[PATCH v2 1/3] rng: add OP-TEE based Random Number Generator
Add driver for OP-TEE based Random Number Generator on ARM SoCs where hardware entropy sources are not accessible to normal world and the RNG service is provided by a HWRNG Trusted Application (TA).
This driver is based on the linux driver: char/hw_random/optee-rng.c
Series_changes: 2 - change SPDX-License-Identifier, becausee "GPL-2.0+” is obsolete reference: https://spdx.dev/ids/ - update Kconfig long help message as proposed by Heinrich - replace memset(.., 0, sizeof(..)) by struct initialisation (= {0};) - add function descriptions
Signed-off-by: Patrick Delaunay patrick.delaunay@foss.st.com ---
(no changes since v1)
MAINTAINERS | 1 + drivers/rng/Kconfig | 9 ++ drivers/rng/Makefile | 1 + drivers/rng/optee_rng.c | 180 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 191 insertions(+) create mode 100644 drivers/rng/optee_rng.c
diff --git a/MAINTAINERS b/MAINTAINERS index f25ca7cd00..3356c65dd0 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -481,6 +481,7 @@ F: drivers/power/regulator/stpmic1.c F: drivers/ram/stm32mp1/ F: drivers/remoteproc/stm32_copro.c F: drivers/reset/stm32-reset.c +F: drivers/rng/optee_rng.c F: drivers/rng/stm32mp1_rng.c F: drivers/rtc/stm32_rtc.c F: drivers/serial/serial_stm32.* diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig index b1c5ab93d1..c10f7d345b 100644 --- a/drivers/rng/Kconfig +++ b/drivers/rng/Kconfig @@ -31,6 +31,15 @@ config RNG_MSM This driver provides support for the Random Number Generator hardware found on Qualcomm SoCs.
+config RNG_OPTEE + bool "OP-TEE based Random Number Generator support" + depends on DM_RNG && OPTEE + help + This driver provides support for the OP-TEE based Random Number + Generator on ARM SoCs where hardware entropy sources are not + accessible to normal world but reserved and used by the OP-TEE + to avoid the weakness of a software PRNG. + config RNG_STM32MP1 bool "Enable random number generator for STM32MP1" depends on ARCH_STM32MP diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile index 39f7ee3f03..435b3b965a 100644 --- a/drivers/rng/Makefile +++ b/drivers/rng/Makefile @@ -7,6 +7,7 @@ obj-$(CONFIG_DM_RNG) += rng-uclass.o obj-$(CONFIG_RNG_MESON) += meson-rng.o obj-$(CONFIG_RNG_SANDBOX) += sandbox_rng.o obj-$(CONFIG_RNG_MSM) += msm_rng.o +obj-$(CONFIG_RNG_OPTEE) += optee_rng.o obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o obj-$(CONFIG_RNG_ROCKCHIP) += rockchip_rng.o obj-$(CONFIG_RNG_IPROC200) += iproc_rng200.o diff --git a/drivers/rng/optee_rng.c b/drivers/rng/optee_rng.c new file mode 100644 index 0000000000..7be428ac91 --- /dev/null +++ b/drivers/rng/optee_rng.c @@ -0,0 +1,180 @@ +// SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause +/* + * Copyright (C) 2022, STMicroelectronics - All Rights Reserved + */ +#define LOG_CATEGORY UCLASS_RNG + +#include <common.h> + +#include <rng.h> +#include <tee.h> +#include <dm/device.h> +#include <dm/device_compat.h> +#include <linux/sizes.h> + +#define TEE_ERROR_HEALTH_TEST_FAIL 0x00000001 + +/* + * TA_CMD_GET_ENTROPY - Get Entropy from RNG + * + * param[0] (inout memref) - Entropy buffer memory reference + * param[1] unused + * param[2] unused + * param[3] unused + * + * Result: + * TEE_SUCCESS - Invoke command success + * TEE_ERROR_BAD_PARAMETERS - Incorrect input param + * TEE_ERROR_NOT_SUPPORTED - Requested entropy size greater than size of pool + * TEE_ERROR_HEALTH_TEST_FAIL - Continuous health testing failed + */ +#define TA_CMD_GET_ENTROPY 0x0 + +#define MAX_ENTROPY_REQ_SZ SZ_4K + +#define