This change defines resources for OP-TEE service drivers to register themselves for being bound to when OP-TEE firmware reports the related service is supported. OP-TEE services are discovered during optee driver probe sequence which mandates optee driver is always probe once bound.

Discovery of optee services and binding to related U-Boot drivers is embedded upon configuration switch CONFIG_OPTEE_SERVICE_DISCOVERY.

Cc: Jens Wiklander jens.wiklander@linaro.org Cc: Patrick Delaunay patrick.delaunay@foss.st.com Signed-off-by: Etienne Carriere etienne.carriere@linaro.org --- Changes since v3: - Stub OPTEE_SERVICE_DRIVER() macro when CONFIG_OPTEE_SERVICE_DISCOVERY is disable.

Changes since v2: - Release allocated shared memory from bind_service_drivers() only. - Remove definition of useless macro OPTEE_SERVICE_DRIVER_GET().

Changes since v1: - Remove all #ifdef CONFIG_OPTEE_SERVICE_DISCOVERY directives and replace with if (IS_ENABLED()) where applicable. - Incidentally rename local function open_session() to open_enum_session() and remove local function close_session() for clarity. - Update commit log to highlight that "optee driver is always probe once bound" when CONFIG_OPTEE_SERVICE_DISCOVERY is enable. --- drivers/tee/optee/Kconfig | 8 ++ drivers/tee/optee/core.c | 171 ++++++++++++++++++++++++++++++++++-- include/tee/optee_service.h | 34 +++++++ 3 files changed, 208 insertions(+), 5 deletions(-) create mode 100644 include/tee/optee_service.h

diff --git a/drivers/tee/optee/Kconfig b/drivers/tee/optee/Kconfig index d03028070b..9dc65b0501 100644 --- a/drivers/tee/optee/Kconfig +++ b/drivers/tee/optee/Kconfig @@ -37,6 +37,14 @@ config OPTEE_TA_SCP03 help Enables support for controlling (enabling, provisioning) the Secure Channel Protocol 03 operation in the OP-TEE SCP03 TA. + +config OPTEE_SERVICE_DISCOVERY + bool "OP-TEE service discovery" + default y + help + This implements automated driver binding of OP-TEE service drivers by + requesting OP-TEE firmware to enumerate its hosted services. + endmenu

endif diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index c1f5fc4c7a..41fa615b35 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -14,6 +14,7 @@ #include <linux/arm-smccc.h> #include <linux/err.h> #include <linux/io.h> +#include <tee/optee_service.h>

#include "optee_smc.h" #include "optee_msg.h" @@ -22,6 +23,25 @@ #define PAGELIST_ENTRIES_PER_PAGE \ ((OPTEE_MSG_NONCONTIG_PAGE_SIZE / sizeof(u64)) - 1)

+/* + * PTA_DEVICE_ENUM interface exposed by OP-TEE to discover enumerated services + */ +#define PTA_DEVICE_ENUM { 0x7011a688, 0xddde, 0x4053, \ + { 0xa5, 0xa9, 0x7b, 0x3c, 0x4d, 0xdf, 0x13, 0xb8 } } +/* + * PTA_CMD_GET_DEVICES - List services without supplicant dependencies + * + * [out] memref[0]: List of the UUIDs of service enumerated by OP-TEE + */ +#define PTA_CMD_GET_DEVICES 0x0 + +/* + * PTA_CMD_GET_DEVICES_SUPP - List services depending on tee supplicant + * + * [out] memref[0]: List of the UUIDs of service enumerated by OP-TEE + */ +#define PTA_CMD_GET_DEVICES_SUPP 0x1 + typedef void (optee_invoke_fn)(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, @@ -42,6 +62,134 @@ struct rpc_param { u32 a7; };

