[PATCH v5 08/11] firmware: imx: enable trng

Pankaj Gupta
2023-08-23T07:36:58Z

Enabled trng on imx93 platform through enclave fw.

Signed-off-by: Gaurav Jain <gaurav.jain@nxp.com>
Signed-off-by: Pankaj Gupta <pankaj.gupta@nxp.com>
---
drivers/firmware/imx/Kconfig | 9 +++
drivers/firmware/imx/Makefile | 3 +-
drivers/firmware/imx/ele_base_msg.c | 88 +++++++++++++++++++++++
drivers/firmware/imx/ele_common.c | 44 +++++++++++-
drivers/firmware/imx/ele_common.h | 2 +
drivers/firmware/imx/ele_fw_api.c | 54 ++++++++++++++
drivers/firmware/imx/ele_trng.c | 48 +++++++++++++
drivers/firmware/imx/se_fw.c | 23 +++++-
include/linux/firmware/imx/ele_base_msg.h | 11 +++
include/linux/firmware/imx/ele_fw_api.h | 5 ++
10 files changed, 283 insertions(+), 4 deletions(-)
create mode 100644 drivers/firmware/imx/ele_trng.c

diff --git a/drivers/firmware/imx/Kconfig b/drivers/firmware/imx/Kconfig
index 2822e5d4b24c..ffc02593293c 100644
--- a/drivers/firmware/imx/Kconfig
+++ b/drivers/firmware/imx/Kconfig
@@ -40,3 +40,12 @@ config IMX_SEC_ENCLAVE
like base, HSM, V2X & SHE using the SAB protocol via the shared Messaging
Unit. This driver exposes these interfaces via a set of file descriptors
allowing to configure shared memory, send and receive messages.
+
+config IMX_ELE_TRNG
+ tristate "i.MX ELE True Random Number Generator"
+ default y
+ select CRYPTO_RNG
+ select HW_RANDOM
+ help
+ This driver provides kernel-side support for the Random Number generation,
+ through NXP hardware IP for secure-enclave called EdgeLock Enclave.
diff --git a/drivers/firmware/imx/Makefile b/drivers/firmware/imx/Makefile
index bc6ed5514a19..e46f3053707f 100644
--- a/drivers/firmware/imx/Makefile
+++ b/drivers/firmware/imx/Makefile
@@ -2,5 +2,6 @@
obj-$(CONFIG_IMX_DSP) += imx-dsp.o
obj-$(CONFIG_IMX_SCU) += imx-scu.o misc.o imx-scu-irq.o rm.o imx-scu-soc.o
obj-$(CONFIG_IMX_SCU_PD) += scu-pd.o
-sec_enclave-objs = se_fw.o ele_common.o ele_base_msg.o ele_fw_api.o
+sec_enclave-objs = ele_common.o se_fw.o ele_base_msg.o ele_fw_api.o
obj-${CONFIG_IMX_SEC_ENCLAVE} += sec_enclave.o
+sec_enclave-${CONFIG_IMX_ELE_TRNG} += ele_trng.o
diff --git a/drivers/firmware/imx/ele_base_msg.c b/drivers/firmware/imx/ele_base_msg.c
index 2eb675a1b389..c42e29e14662 100644
--- a/drivers/firmware/imx/ele_base_msg.c
+++ b/drivers/firmware/imx/ele_base_msg.c
@@ -60,3 +60,91 @@ int ele_get_info(struct device *dev, phys_addr_t addr, u32 data_size)