TA_HWRNG_UUID { 0xab7a617c, 0xb8e7, 0x4d8f, \ + { 0x83, 0x01, 0xd0, 0x9b, 0x61, 0x03, 0x6b, 0x64 } } + +/** + * struct optee_rng_priv - OP-TEE Random Number Generator private data + * @session_id: RNG TA session identifier. + */ +struct optee_rng_priv { + u32 session_id; +}; + +/** + * get_optee_rng_data() - read RNG data from OP-TEE TA + * + * @dev: device + * @entropy_shm_pool: shared memory pool used for TEE message + * @buf: buffer to receive data + * @size: size of buffer, limited by entropy_shm_pool size + * Return: 0 if ok + */ +static int get_optee_rng_data(struct udevice *dev, + struct tee_shm *entropy_shm_pool, + void *buf, size_t *size) +{ + struct optee_rng_priv *priv = dev_get_priv(dev); + int ret = 0; + struct tee_invoke_arg arg = {0}; + struct tee_param param = {0}; + + /* Invoke TA_CMD_GET_ENTROPY function of Trusted App */ + arg.func = TA_CMD_GET_ENTROPY; + arg.session = priv->session_id; + + /* Fill invoke cmd params */ + param.attr = TEE_PARAM_ATTR_TYPE_MEMREF_INOUT; + param.u.memref.shm = entropy_shm_pool; + param.u.memref.size = *size; + + ret = tee_invoke_func(dev->parent, &arg, 1, ¶m); + if (ret || arg.ret) { + if (!ret) + ret = -EPROTO; + dev_err(dev, "TA_CMD_GET_ENTROPY invoke err: %d 0x%x\n", ret, arg.ret); + *size = 0; + + return ret; + } + + memcpy(buf, param.u.memref.shm->addr, param.u.memref.size); + *size = param.u.memref.size; + + return 0; +} + +/** + * optee_rng_read() - rng read ops for OP-TEE RNG device + * + * @dev: device + * @buf: buffer to receive data + * @len: size of buffer + * Return: 0 if ok + */ +static int optee_rng_read(struct udevice *dev, void *buf, size_t len) +{ + size_t read = 0, rng_size = 0; + struct tee_shm *entropy_shm_pool; + u8 *data = buf; + int ret; + + ret = tee_shm_alloc(dev->parent, MAX_ENTROPY_REQ_SZ, 0, &entropy_shm_pool); + if (ret) { + dev_err(dev, "tee_shm_alloc failed: %d\n", ret); + return ret; + } + + while (read < len) { + rng_size = min(len - read, (size_t)MAX_ENTROPY_REQ_SZ); + ret = get_optee_rng_data(dev, entropy_shm_pool, data, &rng_size); + if (ret) + goto shm_free; + data += rng_size; + read += rng_size; + } + +shm_free: + tee_shm_free(entropy_shm_pool); + + return ret; +} + +/** + * optee_rng_probe() - probe function for OP-TEE RNG device + * + * @dev: device + * Return: 0 if ok + */ +static int optee_rng_probe(struct udevice *dev) +{ + const struct tee_optee_ta_uuid uuid = TA_HWRNG_UUID; + struct optee_rng_priv *priv = dev_get_priv(dev); + struct tee_open_session_arg sess_arg = {0}; + int ret; + + /* Open session with hwrng Trusted App */ + tee_optee_ta_uuid_to_octets(sess_arg.uuid, &uuid); + sess_arg.clnt_login = TEE_LOGIN_PUBLIC; + + ret = tee_open_session(dev->parent, &sess_arg, 0, NULL); + if (ret || sess_arg.ret) { + if (!ret) + ret = -EIO; + dev_err(dev, "can't open session: %d 0x%x\n", ret, sess_arg.ret); + return ret; + } + priv->session_id = sess_arg.session; + + return 0; +} + +/** + * optee_rng_remove() - remove function for OP-TEE RNG device + * + * @dev: device + * Return: 0 + */ +static int optee_rng_remove(struct udevice *dev) +{ + struct optee_rng_priv *priv = dev_get_priv(dev); + + tee_close_session(dev->parent, priv->session_id); + + return 0; +} + +static const struct dm_rng_ops optee_rng_ops = { + .read = optee_rng_read, +}; + +U_BOOT_DRIVER(optee_rng) = { + .name = "optee-rng", + .id = UCLASS_RNG, + .ops = &optee_rng_ops, + .probe = optee_rng_probe, + .remove = optee_rng_remove, + .priv_auto = sizeof(struct optee_rng_priv), +};
In U-Boot, the discovery of TA based on its UUID on the TEE bus is not supported.
