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>

MAINTAINERS

@@ -9369,6 +9369,11 @@ F:	arch/*/oprofile/
 F:	drivers/oprofile/
 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)
 M:	Mark Fasheh <mfasheh@versity.com>
 M:	Joel Becker <jlbec@evilplan.org>

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

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/

drivers/tee/optee/Kconfig

+# 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.

drivers/tee/optee/Makefile

+obj-$(CONFIG_OPTEE) += optee.o
+optee-objs += core.o
+optee-objs += call.o
+optee-objs += rpc.o
+optee-objs += supp.o

drivers/tee/optee/call.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);
+}

drivers/tee/optee/core.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.
+ *
+ */
+
+#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);
+	}
+	if (pool)
+		tee_shm_pool_free(pool);
+	if (memremaped_shm)
+		memunmap(memremaped_shm);
+	return ERR_PTR(rc);
+}
+
+static void optee_remove(struct optee *optee)
+{
+	/*
+	 * Ask OP-TEE to free all cached shared memory objects to decrease
+	 * reference counters and also avoid wild pointers in secure world
+	 * into the old shared memory range.
+	 */
+	optee_disable_shm_cache(optee);
+
+	/*
+	 * The two devices has to be unregistered before we can free the
+	 * other resources.
+	 */
+	tee_device_unregister(optee->supp_teedev);
+	tee_device_unregister(optee->teedev);
+
+	tee_shm_pool_free(optee->pool);
+	if (optee->memremaped_shm)
+		memunmap(optee->memremaped_shm);
+	optee_wait_queue_exit(&optee->wait_queue);
+	optee_supp_uninit(&optee->supp);
+	mutex_destroy(&optee->call_queue.mutex);
+
+	kfree(optee);
+}
+
+static const struct of_device_id optee_match[] = {
+	{ .compatible = "linaro,optee-tz" },
+	{},
+};
+
+static struct optee *optee_svc;
+
+static int __init optee_driver_init(void)
+{
+	struct device_node *fw_np;
+	struct device_node *np;
+	struct optee *optee;
+
+	/* Node is supposed to be below /firmware */
+	fw_np = of_find_node_by_name(NULL, "firmware");
+	if (!fw_np)
+		return -ENODEV;
+
+	np = of_find_matching_node(fw_np, optee_match);
+	of_node_put(fw_np);
+	if (!np)
+		return -ENODEV;
+
+	optee = optee_probe(np);
+	of_node_put(np);
+
+	if (IS_ERR(optee))
+		return PTR_ERR(optee);
+
+	optee_svc = optee;
+
+	return 0;
+}
+module_init(optee_driver_init);
+
+static void __exit optee_driver_exit(void)
+{
+	struct optee *optee = optee_svc;
+
+	optee_svc = NULL;
+	if (optee)
+		optee_remove(optee);
+}
+module_exit(optee_driver_exit);
+
+MODULE_AUTHOR("Linaro");
+MODULE_DESCRIPTION("OP-TEE driver");
+MODULE_SUPPORTED_DEVICE("");
+MODULE_VERSION("1.0");
+MODULE_LICENSE("GPL v2");

