diff options
Diffstat (limited to 'drivers/tee/optee/call.c')
| -rw-r--r-- | drivers/tee/optee/call.c | 444 |
1 files changed, 444 insertions, 0 deletions
diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c new file mode 100644 index 0000000000000..f7b7b404c990b --- /dev/null +++ b/drivers/tee/optee/call.c @@ -0,0 +1,444 @@ +/* + * 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 <linux/arm-smccc.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/tee_drv.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#include "optee_private.h" +#include "optee_smc.h" + +struct optee_call_waiter { + struct list_head list_node; + struct completion c; +}; + +static void optee_cq_wait_init(struct optee_call_queue *cq, + struct optee_call_waiter *w) +{ + /* + * We're preparing to make a call to secure world. In case we can't + * allocate a thread in secure world we'll end up waiting in + * optee_cq_wait_for_completion(). + * + * Normally if there's no contention in secure world the call will + * complete and we can cleanup directly with optee_cq_wait_final(). + */ + mutex_lock(&cq->mutex); + + /* + * We add ourselves to the queue, but we don't wait. This + * guarantees that we don't lose a completion if secure world + * returns busy and another thread just exited and try to complete + * someone. + */ + init_completion(&w->c); + list_add_tail(&w->list_node, &cq->waiters); + + mutex_unlock(&cq->mutex); +} + +static void optee_cq_wait_for_completion(struct optee_call_queue *cq, + struct optee_call_waiter *w) +{ + wait_for_completion(&w->c); + + mutex_lock(&cq->mutex); + + /* Move to end of list to get out of the way for other waiters */ + list_del(&w->list_node); + reinit_completion(&w->c); + list_add_tail(&w->list_node, &cq->waiters); + + mutex_unlock(&cq->mutex); +} + +static void optee_cq_complete_one(struct optee_call_queue *cq) +{ + struct optee_call_waiter *w; + + list_for_each_entry(w, &cq->waiters, list_node) { + if (!completion_done(&w->c)) { + complete(&w->c); + break; + } + } +} + +static void optee_cq_wait_final(struct optee_call_queue *cq, + struct optee_call_waiter *w) +{ + /* + * We're done with the call to secure world. The thread in secure + * world that was used for this call is now available for some + * other task to use. + */ + mutex_lock(&cq->mutex); + + /* Get out of the list */ + list_del(&w->list_node); + + /* Wake up one eventual waiting task */ + optee_cq_complete_one(cq); + + /* + * If we're completed we've got a completion from another task that + * was just done with its call to secure world. Since yet another + * thread now is available in secure world wake up another eventual + * waiting task. + */ + if (completion_done(&w->c)) + optee_cq_complete_one(cq); + + mutex_unlock(&cq->mutex); +} + +/* Requires the filpstate mutex to be held */ +static struct optee_session *find_session(struct optee_context_data *ctxdata, + u32 session_id) +{ + struct optee_session *sess; + + list_for_each_entry(sess, &ctxdata->sess_list, list_node) + if (sess->session_id == session_id) + return sess; + + return NULL; +} + +/** + * optee_do_call_with_arg() - Do an SMC to OP-TEE in secure world + * @ctx: calling context + * @parg: physical address of message to pass to secure world + * + * Does and SMC to OP-TEE in secure world and handles eventual resulting + * Remote Procedure Calls (RPC) from OP-TEE. + * + * Returns return code from secure world, 0 is OK + */ +u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg) +{ + struct optee *optee = tee_get_drvdata(ctx->teedev); + struct optee_call_waiter w; + struct optee_rpc_param param = { }; + u32 ret; + + param.a0 = OPTEE_SMC_CALL_WITH_ARG; + reg_pair_from_64(¶m.a1, ¶m.a2, parg); + /* Initialize waiter */ + optee_cq_wait_init(&optee->call_queue, &w); + while (true) { + struct