This patch only binds the driver associated to the new supported OP-TEE TA = TA_HWRNG when this driver is enable.
Signed-off-by: Patrick Delaunay patrick.delaunay@foss.st.com ---
(no changes since v1)
drivers/tee/optee/core.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index dad46aa388..a89d62aaf0 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -7,6 +7,7 @@ #include <cpu_func.h> #include <dm.h> #include <dm/device_compat.h> +#include <dm/lists.h> #include <log.h> #include <malloc.h> #include <tee.h> @@ -641,6 +642,8 @@ static int optee_probe(struct udevice *dev) { struct optee_pdata *pdata = dev_get_plat(dev); u32 sec_caps; + struct udevice *child; + int ret;
if (!is_optee_api(pdata->invoke_fn)) { dev_err(dev, "OP-TEE api uid mismatch\n"); @@ -665,6 +668,16 @@ static int optee_probe(struct udevice *dev) return -ENOENT; }
+ /* + * in U-Boot, the discovery of TA on the TEE bus is not supported: + * only bind the drivers associated to the supported OP-TEE TA + */ + if (IS_ENABLED(CONFIG_RNG_OPTEE)) { + ret = device_bind_driver(dev, "optee-rng", "optee-rng", &child); + if (ret) + return ret; + } + return 0; }
When the RNG device is secured with OP-TEE, it is only accessible with the HWRNG TA, the CONFIG_RNG_OPTEE is needed for STM32MP15 targets with OP-TEE support.
The probe of this RNG driver fails when the TA is not available in OP-TEE and the previous driver can be used, as CONFIG_RNG_STM32MP1 is activated and when the associated node is activated in the device tree with:
&rng1 { status = "okay"; };
When the RNG is used in OP-TEE, this node should be deactivated in the Linux and U-Boot device tree.
Signed-off-by: Patrick Delaunay patrick.delaunay@foss.st.com ---
(no changes since v1)
configs/stm32mp15_defconfig | 1 + configs/stm32mp15_trusted_defconfig | 1 + 2 files changed, 2 insertions(+)
diff --git a/configs/stm32mp15_defconfig b/configs/stm32mp15_defconfig index 2beb88e81d..3f48c677e6 100644 --- a/configs/stm32mp15_defconfig +++ b/configs/stm32mp15_defconfig @@ -119,6 +119,7 @@ CONFIG_DM_REGULATOR_STPMIC1=y CONFIG_REMOTEPROC_STM32_COPRO=y CONFIG_RESET_SCMI=y CONFIG_DM_RNG=y +CONFIG_RNG_OPTEE=y CONFIG_RNG_STM32MP1=y CONFIG_DM_RTC=y CONFIG_RTC_STM32=y diff --git a/configs/stm32mp15_trusted_defconfig b/configs/stm32mp15_trusted_defconfig index c6857d08ec..9f869aca36 100644 --- a/configs/stm32mp15_trusted_defconfig +++ b/configs/stm32mp15_trusted_defconfig @@ -120,6 +120,7 @@ CONFIG_DM_REGULATOR_STPMIC1=y CONFIG_REMOTEPROC_STM32_COPRO=y CONFIG_RESET_SCMI=y CONFIG_DM_RNG=y +CONFIG_RNG_OPTEE=y CONFIG_RNG_STM32MP1=y CONFIG_DM_RTC=y CONFIG_RTC_STM32=y
On 3/28/22 15:11, Patrick Delaunay wrote:
Add driver for OP-TEE based Random Number Generator on ARM SoCs where hardware entropy sources are not accessible to normal world and the RNG service is provided by a HWRNG Trusted Application (TA).