drivers/tee/optee/optee_msg.h

+/*
+ * Copyright (c) 2015-2016, Linaro Limited
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef _OPTEE_MSG_H
+#define _OPTEE_MSG_H
+
+#include <linux/bitops.h>
+#include <linux/types.h>
+
+/*
+ * This file defines the OP-TEE message protocol used to communicate
+ * with an instance of OP-TEE running in secure world.
+ *
+ * This file is divided into three sections.
+ * 1. Formatting of messages.
+ * 2. Requests from normal world
+ * 3. Requests from secure world, Remote Procedure Call (RPC), handled by
+ *    tee-supplicant.
+ */
+
+/*****************************************************************************
+ * Part 1 - formatting of messages
+ *****************************************************************************/
+
+#define OPTEE_MSG_ATTR_TYPE_NONE		0x0
+#define OPTEE_MSG_ATTR_TYPE_VALUE_INPUT		0x1
+#define OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT	0x2
+#define OPTEE_MSG_ATTR_TYPE_VALUE_INOUT		0x3
+#define OPTEE_MSG_ATTR_TYPE_RMEM_INPUT		0x5
+#define OPTEE_MSG_ATTR_TYPE_RMEM_OUTPUT		0x6
+#define OPTEE_MSG_ATTR_TYPE_RMEM_INOUT		0x7
+#define OPTEE_MSG_ATTR_TYPE_TMEM_INPUT		0x9
+#define OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT		0xa
+#define OPTEE_MSG_ATTR_TYPE_TMEM_INOUT		0xb
+
+#define OPTEE_MSG_ATTR_TYPE_MASK		GENMASK(7, 0)
+
+/*
+ * Meta parameter to be absorbed by the Secure OS and not passed
+ * to the Trusted Application.
+ *
+ * Currently only used with OPTEE_MSG_CMD_OPEN_SESSION.
+ */
+#define OPTEE_MSG_ATTR_META			BIT(8)
+
+/*
+ * The temporary shared memory object is not physically contigous and this
+ * temp memref is followed by another fragment until the last temp memref
+ * that doesn't have this bit set.
+ */
+#define OPTEE_MSG_ATTR_FRAGMENT			BIT(9)
+
+/*
+ * Memory attributes for caching passed with temp memrefs. The actual value
+ * used is defined outside the message protocol with the exception of
+ * OPTEE_MSG_ATTR_CACHE_PREDEFINED which means the attributes already
+ * defined for the memory range should be used. If optee_smc.h is used as
+ * bearer of this protocol OPTEE_SMC_SHM_* is used for values.
+ */
+#define OPTEE_MSG_ATTR_CACHE_SHIFT		16
+#define OPTEE_MSG_ATTR_CACHE_MASK		GENMASK(2, 0)
+#define OPTEE_MSG_ATTR_CACHE_PREDEFINED		0
+
+/*
+ * Same values as TEE_LOGIN_* from TEE Internal API
+ */
+#define OPTEE_MSG_LOGIN_PUBLIC			0x00000000
+#define OPTEE_MSG_LOGIN_USER			0x00000001
+#define OPTEE_MSG_LOGIN_GROUP			0x00000002
+#define OPTEE_MSG_LOGIN_APPLICATION		0x00000004
+#define OPTEE_MSG_LOGIN_APPLICATION_USER	0x00000005
+#define OPTEE_MSG_LOGIN_APPLICATION_GROUP	0x00000006
+
+/**
+ * struct optee_msg_param_tmem - temporary memory reference parameter
+ * @buf_ptr:	Address of the buffer
+ * @size:	Size of the buffer
+ * @shm_ref:	Temporary shared memory reference, pointer to a struct tee_shm
+ *
+ * Secure and normal world communicates pointers as physical address
+ * instead of the virtual address. This is because secure and normal world
+ * have completely independent memory mapping. Normal world can even have a
+ * hypervisor which need to translate the guest physical address (AKA IPA
+ * in ARM documentation) to a real physical address before passing the
+ * structure to secure world.
+ */
+struct optee_msg_param_tmem {
+	u64 buf_ptr;
+	u64 size;
+	u64 shm_ref;
+};
+
+/**
+ * struct optee_msg_param_rmem - registered memory reference parameter
+ * @offs:	Offset into shared memory reference
+ * @size:	Size of the buffer
+ * @shm_ref:	Shared memory reference, pointer to a struct tee_shm
+ */
+struct optee_msg_param_rmem {
+	u64 offs;
+	u64 size;
+	u64 shm_ref;
+};
+
+/**
+ * struct optee_msg_param_value - opaque value parameter
+ *
+ * Value parameters are passed unchecked between normal and secure world.
+ */
+struct optee_msg_param_value {
+	u64 a;
+	u64 b;
+	u64 c;
+};
+
+/**
+ * struct optee_msg_param - parameter used together with struct optee_msg_arg
+ * @attr:	attributes
+ * @tmem:	parameter by temporary memory reference
+ * @rmem:	parameter by registered memory reference
+ * @value:	parameter by opaque value
+ *
+ * @attr & OPTEE_MSG_ATTR_TYPE_MASK indicates if tmem, rmem or value is used in
+ * the union. OPTEE_MSG_ATTR_TYPE_VALUE_* indicates value,
+ * OPTEE_MSG_ATTR_TYPE_TMEM_* indicates tmem and
+ * OPTEE_MSG_ATTR_TYPE_RMEM_* indicates rmem.
+ * OPTEE_MSG_ATTR_TYPE_NONE indicates that none of the members are used.
+ */
+struct optee_msg_param {
+	u64 attr;
+	union {
+		struct optee_msg_param_tmem tmem;
+		struct optee_msg_param_rmem rmem;
+		struct optee_msg_param_value value;
+	} u;
+};
+
+/**
+ * struct optee_msg_arg - call argument
+ * @cmd: Command, one of OPTEE_MSG_CMD_* or OPTEE_MSG_RPC_CMD_*
