Commit 4fb0a5eb authored by Jens Wiklander's avatar Jens Wiklander

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: default avatarAndreas 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: default avatarScott Branden <scott.branden@broadcom.com>
Reviewed-by: default avatarJavier González <javier@javigon.com>
Signed-off-by: default avatarJens Wiklander <jens.wiklander@linaro.org>
parent 967c9cca
...@@ -9369,6 +9369,11 @@ F: arch/*/oprofile/ ...@@ -9369,6 +9369,11 @@ F: arch/*/oprofile/
F: drivers/oprofile/ F: drivers/oprofile/
F: include/linux/oprofile.h F: include/linux/oprofile.h
OP-TEE DRIVER
M: Jens Wiklander <jens.wiklander@linaro.org>
S: Maintained
F: drivers/tee/optee/
ORACLE CLUSTER FILESYSTEM 2 (OCFS2) ORACLE CLUSTER FILESYSTEM 2 (OCFS2)
M: Mark Fasheh <mfasheh@versity.com> M: Mark Fasheh <mfasheh@versity.com>
M: Joel Becker <jlbec@evilplan.org> M: Joel Becker <jlbec@evilplan.org>
......
...@@ -6,3 +6,13 @@ config TEE ...@@ -6,3 +6,13 @@ config TEE
help help
This implements a generic interface towards a Trusted Execution This implements a generic interface towards a Trusted Execution
Environment (TEE). Environment (TEE).
if TEE
menu "TEE drivers"
source "drivers/tee/optee/Kconfig"
endmenu
endif
...@@ -2,3 +2,4 @@ obj-$(CONFIG_TEE) += tee.o ...@@ -2,3 +2,4 @@ obj-$(CONFIG_TEE) += tee.o
tee-objs += tee_core.o tee-objs += tee_core.o
tee-objs += tee_shm.o tee-objs += tee_shm.o
tee-objs += tee_shm_pool.o tee-objs += tee_shm_pool.o
obj-$(CONFIG_OPTEE) += optee/
# OP-TEE Trusted Execution Environment Configuration
config OPTEE
tristate "OP-TEE"
depends on HAVE_ARM_SMCCC
help
This implements the OP-TEE Trusted Execution Environment (TEE)
driver.
obj-$(CONFIG_OPTEE) += optee.o
optee-objs += core.o
optee-objs += call.o
optee-objs += rpc.o
optee-objs += supp.o
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/*
* 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.
*
*/
#ifndef OPTEE_PRIVATE_H
#define OPTEE_PRIVATE_H
#include <linux/arm-smccc.h>
#include <linux/semaphore.h>
#include <linux/tee_drv.h>
#include <linux/types.h>
#include "optee_msg.h"
#define OPTEE_MAX_ARG_SIZE 1024
/* Some Global Platform error codes used in this driver */
#define TEEC_SUCCESS 0x00000000
#define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006
#define TEEC_ERROR_COMMUNICATION 0xFFFF000E
#define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C
#define TEEC_ORIGIN_COMMS 0x00000002
typedef void (optee_invoke_fn)(unsigned long, unsigned long, unsigned long,
unsigned long, unsigned long, unsigned long,
unsigned long, unsigned long,
struct arm_smccc_res *);
struct optee_call_queue {
/* Serializes access to this struct */
struct mutex mutex;
struct list_head waiters;
};
struct optee_wait_queue {
/* Serializes access to this struct */
struct mutex mu;
struct list_head db;
};
/**
* struct optee_supp - supplicant synchronization struct
* @ctx the context of current connected supplicant.
