[PATCH 0/2] OP-TEE FF-A notifications

[PATCH 0/2] OP-TEE FF-A notifications

[Jens Wiklander]

Hi all,

This patchset adds support for using FF-A notifications as a delivery
mechanism of asynchronous notifications from OP-TEE running in the secure
world. Support for asynchronous notifications via the SMC ABI was added in
[1], here we add the counterpart needed when using the the FF-A ABI.

Support for FF-A notifications is added with [2] and this patch set is based
on Sudeeps tree at [3].

[1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
[2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
[3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
    commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")

Thanks,
Jens

Jens Wiklander (2):
  optee: provide optee_do_bottom_half() as a common function
  optee: ffa_abi: add asynchronous notifications

 drivers/tee/optee/call.c          | 31 ++++++++++-
 drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
 drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
 drivers/tee/optee/optee_private.h |  9 ++-
 drivers/tee/optee/smc_abi.c       | 36 ++----------
 5 files changed, 153 insertions(+), 42 deletions(-)


base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
-- 
2.34.1

[PATCH 1/2] optee: provide optee_do_bottom_half() as a common function

[Jens Wiklander]

Provides optee_do_bottom_half() and optee_stop_async_notif() as common
functions callable from the FF-A ABI part of the driver too.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
 drivers/tee/optee/call.c          | 31 +++++++++++++++++++++++++-
 drivers/tee/optee/optee_private.h |  5 ++++-
 drivers/tee/optee/smc_abi.c       | 36 ++++---------------------------
 3 files changed, 38 insertions(+), 34 deletions(-)

diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c
index df5fb5410b72..5afc759794ce 100644
--- a/drivers/tee/optee/call.c
+++ b/drivers/tee/optee/call.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2015-2021, Linaro Limited
+ * Copyright (c) 2015-2021, 2023 Linaro Limited
  */
 #include <linux/device.h>
 #include <linux/err.h>
@@ -524,3 +524,32 @@ int optee_check_mem_type(unsigned long start, size_t num_pages)
 
 	return rc;
 }
+
+static int simple_call_with_arg(struct tee_context *ctx, u32 cmd)
+{
+	struct optee *optee = tee_get_drvdata(ctx->teedev);
+	struct optee_shm_arg_entry *entry;
+	struct optee_msg_arg *msg_arg;
+	struct tee_shm *shm;
+	u_int offs;
+
+	msg_arg = optee_get_msg_arg(ctx, 0, &entry, &shm, &offs);
+	if (IS_ERR(msg_arg))
+		return PTR_ERR(msg_arg);
+
+	msg_arg->cmd = cmd;
+	optee->ops->do_call_with_arg(ctx, shm, offs);
+
+	optee_free_msg_arg(ctx, entry, offs);
+	return 0;
+}
+
+int optee_do_bottom_half(struct tee_context *ctx)
+{
+	return simple_call_with_arg(ctx, OPTEE_MSG_CMD_DO_BOTTOM_HALF);
+}
+
+int optee_stop_async_notif(struct tee_context *ctx)
+{
+	return simple_call_with_arg(ctx, OPTEE_MSG_CMD_STOP_ASYNC_NOTIF);
+}
diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
index 72685ee0d53f..2165bd11e6ac 100644
--- a/drivers/tee/optee/optee_private.h
+++ b/drivers/tee/optee/optee_private.h
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (c) 2015-2021, Linaro Limited
+ * Copyright (c) 2015-2021, 2023 Linaro Limited
  */
 
 #ifndef OPTEE_PRIVATE_H
@@ -325,6 +325,9 @@ void optee_rpc_cmd_free_suppl(struct tee_context *ctx, struct tee_shm *shm);
 void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
 		   struct optee_msg_arg *arg);
 
+int optee_do_bottom_half(struct tee_context *ctx);
+int optee_stop_async_notif(struct tee_context *ctx);
+
 /*
  * Small helpers
  */
diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
index d5b28fd35d66..94e96803a722 100644
--- a/drivers/tee/optee/smc_abi.c
+++ b/drivers/tee/optee/smc_abi.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2015-2021, Linaro Limited
+ * Copyright (c) 2015-2021, 2023 Linaro Limited
  * Copyright (c) 2016, EPAM Systems
  */
 
@@ -965,34 +965,6 @@ static int optee_smc_do_call_with_arg(struct tee_context *ctx,
 	return rc;
 }
 
