Loongson's Random Number Generator is found inside Loongson Security
Engine chip.
Co-developed-by: Yinggang Gu <guyingg...@loongson.cn>
Signed-off-by: Yinggang Gu <guyingg...@loongson.cn>
Signed-off-by: Qunqin Zhao <zhaoqun...@loongson.cn>
Reviewed-by: Huacai Chen <chenhua...@loongson.cn>
---
v8: Added reseed callbak. "lsrng" --> "loongson_rng".
v7: Change the lsrng_ prefix to loongson_rng_
v6: Replace all "ls6000se" with "loongson"
v2-v5: None
drivers/crypto/loongson/Kconfig | 6 +
drivers/crypto/loongson/Makefile | 1 +
drivers/crypto/loongson/loongson-rng.c | 198 +++++++++++++++++++++++++
3 files changed, 205 insertions(+)
create mode 100644 drivers/crypto/loongson/loongson-rng.c
diff --git a/drivers/crypto/loongson/Kconfig b/drivers/crypto/loongson/Kconfig
index 9fdcc73bc..2a5ac65ea 100644
--- a/drivers/crypto/loongson/Kconfig
+++ b/drivers/crypto/loongson/Kconfig
@@ -9,3 +9,9 @@ config CRYPTO_DEV_LOONGSON_SE
provided by the controller. The kernel cannot directly send
commands to the engine and must first send them to the controller,
which will forward them to the corresponding engine.
+
+config CRYPTO_DEV_LOONGSON_RNG
+ tristate "Support for Loongson RNG Driver"
+ depends on CRYPTO_DEV_LOONGSON_SE
+ help
+ Support for Loongson RNG Driver.
diff --git a/drivers/crypto/loongson/Makefile b/drivers/crypto/loongson/Makefile
index 5ebcd9ff8..1a614b28c 100644
--- a/drivers/crypto/loongson/Makefile
+++ b/drivers/crypto/loongson/Makefile
@@ -1,2 +1,3 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_CRYPTO_DEV_LOONGSON_SE) += loongson-se.o
+obj-$(CONFIG_CRYPTO_DEV_LOONGSON_RNG) += loongson-rng.o
diff --git a/drivers/crypto/loongson/loongson-rng.c
b/drivers/crypto/loongson/loongson-rng.c
new file mode 100644
index 000000000..2fb989811
--- /dev/null
+++ b/drivers/crypto/loongson/loongson-rng.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 HiSilicon Limited. */
+/* Copyright (c) 2025 Loongson Technology Corporation Limited. */
+
+#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>
+#include <crypto/internal/rng.h>
+
+#include "loongson-se.h"
+
+#define SE_SEED_SIZE 32
+
+struct loongson_rng_list {
+ struct mutex lock;
+ struct list_head list;
+ int is_init;
+};
+
+struct loongson_rng {
+ bool is_used;
+ struct loongson_se_engine *engine;
+ struct list_head list;
+};
+
+struct loongson_rng_ctx {
+ struct loongson_rng *rng;
+};
+
+struct loongson_rng_cmd {
+ u32 cmd_id;
+ union {
+ u32 len;
+ u32 ret;
+ } u;
+ u32 seed_off;
+ u32 out_off;
+ u32 pad[4];
+};
+
+static atomic_t rng_active_devs;
+static struct loongson_rng_list rng_devices;
+
+static int loongson_rng_generate(struct crypto_rng *tfm, const u8 *src,
+ unsigned int slen, u8 *dstn, unsigned int dlen)
+{
+ struct loongson_rng_ctx *ctx = crypto_rng_ctx(tfm);
+ struct loongson_rng *rng = ctx->rng;
+ struct loongson_rng_cmd *cmd = rng->engine->command;
+ int err, len;
+
+ cmd->seed_off = 0;
+ do {
+ len = min(dlen, rng->engine->buffer_size);
+ cmd = rng->engine->command;
+ cmd->u.len = len;
+ err = loongson_se_send_engine_cmd(rng->engine);
+ if (err)
+ return err;
+
+ cmd = rng->engine->command_ret;
+ if (cmd->u.ret)