+ * @func: Trusted Application function, specific to the Trusted Application,
+ *	     used if cmd == OPTEE_MSG_CMD_INVOKE_COMMAND
+ * @session: In parameter for all OPTEE_MSG_CMD_* except
+ *	     OPTEE_MSG_CMD_OPEN_SESSION where it's an output parameter instead
+ * @cancel_id: Cancellation id, a unique value to identify this request
+ * @ret: return value
+ * @ret_origin: origin of the return value
+ * @num_params: number of parameters supplied to the OS Command
+ * @params: the parameters supplied to the OS Command
+ *
+ * All normal calls to Trusted OS uses this struct. If cmd requires further
+ * information than what these field holds it can be passed as a parameter
+ * tagged as meta (setting the OPTEE_MSG_ATTR_META bit in corresponding
+ * attrs field). All parameters tagged as meta has to come first.
+ *
+ * Temp memref parameters can be fragmented if supported by the Trusted OS
+ * (when optee_smc.h is bearer of this protocol this is indicated with
+ * OPTEE_SMC_SEC_CAP_UNREGISTERED_SHM). If a logical memref parameter is
+ * fragmented then has all but the last fragment the
+ * OPTEE_MSG_ATTR_FRAGMENT bit set in attrs. Even if a memref is fragmented
+ * it will still be presented as a single logical memref to the Trusted
+ * Application.
+ */
+struct optee_msg_arg {
+	u32 cmd;
+	u32 func;
+	u32 session;
+	u32 cancel_id;
+	u32 pad;
+	u32 ret;
+	u32 ret_origin;
+	u32 num_params;
+
+	/* num_params tells the actual number of element in params */
+	struct optee_msg_param params[0];
+};
+
+/**
+ * OPTEE_MSG_GET_ARG_SIZE - return size of struct optee_msg_arg
+ *
+ * @num_params: Number of parameters embedded in the struct optee_msg_arg
+ *
+ * Returns the size of the struct optee_msg_arg together with the number
+ * of embedded parameters.
+ */
+#define OPTEE_MSG_GET_ARG_SIZE(num_params) \
+	(sizeof(struct optee_msg_arg) + \
+	 sizeof(struct optee_msg_param) * (num_params))
+
+/*****************************************************************************
+ * Part 2 - requests from normal world
+ *****************************************************************************/
+
+/*
+ * Return the following UID if using API specified in this file without
+ * further extensions:
+ * 384fb3e0-e7f8-11e3-af63-0002a5d5c51b.
+ * Represented in 4 32-bit words in OPTEE_MSG_UID_0, OPTEE_MSG_UID_1,
+ * OPTEE_MSG_UID_2, OPTEE_MSG_UID_3.
+ */
+#define OPTEE_MSG_UID_0			0x384fb3e0
+#define OPTEE_MSG_UID_1			0xe7f811e3
+#define OPTEE_MSG_UID_2			0xaf630002
+#define OPTEE_MSG_UID_3			0xa5d5c51b
+#define OPTEE_MSG_FUNCID_CALLS_UID	0xFF01
+
+/*
+ * Returns 2.0 if using API specified in this file without further
+ * extensions. Represented in 2 32-bit words in OPTEE_MSG_REVISION_MAJOR
+ * and OPTEE_MSG_REVISION_MINOR
+ */
+#define OPTEE_MSG_REVISION_MAJOR	2
+#define OPTEE_MSG_REVISION_MINOR	0
+#define OPTEE_MSG_FUNCID_CALLS_REVISION	0xFF03
+
+/*
+ * Get UUID of Trusted OS.
+ *
+ * Used by non-secure world to figure out which Trusted OS is installed.
+ * Note that returned UUID is the UUID of the Trusted OS, not of the API.
+ *
+ * Returns UUID in 4 32-bit words in the same way as
+ * OPTEE_MSG_FUNCID_CALLS_UID described above.
+ */
+#define OPTEE_MSG_OS_OPTEE_UUID_0	0x486178e0
+#define OPTEE_MSG_OS_OPTEE_UUID_1	0xe7f811e3
+#define OPTEE_MSG_OS_OPTEE_UUID_2	0xbc5e0002
+#define OPTEE_MSG_OS_OPTEE_UUID_3	0xa5d5c51b
+#define OPTEE_MSG_FUNCID_GET_OS_UUID	0x0000
+
+/*
+ * Get revision of Trusted OS.
+ *
+ * Used by non-secure world to figure out which version of the Trusted OS
+ * is installed. Note that the returned revision is the revision of the
+ * Trusted OS, not of the API.
+ *
+ * Returns revision in 2 32-bit words in the same way as
+ * OPTEE_MSG_CALLS_REVISION described above.
+ */
+#define OPTEE_MSG_FUNCID_GET_OS_REVISION	0x0001
+
+/*
+ * Do a secure call with struct optee_msg_arg as argument
+ * The OPTEE_MSG_CMD_* below defines what goes in struct optee_msg_arg::cmd
+ *
+ * OPTEE_MSG_CMD_OPEN_SESSION opens a session to a Trusted Application.
+ * The first two parameters are tagged as meta, holding two value
+ * parameters to pass the following information:
+ * param[0].u.value.a-b uuid of Trusted Application
+ * param[1].u.value.a-b uuid of Client
+ * param[1].u.value.c Login class of client OPTEE_MSG_LOGIN_*
+ *
+ * OPTEE_MSG_CMD_INVOKE_COMMAND invokes a command a previously opened
+ * session to a Trusted Application.  struct optee_msg_arg::func is Trusted
+ * Application function, specific to the Trusted Application.
+ *
+ * OPTEE_MSG_CMD_CLOSE_SESSION closes a previously opened session to
+ * Trusted Application.
+ *
+ * OPTEE_MSG_CMD_CANCEL cancels a currently invoked command.
