1 files changed, 382 insertions, 0 deletions
diff --git a/drivers/tee/optee/supp.c b/drivers/tee/optee/supp.c
new file mode 100644
index 000000000000..df35fc01fd3e
--- /dev/null
+++ b/drivers/tee/optee/supp.c
@@ -0,0 +1,382 @@
+/*
+ * 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"
+
+struct optee_supp_req {
+	struct list_head link;
+
+	bool busy;
+	u32 func;
+	u32 ret;
+	size_t num_params;
+	struct tee_param *param;
+
+	struct completion c;
+};
+
+void optee_supp_init(struct optee_supp *supp)
+{
+	memset(supp, 0, sizeof(*supp));
+	mutex_init(&supp->mutex);
+	init_completion(&supp->reqs_c);
+	idr_init(&supp->idr);
+	INIT_LIST_HEAD(&supp->reqs);
+	supp->req_id = -1;
+}
+
+void optee_supp_uninit(struct optee_supp *supp)
+{
+	mutex_destroy(&supp->mutex);
+	idr_destroy(&supp->idr);
+}
+
+void optee_supp_release(struct optee_supp *supp)
+{
+	int id;
+	struct optee_supp_req *req;
+	struct optee_supp_req *req_tmp;
+
+	mutex_lock(&supp->mutex);
+
+	/* Abort all request retrieved by supplicant */
+	idr_for_each_entry(&supp->idr, req, id) {
+		req->busy = false;
+		idr_remove(&supp->idr, id);
+		req->ret = TEEC_ERROR_COMMUNICATION;
+		complete(&req->c);
+	}
+
+	/* Abort all queued requests */
+	list_for_each_entry_safe(req, req_tmp, &supp->reqs, link) {
+		list_del(&req->link);
+		req->ret = TEEC_ERROR_COMMUNICATION;
+		complete(&req->c);
+	}
+
+	supp->ctx = NULL;
+	supp->req_id = -1;
+
+	mutex_unlock(&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)
+
+{
+	struct optee *optee = tee_get_drvdata(ctx->teedev);
+	struct optee_supp *supp = &optee->supp;
+	struct optee_supp_req *req = kzalloc(sizeof(*req), GFP_KERNEL);
+	bool interruptable;
+	u32 ret;
+
+	if (!req)
+		return TEEC_ERROR_OUT_OF_MEMORY;
+
+	init_completion(&req->c);
+	req->func = func;
+	req->num_params = num_params;
+	req->param = param;
+
+	/* Insert the request in the request list */
+	mutex_lock(&supp->mutex);
+	list_add_tail(&req->link, &supp->reqs);
+	mutex_unlock(&supp->mutex);
+
+	/* Tell an eventual waiter there's a new request */
+	complete(&supp->reqs_c);
+
+	/*
+	 * Wait for supplicant to process and return result, once we've
+	 * returned from wait_for_completion(&req->c) successfully we have
+	 * exclusive access again.
+	 */
+	while (wait_for_completion_interruptible(&req->c)) {
+		mutex_lock(&supp->mutex);
+		interruptable = !supp->ctx;
+		if (interruptable) {
+			/*
+			 * There's no supplicant available and since the
+			 * supp->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.
+			 */
+			interruptable = !req->busy;
+			if (!req->busy)
+				list_del(&req->link);
+		}
+		mutex_unlock(&supp->mutex);
+
+		if (interruptable) {
+			req->ret = TEEC_ERROR_COMMUNICATION;
+			break;
+		}
+	}
+
+	ret = req->ret;
+	kfree(req);
+
+	return ret;
+}
+
+static struct optee_supp_req  *supp_pop_entry(struct optee_supp *supp,
+					      int num_params, int *id)
+{
+	struct optee_supp_req *req;
+
+	if (supp->req_id != -1) {
+		/*
+		 * Supplicant should not mix synchronous and asnynchronous
+		 * requests.
+		 */
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (list_empty(&supp->reqs))
+		return NULL;
+
+	req = list_first_entry(&supp->reqs, struct optee_supp_req, link);
+
+	if (num_params < req->num_params) {
+		/* Not enough room for parameters */
+		return ERR_PTR(-EINVAL);
+	}
+
+	*id = idr_alloc(&supp->idr, req, 1, 0, GFP_KERNEL);
+	if (*id < 0)
+		return ERR_PTR(-ENOMEM);
+
+	list_del(&req->link);
+	req->busy = true;
+
+	return req;
+}
+
+static int supp_check_recv_params(size_t num_params, struct tee_param *params,
+				  size_t *num_meta)
+{
+	size_t n;
+
+	if (!num_params)
+		return -EINVAL;
+
+	/*
+	 * If there's memrefs we need to decrease those as they where
+	 * increased earlier and we'll even refuse to accept any below.