* if !NULL the supplicant device is available for use,
* else busy
* @ctx_mutex: held while accessing @ctx
* @func: supplicant function id to call
* @ret: call return value
* @num_params: number of elements in @param
* @param: parameters for @func
* @req_posted: if true, a request has been posted to the supplicant
* @supp_next_send: if true, next step is for supplicant to send response
* @thrd_mutex: held by the thread doing a request to supplicant
* @supp_mutex: held by supplicant while operating on this struct
* @data_to_supp: supplicant is waiting on this for next request
* @data_from_supp: requesting thread is waiting on this to get the result
*/
struct optee_supp {
struct tee_context *ctx;
/* Serializes access of ctx */
struct mutex ctx_mutex;
u32 func;
u32 ret;
size_t num_params;
struct tee_param *param;
bool req_posted;
bool supp_next_send;
/* Serializes access to this struct for requesting thread */
struct mutex thrd_mutex;
/* Serializes access to this struct for supplicant threads */
struct mutex supp_mutex;
struct completion data_to_supp;
struct completion data_from_supp;
};
/**
* struct optee - main service struct
* @supp_teedev: supplicant device
* @teedev: client device
* @invoke_fn: function to issue smc or hvc
* @call_queue: queue of threads waiting to call @invoke_fn
* @wait_queue: queue of threads from secure world waiting for a
* secure world sync object
* @supp: supplicant synchronization struct for RPC to supplicant
* @pool: shared memory pool
* @memremaped_shm virtual address of memory in shared memory pool
*/
struct optee {
struct tee_device *supp_teedev;
struct tee_device *teedev;
optee_invoke_fn *invoke_fn;
struct optee_call_queue call_queue;
struct optee_wait_queue wait_queue;
struct optee_supp supp;
struct tee_shm_pool *pool;
void *memremaped_shm;
};
struct optee_session {
struct list_head list_node;
u32 session_id;
};
struct optee_context_data {
/* Serializes access to this struct */
struct mutex mutex;
struct list_head sess_list;
};
struct optee_rpc_param {
u32 a0;
u32 a1;
u32 a2;
u32 a3;
u32 a4;
u32 a5;
u32 a6;
u32 a7;
};
void optee_handle_rpc(struct tee_context *ctx, struct optee_rpc_param *param);
void optee_wait_queue_init(struct optee_wait_queue *wq);
void optee_wait_queue_exit(struct optee_wait_queue *wq);
u32 optee_supp_thrd_req(struct tee_context *ctx, u32 func, size_t num_params,
struct tee_param *param);
int optee_supp_read(struct tee_context *ctx, void __user *buf, size_t len);
int optee_supp_write(struct tee_context *ctx, void __user *buf, size_t len);
void optee_supp_init(struct optee_supp *supp);
void optee_supp_uninit(struct optee_supp *supp);
int optee_supp_recv(struct tee_context *ctx, u32 *func, u32 *num_params,
struct tee_param *param);
int optee_supp_send(struct tee_context *ctx, u32 ret, u32 num_params,
struct tee_param *param);
u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg);
int optee_open_session(struct tee_context *ctx,
struct tee_ioctl_open_session_arg *arg,
struct tee_param *param);
int optee_close_session(struct tee_context *ctx, u32 session);
int optee_invoke_func(struct tee_context *ctx, struct tee_ioctl_invoke_arg *arg,
struct tee_param *param);
int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session);
void optee_enable_shm_cache(struct optee *optee);
void optee_disable_shm_cache(struct optee *optee);
int optee_from_msg_param(struct tee_param *params, size_t num_params,
const struct optee_msg_param *msg_params);
int optee_to_msg_param(struct optee_msg_param *msg_params, size_t num_params,
const struct tee_param *params);
/*
* Small helpers
*/
static inline void *reg_pair_to_ptr(u32 reg0, u32 reg1)
{
return (void *)(unsigned long)(((u64)reg0 << 32) | reg1);
}
static inline void reg_pair_from_64(u32 *reg0, u32 *reg1, u64 val)
{
*reg0 = val >> 32;
*reg1 = val;
}
#endif /*OPTEE_PRIVATE_H*/
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/*
* Copyright (c) 2015-2016, 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.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
#include "optee_private.h"
#include "optee_smc.h"
struct wq_entry {
struct list_head link;
struct completion c;
u32 key;
};
void optee_wait_queue_init(struct optee_wait_queue *priv)
{
mutex_init(&priv->mu);
INIT_LIST_HEAD(&priv->db);
}
void optee_wait_queue_exit(struct optee_wait_queue *priv)
{
mutex_destroy(&priv->mu);
}
static void handle_rpc_func_cmd_get_time(struct optee_msg_arg *arg)
{
struct timespec64 ts;
if (arg->num_params != 1)
goto bad;
if ((arg->params[0].attr & OPTEE_MSG_ATTR_TYPE_MASK) !=
OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT)
goto bad;
getnstimeofday64(&ts);
arg->params[0].u.value.a = ts.tv_sec;
