linux/drivers/tee/optee/call.c
Jens Wiklander 4fb0a5eb36 tee: add OP-TEE driver
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 <dannenberg@ti.com>
Tested-by: Jerome Forissier <jerome.forissier@linaro.org> (HiKey)
Tested-by: Volodymyr Babchuk <vlad.babchuk@gmail.com> (RCAR H3)
Tested-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2017-03-10 14:51:52 +01:00

445 lines
11 KiB
C

/*
* 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(&param.a1, &param.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, &param);
} 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);
}