Merge tag 'armsoc-tee' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull TEE driver infrastructure and OP-TEE drivers from Arnd Bergmann:
 "This introduces a generic TEE framework in the kernel, to handle
  trusted environemtns (security coprocessor or software implementations
  such as OP-TEE/TrustZone). I'm sending it separately from the other
  arm-soc driver changes to give it a little more visibility, once the
  subsystem is merged, we will likely keep this in the arm₋soc drivers
  branch or have the maintainers submit pull requests directly,
  depending on the patch volume.

  I have reviewed earlier versions in the past, and have reviewed the
  latest version in person during Linaro Connect BUD17.

  Here is my overall assessment of the subsystem:

   - There is clearly demand for this, both for the generic
     infrastructure and the specific OP-TEE implementation.

   - The code has gone through a large number of reviews, and the review
     comments have all been addressed, but the reviews were not coming
     up with serious issues any more and nobody volunteered to vouch for
     the quality.

   - The user space ioctl interface is sufficient to work with the
     OP-TEE driver, and it should in principle work with other TEE
     implementations that follow the GlobalPlatform[1] standards, but it
     might need to be extended in minor ways depending on specific
     requirements of future TEE implementations

   - The main downside of the API to me is how the user space is tied to
     the TEE implementation in hardware or firmware, but uses a generic
     way to communicate with it. This seems to be an inherent problem
     with what it is trying to do, and I could not come up with any
     better solution than what is implemented here.

  For a detailed history of the patch series, see

    https://lkml.org/lkml/2017/3/10/1277"

* tag 'armsoc-tee' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  arm64: dt: hikey: Add optee node
  Documentation: tee subsystem and op-tee driver
  tee: add OP-TEE driver
  tee: generic TEE subsystem
  dt/bindings: add bindings for optee

