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>

11 files changed, 2809 insertions, 0 deletions

diff --git a/drivers/tee/Kconfig b/drivers/tee/Kconfig
index 50c244ead46d..2330a4eb4e8b 100644
--- a/drivers/tee/Kconfig
+++ b/drivers/tee/Kconfig
@@ -6,3 +6,13 @@ config TEE
 	help
 	  This implements a generic interface towards a Trusted Execution
 	  Environment (TEE).
+
+if TEE
+
+menu "TEE drivers"
+
+source "drivers/tee/optee/Kconfig"
+
+endmenu
+
+endif
diff --git a/drivers/tee/Makefile b/drivers/tee/Makefile
index ec64047a86e2..7a4e4a1ac39c 100644
--- a/drivers/tee/Makefile
+++ b/drivers/tee/Makefile
@@ -2,3 +2,4 @@ obj-$(CONFIG_TEE) += tee.o
 tee-objs += tee_core.o
 tee-objs += tee_shm.o
 tee-objs += tee_shm_pool.o
+obj-$(CONFIG_OPTEE) += optee/
diff --git a/drivers/tee/optee/Kconfig b/drivers/tee/optee/Kconfig
new file mode 100644
index 000000000000..0126de898036
--- /dev/null
+++ b/drivers/tee/optee/Kconfig
@@ -0,0 +1,7 @@
+# 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.
diff --git a/drivers/tee/optee/Makefile b/drivers/tee/optee/Makefile
new file mode 100644
index 000000000000..92fe5789bcce
--- /dev/null
+++ b/drivers/tee/optee/Makefile
@@ -0,0 +1,5 @@
+obj-$(CONFIG_OPTEE) += optee.o
+optee-objs += core.o
+optee-objs += call.o
+optee-objs += rpc.o
+optee-objs += supp.o
diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c
new file mode 100644
index 000000000000..f7b7b404c990
--- /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(&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);
+}
diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
new file mode 100644
index 000000000000..58169e519422
--- /dev/null
+++ b/drivers/tee/optee/core.c
@@ -0,0 +1,622 @@
+/*
+ * 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.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/arm-smccc.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/tee_drv.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include "optee_private.h"
+#include "optee_smc.h"
+
+#define DRIVER_NAME "optee"
+
+#define OPTEE_SHM_NUM_PRIV_PAGES	1
+
+/**
+ * optee_from_msg_param() - convert from OPTEE_MSG parameters to
+ *			    struct tee_param
+ * @params:	subsystem internal parameter representation
+ * @num_params:	number of elements in the parameter arrays
+ * @msg_params:	OPTEE_MSG parameters
+ * Returns 0 on success or <0 on failure
+ */
+int optee_from_msg_param(struct tee_param *params, size_t num_params,
+			 const struct optee_msg_param *msg_params)
+{
+	int rc;
+	size_t n;
+	struct tee_shm *shm;
+	phys_addr_t pa;
+
+	for (n = 0; n < num_params; n++) {
+		struct tee_param *p = params + n;
+		const struct optee_msg_param *mp = msg_params + n;
+		u32 attr = mp->attr & OPTEE_MSG_ATTR_TYPE_MASK;
+
+		switch (attr) {
+		case OPTEE_MSG_ATTR_TYPE_NONE:
+			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
+			memset(&p->u, 0, sizeof(p->u));
+			break;
+		case OPTEE_MSG_ATTR_TYPE_VALUE_INPUT:
+		case OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT:
+		case OPTEE_MSG_ATTR_TYPE_VALUE_INOUT:
+			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT +
+				  attr - OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
+			p->u.value.a = mp->u.value.a;
+			p->u.value.b = mp->u.value.b;
+			p->u.value.c = mp->u.value.c;
+			break;
+		case OPTEE_MSG_ATTR_TYPE_TMEM_INPUT:
+		case OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT:
+		case OPTEE_MSG_ATTR_TYPE_TMEM_INOUT:
+			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
+				  attr - OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
+			p->u.memref.size = mp->u.tmem.size;
+			shm = (struct tee_shm *)(unsigned long)
+				mp->u.tmem.shm_ref;
+			if (!shm) {
+				p->u.memref.shm_offs = 0;
+				p->u.memref.shm = NULL;
+				break;
+			}
+			rc = tee_shm_get_pa(shm, 0, &pa);
+			if (rc)
+				return rc;
+			p->u.memref.shm_offs = mp->u.tmem.buf_ptr - pa;
+			p->u.memref.shm = shm;
+