+static struct optee_service *find_service_driver(const struct tee_optee_ta_uuid *uuid) +{ + struct optee_service *service; + u8 loc_uuid[TEE_UUID_LEN]; + size_t service_cnt, idx; + + service_cnt = ll_entry_count(struct optee_service, optee_service); + service = ll_entry_start(struct optee_service, optee_service); + + for (idx = 0; idx < service_cnt; idx++, service++) { + tee_optee_ta_uuid_to_octets(loc_uuid, &service->uuid); + if (!memcmp(uuid, loc_uuid, sizeof(uuid))) + return service; + } + + return NULL; +} + +static int bind_service_list(struct udevice *dev, struct tee_shm *service_list, size_t count) +{ + const struct tee_optee_ta_uuid *service_uuid = (const void *)service_list->addr; + struct optee_service *service; + size_t idx; + int ret; + + for (idx = 0; idx < count; idx++) { + service = find_service_driver(service_uuid + idx); + if (!service) + continue; + + ret = device_bind_driver(dev, service->driver_name, service->driver_name, NULL); + if (ret) { + dev_warn(dev, "%s was not bound: %d, ignored\n", service->driver_name, ret); + continue; + } + } + + return 0; +} + +static int __enum_services(struct udevice *dev, struct tee_shm *shm, u32 *shm_size, u32 tee_sess) +{ + struct tee_invoke_arg arg = { }; + struct tee_param param = { }; + int ret = 0; + + arg.func = PTA_CMD_GET_DEVICES; + arg.session = tee_sess; + + /* Fill invoke cmd params */ + param.attr = TEE_PARAM_ATTR_TYPE_MEMREF_OUTPUT; + param.u.memref.shm = shm; + param.u.memref.size = *shm_size; + + ret = tee_invoke_func(dev, &arg, 1, &param); + if (ret || (arg.ret && arg.ret != TEE_ERROR_SHORT_BUFFER)) { + dev_err(dev, "PTA_CMD_GET_DEVICES invoke function err: 0x%x\n", arg.ret); + return -EINVAL; + } + + *shm_size = param.u.memref.size; + + return 0; +} + +static int enum_services(struct udevice *dev, struct tee_shm **shm, size_t *count, u32 tee_sess) +{ + size_t shm_size = 0; + int ret; + + ret = __enum_services(dev, NULL, &shm_size, tee_sess); + if (ret) + return ret; + + ret = tee_shm_alloc(dev, shm_size, 0, shm); + if (ret) { + dev_err(dev, "Failed to allocated shared memory: %d\n", ret); + return ret; + } + + ret = __enum_services(dev, *shm, &shm_size, tee_sess); + if (!ret) + *count = shm_size / sizeof(struct tee_optee_ta_uuid); + + return ret; +} + +static int open_enum_session(struct udevice *dev, u32 *tee_sess) +{ + const struct tee_optee_ta_uuid pta_uuid = PTA_DEVICE_ENUM; + struct tee_open_session_arg arg = { }; + int ret; + + tee_optee_ta_uuid_to_octets(arg.uuid, &pta_uuid); + + ret = tee_open_session(dev, &arg, 0, NULL); + if (ret || arg.ret) { + if (!ret) + ret = -EIO; + return ret; + } + + *tee_sess = arg.session; + + return 0; +} + +static int bind_service_drivers(struct udevice *dev) +{ + struct tee_shm *service_list = NULL; + size_t service_count; + u32 tee_sess; + int ret; + + ret = open_enum_session(dev, &tee_sess); + if (ret) + return ret; + + ret = enum_services(dev, &service_list, &service_count, tee_sess); + if (!ret) + ret = bind_service_list(dev, service_list, service_count); + + tee_shm_free(service_list); + tee_close_session(dev, tee_sess); + + return ret; +} + /** * reg_pair_to_ptr() - Make a pointer of 2 32-bit values * @reg0: High bits of the pointer @@ -638,6 +786,14 @@ static int optee_of_to_plat(struct udevice *dev) return 0; }