1 files changed, 444 insertions, 0 deletions

diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c
new file mode 100644
index 0000000000000..f7b7b404c990b
--- /dev/null
+++ b/drivers/tee/optee/call.c
@@ -0,0 +1,444 @@
+/*
+ * Copyright (c) 2015, Linaro Limited
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/arm-smccc.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/tee_drv.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include "optee_private.h"
+#include "optee_smc.h"
+
+struct optee_call_waiter {
+	struct list_head list_node;
+	struct completion c;
+};
+
+static void optee_cq_wait_init(struct optee_call_queue *cq,
+			       struct optee_call_waiter *w)
+{
+	/*
+	 * We're preparing to make a call to secure world. In case we can't
+	 * allocate a thread in secure world we'll end up waiting in
+	 * optee_cq_wait_for_completion().
+	 *
+	 * Normally if there's no contention in secure world the call will
+	 * complete and we can cleanup directly with optee_cq_wait_final().
+	 */
+	mutex_lock(&cq->mutex);
+
+	/*
+	 * We add ourselves to the queue, but we don't wait. This
+	 * guarantees that we don't lose a completion if secure world
+	 * returns busy and another thread just exited and try to complete
+	 * someone.
+	 */
+	init_completion(&w->c);
+	list_add_tail(&w->list_node, &cq->waiters);
+
+	mutex_unlock(&cq->mutex);
+}
+
+static void optee_cq_wait_for_completion(struct optee_call_queue *cq,
+					 struct optee_call_waiter *w)
+{
+	wait_for_completion(&w->c);
+
+	mutex_lock(&cq->mutex);
+
+	/* Move to end of list to get out of the way for other waiters */
+	list_del(&w->list_node);
+	reinit_completion(&w->c);
+	list_add_tail(&w->list_node, &cq->waiters);
+
+	mutex_unlock(&cq->mutex);
+}
+
+static void optee_cq_complete_one(struct optee_call_queue *cq)
+{
+	struct optee_call_waiter *w;
+
+	list_for_each_entry(w, &cq->waiters, list_node) {
+		if (!completion_done(&w->c)) {
+			complete(&w->c);
+			break;
+		}
+	}
+}
+
+static void optee_cq_wait_final(struct optee_call_queue *cq,
+				struct optee_call_waiter *w)
+{
+	/*
+	 * We're done with the call to secure world. The thread in secure
+	 * world that was used for this call is now available for some
+	 * other task to use.
+	 */
+	mutex_lock(&cq->mutex);
+
+	/* Get out of the list */
+	list_del(&w->list_node);
+
+	/* Wake up one eventual waiting task */
+	optee_cq_complete_one(cq);
+
+	/*
+	 * If we're completed we've got a completion from another task that
+	 * was just done with its call to secure world. Since yet another
+	 * thread now is available in secure world wake up another eventual
+	 * waiting task.
+	 */
+	if (completion_done(&w->c))
+		optee_cq_complete_one(cq);
+
+	mutex_unlock(&cq->mutex);
+}
+
+/* Requires the filpstate mutex to be held */
+static struct optee_session *find_session(struct optee_context_data *ctxdata,
+					  u32 session_id)
+{
+	struct optee_session *sess;
+
+	list_for_each_entry(sess, &ctxdata->sess_list, list_node)
+		if (sess->session_id == session_id)
+			return sess;
+
+	return NULL;
+}
+
+/**
+ * optee_do_call_with_arg() - Do an SMC to OP-TEE in secure world
+ * @ctx:	calling context
+ * @parg:	physical address of message to pass to secure world
+ *
+ * Does and SMC to OP-TEE in secure world and handles eventual resulting
+ * Remote Procedure Calls (RPC) from OP-TEE.
+ *
+ * Returns return code from secure world, 0 is OK
+ */
+u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg)
+{
+	struct optee *optee = tee_get_drvdata(ctx->teedev);
+	struct optee_call_waiter w;
+	struct optee_rpc_param param = { };
+	u32 ret;
+
+	param.a0 = OPTEE_SMC_CALL_WITH_ARG;
+	reg_pair_from_64(&param.a1, &param.a2, parg);
+	/* Initialize waiter */
+	optee_cq_wait_init(&optee->call_queue, &w);
+	while (true) {
+		struct arm_smccc_res res;
+
+		optee->invoke_fn(param.a0, param.a1, param.a2, param.a3,