+			/* Check that the memref is covered by the shm object */
+			if (p->u.memref.size) {
+				size_t o = p->u.memref.shm_offs +
+					   p->u.memref.size - 1;
+
+				rc = tee_shm_get_pa(shm, o, NULL);
+				if (rc)
+					return rc;
+			}
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+/**
+ * optee_to_msg_param() - convert from struct tee_params to OPTEE_MSG parameters
+ * @msg_params:	OPTEE_MSG parameters
+ * @num_params:	number of elements in the parameter arrays
+ * @params:	subsystem itnernal parameter representation
+ * Returns 0 on success or <0 on failure
+ */
+int optee_to_msg_param(struct optee_msg_param *msg_params, size_t num_params,
+		       const struct tee_param *params)
+{
+	int rc;
+	size_t n;
+	phys_addr_t pa;
+
+	for (n = 0; n < num_params; n++) {
+		const struct tee_param *p = params + n;
+		struct optee_msg_param *mp = msg_params + n;
+
+		switch (p->attr) {
+		case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
+			mp->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
+			memset(&mp->u, 0, sizeof(mp->u));
+			break;
+		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
+		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
+		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
+			mp->attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT + p->attr -
+				   TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
+			mp->u.value.a = p->u.value.a;
+			mp->u.value.b = p->u.value.b;
+			mp->u.value.c = p->u.value.c;
+			break;
+		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
+		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
+		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
+			mp->attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT +
+				   p->attr -
+				   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+			mp->u.tmem.shm_ref = (unsigned long)p->u.memref.shm;
+			mp->u.tmem.size = p->u.memref.size;
+			if (!p->u.memref.shm) {
+				mp->u.tmem.buf_ptr = 0;
+				break;
+			}
+			rc = tee_shm_get_pa(p->u.memref.shm,
+					    p->u.memref.shm_offs, &pa);
+			if (rc)
+				return rc;
+			mp->u.tmem.buf_ptr = pa;
+			mp->attr |= OPTEE_MSG_ATTR_CACHE_PREDEFINED <<
+					OPTEE_MSG_ATTR_CACHE_SHIFT;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+static void optee_get_version(struct tee_device *teedev,
+			      struct tee_ioctl_version_data *vers)
+{
+	struct tee_ioctl_version_data v = {
+		.impl_id = TEE_IMPL_ID_OPTEE,
+		.impl_caps = TEE_OPTEE_CAP_TZ,
+		.gen_caps = TEE_GEN_CAP_GP,
+	};
+	*vers = v;
+}
+
+static int optee_open(struct tee_context *ctx)
+{
+	struct optee_context_data *ctxdata;
+	struct tee_device *teedev = ctx->teedev;
+	struct optee *optee = tee_get_drvdata(teedev);
+
+	ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
+	if (!ctxdata)
+		return -ENOMEM;
+
+	if (teedev == optee->supp_teedev) {
+		bool busy = true;
+
+		mutex_lock(&optee->supp.ctx_mutex);
+		if (!optee->supp.ctx) {
+			busy = false;
+			optee->supp.ctx = ctx;
+		}
+		mutex_unlock(&optee->supp.ctx_mutex);
+		if (busy) {
+			kfree(ctxdata);
+			return -EBUSY;
+		}
+	}
+
+	mutex_init(&ctxdata->mutex);
+	INIT_LIST_HEAD(&ctxdata->sess_list);
+
+	ctx->data = ctxdata;
+	return 0;
+}
+
+static void optee_release(struct tee_context *ctx)
+{
+	struct optee_context_data *ctxdata = ctx->data;
+	struct tee_device *teedev = ctx->teedev;
+	struct optee *optee = tee_get_drvdata(teedev);
+	struct tee_shm *shm;
+	struct optee_msg_arg *arg = NULL;
+	phys_addr_t parg;
+	struct optee_session *sess;
+	struct optee_session *sess_tmp;
+
+	if (!ctxdata)
+		return;
+
+	shm = tee_shm_alloc(ctx, sizeof(struct optee_msg_arg), TEE_SHM_MAPPED);
+	if (!IS_ERR(shm)) {
+		arg = tee_shm_get_va(shm, 0);
+		/*
+		 * If va2pa fails for some reason, we can't call
+		 * optee_close_session(), only free the memory. Secure OS
+		 * will leak sessions and finally refuse more sessions, but
+		 * we will at least let normal world reclaim its memory.