arg->params[0].u.value.b = ts.tv_nsec;
arg->ret = TEEC_SUCCESS;
return;
bad:
arg->ret = TEEC_ERROR_BAD_PARAMETERS;
}
static struct wq_entry *wq_entry_get(struct optee_wait_queue *wq, u32 key)
{
struct wq_entry *w;
mutex_lock(&wq->mu);
list_for_each_entry(w, &wq->db, link)
if (w->key == key)
goto out;
w = kmalloc(sizeof(*w), GFP_KERNEL);
if (w) {
init_completion(&w->c);
w->key = key;
list_add_tail(&w->link, &wq->db);
}
out:
mutex_unlock(&wq->mu);
return w;
}
static void wq_sleep(struct optee_wait_queue *wq, u32 key)
{
struct wq_entry *w = wq_entry_get(wq, key);
if (w) {
wait_for_completion(&w->c);
mutex_lock(&wq->mu);
list_del(&w->link);
mutex_unlock(&wq->mu);
kfree(w);
}
}
static void wq_wakeup(struct optee_wait_queue *wq, u32 key)
{
struct wq_entry *w = wq_entry_get(wq, key);
if (w)
complete(&w->c);
}
static void handle_rpc_func_cmd_wq(struct optee *optee,
struct optee_msg_arg *arg)
{
if (arg->num_params != 1)
goto bad;
if ((arg->params[0].attr & OPTEE_MSG_ATTR_TYPE_MASK) !=
OPTEE_MSG_ATTR_TYPE_VALUE_INPUT)
goto bad;
switch (arg->params[0].u.value.a) {
case OPTEE_MSG_RPC_WAIT_QUEUE_SLEEP:
wq_sleep(&optee->wait_queue, arg->params[0].u.value.b);
break;
case OPTEE_MSG_RPC_WAIT_QUEUE_WAKEUP:
wq_wakeup(&optee->wait_queue, arg->params[0].u.value.b);
break;
default:
goto bad;
}
arg->ret = TEEC_SUCCESS;
return;
bad:
arg->ret = TEEC_ERROR_BAD_PARAMETERS;
}
static void handle_rpc_func_cmd_wait(struct optee_msg_arg *arg)
{
u32 msec_to_wait;
if (arg->num_params != 1)
goto bad;
if ((arg->params[0].attr & OPTEE_MSG_ATTR_TYPE_MASK) !=
OPTEE_MSG_ATTR_TYPE_VALUE_INPUT)
goto bad;
msec_to_wait = arg->params[0].u.value.a;
/* set task's state to interruptible sleep */
set_current_state(TASK_INTERRUPTIBLE);
/* take a nap */
msleep(msec_to_wait);
arg->ret = TEEC_SUCCESS;
return;
bad:
arg->ret = TEEC_ERROR_BAD_PARAMETERS;
}
static void handle_rpc_supp_cmd(struct tee_context *ctx,
struct optee_msg_arg *arg)
{
struct tee_param *params;
arg->ret_origin = TEEC_ORIGIN_COMMS;
params = kmalloc_array(arg->num_params, sizeof(struct tee_param),
GFP_KERNEL);
if (!params) {
arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
return;
}
if (optee_from_msg_param(params, arg->num_params, arg->params)) {
arg->ret = TEEC_ERROR_BAD_PARAMETERS;
goto out;
}
arg->ret = optee_supp_thrd_req(ctx, arg->cmd, arg->num_params, params);
if (optee_to_msg_param(arg->params, arg->num_params, params))
arg->ret = TEEC_ERROR_BAD_PARAMETERS;
out:
kfree(params);
}
static struct tee_shm *cmd_alloc_suppl(struct tee_context *ctx, size_t sz)
{
u32 ret;
struct tee_param param;
struct optee *optee = tee_get_drvdata(ctx->teedev);
struct tee_shm *shm;
param.attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT;
param.u.value.a = OPTEE_MSG_RPC_SHM_TYPE_APPL;
param.u.value.b = sz;
param.u.value.c = 0;
ret = optee_supp_thrd_req(ctx, OPTEE_MSG_RPC_CMD_SHM_ALLOC, 1, &param);
if (ret)
return ERR_PTR(-ENOMEM);
mutex_lock(&optee->supp.ctx_mutex);
/* Increases count as secure world doesn't have a reference */
shm = tee_shm_get_from_id(optee->supp.ctx, param.u.value.c);
mutex_unlock(&optee->supp.ctx_mutex);
return shm;
}
static void handle_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
struct optee_msg_arg *arg)
{
phys_addr_t pa;
struct tee_shm *shm;
size_t sz;
size_t n;
arg->ret_origin = TEEC_ORIGIN_COMMS;
if (!arg->num_params ||
arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
arg->ret = TEEC_ERROR_BAD_PARAMETERS;
return;
}
for (n = 1; n < arg->num_params; n++) {
if (arg->params[n].attr != OPTEE_MSG_ATTR_TYPE_NONE) {
arg->ret = TEEC_ERROR_BAD_PARAMETERS;
return;
}
}
sz = arg->params[0].u.value.b;
switch (arg->params[0].u.value.a) {
case OPTEE_MSG_RPC_SHM_TYPE_APPL:
shm = cmd_alloc_suppl(ctx, sz);
break;
case OPTEE_MSG_RPC_SHM_TYPE_KERNEL:
shm = tee_shm_alloc(ctx, sz, TEE_SHM_MAPPED);
break;
default:
arg->ret = TEEC_ERROR_BAD_PARAMETERS;
return;
}
if (IS_ERR(shm)) {
arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
return;
}
if (tee_shm_get_pa(shm, 0, &pa)) {
arg->ret = TEEC_ERROR_BAD_PARAMETERS;
goto bad;
}
arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT;
arg->params[0].u.tmem.buf_ptr = pa;
arg->params[0].u.tmem.size = sz;
arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
arg->ret = TEEC_SUCCESS;
return;
bad:
tee_shm_free(shm);
}
static void cmd_free_suppl(struct tee_context *ctx, struct tee_shm *shm)
{
struct tee_param param;
param.attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT;
param.u.value.a = OPTEE_MSG_RPC_SHM_TYPE_APPL;
param.u.value.b = tee_shm_get_id(shm);
param.u.value.c = 0;
/*
* Match the tee_shm_get_from_id() in cmd_alloc_suppl() as secure
* world has released its reference.