return -EINVAL;
}
+
+/*
+ * ele_get_trng_state() - prepare and send the command to read
+ * crypto lib and TRNG state
+ * TRNG state
+ * 0x1 TRNG is in program mode
+ * 0x2 TRNG is still generating entropy
+ * 0x3 TRNG entropy is valid and ready to be read
+ * 0x4 TRNG encounter an error while generating entropy
+ *
+ * CSAL state
+ * 0x0 Crypto Lib random context initialization is not done yet
+ * 0x1 Crypto Lib random context initialization is on-going
+ * 0x2 Crypto Lib random context initialization succeed
+ * 0x3 Crypto Lib random context initialization failed
+ *
+ * returns: csal and trng state.
+ *
+ */
+int ele_get_trng_state(struct device *dev)
+{
+ struct ele_mu_priv *priv = dev_get_drvdata(dev);
+ int ret;
+ unsigned int tag, command, size, ver, status;
+
+ ret = plat_fill_cmd_msg_hdr(priv,
+ (struct mu_hdr *)&priv->tx_msg.header,
+ ELE_GET_TRNG_STATE_REQ, 4);
+ if (ret)
+ return ret;
+
+ ret = imx_ele_msg_send_rcv(priv);
+ if (ret < 0)
+ return ret;
+
+ tag = MSG_TAG(priv->rx_msg.header);
+ command = MSG_COMMAND(priv->rx_msg.header);
+ size = MSG_SIZE(priv->rx_msg.header);
+ ver = MSG_VER(priv->rx_msg.header);
+ status = RES_STATUS(priv->rx_msg.data[0]);
+ if (tag == priv->rsp_tag &&
+ command == ELE_GET_TRNG_STATE_REQ &&
+ size == ELE_GET_TRNG_STATE_REQ_MSG_SZ &&
+ ver == ELE_BASE_API_VERSION &&
+ status == priv->success_tag) {
+ return (priv->rx_msg.data[1] & CSAL_TRNG_STATE_MASK);
+ }
+
+ return -EINVAL;
+}
+
+/*
+ * ele_start_rng() - prepare and send the command to start
+ * initialization of the ELE RNG context
+ *
+ * returns: 0 on success.
+ */
+int ele_start_rng(struct device *dev)
+{
+ struct ele_mu_priv *priv = dev_get_drvdata(dev);
+ int ret;
+ unsigned int tag, command, size, ver, status;
+
+ ret = plat_fill_cmd_msg_hdr(priv,
+ (struct mu_hdr *)&priv->tx_msg.header,
+ ELE_START_RNG_REQ, 4);
+ if (ret)
+ return ret;
+
+ ret = imx_ele_msg_send_rcv(priv);
+ if (ret < 0)
+ return ret;
+
+ tag = MSG_TAG(priv->rx_msg.header);
+ command = MSG_COMMAND(priv->rx_msg.header);
+ size = MSG_SIZE(priv->rx_msg.header);
+ ver = MSG_VER(priv->rx_msg.header);
+ status = RES_STATUS(priv->rx_msg.data[0]);
+ if (tag == priv->rsp_tag &&
+ command == ELE_START_RNG_REQ &&
+ size == ELE_START_RNG_REQ_MSG_SZ &&
+ ver == ELE_BASE_API_VERSION &&
+ status == priv->success_tag) {
+ return 0;
+ }
+
+ return -EINVAL;
+}
diff --git a/drivers/firmware/imx/ele_common.c b/drivers/firmware/imx/ele_common.c
index 08adc7200ceb..f01e5e3255f9 100644
--- a/drivers/firmware/imx/ele_common.c
+++ b/drivers/firmware/imx/ele_common.c
@@ -1,9 +1,13 @@
// SPDX-License-Identifier: GPL-2.0+
/*
- * Copyright 2021-2023 NXP
+ * Copyright 2023 NXP
*/

-#include "se_fw.h"
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/firmware/imx/ele_base_msg.h>
+
+#include "ele_common.h"

int imx_ele_msg_send_rcv(struct ele_mu_priv *priv)
{
@@ -32,3 +36,39 @@ int imx_ele_msg_send_rcv(struct ele_mu_priv *priv)
return err;
}

+int ele_do_start_rng(struct device *dev)
+{
+ int ret;
+ int count = ELE_GET_TRNG_STATE_RETRY_COUNT;
+
+ ret = ele_get_trng_state(dev);
+ if (ret < 0) {
+ dev_err(dev, "Failed to get trng state\n");
+ return ret;
+ } else if (ret != ELE_TRNG_STATE_OK) {
+ /* call start rng */
+ ret = ele_start_rng(dev);
+ if (ret) {
+ dev_err(dev, "Failed to start rng\n");
+ return ret;
+ }
+
+ /* poll get trng state API, ELE_GET_TRNG_STATE_RETRY_COUNT times
+ * or while trng state != 0x203
+ */
+ do {
+ msleep(10);
+ ret = ele_get_trng_state(dev);
+ if (ret < 0) {
+ dev_err(dev, "Failed to get trng state\n");
+ return ret;
+ }
+ count--;
+ } while ((ret != ELE_TRNG_STATE_OK) && count);
+ if (ret != ELE_TRNG_STATE_OK)
+ return -EIO;
+ }
+
+ return 0;
+}
+
diff --git a/drivers/firmware/imx/ele_common.h b/drivers/firmware/imx/ele_common.h
index 6af0296b76fd..ed68e5cf9638 100644
--- a/drivers/firmware/imx/ele_common.h
+++ b/drivers/firmware/imx/ele_common.h
@@ -18,4 +18,6 @@ static inline int ele_trng_init(struct device *dev)
return 0;
}
#endif
+
+int ele_do_start_rng(struct device *dev);
#endif
diff --git a/drivers/firmware/imx/ele_fw_api.c b/drivers/firmware/imx/ele_fw_api.c
index 1df1fbcb6d9e..8e0b331531a2 100644
--- a/drivers/firmware/imx/ele_fw_api.c
+++ b/drivers/firmware/imx/ele_fw_api.c
@@ -54,3 +54,57 @@ int ele_init_fw(struct device *dev)