+ *
+ * OPTEE_MSG_CMD_REGISTER_SHM registers a shared memory reference. The
+ * information is passed as:
+ * [in] param[0].attr			OPTEE_MSG_ATTR_TYPE_TMEM_INPUT
+ *					[| OPTEE_MSG_ATTR_FRAGMENT]
+ * [in] param[0].u.tmem.buf_ptr		physical address (of first fragment)
+ * [in] param[0].u.tmem.size		size (of first fragment)
+ * [in] param[0].u.tmem.shm_ref		holds shared memory reference
+ * ...
+ * The shared memory can optionally be fragmented, temp memrefs can follow
+ * each other with all but the last with the OPTEE_MSG_ATTR_FRAGMENT bit set.
+ *
+ * OPTEE_MSG_CMD_UNREGISTER_SHM unregisteres a previously registered shared
+ * memory reference. The information is passed as:
+ * [in] param[0].attr			OPTEE_MSG_ATTR_TYPE_RMEM_INPUT
+ * [in] param[0].u.rmem.shm_ref		holds shared memory reference
+ * [in] param[0].u.rmem.offs		0
+ * [in] param[0].u.rmem.size		0
+ */
+#define OPTEE_MSG_CMD_OPEN_SESSION	0
+#define OPTEE_MSG_CMD_INVOKE_COMMAND	1
+#define OPTEE_MSG_CMD_CLOSE_SESSION	2
+#define OPTEE_MSG_CMD_CANCEL		3
+#define OPTEE_MSG_CMD_REGISTER_SHM	4
+#define OPTEE_MSG_CMD_UNREGISTER_SHM	5
+#define OPTEE_MSG_FUNCID_CALL_WITH_ARG	0x0004
+
+/*****************************************************************************
+ * Part 3 - Requests from secure world, RPC
+ *****************************************************************************/
+
+/*
+ * All RPC is done with a struct optee_msg_arg as bearer of information,
+ * struct optee_msg_arg::arg holds values defined by OPTEE_MSG_RPC_CMD_* below
+ *
+ * RPC communication with tee-supplicant is reversed compared to normal
+ * client communication desribed above. The supplicant receives requests
+ * and sends responses.
+ */
+
+/*
+ * Load a TA into memory, defined in tee-supplicant
+ */
+#define OPTEE_MSG_RPC_CMD_LOAD_TA	0
+
+/*
+ * Reserved
+ */
+#define OPTEE_MSG_RPC_CMD_RPMB		1
+
+/*
+ * File system access, defined in tee-supplicant
+ */
+#define OPTEE_MSG_RPC_CMD_FS		2
+
+/*
+ * Get time
+ *
+ * Returns number of seconds and nano seconds since the Epoch,
+ * 1970-01-01 00:00:00 +0000 (UTC).
+ *
+ * [out] param[0].u.value.a	Number of seconds
+ * [out] param[0].u.value.b	Number of nano seconds.
+ */
+#define OPTEE_MSG_RPC_CMD_GET_TIME	3
+
+/*
+ * Wait queue primitive, helper for secure world to implement a wait queue.
+ *
+ * If secure world need to wait for a secure world mutex it issues a sleep
+ * request instead of spinning in secure world. Conversely is a wakeup
+ * request issued when a secure world mutex with a thread waiting thread is
+ * unlocked.
+ *
+ * Waiting on a key
+ * [in] param[0].u.value.a OPTEE_MSG_RPC_WAIT_QUEUE_SLEEP
+ * [in] param[0].u.value.b wait key
+ *
+ * Waking up a key
+ * [in] param[0].u.value.a OPTEE_MSG_RPC_WAIT_QUEUE_WAKEUP
+ * [in] param[0].u.value.b wakeup key
+ */
+#define OPTEE_MSG_RPC_CMD_WAIT_QUEUE	4
+#define OPTEE_MSG_RPC_WAIT_QUEUE_SLEEP	0
+#define OPTEE_MSG_RPC_WAIT_QUEUE_WAKEUP	1
+
+/*
+ * Suspend execution
+ *
+ * [in] param[0].value	.a number of milliseconds to suspend
+ */
+#define OPTEE_MSG_RPC_CMD_SUSPEND	5
+
+/*
+ * Allocate a piece of shared memory
+ *
+ * Shared memory can optionally be fragmented, to support that additional
+ * spare param entries are allocated to make room for eventual fragments.
+ * The spare param entries has .attr = OPTEE_MSG_ATTR_TYPE_NONE when
+ * unused. All returned temp memrefs except the last should have the
+ * OPTEE_MSG_ATTR_FRAGMENT bit set in the attr field.
+ *
+ * [in]  param[0].u.value.a		type of memory one of
+ *					OPTEE_MSG_RPC_SHM_TYPE_* below
+ * [in]  param[0].u.value.b		requested size
+ * [in]  param[0].u.value.c		required alignment
+ *
+ * [out] param[0].u.tmem.buf_ptr	physical address (of first fragment)
+ * [out] param[0].u.tmem.size		size (of first fragment)
+ * [out] param[0].u.tmem.shm_ref	shared memory reference
+ * ...
+ * [out] param[n].u.tmem.buf_ptr	physical address
+ * [out] param[n].u.tmem.size		size
+ * [out] param[n].u.tmem.shm_ref	shared memory reference (same value
+ *					as in param[n-1].u.tmem.shm_ref)
+ */
+#define OPTEE_MSG_RPC_CMD_SHM_ALLOC	6
+/* Memory that can be shared with a non-secure user space application */
+#define OPTEE_MSG_RPC_SHM_TYPE_APPL	0
+/* Memory only shared with non-secure kernel */
+#define OPTEE_MSG_RPC_SHM_TYPE_KERNEL	1
+
+/*
+ * Free shared memory previously allocated with OPTEE_MSG_RPC_CMD_SHM_ALLOC
+ *
+ * [in]  param[0].u.value.a		type of memory one of
+ *					OPTEE_MSG_RPC_SHM_TYPE_* above
+ * [in]  param[0].u.value.b		value of shared memory reference
+ *					returned in param[0].u.tmem.shm_ref
+ *					above
+ */
+#define OPTEE_MSG_RPC_CMD_SHM_FREE	7
+
+#endif /* _OPTEE_MSG_H */