+		 */
+		if (!IS_ERR(arg))
+			tee_shm_va2pa(shm, arg, &parg);
+	}
+
+	list_for_each_entry_safe(sess, sess_tmp, &ctxdata->sess_list,
+				 list_node) {
+		list_del(&sess->list_node);
+		if (!IS_ERR_OR_NULL(arg)) {
+			memset(arg, 0, sizeof(*arg));
+			arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION;
+			arg->session = sess->session_id;
+			optee_do_call_with_arg(ctx, parg);
+		}
+		kfree(sess);
+	}
+	kfree(ctxdata);
+
+	if (!IS_ERR(shm))
+		tee_shm_free(shm);
+
+	ctx->data = NULL;
+
+	if (teedev == optee->supp_teedev) {
+		mutex_lock(&optee->supp.ctx_mutex);
+		optee->supp.ctx = NULL;
+		mutex_unlock(&optee->supp.ctx_mutex);
+	}
+}
+
+static struct tee_driver_ops optee_ops = {
+	.get_version = optee_get_version,
+	.open = optee_open,
+	.release = optee_release,
+	.open_session = optee_open_session,
+	.close_session = optee_close_session,
+	.invoke_func = optee_invoke_func,
+	.cancel_req = optee_cancel_req,
+};
+
+static struct tee_desc optee_desc = {
+	.name = DRIVER_NAME "-clnt",
+	.ops = &optee_ops,
+	.owner = THIS_MODULE,
+};
+
+static struct tee_driver_ops optee_supp_ops = {
+	.get_version = optee_get_version,
+	.open = optee_open,
+	.release = optee_release,
+	.supp_recv = optee_supp_recv,
+	.supp_send = optee_supp_send,
+};
+
+static struct tee_desc optee_supp_desc = {
+	.name = DRIVER_NAME "-supp",
+	.ops = &optee_supp_ops,
+	.owner = THIS_MODULE,
+	.flags = TEE_DESC_PRIVILEGED,
+};
+
+static bool optee_msg_api_uid_is_optee_api(optee_invoke_fn *invoke_fn)
+{
+	struct arm_smccc_res res;
+
+	invoke_fn(OPTEE_SMC_CALLS_UID, 0, 0, 0, 0, 0, 0, 0, &res);
+
+	if (res.a0 == OPTEE_MSG_UID_0 && res.a1 == OPTEE_MSG_UID_1 &&
+	    res.a2 == OPTEE_MSG_UID_2 && res.a3 == OPTEE_MSG_UID_3)
+		return true;
+	return false;
+}
+
+static bool optee_msg_api_revision_is_compatible(optee_invoke_fn *invoke_fn)
+{
+	union {
+		struct arm_smccc_res smccc;
+		struct optee_smc_calls_revision_result result;
+	} res;
+
+	invoke_fn(OPTEE_SMC_CALLS_REVISION, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
+
+	if (res.result.major == OPTEE_MSG_REVISION_MAJOR &&
+	    (int)res.result.minor >= OPTEE_MSG_REVISION_MINOR)
+		return true;
+	return false;
+}
+
+static bool optee_msg_exchange_capabilities(optee_invoke_fn *invoke_fn,
+					    u32 *sec_caps)
+{
+	union {
+		struct arm_smccc_res smccc;
+		struct optee_smc_exchange_capabilities_result result;
+	} res;
+	u32 a1 = 0;
+
+	/*
+	 * TODO This isn't enough to tell if it's UP system (from kernel
+	 * point of view) or not, is_smp() returns the the information
+	 * needed, but can't be called directly from here.
+	 */
+	if (!IS_ENABLED(CONFIG_SMP) || nr_cpu_ids == 1)
+		a1 |= OPTEE_SMC_NSEC_CAP_UNIPROCESSOR;
+
+	invoke_fn(OPTEE_SMC_EXCHANGE_CAPABILITIES, a1, 0, 0, 0, 0, 0, 0,
+		  &res.smccc);
+
+	if (res.result.status != OPTEE_SMC_RETURN_OK)
+		return false;
+
+	*sec_caps = res.result.capabilities;
+	return true;
+}
+
+static struct tee_shm_pool *
+optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm)
+{
+	union {
+		struct arm_smccc_res smccc;
+		struct optee_smc_get_shm_config_result result;
+	} res;
+	struct tee_shm_pool *pool;
+	unsigned long vaddr;
+	phys_addr_t paddr;
+	size_t size;
+	phys_addr_t begin;
+	phys_addr_t end;
+	void *va;
+	struct tee_shm_pool_mem_info priv_info;
+	struct tee_shm_pool_mem_info dmabuf_info;
+
+	invoke_fn(OPTEE_SMC_GET_SHM_CONFIG, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
+	if (res.result.status != OPTEE_SMC_RETURN_OK) {
+		pr_info("shm service not available\n");
+		return ERR_PTR(-ENOENT);
+	}
+
+	if (res.result.settings != OPTEE_SMC_SHM_CACHED) {
+		pr_err("only normal cached shared memory supported\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	begin = roundup(res.result.start, PAGE_SIZE);
+	end = rounddown(res.result.start + res.result.size, PAGE_SIZE);
+	paddr = begin;
+	size = end - begin;
+
+	if (size < 2 * OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE) {
+		pr_err("too small shared memory area\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	va = memremap(paddr, size, MEMREMAP_WB);
+	if (!va) {