return -EINVAL;
}
+
+/*
+ * ele_get_random() - prepare and send the command to proceed
+ * with a random number generation operation
+ *
+ * returns: size of the rondom number generated
+ */
+int ele_get_random(struct device *dev,
+ void *data, size_t len)
+{
+ struct ele_mu_priv *priv = dev_get_drvdata(dev);
+ unsigned int tag, command, size, ver, status;
+ dma_addr_t dst_dma;
+ u8 *buf;
+ int ret;
+
+ buf = dmam_alloc_coherent(priv->dev, len, &dst_dma, GFP_KERNEL);
+ if (!buf) {
+ dev_err(priv->dev, "Failed to map destination buffer memory\n");
+ return -ENOMEM;
+ }
+
+ ret = plat_fill_cmd_msg_hdr(priv,
+ (struct mu_hdr *)&priv->tx_msg.header,
+ ELE_GET_RANDOM_REQ, 16);
+ if (ret)
+ goto exit;
+
+ priv->tx_msg.data[0] = 0x0;
+ priv->tx_msg.data[1] = dst_dma;
+ priv->tx_msg.data[2] = len;
+ ret = imx_ele_msg_send_rcv(priv);
+ if (ret < 0)
+ goto exit;
+
+ tag = MSG_TAG(priv->rx_msg.header);
+ command = MSG_COMMAND(priv->rx_msg.header);
+ size = MSG_SIZE(priv->rx_msg.header);
+ ver = MSG_VER(priv->rx_msg.header);
+ status = RES_STATUS(priv->rx_msg.data[0]);
+ if (tag == priv->rsp_tag
+ && command == ELE_GET_RANDOM_REQ
+ && size == ELE_GET_RANDOM_REQ_SZ
+ && ver == MESSAGING_VERSION_7
+ && status == priv->success_tag) {
+ memcpy(data, buf, len);
+ ret = len;
+ } else
+ ret = -EINVAL;
+
+exit:
+ dmam_free_coherent(priv->dev, len, buf, dst_dma);
+ return ret;
+}
diff --git a/drivers/firmware/imx/ele_trng.c b/drivers/firmware/imx/ele_trng.c
new file mode 100644
index 000000000000..23d5891f9569
--- /dev/null
+++ b/drivers/firmware/imx/ele_trng.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ELE Random Number Generator Driver NXP's Platforms
+ *
+ * Copyright 2023 NXP
+ */
+
+#include <linux/firmware/imx/ele_fw_api.h>
+
+#include "ele_common.h"
+
+struct ele_trng {
+ struct hwrng rng;
+ struct device *dev;
+};
+
+int ele_trng_init(struct device *dev)
+{
+ struct ele_trng *trng;
+ int ret;
+
+ trng = devm_kzalloc(dev, sizeof(*trng), GFP_KERNEL);
+ if (!trng)
+ return -ENOMEM;
+
+ trng->dev = dev;
+ trng->rng.name = "ele-trng";
+ trng->rng.read = ele_get_hwrng;
+ trng->rng.priv = (unsigned long)trng;
+ trng->rng.quality = 1024;
+
+ dev_dbg(dev, "registering ele-trng\n");
+
+ ret = devm_hwrng_register(dev, &trng->rng);
+ if (ret)
+ return ret;
+
+ dev_info(dev, "Successfully registered ele-trng\n");
+ return 0;
+}
+
+int ele_get_hwrng(struct hwrng *rng,
+ void *data, size_t len, bool wait)
+{
+ struct ele_trng *trng = (struct ele_trng *)rng->priv;
+
+ return ele_get_random(trng->dev, data, len);
+}
diff --git a/drivers/firmware/imx/se_fw.c b/drivers/firmware/imx/se_fw.c
index 88300c41d62b..6083c42dcda3 100644
--- a/drivers/firmware/imx/se_fw.c
+++ b/drivers/firmware/imx/se_fw.c
@@ -21,10 +21,10 @@
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
-#include <linux/delay.h>
#include <linux/sys_soc.h>