+ return -EFAULT;
+
+ memcpy(dstn, rng->engine->data_buffer, len);
+ dlen -= len;
+ dstn += len;
+ } while (dlen > 0);
+
+ return 0;
+}
+
+static int loongson_rng_init(struct crypto_tfm *tfm)
+{
+ struct loongson_rng_ctx *ctx = crypto_tfm_ctx(tfm);
+ struct loongson_rng *rng;
+ int ret = -EBUSY;
+
+ mutex_lock(&rng_devices.lock);
+ list_for_each_entry(rng, &rng_devices.list, list) {
+ if (!rng->is_used) {
+ rng->is_used = true;
+ ctx->rng = rng;
+ ret = 0;
+ break;
+ }
+ }
+ mutex_unlock(&rng_devices.lock);
+
+ return ret;
+}
+
+static void loongson_rng_exit(struct crypto_tfm *tfm)
+{
+ struct loongson_rng_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ mutex_lock(&rng_devices.lock);
+ ctx->rng->is_used = false;
+ mutex_unlock(&rng_devices.lock);
+}
+
+static int loongson_rng_seed(struct crypto_rng *tfm, const u8 *seed,
+ unsigned int slen)
+{
+ struct loongson_rng_ctx *ctx = crypto_rng_ctx(tfm);
+ struct loongson_rng *rng = ctx->rng;
+ struct loongson_rng_cmd *cmd;
+ int err;
+
+ cmd = rng->engine->command;
+ cmd->u.len = slen;
+ cmd->seed_off = rng->engine->buffer_off;
+ memcpy(rng->engine->data_buffer, seed, slen);
+ err = loongson_se_send_engine_cmd(rng->engine);
+ cmd = rng->engine->command_ret;
+ if (err || cmd->u.ret)
+ return -EFAULT;
+
+ return 0;
+}
+
+static struct rng_alg loongson_rng_alg = {
+ .generate = loongson_rng_generate,
+ .seed = loongson_rng_seed,
+ .seedsize = SE_SEED_SIZE,
+ .base = {
+ .cra_name = "stdrng",
+ .cra_driver_name = "loongson_stdrng",
+ .cra_priority = 300,
+ .cra_ctxsize = sizeof(struct loongson_rng_ctx),
+ .cra_module = THIS_MODULE,
+ .cra_init = loongson_rng_init,
+ .cra_exit = loongson_rng_exit,
+ },
+};
+
+static void loongson_rng_add_to_list(struct loongson_rng *rng)
+{
+ mutex_lock(&rng_devices.lock);
+ list_add_tail(&rng->list, &rng_devices.list);
+ mutex_unlock(&rng_devices.lock);
+}
+
+static int loongson_rng_probe(struct platform_device *pdev)
+{
+ struct loongson_rng_cmd *cmd;
+ struct loongson_rng *rng;
+ int ret;
+
+ rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
+ if (!rng)
+ return -ENOMEM;
+
+ rng->engine = loongson_se_init_engine(pdev->dev.parent, SE_ENGINE_RNG);
+ if (!rng->engine)
+ return -ENODEV;
+ cmd = rng->engine->command;
+ cmd->cmd_id = SE_CMD_RNG;
+ cmd->out_off = rng->engine->buffer_off;
+
+ if (!rng_devices.is_init) {
+ ret = crypto_register_rng(&loongson_rng_alg);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register crypto(%d)\n",
ret);
+ return ret;
+ }
+ INIT_LIST_HEAD(&rng_devices.list);
+ mutex_init(&rng_devices.lock);
+ rng_devices.is_init = true;
+ }
+
+ loongson_rng_add_to_list(rng);
+ atomic_inc(&rng_active_devs);
+
+ return 0;
+}
+
+static struct platform_driver loongson_rng_driver = {
+ .probe = loongson_rng_probe,
+ .driver = {
+ .name = "loongson-rng",
+ },
+};
+module_platform_driver(loongson_rng_driver);
+
+MODULE_ALIAS("platform:loongson-rng");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Yinggang Gu <guyingg...@loongson.cn>");
+MODULE_AUTHOR("Qunqin Zhao <zhaoqun...@loongson.cn>");
+MODULE_DESCRIPTION("Loongson random number generator driver");
--
2.45.2
