Adds TEE system invocation context provisioning for a Linux driver to provision execution contexts for invocation of system service hosted in TEE. OP-TEE SMC ABI implements such invocation context provisioning.
This feature is needed when a TEE invocation cannot afford to wait for a free TEE thread when all TEE threads context are used and suspended as these may be suspended waiting for a system service, as an SCMI clock or voltage regulator, to be enabled. An example is when OP-TEE invokes a Linux OS remote service (RPC) to access an eMMC RPMB partition and the eMMC device is supplied by an OP-TEE SCMI regulator.
Signed-off-by: Etienne Carriere etienne.carriere@linaro.org --- Change since v1 - Addressed comment on Linux client to claim reservation on TEE context. This brings 2 new operations from client to TEE to request and release system thread contexts: 2 new tee_drv.h API functions, 2 new ops functions in struct tee_driver_ops. The OP-TEE implement shall implement 2 new fastcall SMC funcIDs. - Fixed typos in commit message. --- drivers/tee/optee/optee_smc.h | 60 +++++++++++++++++++++++++++++++++-- drivers/tee/optee/smc_abi.c | 34 +++++++++++++++++++- drivers/tee/tee_core.c | 30 ++++++++++++++++++ include/linux/tee_drv.h | 21 ++++++++++++ 4 files changed, 141 insertions(+), 4 deletions(-)
diff --git a/drivers/tee/optee/optee_smc.h b/drivers/tee/optee/optee_smc.h index 73b5e7760d10..75b19e1bd185 100644 --- a/drivers/tee/optee/optee_smc.h +++ b/drivers/tee/optee/optee_smc.h @@ -108,7 +108,8 @@ struct optee_smc_call_get_os_revision_result { * Call with struct optee_msg_arg as argument * * When called with OPTEE_SMC_CALL_WITH_RPC_ARG or - * OPTEE_SMC_CALL_WITH_REGD_ARG in a0 there is one RPC struct optee_msg_arg + * OPTEE_SMC_CALL_WITH_REGD_ARG or OPTEE_SMC_FUNCID_CALL_SYSTEM_WITH_REGD_ARG + * in a0 there is one RPC struct optee_msg_arg * following after the first struct optee_msg_arg. The RPC struct * optee_msg_arg has reserved space for the number of RPC parameters as * returned by OPTEE_SMC_EXCHANGE_CAPABILITIES. @@ -130,8 +131,8 @@ struct optee_smc_call_get_os_revision_result { * a4-6 Not used * a7 Hypervisor Client ID register * - * Call register usage, OPTEE_SMC_CALL_WITH_REGD_ARG: - * a0 SMC Function ID, OPTEE_SMC_CALL_WITH_REGD_ARG + * Call register usage, OPTEE_SMC_CALL_WITH_REGD_ARG and OPTEE_SMC_FUNCID_CALL_SYSTEM_WITH_REGD_ARG: + * a0 SMC Function ID, OPTEE_SMC_CALL_WITH_REGD_ARG or OPTEE_SMC_FUNCID_CALL_SYSTEM_WITH_REGD_ARG * a1 Upper 32 bits of a 64-bit shared memory cookie * a2 Lower 32 bits of a 64-bit shared memory cookie * a3 Offset of the struct optee_msg_arg in the shared memory with the @@ -175,6 +176,8 @@ struct optee_smc_call_get_os_revision_result { OPTEE_SMC_STD_CALL_VAL(OPTEE_SMC_FUNCID_CALL_WITH_RPC_ARG) #define OPTEE_SMC_CALL_WITH_REGD_ARG \ OPTEE_SMC_STD_CALL_VAL(OPTEE_SMC_FUNCID_CALL_WITH_REGD_ARG) +#define OPTEE_SMC_CALL_SYSTEM_WITH_REGD_ARG \ + OPTEE_SMC_STD_CALL_VAL(OPTEE_SMC_FUNCID_CALL_SYSTEM_WITH_REGD_ARG)
/* * Get Shared Memory Config @@ -254,6 +257,8 @@ struct optee_smc_get_shm_config_result { #define OPTEE_SMC_SEC_CAP_ASYNC_NOTIF BIT(5) /* Secure world supports pre-allocating RPC arg struct */ #define OPTEE_SMC_SEC_CAP_RPC_ARG BIT(6) +/* Secure world provisions thread for system service invocation */ +#define OPTEE_SMC_SEC_CAP_SYSTEM_THREAD BIT(7)