#include "se_fw.h"
+#include "ele_common.h"

#define SOC_ID_OF_IMX8ULP 0x084D
#define SOC_ID_OF_IMX93 0x9300
@@ -43,6 +43,9 @@ struct imx_info {
uint8_t *pool_name;
bool reserved_dma_ranges;
bool init_fw;
+ /* platform specific flag to enable/disable the ELE True RNG */
+ bool start_rng;
+ bool enable_ele_trng;
};

static LIST_HEAD(priv_data_list);
@@ -58,6 +61,8 @@ static const struct imx_info imx8ulp_info = {
.pool_name = "sram-pool",
.reserved_dma_ranges = true,
.init_fw = false,
+ .start_rng = true,
+ .enable_ele_trng = false,
};

static const struct imx_info imx93_info = {
@@ -71,6 +76,8 @@ static const struct imx_info imx93_info = {
.pool_name = NULL,
.reserved_dma_ranges = true,
.init_fw = true,
+ .start_rng = true,
+ .enable_ele_trng = true,
};

static const struct of_device_id se_fw_match[] = {
@@ -1140,9 +1147,23 @@ static int se_fw_probe(struct platform_device *pdev)
}
}

+ /* start ele rng */
+ if (info->start_rng) {
+ ret = ele_do_start_rng(dev);
+ if (ret)
+ dev_err(dev, "Failed to start ele rng\n");
+ }
+
+ if (!ret && info->enable_ele_trng) {
+ ret = ele_trng_init(dev);
+ if (ret)
+ dev_err(dev, "Failed to init ele-trng\n");
+ }
+
pr_info("i.MX secure-enclave: %s's mu#%d interface to firmware, configured.\n",
info->se_name,
priv->ele_mu_id);
+
return devm_of_platform_populate(dev);

exit:
diff --git a/include/linux/firmware/imx/ele_base_msg.h b/include/linux/firmware/imx/ele_base_msg.h
index 9c05936ba813..8a5c385210fc 100644
--- a/include/linux/firmware/imx/ele_base_msg.h
+++ b/include/linux/firmware/imx/ele_base_msg.h
@@ -28,10 +28,21 @@
#define ELE_GET_INFO_REQ 0xDA
#define ELE_GET_INFO_REQ_MSG_SZ 0x02

+#define ELE_START_RNG_REQ 0xA3
+#define ELE_START_RNG_REQ_MSG_SZ 0x02
+
+#define ELE_GET_TRNG_STATE_REQ 0xA4
+#define ELE_GET_TRNG_STATE_REQ_MSG_SZ 0x03
+#define ELE_TRNG_STATE_OK 0x203
+#define ELE_GET_TRNG_STATE_RETRY_COUNT 0x5
+#define CSAL_TRNG_STATE_MASK 0x0000ffff
+
#define ELE_BASE_API_VERSION 0x6
#define ELE_SUCCESS_IND 0xD6
#define ELE_FAILURE_IND 0x29

int ele_get_info(struct device *dev, phys_addr_t addr, u32 data_size);
+int ele_start_rng(struct device *dev);
+int ele_get_trng_state(struct device *dev);

#endif
diff --git a/include/linux/firmware/imx/ele_fw_api.h b/include/linux/firmware/imx/ele_fw_api.h
index 36c3f743cb38..5e640148e211 100644
--- a/include/linux/firmware/imx/ele_fw_api.h
+++ b/include/linux/firmware/imx/ele_fw_api.h
@@ -13,7 +13,12 @@
#define ELE_INIT_FW_REQ 0x17
#define ELE_INIT_FW_RSP_SZ 0x2

+#define ELE_GET_RANDOM_REQ 0xCD
+#define ELE_GET_RANDOM_REQ_SZ 0x2
+

int ele_init_fw(struct device *dev);
+int ele_get_random(struct device *dev, void *data, size_t len);
+int ele_get_hwrng(struct hwrng *rng, void *data, size_t len, bool wait);

#endif /* ELE_FW_API_H */
--
2.34.1