From 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2 Mon Sep 17 00:00:00 2001 From: Jens Wiklander Date: Tue, 14 Apr 2015 14:33:20 +0200 Subject: tee: add OP-TEE driver MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Adds a OP-TEE driver which also can be compiled as a loadable module. * Targets ARM and ARM64 * Supports using reserved memory from OP-TEE as shared memory * Probes OP-TEE version using SMCs * Accepts requests on privileged and unprivileged device * Uses OPTEE message protocol version 2 to communicate with secure world Acked-by: Andreas Dannenberg Tested-by: Jerome Forissier (HiKey) Tested-by: Volodymyr Babchuk (RCAR H3) Tested-by: Scott Branden Reviewed-by: Javier González Signed-off-by: Jens Wiklander --- drivers/tee/optee/supp.c | 273 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 273 insertions(+) create mode 100644 drivers/tee/optee/supp.c (limited to 'drivers/tee/optee/supp.c') diff --git a/drivers/tee/optee/supp.c b/drivers/tee/optee/supp.c new file mode 100644 index 000000000000..b4ea0678a436 --- /dev/null +++ b/drivers/tee/optee/supp.c @@ -0,0 +1,273 @@ +/* + * Copyright (c) 2015, Linaro Limited + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ +#include +#include +#include +#include "optee_private.h" + +void optee_supp_init(struct optee_supp *supp) +{ + memset(supp, 0, sizeof(*supp)); + mutex_init(&supp->ctx_mutex); + mutex_init(&supp->thrd_mutex); + mutex_init(&supp->supp_mutex); + init_completion(&supp->data_to_supp); + init_completion(&supp->data_from_supp); +} + +void optee_supp_uninit(struct optee_supp *supp) +{ + mutex_destroy(&supp->ctx_mutex); + mutex_destroy(&supp->thrd_mutex); + mutex_destroy(&supp->supp_mutex); +} + +/** + * optee_supp_thrd_req() - request service from supplicant + * @ctx: context doing the request + * @func: function requested + * @num_params: number of elements in @param array + * @param: parameters for function + * + * Returns result of operation to be passed to secure world + */ +u32 optee_supp_thrd_req(struct tee_context *ctx, u32 func, size_t num_params, + struct tee_param *param) +{ + bool interruptable; + struct optee *optee = tee_get_drvdata(ctx->teedev); + struct optee_supp *supp = &optee->supp; + u32 ret; + + /* + * Other threads blocks here until we've copied our answer from + * supplicant. + */ + while (mutex_lock_interruptible(&supp->thrd_mutex)) { + /* See comment below on when the RPC can be interrupted. */ + mutex_lock(&supp->ctx_mutex); + interruptable = !supp->ctx; + mutex_unlock(&supp->ctx_mutex); + if (interruptable) + return TEEC_ERROR_COMMUNICATION; + } + + /* + * We have exclusive access now since the supplicant at this + * point is either doing a + * wait_for_completion_interruptible(&supp->data_to_supp) or is in + * userspace still about to do the ioctl() to enter + * optee_supp_recv() below. + */ + + supp->func = func; + supp->num_params = num_params; + supp->param = param; + supp->req_posted = true; + + /* Let supplicant get the data */ + complete(&supp->data_to_supp); + + /* + * Wait for supplicant to process and return result, once we've + * returned from wait_for_completion(data_from_supp) we have + * exclusive access again. + */ + while (wait_for_completion_interruptible(&supp->data_from_supp)) { + mutex_lock(&supp->ctx_mutex); + interruptable = !supp->ctx; + if (interruptable) { + /* + * There's no supplicant available and since the + * supp->ctx_mutex currently is held none can + * become available until the mutex released + * again. + * + * Interrupting an RPC to supplicant is only + * allowed as a way of slightly improving the user + * experience in case the supplicant hasn't been + * started yet. During normal operation the supplicant + * will serve all requests in a timely manner and + * interrupting then wouldn't make sense. + */ + supp->ret = TEEC_ERROR_COMMUNICATION; + init_completion(&supp->data_to_supp); + } + mutex_unlock(&supp->ctx_mutex); + if (interruptable) + break; + } + + ret = supp->ret; + supp->param = NULL; + supp->req_posted = false; + + /* We're done, let someone else talk to the supplicant now. */ + mutex_unlock(&supp->thrd_mutex); + + return ret; +} + +/** + * optee_supp_recv() - receive request for supplicant + * @ctx: context receiving the request + * @func: requested function in supplicant + * @num_params: number of elements allocated in @param, updated with number + * used elements + * @param: space for parameters for @func + * + * Returns 0 on success or <0 on failure + */ +int optee_supp_recv(struct tee_context *ctx, u32 *func, u32 *num_params, + struct tee_param *param) +{ + struct tee_device *teedev = ctx->teedev; + struct optee *optee = tee_get_drvdata(teedev); + struct optee_supp *supp = &optee->supp; + int rc; + + /* + * In case two threads in one supplicant is calling this function + * simultaneously we need to protect the data with a mutex which + * we'll release before returning. + */ + mutex_lock(&supp->supp_mutex); + + if (supp->supp_next_send) { + /* + * optee_supp_recv() has been called again without + * a optee_supp_send() in between. Supplicant has + * probably been restarted before it was able to + * write back last result. Abort last request and + * wait for a new. + */ + if (supp->req_posted) { + supp->ret = TEEC_ERROR_COMMUNICATION; + supp->supp_next_send = false; + complete(&supp->data_from_supp); + } + } + + /* + * This is where supplicant will be hanging most of the + * time, let's make this interruptable so we can easily + * restart supplicant if needed. + */ + if (wait_for_completion_interruptible(&supp->data_to_supp)) { + rc = -ERESTARTSYS; + goto out; + } + + /* We have exlusive access to the data */ + + if (*num_params < supp->num_params) { + /* + * Not enough room for parameters, tell supplicant + * it failed and abort last request. + */ + supp->ret = TEEC_ERROR_COMMUNICATION; + rc = -EINVAL; + complete(&supp->data_from_supp); + goto out; + } + + *func = supp->func; + *num_params = supp->num_params; + memcpy(param, supp->param, + sizeof(struct tee_param) * supp->num_params); + + /* Allow optee_supp_send() below to do its work */ + supp->supp_next_send = true; + + rc = 0; +out: + mutex_unlock(&supp->supp_mutex); + return rc; +} + +/** + * optee_supp_send() - send result of request from supplicant + * @ctx: context sending result + * @ret: return value of request + * @num_params: number of parameters returned + * @param: returned parameters + * + * Returns 0 on success or <0 on failure. + */ +int optee_supp_send(struct tee_context *ctx, u32 ret, u32 num_params, + struct tee_param *param) +{ + struct tee_device *teedev = ctx->teedev; + struct optee *optee = tee_get_drvdata(teedev); + struct optee_supp *supp = &optee->supp; + size_t n; + int rc = 0; + + /* + * We still have exclusive access to the data since that's how we + * left it when returning from optee_supp_read(). + */ + + /* See comment on mutex in optee_supp_read() above */ + mutex_lock(&supp->supp_mutex); + + if (!supp->supp_next_send) { + /* + * Something strange is going on, supplicant shouldn't + * enter optee_supp_send() in this state + */ + rc = -ENOENT; + goto out; + } + + if (num_params != supp->num_params) { + /* + * Something is wrong, let supplicant restart. Next call to + * optee_supp_recv() will give an error to the requesting + * thread and release it. + */ + rc = -EINVAL; + goto out; + } + + /* Update out and in/out parameters */ + for (n = 0; n < num_params; n++) { + struct tee_param *p = supp->param + n; + + switch (p->attr) { + case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT: + case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT: + p->u.value.a = param[n].u.value.a; + p->u.value.b = param[n].u.value.b; + p->u.value.c = param[n].u.value.c; + break; + case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT: + case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT: + p->u.memref.size = param[n].u.memref.size; + break; + default: + break; + } + } + supp->ret = ret; + + /* Allow optee_supp_recv() above to do its work */ + supp->supp_next_send = false; + + /* Let the requesting thread continue */ + complete(&supp->data_from_supp); +out: + mutex_unlock(&supp->supp_mutex); + return rc; +} -- cgit v1.2.3