drivers/tee/optee/optee_private.h

+/*
+ * 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*/

drivers/tee/optee/optee_smc.h

+/*
+ * Copyright (c) 2015-2016, Linaro Limited
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef OPTEE_SMC_H
+#define OPTEE_SMC_H
+
+#include <linux/arm-smccc.h>
+#include <linux/bitops.h>
+
+#define OPTEE_SMC_STD_CALL_VAL(func_num) \
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_STD_CALL, ARM_SMCCC_SMC_32, \
+			   ARM_SMCCC_OWNER_TRUSTED_OS, (func_num))
+#define OPTEE_SMC_FAST_CALL_VAL(func_num) \
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, ARM_SMCCC_SMC_32, \
+			   ARM_SMCCC_OWNER_TRUSTED_OS, (func_num))
+
+/*
+ * Function specified by SMC Calling convention.
+ */
+#define OPTEE_SMC_FUNCID_CALLS_COUNT	0xFF00
+#define OPTEE_SMC_CALLS_COUNT \
+	ARM_SMCCC_CALL_VAL(OPTEE_SMC_FAST_CALL, SMCCC_SMC_32, \
+			   SMCCC_OWNER_TRUSTED_OS_END, \
+			   OPTEE_SMC_FUNCID_CALLS_COUNT)
+
+/*
+ * Normal cached memory (write-back), shareable for SMP systems and not
+ * shareable for UP systems.
+ */
+#define OPTEE_SMC_SHM_CACHED		1
+
+/*
+ * a0..a7 is used as register names in the descriptions below, on arm32
+ * that translates to r0..r7 and on arm64 to w0..w7. In both cases it's
+ * 32-bit registers.
+ */
+
+/*
+ * Function specified by SMC Calling convention
+ *
+ * Return one of the following UIDs if using API specified in this file
+ * without further extentions:
+ * 65cb6b93-af0c-4617-8ed6-644a8d1140f8
+ * see also OPTEE_SMC_UID_* in optee_msg.h
+ */
+#define OPTEE_SMC_FUNCID_CALLS_UID OPTEE_MSG_FUNCID_CALLS_UID
+#define OPTEE_SMC_CALLS_UID \
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, ARM_SMCCC_SMC_32, \
+			   ARM_SMCCC_OWNER_TRUSTED_OS_END, \
+			   OPTEE_SMC_FUNCID_CALLS_UID)
+
+/*
+ * Function specified by SMC Calling convention
+ *
+ * Returns 2.0 if using API specified in this file without further extentions.
+ * see also OPTEE_MSG_REVISION_* in optee_msg.h
+ */
+#define OPTEE_SMC_FUNCID_CALLS_REVISION OPTEE_MSG_FUNCID_CALLS_REVISION
+#define OPTEE_SMC_CALLS_REVISION \
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, ARM_SMCCC_SMC_32, \
+			   ARM_SMCCC_OWNER_TRUSTED_OS_END, \
+			   OPTEE_SMC_FUNCID_CALLS_REVISION)
+
+struct optee_smc_calls_revision_result {
+	unsigned long major;
+	unsigned long minor;
+	unsigned long reserved0;
+	unsigned long reserved1;
+};
+
+/*
+ * Get UUID of Trusted OS.
+ *
+ * Used by non-secure world to figure out which Trusted OS is installed.
+ * Note that returned UUID is the UUID of the Trusted OS, not of the API.
+ *
+ * Returns UUID in a0-4 in the same way as OPTEE_SMC_CALLS_UID
+ * described above.
+ */
+#define OPTEE_SMC_FUNCID_GET_OS_UUID OPTEE_MSG_FUNCID_GET_OS_UUID
+#define OPTEE_SMC_CALL_GET_OS_UUID \
+	OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_GET_OS_UUID)
+
+/*
+ * Get revision of Trusted OS.
+ *
+ * Used by non-secure world to figure out which version of the Trusted OS
+ * is installed. Note that the returned revision is the revision of the
+ * Trusted OS, not of the API.
+ *
+ * Returns revision in a0-1 in the same way as OPTEE_SMC_CALLS_REVISION
+ * described above.
+ */
+#define OPTEE_SMC_FUNCID_GET_OS_REVISION OPTEE_MSG_FUNCID_GET_OS_REVISION
+#define OPTEE_SMC_CALL_GET_OS_REVISION \
+	OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_GET_OS_REVISION)
+
+/*
+ * Call with struct optee_msg_arg as argument
+ *
+ * Call register usage:
+ * a0	SMC Function ID, OPTEE_SMC*CALL_WITH_ARG
+ * a1	Upper 32bit of a 64bit physical pointer to a struct optee_msg_arg
+ * a2	Lower 32bit of a 64bit physical pointer to a struct optee_msg_arg
