2] crypto: hisi-trng - Remove crypto_rng interface
2026-05-30 20:26 [PATCH 0/2] HiSilicon TRNG fix and simplification Eric Biggers
@ 2026-05-30 20:26 ` Eric Biggers
2026-05-30 20:26 ` [PATCH 2/2] hwrng: hisi-trng - Move hisi-trng into drivers/char/hw_random/ Eric Biggers
1 sibling, 0 replies; 3+ messages in thread
From: Eric Biggers @ 2026-05-30 20:26 UTC (permalink / raw)
To: linux-crypto, Herbert Xu
Cc: Olivia Mackall, Weili Qian, Wei Xu, Longfang Liu,
linux-arm-kernel, linux-kernel, Eric Biggers, stable
drivers/crypto/hisilicon/trng/trng.c exposes the same hardware through
two completely separate interfaces, crypto_rng and hwrng. However, the
implementation of this is buggy because it permits generation operations
from these interfaces to run concurrently with each other, accessing the
same registers. That is, hisi_trng_generate() synchronizes with itself
but not with hisi_trng_read(). This results in potential repetition of
output from the RNG, output of non-random values, etc.
Fortunately, there's actually no point in hardware RNG drivers
implementing the crypto_rng interface. It's not actually used by
anything besides the "rng" algorithm type of AF_ALG, which in turn is
not actually used in practice. Other crypto_rng hardware drivers are
likewise being phased out, leaving just the hwrng support.
Thus, remove it to simplify the code and avoid conflict (and confusion)
with the hwrng interface which is the one that actually matters.
Fixes: e4d9d10ef4be ("crypto: hisilicon/trng - add support for PRNG")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
drivers/crypto/hisilicon/Kconfig | 1 -
drivers/crypto/hisilicon/trng/trng.c | 296 +--------------------------
2 files changed, 2 insertions(+), 295 deletions(-)
diff --git a/drivers/crypto/hisilicon/Kconfig b/drivers/crypto/hisilicon/Kconfig
index 1e6d772f4bb6..8aa23c939775 100644
--- a/drivers/crypto/hisilicon/Kconfig
+++ b/drivers/crypto/hisilicon/Kconfig
@@ -78,8 +78,7 @@ config CRYPTO_DEV_HISI_HPRE
config CRYPTO_DEV_HISI_TRNG
tristate "Support for HISI TRNG Driver"
depends on ARM64 && ACPI
select HW_RANDOM
- select CRYPTO_RNG
help
Support for HiSilicon TRNG Driver.
diff --git a/drivers/crypto/hisilicon/trng/trng.c b/drivers/crypto/hisilicon/trng/trng.c
index 5ca0b90859a8..6584ed051e09 100644
--- a/drivers/crypto/hisilicon/trng/trng.c
+++ b/drivers/crypto/hisilicon/trng/trng.c
@@ -1,236 +1,29 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2019 HiSilicon Limited. */
-#include <crypto/internal/rng.h>
#include <linux/acpi.h>
-#include <linux/crypto.h>
#include <linux/err.h>
#include <linux/hw_random.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
-#include <linux/list.h>
#include <linux/module.h>
-#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/random.h>
#define HISI_TRNG_REG 0x00F0
#define HISI_TRNG_BYTES 4
#define HISI_TRNG_QUALITY 512
-#define HISI_TRNG_VERSION 0x01B8
-#define HISI_TRNG_VER_V1 GENMASK(31, 0)
#define SLEEP_US 10