*
* It's better to do this before sending the request to supplicant
* as we'd like to let the process doing the initial allocation to
* do release the last reference too in order to avoid stacking
* many pending fput() on the client process. This could otherwise
* happen if secure world does many allocate and free in a single
* invoke.
*/
tee_shm_put(shm);
optee_supp_thrd_req(ctx, OPTEE_MSG_RPC_CMD_SHM_FREE, 1, &param);
}
static void handle_rpc_func_cmd_shm_free(struct tee_context *ctx,
struct optee_msg_arg *arg)
{
struct tee_shm *shm;
arg->ret_origin = TEEC_ORIGIN_COMMS;
if (arg->num_params != 1 ||
arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
arg->ret = TEEC_ERROR_BAD_PARAMETERS;
return;
}
shm = (struct tee_shm *)(unsigned long)arg->params[0].u.value.b;
switch (arg->params[0].u.value.a) {
case OPTEE_MSG_RPC_SHM_TYPE_APPL:
cmd_free_suppl(ctx, shm);
break;
case OPTEE_MSG_RPC_SHM_TYPE_KERNEL:
tee_shm_free(shm);
break;
default:
arg->ret = TEEC_ERROR_BAD_PARAMETERS;
}
arg->ret = TEEC_SUCCESS;
}
static void handle_rpc_func_cmd(struct tee_context *ctx, struct optee *optee,
struct tee_shm *shm)
{
struct optee_msg_arg *arg;
arg = tee_shm_get_va(shm, 0);
if (IS_ERR(arg)) {
pr_err("%s: tee_shm_get_va %p failed\n", __func__, shm);
return;
}
switch (arg->cmd) {
case OPTEE_MSG_RPC_CMD_GET_TIME:
handle_rpc_func_cmd_get_time(arg);
break;
case OPTEE_MSG_RPC_CMD_WAIT_QUEUE:
handle_rpc_func_cmd_wq(optee, arg);
break;
case OPTEE_MSG_RPC_CMD_SUSPEND:
handle_rpc_func_cmd_wait(arg);
break;
case OPTEE_MSG_RPC_CMD_SHM_ALLOC:
handle_rpc_func_cmd_shm_alloc(ctx, arg);
break;
case OPTEE_MSG_RPC_CMD_SHM_FREE:
handle_rpc_func_cmd_shm_free(ctx, arg);
break;
default:
handle_rpc_supp_cmd(ctx, arg);
}
}
/**
* optee_handle_rpc() - handle RPC from secure world
* @ctx: context doing the RPC
* @param: value of registers for the RPC
*
* Result of RPC is written back into @param.
*/
void optee_handle_rpc(struct tee_context *ctx, struct optee_rpc_param *param)
{
struct tee_device *teedev = ctx->teedev;
struct optee *optee = tee_get_drvdata(teedev);
struct tee_shm *shm;
phys_addr_t pa;
switch (OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0)) {
case OPTEE_SMC_RPC_FUNC_ALLOC:
shm = tee_shm_alloc(ctx, param->a1, TEE_SHM_MAPPED);
if (!IS_ERR(shm) && !tee_shm_get_pa(shm, 0, &pa)) {
reg_pair_from_64(&param->a1, &param->a2, pa);
reg_pair_from_64(&param->a4, &param->a5,
(unsigned long)shm);
} else {
param->a1 = 0;
param->a2 = 0;
param->a4 = 0;
param->a5 = 0;
}
break;
case OPTEE_SMC_RPC_FUNC_FREE:
shm = reg_pair_to_ptr(param->a1, param->a2);
tee_shm_free(shm);
break;
case OPTEE_SMC_RPC_FUNC_IRQ:
/*
* An IRQ was raised while secure world was executing,
* since all IRQs are handled in Linux a dummy RPC is
* performed to let Linux take the IRQ through the normal
* vector.
*/
break;
case OPTEE_SMC_RPC_FUNC_CMD:
shm = reg_pair_to_ptr(param->a1, param->a2);
handle_rpc_func_cmd(ctx, optee, shm);
break;
default:
pr_warn("Unknown RPC func 0x%x\n",
(u32)OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0));
break;
}
param->a0 = OPTEE_SMC_CALL_RETURN_FROM_RPC;
}
/*
* 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/device.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#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;
}
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