+ * a3	Cache settings, not used if physical pointer is in a predefined shared
+ *	memory area else per OPTEE_SMC_SHM_*
+ * a4-6	Not used
+ * a7	Hypervisor Client ID register
+ *
+ * Normal return register usage:
+ * a0	Return value, OPTEE_SMC_RETURN_*
+ * a1-3	Not used
+ * a4-7	Preserved
+ *
+ * OPTEE_SMC_RETURN_ETHREAD_LIMIT return register usage:
+ * a0	Return value, OPTEE_SMC_RETURN_ETHREAD_LIMIT
+ * a1-3	Preserved
+ * a4-7	Preserved
+ *
+ * RPC return register usage:
+ * a0	Return value, OPTEE_SMC_RETURN_IS_RPC(val)
+ * a1-2	RPC parameters
+ * a3-7	Resume information, must be preserved
+ *
+ * Possible return values:
+ * OPTEE_SMC_RETURN_UNKNOWN_FUNCTION	Trusted OS does not recognize this
+ *					function.
+ * OPTEE_SMC_RETURN_OK			Call completed, result updated in
+ *					the previously supplied struct
+ *					optee_msg_arg.
+ * OPTEE_SMC_RETURN_ETHREAD_LIMIT	Number of Trusted OS threads exceeded,
+ *					try again later.
+ * OPTEE_SMC_RETURN_EBADADDR		Bad physcial pointer to struct
+ *					optee_msg_arg.
+ * OPTEE_SMC_RETURN_EBADCMD		Bad/unknown cmd in struct optee_msg_arg
+ * OPTEE_SMC_RETURN_IS_RPC()		Call suspended by RPC call to normal
+ *					world.
+ */
+#define OPTEE_SMC_FUNCID_CALL_WITH_ARG OPTEE_MSG_FUNCID_CALL_WITH_ARG
+#define OPTEE_SMC_CALL_WITH_ARG \
+	OPTEE_SMC_STD_CALL_VAL(OPTEE_SMC_FUNCID_CALL_WITH_ARG)
+
+/*
+ * Get Shared Memory Config
+ *
+ * Returns the Secure/Non-secure shared memory config.
+ *
+ * Call register usage:
+ * a0	SMC Function ID, OPTEE_SMC_GET_SHM_CONFIG
+ * a1-6	Not used
+ * a7	Hypervisor Client ID register
+ *
+ * Have config return register usage:
+ * a0	OPTEE_SMC_RETURN_OK
+ * a1	Physical address of start of SHM
+ * a2	Size of of SHM
+ * a3	Cache settings of memory, as defined by the
+ *	OPTEE_SMC_SHM_* values above
+ * a4-7	Preserved
+ *
+ * Not available register usage:
+ * a0	OPTEE_SMC_RETURN_ENOTAVAIL
+ * a1-3 Not used
+ * a4-7	Preserved
+ */
+#define OPTEE_SMC_FUNCID_GET_SHM_CONFIG	7
+#define OPTEE_SMC_GET_SHM_CONFIG \
+	OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_GET_SHM_CONFIG)
+
+struct optee_smc_get_shm_config_result {
+	unsigned long status;
+	unsigned long start;
+	unsigned long size;
+	unsigned long settings;
+};
+
+/*
+ * Exchanges capabilities between normal world and secure world
+ *
+ * Call register usage:
+ * a0	SMC Function ID, OPTEE_SMC_EXCHANGE_CAPABILITIES
+ * a1	bitfield of normal world capabilities OPTEE_SMC_NSEC_CAP_*
+ * a2-6	Not used
+ * a7	Hypervisor Client ID register
+ *
+ * Normal return register usage:
+ * a0	OPTEE_SMC_RETURN_OK
+ * a1	bitfield of secure world capabilities OPTEE_SMC_SEC_CAP_*
+ * a2-7	Preserved
+ *
+ * Error return register usage:
+ * a0	OPTEE_SMC_RETURN_ENOTAVAIL, can't use the capabilities from normal world
+ * a1	bitfield of secure world capabilities OPTEE_SMC_SEC_CAP_*
+ * a2-7 Preserved
+ */
+/* Normal world works as a uniprocessor system */
+#define OPTEE_SMC_NSEC_CAP_UNIPROCESSOR		BIT(0)
+/* Secure world has reserved shared memory for normal world to use */
+#define OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM	BIT(0)
+/* Secure world can communicate via previously unregistered shared memory */
+#define OPTEE_SMC_SEC_CAP_UNREGISTERED_SHM	BIT(1)
+#define OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES	9
+#define OPTEE_SMC_EXCHANGE_CAPABILITIES \
+	OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES)
+
+struct optee_smc_exchange_capabilities_result {
+	unsigned long status;
+	unsigned long capabilities;
+	unsigned long reserved0;
+	unsigned long reserved1;
+};
+
+/*
+ * Disable and empties cache of shared memory objects
+ *