This driver is based on the linux driver: char/hw_random/optee-rng.c
Series_changes: 2
- change SPDX-License-Identifier, becausee "GPL-2.0+” is obsolete reference: https://spdx.dev/ids/
- update Kconfig long help message as proposed by Heinrich
- replace memset(.., 0, sizeof(..)) by struct initialisation (= {0};)
- add function descriptions
Signed-off-by: Patrick Delaunay patrick.delaunay@foss.st.com
(no changes since v1)
MAINTAINERS | 1 + drivers/rng/Kconfig | 9 ++ drivers/rng/Makefile | 1 + drivers/rng/optee_rng.c | 180 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 191 insertions(+) create mode 100644 drivers/rng/optee_rng.c
diff --git a/MAINTAINERS b/MAINTAINERS index f25ca7cd00..3356c65dd0 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -481,6 +481,7 @@ F: drivers/power/regulator/stpmic1.c F: drivers/ram/stm32mp1/ F: drivers/remoteproc/stm32_copro.c F: drivers/reset/stm32-reset.c +F: drivers/rng/optee_rng.c F: drivers/rng/stm32mp1_rng.c F: drivers/rtc/stm32_rtc.c F: drivers/serial/serial_stm32.* diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig index b1c5ab93d1..c10f7d345b 100644 --- a/drivers/rng/Kconfig +++ b/drivers/rng/Kconfig @@ -31,6 +31,15 @@ config RNG_MSM This driver provides support for the Random Number Generator hardware found on Qualcomm SoCs.
+config RNG_OPTEE
- bool "OP-TEE based Random Number Generator support"
- depends on DM_RNG && OPTEE
- help
This driver provides support for the OP-TEE based Random NumberGenerator on ARM SoCs where hardware entropy sources are notaccessible to normal world but reserved and used by the OP-TEEto avoid the weakness of a software PRNG.- config RNG_STM32MP1 bool "Enable random number generator for STM32MP1" depends on ARCH_STM32MP
diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile index 39f7ee3f03..435b3b965a 100644 --- a/drivers/rng/Makefile +++ b/drivers/rng/Makefile @@ -7,6 +7,7 @@ obj-$(CONFIG_DM_RNG) += rng-uclass.o obj-$(CONFIG_RNG_MESON) += meson-rng.o obj-$(CONFIG_RNG_SANDBOX) += sandbox_rng.o obj-$(CONFIG_RNG_MSM) += msm_rng.o +obj-$(CONFIG_RNG_OPTEE) += optee_rng.o obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o obj-$(CONFIG_RNG_ROCKCHIP) += rockchip_rng.o obj-$(CONFIG_RNG_IPROC200) += iproc_rng200.o diff --git a/drivers/rng/optee_rng.c b/drivers/rng/optee_rng.c new file mode 100644 index 0000000000..7be428ac91 --- /dev/null +++ b/drivers/rng/optee_rng.c @@ -0,0 +1,180 @@ +// SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause +/*
- Copyright (C) 2022, STMicroelectronics - All Rights Reserved
- */
+#define LOG_CATEGORY UCLASS_RNG
+#include <common.h>
+#include <rng.h> +#include <tee.h> +#include <dm/device.h> +#include <dm/device_compat.h> +#include <linux/sizes.h>
+#define TEE_ERROR_HEALTH_TEST_FAIL 0x00000001
+/*
- TA_CMD_GET_ENTROPY - Get Entropy from RNG
- param[0] (inout memref) - Entropy buffer memory reference
- param[1] unused
- param[2] unused
- param[3] unused
- Result:
- TEE_SUCCESS - Invoke command success
- TEE_ERROR_BAD_PARAMETERS - Incorrect input param
- TEE_ERROR_NOT_SUPPORTED - Requested entropy size greater than size of pool
- TEE_ERROR_HEALTH_TEST_FAIL - Continuous health testing failed
- */
+#define TA_CMD_GET_ENTROPY 0x0
+#define MAX_ENTROPY_REQ_SZ SZ_4K
+#define TA_HWRNG_UUID { 0xab7a617c, 0xb8e7, 0x4d8f, \
{ 0x83, 0x01, 0xd0, 0x9b, 0x61, 0x03, 0x6b, 0x64 } }+/**
- struct optee_rng_priv - OP-TEE Random Number Generator private data
- @session_id: RNG TA session identifier.