#define TIMEOUT_US 10000
-#define SW_DRBG_NUM_SHIFT 2
-#define SW_DRBG_KEY_BASE 0x082C
-#define SW_DRBG_SEED(n) (SW_DRBG_KEY_BASE - ((n) << SW_DRBG_NUM_SHIFT))
-#define SW_DRBG_SEED_REGS_NUM 12
-#define SW_DRBG_SEED_SIZE 48
-#define SW_DRBG_BLOCKS 0x0830
-#define SW_DRBG_INIT 0x0834
-#define SW_DRBG_GEN 0x083c
-#define SW_DRBG_STATUS 0x0840
-#define SW_DRBG_BLOCKS_NUM 4095
-#define SW_DRBG_DATA_BASE 0x0850
-#define SW_DRBG_DATA_NUM 4
-#define SW_DRBG_DATA(n) (SW_DRBG_DATA_BASE - ((n) << SW_DRBG_NUM_SHIFT))
-#define SW_DRBG_BYTES 16
-#define SW_DRBG_ENABLE_SHIFT 12
-#define SEED_SHIFT_24 24
-#define SEED_SHIFT_16 16
-#define SEED_SHIFT_8 8
-#define SW_MAX_RANDOM_BYTES 65520
-
-struct hisi_trng_list {
- struct mutex lock;
- struct list_head list;
- bool is_init;
-};
struct hisi_trng {
void __iomem *base;
- struct hisi_trng_list *trng_list;
- struct list_head list;
struct hwrng rng;
- u32 ver;
- u32 ctx_num;
- /* The bytes of the random number generated since the last seeding. */
- u32 random_bytes;
- struct mutex lock;
-};
-
-struct hisi_trng_ctx {
- struct hisi_trng *trng;
};
-static atomic_t trng_active_devs;
-static struct hisi_trng_list trng_devices;
-static int hisi_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait);
-
-static int hisi_trng_set_seed(struct hisi_trng *trng, const u8 *seed)
-{
- u32 val, seed_reg, i;
- int ret;
-
- writel(0x0, trng->base + SW_DRBG_BLOCKS);
-
- for (i = 0; i < SW_DRBG_SEED_SIZE;
- i += SW_DRBG_SEED_SIZE / SW_DRBG_SEED_REGS_NUM) {
- val = seed[i] << SEED_SHIFT_24;
- val |= seed[i + 1UL] << SEED_SHIFT_16;
- val |= seed[i + 2UL] << SEED_SHIFT_8;
- val |= seed[i + 3UL];
-
- seed_reg = (i >> SW_DRBG_NUM_SHIFT) % SW_DRBG_SEED_REGS_NUM;
- writel(val, trng->base + SW_DRBG_SEED(seed_reg));
- }
-
- writel(SW_DRBG_BLOCKS_NUM | (0x1 << SW_DRBG_ENABLE_SHIFT),
- trng->base + SW_DRBG_BLOCKS);
- writel(0x1, trng->base + SW_DRBG_INIT);
- ret = readl_relaxed_poll_timeout(trng->base + SW_DRBG_STATUS,
- val, val & BIT(0), SLEEP_US, TIMEOUT_US);
- if (ret) {
- pr_err("failed to init trng(%d)\n", ret);
- return -EIO;
- }
-
- trng->random_bytes = 0;
-
- return 0;
-}
-
-static int hisi_trng_seed(struct crypto_rng *tfm, const u8 *seed,
- unsigned int slen)
-{
- struct hisi_trng_ctx *ctx = crypto_rng_ctx(tfm);
- struct hisi_trng *trng = ctx->trng;
- int ret;
-
- if (slen < SW_DRBG_SEED_SIZE) {
- pr_err("slen(%u) is not matched with trng(%d)\n", slen,
- SW_DRBG_SEED_SIZE);
- return -EINVAL;
- }
-
- mutex_lock(&trng->lock);
- ret = hisi_trng_set_seed(trng, seed);
- mutex_unlock(&trng->lock);
-
- return ret;
-}
-
-static int hisi_trng_reseed(struct hisi_trng *trng)
-{
- u8 seed[SW_DRBG_SEED_SIZE];
- int size;
-
- if (!trng->random_bytes)
- return 0;
-
- size = hisi_trng_read(&trng->rng, seed, SW_DRBG_SEED_SIZE, false);
- if (size != SW_DRBG_SEED_SIZE)
- return -EIO;
-
- return hisi_trng_set_seed(trng, seed);
-}
-
-static int hisi_trng_get_bytes(struct hisi_trng *trng, u8 *dstn, unsigned int dlen)
-{