arm_smccc_res res; + + optee->invoke_fn(param.a0, param.a1, param.a2, param.a3, + param.a4, param.a5, param.a6, param.a7, + &res); + + if (res.a0 == OPTEE_SMC_RETURN_ETHREAD_LIMIT) { + /* + * Out of threads in secure world, wait for a thread + * become available. + */ + optee_cq_wait_for_completion(&optee->call_queue, &w); + } else if (OPTEE_SMC_RETURN_IS_RPC(res.a0)) { + param.a0 = res.a0; + param.a1 = res.a1; + param.a2 = res.a2; + param.a3 = res.a3; + optee_handle_rpc(ctx, ¶m); + } else { + ret = res.a0; + break; + } + } + + /* + * We're done with our thread in secure world, if there's any + * thread waiters wake up one. + */ + optee_cq_wait_final(&optee->call_queue, &w); + + return ret; +} + +static struct tee_shm *get_msg_arg(struct tee_context *ctx, size_t num_params, + struct optee_msg_arg **msg_arg, + phys_addr_t *msg_parg) +{ + int rc; + struct tee_shm *shm; + struct optee_msg_arg *ma; + + shm = tee_shm_alloc(ctx, OPTEE_MSG_GET_ARG_SIZE(num_params), + TEE_SHM_MAPPED); + if (IS_ERR(shm)) + return shm; + + ma = tee_shm_get_va(shm, 0); + if (IS_ERR(ma)) { + rc = PTR_ERR(ma); + goto out; + } + + rc = tee_shm_get_pa(shm, 0, msg_parg); + if (rc) + goto out; + + memset(ma, 0, OPTEE_MSG_GET_ARG_SIZE(num_params)); + ma->num_params = num_params; + *msg_arg = ma; +out: + if (rc) { + tee_shm_free(shm); + return ERR_PTR(rc); + } + + return shm; +} + +int optee_open_session(struct tee_context *ctx, + struct tee_ioctl_open_session_arg *arg, + struct tee_param *param) +{ + struct optee_context_data *ctxdata = ctx->data; + int rc; + struct tee_shm *shm; + struct optee_msg_arg *msg_arg; + phys_addr_t msg_parg; + struct optee_session *sess = NULL; + + /* +2 for the meta parameters added below */ + shm = get_msg_arg(ctx, arg->num_params + 2, &msg_arg, &msg_parg); + if (IS_ERR(shm)) + return PTR_ERR(shm); + + msg_arg->cmd = OPTEE_MSG_CMD_OPEN_SESSION; + msg_arg->cancel_id = arg->cancel_id; + + /* + * Initialize and add the meta parameters needed when opening a + * session. + */ + msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT | + OPTEE_MSG_ATTR_META; + msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT | + OPTEE_MSG_ATTR_META; + memcpy(&msg_arg->params[0].u.value, arg->uuid, sizeof(arg->uuid)); + memcpy(&msg_arg->params[1].u.value, arg->uuid, sizeof(arg->clnt_uuid)); + msg_arg->params[1].u.value.c = arg->clnt_login; + + rc = optee_to_msg_param(msg_arg->params + 2, arg->num_params, param); + if (rc) + goto out; + + sess = kzalloc(sizeof(*sess), GFP_KERNEL); + if (!sess) { + rc = -ENOMEM; + goto out; + } + + if (optee_do_call_with_arg(ctx, msg_parg)) { + msg_arg->ret = TEEC_ERROR_COMMUNICATION; + msg_arg->ret_origin = TEEC_ORIGIN_COMMS; + } + + if (msg_arg->ret == TEEC_SUCCESS) { + /* A new session has been created, add it to the list. */ + sess->session_id = msg_arg->session; + mutex_lock(&ctxdata->mutex); + list_add(&sess->list_node, &ctxdata->sess_list); + mutex_unlock(&ctxdata->mutex); + } else { + kfree(sess); + } + + if (optee_from_msg_param(param, arg->num_params, msg_arg->params + 2)) { + arg->ret = TEEC_ERROR_COMMUNICATION; + arg->ret_origin = TEEC_ORIGIN_COMMS; + /* Close session again to avoid leakage */ + optee_close_session(ctx, msg_arg->session); + } else { + arg->session = msg_arg->session; + arg->ret = msg_arg->ret; + arg->ret_origin = msg_arg->ret_origin; + } +out: + tee_shm_free(shm); + + return rc; +} + +int optee_close_session(struct tee_context *ctx, u32 session) +{ + struct optee_context_data *ctxdata = ctx->data; + struct tee_shm *shm; + struct optee_msg_arg *msg_arg; + phys_addr_t msg_parg; + struct optee_session *sess; + + /* Check that the session is valid and remove it from the list */ + mutex_lock(&ctxdata->mutex); + sess = find_session(ctxdata, session); + if (sess) + list_del(&sess->list_node); + mutex_unlock(&ctxdata->mutex); + if (!sess) + return -EINVAL; + kfree(sess); + + shm = get_msg_arg(ctx, 0, &msg_arg, &msg_parg); + if (IS_ERR(shm)) + return PTR_ERR(shm); + + msg_arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION; + msg_arg->session = session; + optee_do_call_with_arg(ctx, msg_parg); + + tee_shm_free(shm); + return 0; +} + +int optee_invoke_func(struct tee_context *ctx, struct tee_ioctl_invoke_arg *arg, + struct tee_param *param) +{ + struct optee_context_data *ctxdata = ctx->data; + struct tee_shm *shm; + struct optee_msg_arg *msg_arg; + phys_addr_t msg_parg; + struct optee_session *sess; + int rc; + + /* Check that the session is valid */ + mutex_lock(&ctxdata->mutex); + sess = find_session(ctxdata, arg->session); + mutex_unlock(&ctxdata->mutex); + if (!sess) + return -EINVAL; + + shm = get_msg_arg(ctx, arg->num_params, &msg_arg, &msg_parg); + if (IS_ERR(shm)) + return PTR_ERR(shm); + msg_arg->cmd = OPTEE_MSG_CMD_INVOKE_COMMAND; + msg_arg->func = arg->func; + msg_arg->session = arg->session; + msg_arg->cancel_id = arg->cancel_id; + + rc = optee_to_msg_param(msg_arg->params, arg->num_params, param); + if (rc) + goto out; + + if (optee_do_call_with_arg(ctx, msg_parg)) { + msg_arg->ret = TEEC_ERROR_COMMUNICATION; + msg_arg->ret_origin = TEEC_ORIGIN_COMMS; + } + + if (optee_from_msg_param(param, arg->num_params, msg_arg->params)) { + msg_arg->ret = TEEC_ERROR_COMMUNICATION; + msg_arg->ret_origin = TEEC_ORIGIN_COMMS; + } + + arg->ret = msg_arg->ret; + arg->ret_origin = msg_arg->ret_origin; +out: + tee_shm_free(shm); + return rc; +} + +int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session) +{ + struct optee_context_data *ctxdata = ctx->data; + struct tee_shm *shm; + struct optee_msg_arg *msg_arg; + phys_addr_t msg_parg; + struct optee_session *sess; + + /* Check that the session is valid */ + mutex_lock(&ctxdata->mutex); + sess = find_session(ctxdata, session); + mutex_unlock(&ctxdata->mutex); + if (!sess) + return -EINVAL; + + shm = get_msg_arg(ctx, 0, &msg_arg, &msg_parg); + if (IS_ERR(shm)) + return PTR_ERR(shm); + + msg_arg->cmd = OPTEE_MSG_CMD_CANCEL; + msg_arg->session = session; + msg_arg->cancel_id = cancel_id; + optee_do_call_with_arg(ctx, msg_parg); + + tee_shm_free(shm); + return 0; +} + +/** + * optee_enable_shm_cache() - Enables caching of some shared memory allocation + * in OP-TEE + * @optee: main service struct + */ +void optee_enable_shm_cache(struct optee *optee) +{ + struct optee_call_waiter w; + + /* We need to retry until secure world isn't busy. */ + optee_cq_wait_init(&optee->call_queue, &w); + while (true) { + struct arm_smccc_res res; + + optee->invoke_fn(OPTEE_SMC_ENABLE_SHM_CACHE, 0, 0, 0, 0, 0, 0, + 0, &res); + if (res.a0 == OPTEE_SMC_RETURN_OK) + break; + optee_cq_wait_for_completion(&optee->call_queue, &w); + } + optee_cq_wait_final(&optee->call_queue, &w); +} + +/** + * optee_disable_shm_cache() - Disables caching of some shared memory allocation + * in OP-TEE + * @optee: main service struct + */ +void optee_disable_shm_cache(struct optee *optee) +{ + struct optee_call_waiter w; + + /* We need to retry until secure world isn't busy. */ + optee_cq_wait_init(&optee->call_queue, &w); + while (true) { + union { + struct arm_smccc_res smccc; + struct optee_smc_disable_shm_cache_result result; + } res; + + optee->invoke_fn(OPTEE_SMC_DISABLE_SHM_CACHE, 0, 0, 0, 0, 0, 0, + 0, &res.smccc); + if (res.result.status == OPTEE_SMC_RETURN_ENOTAVAIL) + break; /* All shm's freed */ + if (res.result.status == OPTEE_SMC_RETURN_OK) { + struct tee_shm *shm; + + shm = reg_pair_to_ptr(res.result.shm_upper32, + res.result.shm_lower32); + tee_shm_free(shm); + } else { + optee_cq_wait_for_completion(&optee->call_queue, &w); + } + } + optee_cq_wait_final(&optee->call_queue, &w); +} |