- */
+struct optee_rng_priv {
- u32 session_id;
+};
+/**
- get_optee_rng_data() - read RNG data from OP-TEE TA
- @dev: device
- @entropy_shm_pool: shared memory pool used for TEE message
- @buf: buffer to receive data
- @size: size of buffer, limited by entropy_shm_pool size
- Return: 0 if ok
- */
+static int get_optee_rng_data(struct udevice *dev,
struct tee_shm *entropy_shm_pool,void *buf, size_t *size)+{
- struct optee_rng_priv *priv = dev_get_priv(dev);
- int ret = 0;
- struct tee_invoke_arg arg = {0};
- struct tee_param param = {0};
- /* Invoke TA_CMD_GET_ENTROPY function of Trusted App */
- arg.func = TA_CMD_GET_ENTROPY;
- arg.session = priv->session_id;
- /* Fill invoke cmd params */
- param.attr = TEE_PARAM_ATTR_TYPE_MEMREF_INOUT;
- param.u.memref.shm = entropy_shm_pool;
- param.u.memref.size = *size;
- ret = tee_invoke_func(dev->parent, &arg, 1, ¶m);
- if (ret || arg.ret) {
if (!ret)ret = -EPROTO;dev_err(dev, "TA_CMD_GET_ENTROPY invoke err: %d 0x%x\n", ret, arg.ret);*size = 0;return ret;- }
- memcpy(buf, param.u.memref.shm->addr, param.u.memref.size);
- *size = param.u.memref.size;
- return 0;
+}
+/**
- optee_rng_read() - rng read ops for OP-TEE RNG device
- @dev: device
- @buf: buffer to receive data
- @len: size of buffer
- Return: 0 if ok
- */
+static int optee_rng_read(struct udevice *dev, void *buf, size_t len) +{
- size_t read = 0, rng_size = 0;
- struct tee_shm *entropy_shm_pool;
- u8 *data = buf;
- int ret;
- ret = tee_shm_alloc(dev->parent, MAX_ENTROPY_REQ_SZ, 0, &entropy_shm_pool);
- if (ret) {
dev_err(dev, "tee_shm_alloc failed: %d\n", ret);return ret;- }
- while (read < len) {
rng_size = min(len - read, (size_t)MAX_ENTROPY_REQ_SZ);ret = get_optee_rng_data(dev, entropy_shm_pool, data, &rng_size);if (ret)goto shm_free;data += rng_size;read += rng_size;- }
+shm_free:
- tee_shm_free(entropy_shm_pool);
- return ret;
+}
+/**
- optee_rng_probe() - probe function for OP-TEE RNG device
- @dev: device
- Return: 0 if ok
- */
+static int optee_rng_probe(struct udevice *dev) +{
- const struct tee_optee_ta_uuid uuid = TA_HWRNG_UUID;
- struct optee_rng_priv *priv = dev_get_priv(dev);
- struct tee_open_session_arg sess_arg = {0};
- int ret;
- /* Open session with hwrng Trusted App */
- tee_optee_ta_uuid_to_octets(sess_arg.uuid, &uuid);
- sess_arg.clnt_login = TEE_LOGIN_PUBLIC;
- ret = tee_open_session(dev->parent, &sess_arg, 0, NULL);
- if (ret || sess_arg.ret) {
if (!ret)ret = -EIO;dev_err(dev, "can't open session: %d 0x%x\n", ret, sess_arg.ret);return ret;- }
- priv->session_id = sess_arg.session;
Is it really necessary to keep the session open? Or should we reopen a session whenever a random number is requested?