- u32 data[SW_DRBG_DATA_NUM];
- u32 currsize = 0;
- u32 val = 0;
- int ret;
- u32 i;
-
- ret = hisi_trng_reseed(trng);
- if (ret)
- return ret;
-
- do {
- ret = readl_relaxed_poll_timeout(trng->base + SW_DRBG_STATUS,
- val, val & BIT(1), SLEEP_US, TIMEOUT_US);
- if (ret) {
- pr_err("failed to generate random number(%d)!\n", ret);
- break;
- }
-
- for (i = 0; i < SW_DRBG_DATA_NUM; i++)
- data[i] = readl(trng->base + SW_DRBG_DATA(i));
-
- if (dlen - currsize >= SW_DRBG_BYTES) {
- memcpy(dstn + currsize, data, SW_DRBG_BYTES);
- currsize += SW_DRBG_BYTES;
- } else {
- memcpy(dstn + currsize, data, dlen - currsize);
- currsize = dlen;
- }
-
- trng->random_bytes += SW_DRBG_BYTES;
- writel(0x1, trng->base + SW_DRBG_GEN);
- } while (currsize < dlen);
-
- return ret;
-}
-
-static int hisi_trng_generate(struct crypto_rng *tfm, const u8 *src,
- unsigned int slen, u8 *dstn, unsigned int dlen)
-{
- struct hisi_trng_ctx *ctx = crypto_rng_ctx(tfm);
- struct hisi_trng *trng = ctx->trng;
- unsigned int currsize = 0;
- unsigned int block_size;
- int ret;
-
- if (!dstn || !dlen) {
- pr_err("output is error, dlen %u!\n", dlen);
- return -EINVAL;
- }
-
- do {
- block_size = min_t(unsigned int, dlen - currsize, SW_MAX_RANDOM_BYTES);
- mutex_lock(&trng->lock);
- ret = hisi_trng_get_bytes(trng, dstn + currsize, block_size);
- mutex_unlock(&trng->lock);
- if (ret)
- return ret;
- currsize += block_size;
- } while (currsize < dlen);
-
- return 0;
-}
-
-static int hisi_trng_init(struct crypto_tfm *tfm)
-{
- struct hisi_trng_ctx *ctx = crypto_tfm_ctx(tfm);
- struct hisi_trng *trng;
- u32 ctx_num = ~0;
-
- mutex_lock(&trng_devices.lock);
- list_for_each_entry(trng, &trng_devices.list, list) {
- if (trng->ctx_num < ctx_num) {
- ctx_num = trng->ctx_num;
- ctx->trng = trng;
- }
- }
- ctx->trng->ctx_num++;
- mutex_unlock(&trng_devices.lock);
-
- return 0;
-}
-
-static void hisi_trng_exit(struct crypto_tfm *tfm)
-{
- struct hisi_trng_ctx *ctx = crypto_tfm_ctx(tfm);
-
- mutex_lock(&trng_devices.lock);
- ctx->trng->ctx_num--;
- mutex_unlock(&trng_devices.lock);
-}
-
static int hisi_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
{
struct hisi_trng *trng;
int currsize = 0;
u32 val = 0;
@@ -258,126 +51,41 @@ static int hisi_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
} while (currsize < max);
return currsize;
}
-static struct rng_alg hisi_trng_alg = {
- .generate = hisi_trng_generate,
- .seed = hisi_trng_seed,
- .seedsize = SW_DRBG_SEED_SIZE,
- .base = {
- .cra_name = "stdrng",
- .cra_driver_name = "hisi_stdrng",
- .cra_priority = 300,
- .cra_ctxsize = sizeof(struct hisi_trng_ctx),
- .cra_module = THIS_MODULE,
- .cra_init = hisi_trng_init,
- .cra_exit = hisi_trng_exit,
- },
-};
-
-static void hisi_trng_add_to_list(struct hisi_trng *trng)
-{
- mutex_lock(&trng_devices.lock);
- list_add_tail(&trng->list, &trng_devices.list);
- mutex_unlock(&trng_devices.lock);
-}
-
-static int hisi_trng_del_from_list(struct hisi_trng *trng)
-{
- int ret = -EBUSY;