+static int optee_bind(struct udevice *dev) +{ + if (IS_ENABLED(CONFIG_OPTEE_SERVICE_DISCOVERY)) + dev_or_flags(dev, DM_FLAG_PROBE_AFTER_BIND); + + return 0; +} + static int optee_probe(struct udevice *dev) { struct optee_pdata *pdata = dev_get_plat(dev); @@ -667,11 +823,15 @@ 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)) { + if (IS_ENABLED(CONFIG_OPTEE_SERVICE_DISCOVERY)) { + ret = bind_service_drivers(dev); + if (ret) + return ret; + } else if (IS_ENABLED(CONFIG_RNG_OPTEE)) { + /* + * Discovery of TAs on the TEE bus is not supported in U-Boot: + * only bind the drivers associated to the supported OP-TEE TA + */ ret = device_bind_driver(dev, "optee-rng", "optee-rng", NULL); if (ret) return ret; @@ -691,6 +851,7 @@ U_BOOT_DRIVER(optee) = { .of_match = optee_match, .of_to_plat = optee_of_to_plat, .probe = optee_probe, + .bind = optee_bind, .ops = &optee_ops, .plat_auto = sizeof(struct optee_pdata), .priv_auto = sizeof(struct optee_private), diff --git a/include/tee/optee_service.h b/include/tee/optee_service.h new file mode 100644 index 0000000000..fca468af7c --- /dev/null +++ b/include/tee/optee_service.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: BSD-2-Clause */ +/* + * (C) Copyright 2022 Linaro Limited + */ + +#ifndef _OPTEE_SERVICE_H +#define _OPTEE_SERVICE_H + +/* + * struct optee_service - Discoverable OP-TEE service + * + * @driver_name - Name of the related driver + * @uuid - UUID of the OP-TEE service related to the driver + * + * Use macro OPTEE_SERVICE_DRIVER() to register a driver related to an + * OP-TEE service discovered when driver asks OP-TEE services enumaration. + */ +struct optee_service { + const char *driver_name; + const struct tee_optee_ta_uuid uuid; +}; + +#ifdef CONFIG_OPTEE_SERVICE_DISCOVERY +#define OPTEE_SERVICE_DRIVER(__name, __uuid, __drv_name) \ + ll_entry_declare(struct optee_service, __name, optee_service) = { \ + .uuid = __uuid, \ + .driver_name = __drv_name, \ + } +#else +#define OPTEE_SERVICE_DRIVER(__name, __uuid, __drv_name) \ + static int __name##__COUNTER__ __always_unused +#endif + +#endif /* _OPTEE_SERVICE_H */

Changes optee_rng driver to register itself has a OP-TEE service so that a device is bound for the driver when OP-TEE enumerates the PTA RNG service.

Cc: Sughosh Ganu sughosh.ganu@linaro.org Cc: Patrick Delaunay patrick.delaunay@foss.st.com Signed-off-by: Etienne Carriere etienne.carriere@linaro.org --- Changes since v3: - Unconditionally register driver with OPTEE_SERVICE_DRIVER() since the macro is now stubbed when CONFIG_OPTEE_SERVICE_DISCOVERY is disable.

No change since v2.

No change since v1. --- drivers/rng/Kconfig | 1 + drivers/rng/optee_rng.c | 7 ++++++- 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig index c10f7d345b..14e95a6213 100644 --- a/drivers/rng/Kconfig +++ b/drivers/rng/Kconfig @@ -34,6 +34,7 @@ config RNG_MSM config RNG_OPTEE bool "OP-TEE based Random Number Generator support" depends on DM_RNG && OPTEE + default y if OPTEE_SERVICE_DISCOVERY help This driver provides support for the OP-TEE based Random Number Generator on ARM SoCs where hardware entropy sources are not diff --git a/drivers/rng/optee_rng.c b/drivers/rng/optee_rng.c index aa8ce864d3..410dfc053f 100644 --- a/drivers/rng/optee_rng.c +++ b/drivers/rng/optee_rng.c @@ -11,6 +11,9 @@ #include <dm/device.h> #include <dm/device_compat.h> #include <linux/sizes.h> +#include <tee/optee_service.h> + +#define DRIVER_NAME "optee-rng"

#define TEE_ERROR_HEALTH_TEST_FAIL 0x00000001

@@ -35,6 +38,8 @@ #define TA_HWRNG_UUID { 0xab7a617c, 0xb8e7, 0x4d8f, \ { 0x83, 0x01, 0xd0, 0x9b, 0x61, 0x03, 0x6b, 0x64 } }

+OPTEE_SERVICE_DRIVER(optee_rng, TA_HWRNG_UUID, DRIVER_NAME); + /** open_session_ta_hwrng() - Open session with hwrng Trusted App * * @dev: device @@ -177,7 +182,7 @@ static const struct dm_rng_ops optee_rng_ops = { };

U_BOOT_DRIVER(optee_rng) = { - .name = "optee-rng", + .name = DRIVER_NAME, .id = UCLASS_RNG, .ops = &optee_rng_ops, .probe = optee_rng_probe,