+				 param.a4, param.a5, param.a6, param.a7,
+				 &res);
+
+		if (res.a0 == OPTEE_SMC_RETURN_ETHREAD_LIMIT) {
+			/*
+			 * Out of threads in secure world, wait for a thread
+			 * become available.
+			 */
+			optee_cq_wait_for_completion(&optee->call_queue, &w);
+		} else if (OPTEE_SMC_RETURN_IS_RPC(res.a0)) {
+			param.a0 = res.a0;
+			param.a1 = res.a1;
+			param.a2 = res.a2;
+			param.a3 = res.a3;
+			optee_handle_rpc(ctx, &param);
+		} else {
+			ret = res.a0;
+			break;
+		}
+	}
+
+	/*
+	 * We're done with our thread in secure world, if there's any
+	 * thread waiters wake up one.
+	 */
+	optee_cq_wait_final(&optee->call_queue, &w);
+
+	return ret;
+}
+
+static struct tee_shm *get_msg_arg(struct tee_context *ctx, size_t num_params,
+				   struct optee_msg_arg **msg_arg,
+				   phys_addr_t *msg_parg)
+{
+	int rc;
+	struct tee_shm *shm;
+	struct optee_msg_arg *ma;
+
+	shm = tee_shm_alloc(ctx, OPTEE_MSG_GET_ARG_SIZE(num_params),
+			    TEE_SHM_MAPPED);
+	if (IS_ERR(shm))
+		return shm;
+
+	ma = tee_shm_get_va(shm, 0);
+	if (IS_ERR(ma)) {
+		rc = PTR_ERR(ma);
+		goto out;
+	}
+
+	rc = tee_shm_get_pa(shm, 0, msg_parg);
+	if (rc)
+		goto out;
+
+	memset(ma, 0, OPTEE_MSG_GET_ARG_SIZE(num_params));
+	ma->num_params = num_params;
+	*msg_arg = ma;
+out:
+	if (rc) {
+		tee_shm_free(shm);
+		return ERR_PTR(rc);
+	}
+
+	return shm;
+}
+
+int optee_open_session(struct tee_context *ctx,
+		       struct tee_ioctl_open_session_arg *arg,
+		       struct tee_param *param)
+{
+	struct optee_context_data *ctxdata = ctx->data;
+	int rc;
+	struct tee_shm *shm;
+	struct optee_msg_arg *msg_arg;
+	phys_addr_t msg_parg;
+	struct optee_session *sess = NULL;
+
+	/* +2 for the meta parameters added below */
+	shm = get_msg_arg(ctx, arg->num_params + 2, &msg_arg, &msg_parg);
+	if (IS_ERR(shm))
+		return PTR_ERR(shm);
+
+	msg_arg->cmd = OPTEE_MSG_CMD_OPEN_SESSION;
+	msg_arg->cancel_id = arg->cancel_id;
+
+	/*
+	 * Initialize and add the meta parameters needed when opening a
+	 * session.
+	 */
+	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
+				  OPTEE_MSG_ATTR_META;
+	msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
+				  OPTEE_MSG_ATTR_META;
+	memcpy(&msg_arg->params[0].u.value, arg->uuid, sizeof(arg->uuid));
+	memcpy(&msg_arg->params[1].u.value, arg->uuid, sizeof(arg->clnt_uuid));
+	msg_arg->params[1].u.value.c = arg->clnt_login;
+
+	rc = optee_to_msg_param(msg_arg->params + 2, arg->num_params, param);
+	if (rc)
+		goto out;
+
+	sess = kzalloc(sizeof(*sess), GFP_KERNEL);
+	if (!sess) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	if (optee_do_call_with_arg(ctx, msg_parg)) {
+		msg_arg->ret = TEEC_ERROR_COMMUNICATION;
+		msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
+	}
+
+	if (msg_arg->ret == TEEC_SUCCESS) {
+		/* A new session has been created, add it to the list. */
+		sess->session_id = msg_arg->session;
+		mutex_lock(&ctxdata->mutex);
+		list_add(&sess->list_node, &ctxdata->sess_list);
+		mutex_unlock(&ctxdata->mutex);
+	} else {
+		kfree(sess);
+	}
+
+	if (optee_from_msg_param(param, arg->num_params, msg_arg->params + 2)) {
+		arg->ret = TEEC_ERROR_COMMUNICATION;
+		arg->ret_origin = TEEC_ORIGIN_COMMS;
+		/* Close session again to avoid leakage */
+		optee_close_session(ctx, msg_arg->session);
+	} else {
+		arg->session = msg_arg->session;
+		arg->ret = msg_arg->ret;
+		arg->ret_origin = msg_arg->ret_origin;
+	}
+out:
+	tee_shm_free(shm);
+
+	return rc;
+}
+
+int optee_close_session(struct tee_context *ctx, u32 session)
+{
+	struct optee_context_data *ctxdata = ctx->data;
+	struct tee_shm *shm;
+	struct optee_msg_arg *msg_arg;
+	phys_addr_t msg_parg;
+	struct optee_session *sess;
+
+	/* Check that the session is valid and remove it from the list */
+	mutex_lock(&ctxdata->mutex);
+	sess = find_session(ctxdata, session);
+	if (sess)
+		list_del(&sess->list_node);
+	mutex_unlock(&ctxdata->mutex);