-
- mutex_lock(&trng_devices.lock);
- if (!trng->ctx_num) {
- list_del(&trng->list);
- ret = 0;
- }
- mutex_unlock(&trng_devices.lock);
-
- return ret;
-}
-
static int hisi_trng_probe(struct platform_device *pdev)
{
struct hisi_trng *trng;
int ret;
trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);
if (!trng)
return -ENOMEM;
- platform_set_drvdata(pdev, trng);
-
trng->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(trng->base))
return PTR_ERR(trng->base);
- trng->ctx_num = 0;
- trng->random_bytes = SW_MAX_RANDOM_BYTES;
- mutex_init(&trng->lock);
- trng->ver = readl(trng->base + HISI_TRNG_VERSION);
- if (!trng_devices.is_init) {
- INIT_LIST_HEAD(&trng_devices.list);
- mutex_init(&trng_devices.lock);
- trng_devices.is_init = true;
- }
-
- hisi_trng_add_to_list(trng);
- if (trng->ver != HISI_TRNG_VER_V1 &&
- atomic_inc_return(&trng_active_devs) == 1) {
- ret = crypto_register_rng(&hisi_trng_alg);
- if (ret) {
- dev_err(&pdev->dev,
- "failed to register crypto(%d)\n", ret);
- atomic_dec_return(&trng_active_devs);
- goto err_remove_from_list;
- }
- }
-
trng->rng.name = pdev->name;
trng->rng.read = hisi_trng_read;
trng->rng.quality = HISI_TRNG_QUALITY;
+
ret = devm_hwrng_register(&pdev->dev, &trng->rng);
- if (ret) {
+ if (ret)
dev_err(&pdev->dev, "failed to register hwrng: %d!\n", ret);
- goto err_crypto_unregister;
- }
-
- return ret;
-
-err_crypto_unregister:
- if (trng->ver != HISI_TRNG_VER_V1 &&
- atomic_dec_return(&trng_active_devs) == 0)
- crypto_unregister_rng(&hisi_trng_alg);
-
-err_remove_from_list:
- hisi_trng_del_from_list(trng);
return ret;
}
-static void hisi_trng_remove(struct platform_device *pdev)
-{
- struct hisi_trng *trng = platform_get_drvdata(pdev);
-
- /* Wait until the task is finished */
- while (hisi_trng_del_from_list(trng))
- ;
-
- if (trng->ver != HISI_TRNG_VER_V1 &&
- atomic_dec_return(&trng_active_devs) == 0)
- crypto_unregister_rng(&hisi_trng_alg);
-}
-
static const struct acpi_device_id hisi_trng_acpi_match[] = {
{ "HISI02B3", 0 },
{ }
};
MODULE_DEVICE_TABLE(acpi, hisi_trng_acpi_match);
static struct platform_driver hisi_trng_driver = {
.probe = hisi_trng_probe,
- .remove = hisi_trng_remove,
.driver = {
.name = "hisi-trng-v2",
.acpi_match_table = ACPI_PTR(hisi_trng_acpi_match),
},
};
--
2.54.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH 2/2] hwrng: hisi-trng - Move hisi-trng into drivers/char/hw_random/
2026-05-30 20:26 [PATCH 0/2] HiSilicon TRNG fix and simplification Eric Biggers
2026-05-30 20:26 ` [PATCH 1/2] crypto: hisi-trng - Remove crypto_rng interface Eric Biggers
@ 2026-05-30 20:26 ` Eric Biggers
1 sibling, 0 replies; 3+ messages in thread
From: Eric Biggers @ 2026-05-30 20:26 UTC (permalink / raw)
To: linux-crypto, Herbert Xu
Cc: Olivia Mackall, Weili Qian, Wei Xu, Longfang Liu,
linux-arm-kernel, linux-kernel, Eric Biggers
Since this file just implements a hwrng driver, move it into
drivers/char/hw_random/. Rename the kconfig option accordingly as well.