+		pr_err("shared memory ioremap failed\n");
+		return ERR_PTR(-EINVAL);
+	}
+	vaddr = (unsigned long)va;
+
+	priv_info.vaddr = vaddr;
+	priv_info.paddr = paddr;
+	priv_info.size = OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
+	dmabuf_info.vaddr = vaddr + OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
+	dmabuf_info.paddr = paddr + OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
+	dmabuf_info.size = size - OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
+
+	pool = tee_shm_pool_alloc_res_mem(&priv_info, &dmabuf_info);
+	if (IS_ERR(pool)) {
+		memunmap(va);
+		goto out;
+	}
+
+	*memremaped_shm = va;
+out:
+	return pool;
+}
+
+/* Simple wrapper functions to be able to use a function pointer */
+static void optee_smccc_smc(unsigned long a0, unsigned long a1,
+			    unsigned long a2, unsigned long a3,
+			    unsigned long a4, unsigned long a5,
+			    unsigned long a6, unsigned long a7,
+			    struct arm_smccc_res *res)
+{
+	arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res);
+}
+
+static void optee_smccc_hvc(unsigned long a0, unsigned long a1,
+			    unsigned long a2, unsigned long a3,
+			    unsigned long a4, unsigned long a5,
+			    unsigned long a6, unsigned long a7,
+			    struct arm_smccc_res *res)
+{
+	arm_smccc_hvc(a0, a1, a2, a3, a4, a5, a6, a7, res);
+}
+
+static optee_invoke_fn *get_invoke_func(struct device_node *np)
+{
+	const char *method;
+
+	pr_info("probing for conduit method from DT.\n");
+
+	if (of_property_read_string(np, "method", &method)) {
+		pr_warn("missing \"method\" property\n");
+		return ERR_PTR(-ENXIO);
+	}
+
+	if (!strcmp("hvc", method))
+		return optee_smccc_hvc;
+	else if (!strcmp("smc", method))
+		return optee_smccc_smc;
+
+	pr_warn("invalid \"method\" property: %s\n", method);
+	return ERR_PTR(-EINVAL);
+}
+
+static struct optee *optee_probe(struct device_node *np)
+{
+	optee_invoke_fn *invoke_fn;
+	struct tee_shm_pool *pool;
+	struct optee *optee = NULL;
+	void *memremaped_shm = NULL;
+	struct tee_device *teedev;
+	u32 sec_caps;
+	int rc;
+
+	invoke_fn = get_invoke_func(np);
+	if (IS_ERR(invoke_fn))
+		return (void *)invoke_fn;
+
+	if (!optee_msg_api_uid_is_optee_api(invoke_fn)) {
+		pr_warn("api uid mismatch\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (!optee_msg_api_revision_is_compatible(invoke_fn)) {
+		pr_warn("api revision mismatch\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (!optee_msg_exchange_capabilities(invoke_fn, &sec_caps)) {
+		pr_warn("capabilities mismatch\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	/*
+	 * We have no other option for shared memory, if secure world
+	 * doesn't have any reserved memory we can use we can't continue.
+	 */
+	if (!(sec_caps & OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM))
+		return ERR_PTR(-EINVAL);
+
+	pool = optee_config_shm_memremap(invoke_fn, &memremaped_shm);
+	if (IS_ERR(pool))
+		return (void *)pool;
+
+	optee = kzalloc(sizeof(*optee), GFP_KERNEL);
+	if (!optee) {
+		rc = -ENOMEM;
+		goto err;
+	}
+
+	optee->invoke_fn = invoke_fn;
+
+	teedev = tee_device_alloc(&optee_desc, NULL, pool, optee);
+	if (IS_ERR(teedev)) {
+		rc = PTR_ERR(teedev);
+		goto err;
+	}
+	optee->teedev = teedev;
+
+	teedev = tee_device_alloc(&optee_supp_desc, NULL, pool, optee);
+	if (IS_ERR(teedev)) {
+		rc = PTR_ERR(teedev);
+		goto err;
+	}
+	optee->supp_teedev = teedev;
+
+	rc = tee_device_register(optee->teedev);
+	if (rc)
+		goto err;
+
+	rc = tee_device_register(optee->supp_teedev);
+	if (rc)
+		goto err;
+
+	mutex_init(&optee->call_queue.mutex);
+	INIT_LIST_HEAD(&optee->call_queue.waiters);
+	optee_wait_queue_init(&optee->wait_queue);
+	optee_supp_init(&optee->supp);
+	optee->memremaped_shm = memremaped_shm;
+	optee->pool = pool;
+
+	optee_enable_shm_cache(optee);
+
+	pr_info("initialized driver\n");
+	return optee;
+err:
+	if (optee) {
+		/*
+		 * tee_device_unregister() is safe to call even if the
+		 * devices hasn't been registered with
+		 * tee_device_register() yet.
+		 */
+		tee_device_unregister(optee->supp_teedev);
+		tee_device_unregister(optee->teedev);
+		kfree(optee);