+ * Secure world can cache frequently used shared memory objects, for
+ * example objects used as RPC arguments. When secure world is idle this
+ * function returns one shared memory reference to free. To disable the
+ * cache and free all cached objects this function has to be called until
+ * it returns OPTEE_SMC_RETURN_ENOTAVAIL.
+ *
+ * Call register usage:
+ * a0	SMC Function ID, OPTEE_SMC_DISABLE_SHM_CACHE
+ * a1-6	Not used
+ * a7	Hypervisor Client ID register
+ *
+ * Normal return register usage:
+ * a0	OPTEE_SMC_RETURN_OK
+ * a1	Upper 32bit of a 64bit Shared memory cookie
+ * a2	Lower 32bit of a 64bit Shared memory cookie
+ * a3-7	Preserved
+ *
+ * Cache empty return register usage:
+ * a0	OPTEE_SMC_RETURN_ENOTAVAIL
+ * a1-7	Preserved
+ *
+ * Not idle return register usage:
+ * a0	OPTEE_SMC_RETURN_EBUSY
+ * a1-7	Preserved
+ */
+#define OPTEE_SMC_FUNCID_DISABLE_SHM_CACHE	10
+#define OPTEE_SMC_DISABLE_SHM_CACHE \
+	OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_DISABLE_SHM_CACHE)
+
+struct optee_smc_disable_shm_cache_result {
+	unsigned long status;
+	unsigned long shm_upper32;
+	unsigned long shm_lower32;
+	unsigned long reserved0;
+};
+
+/*
+ * Enable cache of shared memory objects
+ *
+ * Secure world can cache frequently used shared memory objects, for
+ * example objects used as RPC arguments. When secure world is idle this
+ * function returns OPTEE_SMC_RETURN_OK and the cache is enabled. If
+ * secure world isn't idle OPTEE_SMC_RETURN_EBUSY is returned.
+ *
+ * Call register usage:
+ * a0	SMC Function ID, OPTEE_SMC_ENABLE_SHM_CACHE
+ * a1-6	Not used
+ * a7	Hypervisor Client ID register
+ *
+ * Normal return register usage:
+ * a0	OPTEE_SMC_RETURN_OK
+ * a1-7	Preserved
+ *
+ * Not idle return register usage:
+ * a0	OPTEE_SMC_RETURN_EBUSY
+ * a1-7	Preserved
+ */
+#define OPTEE_SMC_FUNCID_ENABLE_SHM_CACHE	11
+#define OPTEE_SMC_ENABLE_SHM_CACHE \
+	OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_ENABLE_SHM_CACHE)
+
+/*
+ * Resume from RPC (for example after processing an IRQ)
+ *
+ * Call register usage:
+ * a0	SMC Function ID, OPTEE_SMC_CALL_RETURN_FROM_RPC
+ * a1-3	Value of a1-3 when OPTEE_SMC_CALL_WITH_ARG returned
+ *	OPTEE_SMC_RETURN_RPC in a0
+ *
+ * Return register usage is the same as for OPTEE_SMC_*CALL_WITH_ARG above.
+ *
+ * Possible return values
+ * OPTEE_SMC_RETURN_UNKNOWN_FUNCTION	Trusted OS does not recognize this
+ *					function.
+ * OPTEE_SMC_RETURN_OK			Original call completed, result
+ *					updated in the previously supplied.
+ *					struct optee_msg_arg
+ * OPTEE_SMC_RETURN_RPC			Call suspended by RPC call to normal
+ *					world.
+ * OPTEE_SMC_RETURN_ERESUME		Resume failed, the opaque resume
+ *					information was corrupt.
+ */
+#define OPTEE_SMC_FUNCID_RETURN_FROM_RPC	3
+#define OPTEE_SMC_CALL_RETURN_FROM_RPC \
+	OPTEE_SMC_STD_CALL_VAL(OPTEE_SMC_FUNCID_RETURN_FROM_RPC)
+
+#define OPTEE_SMC_RETURN_RPC_PREFIX_MASK	0xFFFF0000
+#define OPTEE_SMC_RETURN_RPC_PREFIX		0xFFFF0000
+#define OPTEE_SMC_RETURN_RPC_FUNC_MASK		0x0000FFFF
+
+#define OPTEE_SMC_RETURN_GET_RPC_FUNC(ret) \
+	((ret) & OPTEE_SMC_RETURN_RPC_FUNC_MASK)
+
+#define OPTEE_SMC_RPC_VAL(func)		((func) | OPTEE_SMC_RETURN_RPC_PREFIX)
+
+/*
+ * Allocate memory for RPC parameter passing. The memory is used to hold a
+ * struct optee_msg_arg.
+ *
+ * "Call" register usage:
+ * a0	This value, OPTEE_SMC_RETURN_RPC_ALLOC
+ * a1	Size in bytes of required argument memory
+ * a2	Not used
+ * a3	Resume information, must be preserved
+ * a4-5	Not used
+ * a6-7	Resume information, must be preserved
+ *
+ * "Return" register usage:
+ * a0	SMC Function ID, OPTEE_SMC_CALL_RETURN_FROM_RPC.