Note that this moves the file back to its original location.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
MAINTAINERS | 2 +-
arch/arm64/configs/defconfig | 2 +-
drivers/char/hw_random/Kconfig | 10 ++++++++++
drivers/char/hw_random/Makefile | 1 +
.../trng/trng.c => char/hw_random/hisi-trng-v2.c} | 0
drivers/crypto/hisilicon/Kconfig | 7 -------
drivers/crypto/hisilicon/Makefile | 1 -
drivers/crypto/hisilicon/trng/Makefile | 2 --
8 files changed, 13 insertions(+), 12 deletions(-)
rename drivers/{crypto/hisilicon/trng/trng.c => char/hw_random/hisi-trng-v2.c} (100%)
delete mode 100644 drivers/crypto/hisilicon/trng/Makefile
diff --git a/MAINTAINERS b/MAINTAINERS
index 882214b0e7db..dcbbc56368be 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11703,11 +11703,11 @@ F: Documentation/devicetree/bindings/mfd/hisilicon,hi6421-spmi-pmic.yaml
F: drivers/mfd/hi6421-spmi-pmic.c
HISILICON TRUE RANDOM NUMBER GENERATOR V2 SUPPORT
M: Weili Qian <qianweili@huawei.com>
S: Maintained
-F: drivers/crypto/hisilicon/trng/trng.c
+F: drivers/char/hw_random/hisi-trng-v2.c
HISILICON V3XX SPI NOR FLASH Controller Driver
M: Yang Shen <shenyang39@huawei.com>
S: Maintained
W: http://www.hisilicon.com
diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index bb930cce7233..9aa62b675023 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -548,10 +548,11 @@ CONFIG_VIRTIO_CONSOLE=y
CONFIG_IPMI_HANDLER=m
CONFIG_IPMI_DEVICE_INTERFACE=m
CONFIG_IPMI_SI=m
CONFIG_HW_RANDOM=y
CONFIG_HW_RANDOM_VIRTIO=y
+CONFIG_HW_RANDOM_HISI_TRNG=m
CONFIG_HW_RANDOM_QCOM=m
CONFIG_TCG_TPM=y
CONFIG_TCG_TIS=m
CONFIG_TCG_TIS_SPI=m
CONFIG_TCG_TIS_SPI_CR50=y
@@ -1960,11 +1961,10 @@ CONFIG_CRYPTO_DEV_ZYNQMP_AES=m
CONFIG_CRYPTO_DEV_ZYNQMP_SHA3=m
CONFIG_CRYPTO_DEV_CCREE=m
CONFIG_CRYPTO_DEV_HISI_SEC2=m
CONFIG_CRYPTO_DEV_HISI_ZIP=m
CONFIG_CRYPTO_DEV_HISI_HPRE=m
-CONFIG_CRYPTO_DEV_HISI_TRNG=m
CONFIG_CRYPTO_DEV_SA2UL=m
CONFIG_DMA_RESTRICTED_POOL=y
CONFIG_CMA_SIZE_MBYTES=32
CONFIG_PRINTK_TIME=y
CONFIG_DEBUG_KERNEL=y
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 7102e03dcf0a..6d8012d55ac0 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -371,10 +371,20 @@ config HW_RANDOM_HISTB
Generator hardware found on Hisilicon Hi37xx SoC.
To compile this driver as a module, choose M here: the
module will be called histb-rng.