+	if (!sess)
+		return -EINVAL;
+	kfree(sess);
+
+	shm = get_msg_arg(ctx, 0, &msg_arg, &msg_parg);
+	if (IS_ERR(shm))
+		return PTR_ERR(shm);
+
+	msg_arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION;
+	msg_arg->session = session;
+	optee_do_call_with_arg(ctx, msg_parg);
+
+	tee_shm_free(shm);
+	return 0;
+}
+
+int optee_invoke_func(struct tee_context *ctx, struct tee_ioctl_invoke_arg *arg,
+		      struct tee_param *param)
+{
+	struct optee_context_data *ctxdata = ctx->data;
+	struct tee_shm *shm;
+	struct optee_msg_arg *msg_arg;
+	phys_addr_t msg_parg;
+	struct optee_session *sess;
+	int rc;
+
+	/* Check that the session is valid */
+	mutex_lock(&ctxdata->mutex);
+	sess = find_session(ctxdata, arg->session);
+	mutex_unlock(&ctxdata->mutex);
+	if (!sess)
+		return -EINVAL;
+
+	shm = get_msg_arg(ctx, arg->num_params, &msg_arg, &msg_parg);
+	if (IS_ERR(shm))
+		return PTR_ERR(shm);
+	msg_arg->cmd = OPTEE_MSG_CMD_INVOKE_COMMAND;
+	msg_arg->func = arg->func;
+	msg_arg->session = arg->session;
+	msg_arg->cancel_id = arg->cancel_id;
+
+	rc = optee_to_msg_param(msg_arg->params, arg->num_params, param);
+	if (rc)
+		goto out;
+
+	if (optee_do_call_with_arg(ctx, msg_parg)) {
+		msg_arg->ret = TEEC_ERROR_COMMUNICATION;
+		msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
+	}
+
+	if (optee_from_msg_param(param, arg->num_params, msg_arg->params)) {
+		msg_arg->ret = TEEC_ERROR_COMMUNICATION;
+		msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
+	}
+
+	arg->ret = msg_arg->ret;
+	arg->ret_origin = msg_arg->ret_origin;
+out:
+	tee_shm_free(shm);
+	return rc;
+}
+
+int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
+{
+	struct optee_context_data *ctxdata = ctx->data;
+	struct tee_shm *shm;
+	struct optee_msg_arg *msg_arg;
+	phys_addr_t msg_parg;
+	struct optee_session *sess;
+
+	/* Check that the session is valid */
+	mutex_lock(&ctxdata->mutex);
+	sess = find_session(ctxdata, session);
+	mutex_unlock(&ctxdata->mutex);
+	if (!sess)
+		return -EINVAL;
+
+	shm = get_msg_arg(ctx, 0, &msg_arg, &msg_parg);
+	if (IS_ERR(shm))
+		return PTR_ERR(shm);
+
+	msg_arg->cmd = OPTEE_MSG_CMD_CANCEL;
+	msg_arg->session = session;
+	msg_arg->cancel_id = cancel_id;
+	optee_do_call_with_arg(ctx, msg_parg);
+
+	tee_shm_free(shm);
+	return 0;
+}
+
+/**
+ * optee_enable_shm_cache() - Enables caching of some shared memory allocation
+ *			      in OP-TEE
+ * @optee:	main service struct
+ */
+void optee_enable_shm_cache(struct optee *optee)
+{
+	struct optee_call_waiter w;
+
+	/* We need to retry until secure world isn't busy. */
+	optee_cq_wait_init(&optee->call_queue, &w);
+	while (true) {
+		struct arm_smccc_res res;
+
+		optee->invoke_fn(OPTEE_SMC_ENABLE_SHM_CACHE, 0, 0, 0, 0, 0, 0,
+				 0, &res);
+		if (res.a0 == OPTEE_SMC_RETURN_OK)
+			break;
+		optee_cq_wait_for_completion(&optee->call_queue, &w);
+	}
+	optee_cq_wait_final(&optee->call_queue, &w);
+}
+
+/**
+ * optee_disable_shm_cache() - Disables caching of some shared memory allocation
+ *			      in OP-TEE
+ * @optee:	main service struct
+ */
+void optee_disable_shm_cache(struct optee *optee)
+{
+	struct optee_call_waiter w;
+
+	/* We need to retry until secure world isn't busy. */
+	optee_cq_wait_init(&optee->call_queue, &w);
+	while (true) {
+		union {
+			struct arm_smccc_res smccc;
+			struct optee_smc_disable_shm_cache_result result;
+		} res;
+
+		optee->invoke_fn(OPTEE_SMC_DISABLE_SHM_CACHE, 0, 0, 0, 0, 0, 0,
+				 0, &res.smccc);
+		if (res.result.status == OPTEE_SMC_RETURN_ENOTAVAIL)
+			break; /* All shm's freed */
+		if (res.result.status == OPTEE_SMC_RETURN_OK) {
+			struct tee_shm *shm;
+
+			shm = reg_pair_to_ptr(res.result.shm_upper32,
+					      res.result.shm_lower32);
+			tee_shm_free(shm);
+		} else {
+			optee_cq_wait_for_completion(&optee->call_queue, &w);
+		}
+	}
+	optee_cq_wait_final(&optee->call_queue, &w);
+}