#define OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES 9 #define OPTEE_SMC_EXCHANGE_CAPABILITIES \ @@ -426,6 +431,55 @@ struct optee_smc_disable_shm_cache_result { /* See OPTEE_SMC_CALL_WITH_REGD_ARG above */ #define OPTEE_SMC_FUNCID_CALL_WITH_REGD_ARG 19
+/* See OPTEE_SMC_CALL_SYSTEM_WITH_REGD_ARG above */ +#define OPTEE_SMC_FUNCID_CALL_SYSTEM_WITH_REGD_ARG 20 + +/* + * Request reservation of a system invocation thread context in OP-TEE + * + * Call register usage: + * a0 SMC Function ID: OPTEE_SMC_CALL_RESERVE_SYS_THREAD + * a1-6 Not used + * a7 Hypervisor Client ID register + * + * Normal return register usage: + * a0 Return value, OPTEE_SMC_RETURN_* + * a1-3 Not used + * a4-7 Preserved + * + * Possible return values: + * OPTEE_SMC_RETURN_UNKNOWN_FUNCTION Trusted OS does not recognize this + * function. + * OPTEE_SMC_RETURN_OK Call successfully completed. + * OPTEE_SMC_RETURN_ETHREAD_LIMIT Number of Trusted OS threads exceeded + * for the request. + */ +#define OPTEE_SMC_FUNCID_CALL_RESERVE_SYS_THREAD 21 +#define OPTEE_SMC_CALL_RESERVE_SYS_THREAD \ + OPTEE_SMC_STD_CALL_VAL(OPTEE_SMC_FUNCID_CALL_RESERVE_SYS_THREAD) + +/* + * Unregister reservation of a system invocation thread context in OP-TEE + * + * Call register usage: + * a0 SMC Function ID: OPTEE_SMC_CALL_UNRESERVE_SYS_THREAD + * a1-6 Not used + * a7 Hypervisor Client ID register + * + * Normal return register usage: + * a0 Return value, OPTEE_SMC_RETURN_* + * a1-3 Not used + * a4-7 Preserved + * + * Possible return values: + * OPTEE_SMC_RETURN_UNKNOWN_FUNCTION Trusted OS does not recognize this + * function. + * OPTEE_SMC_RETURN_OK Call successfully completed. + */ +#define OPTEE_SMC_FUNCID_CALL_UNRESERVE_SYS_THREAD 22 +#define OPTEE_SMC_CALL_UNRESERVE_SYS_THREAD \ + OPTEE_SMC_STD_CALL_VAL(OPTEE_SMC_FUNCID_CALL_UNRESERVE_SYS_THREAD) + /* * Resume from RPC (for example after processing a foreign interrupt) * diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index a1c1fa1a9c28..013b5ae31c0e 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -889,7 +889,10 @@ static int optee_smc_do_call_with_arg(struct tee_context *ctx, }
if (rpc_arg && tee_shm_is_dynamic(shm)) { - param.a0 = OPTEE_SMC_CALL_WITH_REGD_ARG; + if (ctx->system_ctx_count) + param.a0 = OPTEE_SMC_CALL_SYSTEM_WITH_REGD_ARG; + else + param.a0 = OPTEE_SMC_CALL_WITH_REGD_ARG; reg_pair_from_64(¶m.a1, ¶m.a2, (u_long)shm); param.a3 = offs; } else { @@ -1085,6 +1088,33 @@ static int optee_smc_open(struct tee_context *ctx) return optee_open(ctx, sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL); }
+static int optee_request_sys_ctx(struct tee_context *ctx) +{ + struct optee *optee = tee_get_drvdata(ctx->teedev); + struct arm_smccc_res res; + + if (!(optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_SYSTEM_THREAD)) + return -EINVAL; + + optee->smc.invoke_fn(OPTEE_SMC_CALL_RESERVE_SYS_THREAD, + 0, 0, 0, 0, 0, 0, 0, &res); + + if (res.a0 != OPTEE_SMC_RETURN_OK) + return -EINVAL; + + return 0; +} + +static void optee_release_sys_ctx(struct tee_context *ctx) +{ + struct optee *optee = tee_get_drvdata(ctx->teedev); + struct arm_smccc_res res; + + if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_SYSTEM_THREAD) + optee->smc.invoke_fn(OPTEE_SMC_CALL_UNRESERVE_SYS_THREAD, + 0, 0, 0, 0, 0, 0, 0, &res); +} + static const struct tee_driver_ops optee_clnt_ops = { .get_version = optee_get_version, .open = optee_smc_open, @@ -1095,6 +1125,8 @@ static const struct tee_driver_ops optee_clnt_ops = { .cancel_req = optee_cancel_req, .shm_register = optee_shm_register, .shm_unregister = optee_shm_unregister, + .system_ctx_request = optee_request_sys_ctx, + .system_ctx_release = optee_release_sys_ctx, };