+config HW_RANDOM_HISI_TRNG
+ tristate "HiSilicon True Random Number Generator support"
+ depends on ARM64 && ACPI
+ help
+ This driver provides kernel-side support for the True Random Number
+ Generator hardware found on some HiSilicon SoCs.
+
+ To compile this driver as a module, choose M here: the module will be
+ called hisi-trng-v2.
+
config HW_RANDOM_ST
tristate "ST Microelectronics HW Random Number Generator support"
depends on ARCH_STI || COMPILE_TEST
help
This driver provides kernel-side support for the Random Number
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 605ba8df5a8f..f2888524b6ef 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -29,10 +29,11 @@ obj-$(CONFIG_HW_RANDOM_OCTEON) += octeon-rng.o
obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o
obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o
obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o
obj-$(CONFIG_HW_RANDOM_HISI) += hisi-rng.o
obj-$(CONFIG_HW_RANDOM_HISTB) += histb-rng.o
+obj-$(CONFIG_HW_RANDOM_HISI_TRNG) += hisi-trng-v2.o
obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o
obj-$(CONFIG_HW_RANDOM_BCM74110) += bcm74110-rng.o
obj-$(CONFIG_HW_RANDOM_IPROC_RNG200) += iproc-rng200.o
obj-$(CONFIG_HW_RANDOM_ST) += st-rng.o
obj-$(CONFIG_HW_RANDOM_XGENE) += xgene-rng.o
diff --git a/drivers/crypto/hisilicon/trng/trng.c b/drivers/char/hw_random/hisi-trng-v2.c
similarity index 100%
rename from drivers/crypto/hisilicon/trng/trng.c
rename to drivers/char/hw_random/hisi-trng-v2.c
diff --git a/drivers/crypto/hisilicon/Kconfig b/drivers/crypto/hisilicon/Kconfig
index 8aa23c939775..aeff08ccbadd 100644
--- a/drivers/crypto/hisilicon/Kconfig
+++ b/drivers/crypto/hisilicon/Kconfig
@@ -73,12 +73,5 @@ config CRYPTO_DEV_HISI_HPRE
select CRYPTO_RSA
select CRYPTO_ECDH
help
Support for HiSilicon HPRE(High Performance RSA Engine)
accelerator, which can accelerate RSA and DH algorithms.
-
-config CRYPTO_DEV_HISI_TRNG
- tristate "Support for HISI TRNG Driver"
- depends on ARM64 && ACPI
- select HW_RANDOM
- help
- Support for HiSilicon TRNG Driver.
diff --git a/drivers/crypto/hisilicon/Makefile b/drivers/crypto/hisilicon/Makefile
index 8595a5a5d228..e1068ee9f973 100644
--- a/drivers/crypto/hisilicon/Makefile
+++ b/drivers/crypto/hisilicon/Makefile
@@ -3,6 +3,5 @@ obj-$(CONFIG_CRYPTO_DEV_HISI_HPRE) += hpre/
obj-$(CONFIG_CRYPTO_DEV_HISI_SEC) += sec/
obj-$(CONFIG_CRYPTO_DEV_HISI_SEC2) += sec2/
obj-$(CONFIG_CRYPTO_DEV_HISI_QM) += hisi_qm.o
hisi_qm-objs = qm.o sgl.o debugfs.o
obj-$(CONFIG_CRYPTO_DEV_HISI_ZIP) += zip/
-obj-$(CONFIG_CRYPTO_DEV_HISI_TRNG) += trng/
diff --git a/drivers/crypto/hisilicon/trng/Makefile b/drivers/crypto/hisilicon/trng/Makefile
deleted file mode 100644
index d909079f351c..000000000000
--- a/drivers/crypto/hisilicon/trng/Makefile
+++ /dev/null
@@ -1,2 +0,0 @@
-obj-$(CONFIG_CRYPTO_DEV_HISI_TRNG) += hisi-trng-v2.o
-hisi-trng-v2-objs = trng.o
--
2.54.0
^ permalink raw reply related [flat|nested] 3+ messages in thread