+	 */
+	for (n = 0; n < num_params; n++)
+		if (tee_param_is_memref(params + n) && params[n].u.memref.shm)
+			tee_shm_put(params[n].u.memref.shm);
+
+	/*
+	 * We only expect parameters as TEE_IOCTL_PARAM_ATTR_TYPE_NONE with
+	 * or without the TEE_IOCTL_PARAM_ATTR_META bit set.
+	 */
+	for (n = 0; n < num_params; n++)
+		if (params[n].attr &&
+		    params[n].attr != TEE_IOCTL_PARAM_ATTR_META)
+			return -EINVAL;
+
+	/* At most we'll need one meta parameter so no need to check for more */
+	if (params->attr == TEE_IOCTL_PARAM_ATTR_META)
+		*num_meta = 1;
+	else
+		*num_meta = 0;
+
+	return 0;
+}
+
+/**
+ * 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;
+	struct optee_supp_req *req = NULL;
+	int id;
+	size_t num_meta;
+	int rc;
+
+	rc = supp_check_recv_params(*num_params, param, &num_meta);
+	if (rc)
+		return rc;
+
+	while (true) {
+		mutex_lock(&supp->mutex);
+		req = supp_pop_entry(supp, *num_params - num_meta, &id);
+		mutex_unlock(&supp->mutex);
+
+		if (req) {
+			if (IS_ERR(req))
+				return PTR_ERR(req);
+			break;
+		}
+
+		/*
+		 * If we didn't get a request we'll block in
+		 * wait_for_completion() to avoid needless spinning.
+		 *
+		 * 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->reqs_c))
+			return -ERESTARTSYS;
+	}
+
+	if (num_meta) {
+		/*
+		 * tee-supplicant support meta parameters -> requsts can be
+		 * processed asynchronously.
+		 */
+		param->attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT |
+			      TEE_IOCTL_PARAM_ATTR_META;
+		param->u.value.a = id;
+		param->u.value.b = 0;
+		param->u.value.c = 0;
+	} else {
+		mutex_lock(&supp->mutex);
+		supp->req_id = id;
+		mutex_unlock(&supp->mutex);
+	}
+
+	*func = req->func;
+	*num_params = req->num_params + num_meta;
+	memcpy(param + num_meta, req->param,
+	       sizeof(struct tee_param) * req->num_params);
+
+	return 0;
+}
+
+static struct optee_supp_req *supp_pop_req(struct optee_supp *supp,
+					   size_t num_params,
+					   struct tee_param *param,
+					   size_t *num_meta)
+{
+	struct optee_supp_req *req;
+	int id;
+	size_t nm;
+	const u32 attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT |
+			 TEE_IOCTL_PARAM_ATTR_META;
+
+	if (!num_params)
+		return ERR_PTR(-EINVAL);
+
+	if (supp->req_id == -1) {
+		if (param->attr != attr)
+			return ERR_PTR(-EINVAL);
+		id = param->u.value.a;
+		nm = 1;
+	} else {
+		id = supp->req_id;
+		nm = 0;
+	}
+
+	req = idr_find(&supp->idr, id);
+	if (!req)
+		return ERR_PTR(-ENOENT);
+
+	if ((num_params - nm) != req->num_params)
+		return ERR_PTR(-EINVAL);
+
+	req->busy = false;
+	idr_remove(&supp->idr, id);
+	supp->req_id = -1;
+	*num_meta = nm;
+
+	return req;
+}
+
+/**
+ * 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;
+	struct optee_supp_req *req;
+	size_t n;
+	size_t num_meta;
+
+	mutex_lock(&supp->mutex);
+	req = supp_pop_req(supp, num_params, param, &num_meta);
+	mutex_unlock(&supp->mutex);
+
+	if (IS_ERR(req)) {
+		/* Something is wrong, let supplicant restart. */
+		return PTR_ERR(req);
+	}
+
+	/* Update out and in/out parameters */
+	for (n = 0; n < req->num_params; n++) {
+		struct tee_param *p = req->param + n;
+
+		switch (p->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
+		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
+		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
+			p->u.value.a = param[n + num_meta].u.value.a;
+			p->u.value.b = param[n + num_meta].u.value.b;
+			p->u.value.c = param[n + num_meta].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 + num_meta].u.memref.size;
+			break;
+		default:
+			break;
+		}
+	}
+	req->ret = ret;
+
+	/* Let the requesting thread continue */
+	complete(&req->c);
+
+	return 0;
+}