Best regards
Heinrich
- return 0;
+}
+/**
- optee_rng_remove() - remove function for OP-TEE RNG device
- @dev: device
- Return: 0
- */
+static int optee_rng_remove(struct udevice *dev) +{
- struct optee_rng_priv *priv = dev_get_priv(dev);
- tee_close_session(dev->parent, priv->session_id);
- return 0;
+}
+static const struct dm_rng_ops optee_rng_ops = {
- .read = optee_rng_read,
+};
+U_BOOT_DRIVER(optee_rng) = {
- .name = "optee-rng",
- .id = UCLASS_RNG,
- .ops = &optee_rng_ops,
- .probe = optee_rng_probe,
- .remove = optee_rng_remove,
- .priv_auto = sizeof(struct optee_rng_priv),
+};
Hi,
On 3/28/22 15:25, Heinrich Schuchardt wrote:
On 3/28/22 15:11, Patrick Delaunay wrote:
Add driver for OP-TEE based Random Number Generator on ARM SoCs where hardware entropy sources are not accessible to normal world and the RNG service is provided by a HWRNG Trusted Application (TA).
This driver is based on the linux driver: char/hw_random/optee-rng.c
Series_changes: 2
- change SPDX-License-Identifier, becausee "GPL-2.0+” is obsolete
reference: https://spdx.dev/ids/
- update Kconfig long help message as proposed by Heinrich
- replace memset(.., 0, sizeof(..)) by struct initialisation (= {0};)
- add function descriptions
Signed-off-by: Patrick Delaunay patrick.delaunay@foss.st.com
(no changes since v1)
MAINTAINERS | 1 + drivers/rng/Kconfig | 9 ++ drivers/rng/Makefile | 1 + drivers/rng/optee_rng.c | 180 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 191 insertions(+) create mode 100644 drivers/rng/optee_rng.c
diff --git a/MAINTAINERS b/MAINTAINERS index f25ca7cd00..3356c65dd0 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -481,6 +481,7 @@ F: drivers/power/regulator/stpmic1.c F: drivers/ram/stm32mp1/ F: drivers/remoteproc/stm32_copro.c F: drivers/reset/stm32-reset.c +F: drivers/rng/optee_rng.c F: drivers/rng/stm32mp1_rng.c F: drivers/rtc/stm32_rtc.c F: drivers/serial/serial_stm32.*
(...)
+++ b/drivers/rng/optee_rng.c @@ -0,0 +1,180 @@ +// SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause +/*
- Copyright (C) 2022, STMicroelectronics - All Rights Reserved
- */
+#define LOG_CATEGORY UCLASS_RNG
(...)
+/**
- optee_rng_probe() - probe function for OP-TEE RNG device
- @dev: device
- Return: 0 if ok
- */
+static int optee_rng_probe(struct udevice *dev) +{ + const struct tee_optee_ta_uuid uuid = TA_HWRNG_UUID; + struct optee_rng_priv *priv = dev_get_priv(dev); + struct tee_open_session_arg sess_arg = {0}; + int ret;
+ /* Open session with hwrng Trusted App */ + tee_optee_ta_uuid_to_octets(sess_arg.uuid, &uuid); + sess_arg.clnt_login = TEE_LOGIN_PUBLIC;
+ ret = tee_open_session(dev->parent, &sess_arg, 0, NULL); + if (ret || sess_arg.ret) { + if (!ret) + ret = -EIO; + dev_err(dev, "can't open session: %d 0x%x\n", ret, sess_arg.ret); + return ret; + } + priv->session_id = sess_arg.session;
Is it really necessary to keep the session open? Or should we reopen a session whenever a random number is requested?
Best regards
Heinrich
No, I don't think that it is necessary.
I just use the same mechanism than Linux driver
(drivers/char/hw_random/optee-rng.c:optee_rng_probe/optee_rng_remove)
or in other U-Boot driver = drivers/tpm/tpm2_ftpm_tee.c.
But I check with Etienne, which provide the SCMI over OP-TEE implementation,
It seens that manage the optee session in probe/remove function in U-Boot is
not recommended, because when the drivers are used before relocation the
remove function is not called (so the session is not freed)
and because the time of the session open procedure is not the largest part.
=> I will remove it to simplify this driver.
regards
Patrick
participants (3)
-
Heinrich Schuchardt -
Patrick DELAUNAY -
Patrick Delaunay