+ * a1	Upper 32bits of 64bit physical pointer to allocated
+ *	memory, (a1 == 0 && a2 == 0) if size was 0 or if memory can't
+ *	be allocated.
+ * a2	Lower 32bits of 64bit physical pointer to allocated
+ *	memory, (a1 == 0 && a2 == 0) if size was 0 or if memory can't
+ *	be allocated
+ * a3	Preserved
+ * a4	Upper 32bits of 64bit Shared memory cookie used when freeing
+ *	the memory or doing an RPC
+ * a5	Lower 32bits of 64bit Shared memory cookie used when freeing
+ *	the memory or doing an RPC
+ * a6-7	Preserved
+ */
+#define OPTEE_SMC_RPC_FUNC_ALLOC	0
+#define OPTEE_SMC_RETURN_RPC_ALLOC \
+	OPTEE_SMC_RPC_VAL(OPTEE_SMC_RPC_FUNC_ALLOC)
+
+/*
+ * Free memory previously allocated by OPTEE_SMC_RETURN_RPC_ALLOC
+ *
+ * "Call" register usage:
+ * a0	This value, OPTEE_SMC_RETURN_RPC_FREE
+ * a1	Upper 32bits of 64bit shared memory cookie belonging to this
+ *	argument memory
+ * a2	Lower 32bits of 64bit shared memory cookie belonging to this
+ *	argument memory
+ * a3-7	Resume information, must be preserved
+ *
+ * "Return" register usage:
+ * a0	SMC Function ID, OPTEE_SMC_CALL_RETURN_FROM_RPC.
+ * a1-2	Not used
+ * a3-7	Preserved
+ */
+#define OPTEE_SMC_RPC_FUNC_FREE		2
+#define OPTEE_SMC_RETURN_RPC_FREE \
+	OPTEE_SMC_RPC_VAL(OPTEE_SMC_RPC_FUNC_FREE)
+
+/*
+ * Deliver an IRQ in normal world.
+ *
+ * "Call" register usage:
+ * a0	OPTEE_SMC_RETURN_RPC_IRQ
+ * a1-7	Resume information, must be preserved
+ *
+ * "Return" register usage:
+ * a0	SMC Function ID, OPTEE_SMC_CALL_RETURN_FROM_RPC.
+ * a1-7	Preserved
+ */
+#define OPTEE_SMC_RPC_FUNC_IRQ		4
+#define OPTEE_SMC_RETURN_RPC_IRQ \
+	OPTEE_SMC_RPC_VAL(OPTEE_SMC_RPC_FUNC_IRQ)
+
+/*
+ * Do an RPC request. The supplied struct optee_msg_arg tells which
+ * request to do and the parameters for the request. The following fields
+ * are used (the rest are unused):
+ * - cmd		the Request ID
+ * - ret		return value of the request, filled in by normal world
+ * - num_params		number of parameters for the request
+ * - params		the parameters
+ * - param_attrs	attributes of the parameters
+ *
+ * "Call" register usage:
+ * a0	OPTEE_SMC_RETURN_RPC_CMD
+ * a1	Upper 32bit of a 64bit Shared memory cookie holding a
+ *	struct optee_msg_arg, must be preserved, only the data should
+ *	be updated
+ * a2	Lower 32bit of a 64bit Shared memory cookie holding a
+ *	struct optee_msg_arg, must be preserved, only the data should
+ *	be updated
+ * a3-7	Resume information, must be preserved
+ *
+ * "Return" register usage:
+ * a0	SMC Function ID, OPTEE_SMC_CALL_RETURN_FROM_RPC.
+ * a1-2	Not used
+ * a3-7	Preserved
+ */
+#define OPTEE_SMC_RPC_FUNC_CMD		5
+#define OPTEE_SMC_RETURN_RPC_CMD \
+	OPTEE_SMC_RPC_VAL(OPTEE_SMC_RPC_FUNC_CMD)
+
+/* Returned in a0 */
+#define OPTEE_SMC_RETURN_UNKNOWN_FUNCTION 0xFFFFFFFF
+
+/* Returned in a0 only from Trusted OS functions */
+#define OPTEE_SMC_RETURN_OK		0x0
+#define OPTEE_SMC_RETURN_ETHREAD_LIMIT	0x1
+#define OPTEE_SMC_RETURN_EBUSY		0x2
+#define OPTEE_SMC_RETURN_ERESUME	0x3
+#define OPTEE_SMC_RETURN_EBADADDR	0x4
+#define OPTEE_SMC_RETURN_EBADCMD	0x5
+#define OPTEE_SMC_RETURN_ENOMEM		0x6
+#define OPTEE_SMC_RETURN_ENOTAVAIL	0x7
+#define OPTEE_SMC_RETURN_IS_RPC(ret)	__optee_smc_return_is_rpc((ret))
+
+static inline bool __optee_smc_return_is_rpc(u32 ret)
+{
+	return ret != OPTEE_SMC_RETURN_UNKNOWN_FUNCTION &&
+	       (ret & OPTEE_SMC_RETURN_RPC_PREFIX_MASK) ==
+			OPTEE_SMC_RETURN_RPC_PREFIX;
+}
+
+#endif /* OPTEE_SMC_H */

drivers/tee/optee/rpc.c

+/*
+ * 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;
+}

drivers/tee/optee/supp.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/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;
+}