static const struct tee_desc optee_clnt_desc = { diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index 98da206cd761..a7dfdea5d85b 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -5,6 +5,7 @@
#define pr_fmt(fmt) "%s: " fmt, __func__
+#include <linux/bug.h> #include <linux/cdev.h> #include <linux/cred.h> #include <linux/fs.h> @@ -1141,10 +1142,39 @@ EXPORT_SYMBOL_GPL(tee_client_open_context);
void tee_client_close_context(struct tee_context *ctx) { + while (ctx->system_ctx_count) + tee_client_release_system_context(ctx); + teedev_close_context(ctx); } EXPORT_SYMBOL_GPL(tee_client_close_context);
+int tee_client_request_system_context(struct tee_context *ctx) +{ + int ret; + + if (!ctx->teedev->desc->ops->system_ctx_request || + !ctx->teedev->desc->ops->system_ctx_release) + return -EINVAL; + + ret = ctx->teedev->desc->ops->system_ctx_request(ctx); + if (!ret) + ctx->system_ctx_count++; + + return ret; +} +EXPORT_SYMBOL_GPL(tee_client_request_system_context); + +void tee_client_release_system_context(struct tee_context *ctx) +{ + if (ctx->system_ctx_count && + ctx->teedev->desc->ops->system_ctx_release) { + ctx->teedev->desc->ops->system_ctx_release(ctx); + ctx->system_ctx_count--; + } +} +EXPORT_SYMBOL_GPL(tee_client_release_system_context); + void tee_client_get_version(struct tee_context *ctx, struct tee_ioctl_version_data *vers) { diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h index 17eb1c5205d3..45577256bb71 100644 --- a/include/linux/tee_drv.h +++ b/include/linux/tee_drv.h @@ -47,6 +47,8 @@ struct tee_shm_pool; * non-blocking in nature. * @cap_memref_null: flag indicating if the TEE Client support shared * memory buffer with a NULL pointer. + * @system_ctx_count: Number of system invocation contexts provisioned for + * this TEE client or 0. */ struct tee_context { struct tee_device *teedev; @@ -55,6 +57,7 @@ struct tee_context { bool releasing; bool supp_nowait; bool cap_memref_null; + unsigned int system_ctx_count; };
struct tee_param_memref { @@ -90,6 +93,8 @@ struct tee_param { * @supp_send: called for supplicant to send a response * @shm_register: register shared memory buffer in TEE * @shm_unregister: unregister shared memory buffer in TEE + * @system_ctx_request: Request provisioning of a new system context in TEE + * @system_ctx_release: Release a provisioned system context in TEE */ struct tee_driver_ops { void (*get_version)(struct tee_device *teedev, @@ -112,6 +117,8 @@ struct tee_driver_ops { struct page **pages, size_t num_pages, unsigned long start); int (*shm_unregister)(struct tee_context *ctx, struct tee_shm *shm); + int (*system_ctx_request)(struct tee_context *ctx); + void (*system_ctx_release)(struct tee_context *ctx); };
/** @@ -397,6 +404,20 @@ tee_client_open_context(struct tee_context *start, */ void tee_client_close_context(struct tee_context *ctx);
+/** + * tee_client_request_system_context() - Close a TEE context + * @ctx: TEE context to close + * + * @return 0 on success else an error code + */ +int tee_client_request_system_context(struct tee_context *ctx); + +/** + * tee_client_release_system_context() - Release a reserved system exec context + * @ctx: TEE context reference + */ +void tee_client_release_system_context(struct tee_context *ctx); + /** * tee_client_get_version() - Query version of TEE * @ctx: TEE context to TEE to query