-static int simple_call_with_arg(struct tee_context *ctx, u32 cmd)
-{
-	struct optee_shm_arg_entry *entry;
-	struct optee_msg_arg *msg_arg;
-	struct tee_shm *shm;
-	u_int offs;
-
-	msg_arg = optee_get_msg_arg(ctx, 0, &entry, &shm, &offs);
-	if (IS_ERR(msg_arg))
-		return PTR_ERR(msg_arg);
-
-	msg_arg->cmd = cmd;
-	optee_smc_do_call_with_arg(ctx, shm, offs);
-
-	optee_free_msg_arg(ctx, entry, offs);
-	return 0;
-}
-
-static int optee_smc_do_bottom_half(struct tee_context *ctx)
-{
-	return simple_call_with_arg(ctx, OPTEE_MSG_CMD_DO_BOTTOM_HALF);
-}
-
-static int optee_smc_stop_async_notif(struct tee_context *ctx)
-{
-	return simple_call_with_arg(ctx, OPTEE_MSG_CMD_STOP_ASYNC_NOTIF);
-}
-
 /*
  * 5. Asynchronous notification
  */
@@ -1048,7 +1020,7 @@ static irqreturn_t notif_irq_thread_fn(int irq, void *dev_id)
 {
 	struct optee *optee = dev_id;
 
-	optee_smc_do_bottom_half(optee->ctx);
+	optee_do_bottom_half(optee->ctx);
 
 	return IRQ_HANDLED;
 }
@@ -1086,7 +1058,7 @@ static void notif_pcpu_irq_work_fn(struct work_struct *work)
 						   notif_pcpu_work);
 	struct optee *optee = container_of(optee_smc, struct optee, smc);
 
-	optee_smc_do_bottom_half(optee->ctx);
+	optee_do_bottom_half(optee->ctx);
 }
 
 static int init_pcpu_irq(struct optee *optee, u_int irq)
@@ -1158,7 +1130,7 @@ static void uninit_pcpu_irq(struct optee *optee)
 static void optee_smc_notif_uninit_irq(struct optee *optee)
 {
 	if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_ASYNC_NOTIF) {
-		optee_smc_stop_async_notif(optee->ctx);
+		optee_stop_async_notif(optee->ctx);
 		if (optee->smc.notif_irq) {
 			if (irq_is_percpu_devid(optee->smc.notif_irq))
 				uninit_pcpu_irq(optee);
-- 
2.34.1

Re: [PATCH 1/2] optee: provide optee_do_bottom_half() as a common function

[Sumit Garg]

On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> Provides optee_do_bottom_half() and optee_stop_async_notif() as common
> functions callable from the FF-A ABI part of the driver too.
>
> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> ---
>  drivers/tee/optee/call.c          | 31 +++++++++++++++++++++++++-
>  drivers/tee/optee/optee_private.h |  5 ++++-
>  drivers/tee/optee/smc_abi.c       | 36 ++++---------------------------
>  3 files changed, 38 insertions(+), 34 deletions(-)
>

Reviewed-by: Sumit Garg <sumit.garg@linaro.org>

-Sumit

> diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c
> index df5fb5410b72..5afc759794ce 100644
> --- a/drivers/tee/optee/call.c
> +++ b/drivers/tee/optee/call.c
> @@ -1,6 +1,6 @@
>  // SPDX-License-Identifier: GPL-2.0-only
>  /*
> - * Copyright (c) 2015-2021, Linaro Limited
> + * Copyright (c) 2015-2021, 2023 Linaro Limited
>   */
>  #include <linux/device.h>
>  #include <linux/err.h>
> @@ -524,3 +524,32 @@ int optee_check_mem_type(unsigned long start, size_t num_pages)
>
>         return rc;
>  }
> +
> +static int simple_call_with_arg(struct tee_context *ctx, u32 cmd)
> +{
> +       struct optee *optee = tee_get_drvdata(ctx->teedev);
> +       struct optee_shm_arg_entry *entry;
> +       struct optee_msg_arg *msg_arg;
> +       struct tee_shm *shm;
> +       u_int offs;
> +
> +       msg_arg = optee_get_msg_arg(ctx, 0, &entry, &shm, &offs);
> +       if (IS_ERR(msg_arg))
> +               return PTR_ERR(msg_arg);
> +
> +       msg_arg->cmd = cmd;
> +       optee->ops->do_call_with_arg(ctx, shm, offs);
> +
> +       optee_free_msg_arg(ctx, entry, offs);
> +       return 0;
> +}
> +
> +int optee_do_bottom_half(struct tee_context *ctx)
> +{
> +       return simple_call_with_arg(ctx, OPTEE_MSG_CMD_DO_BOTTOM_HALF);
> +}
> +
> +int optee_stop_async_notif(struct tee_context *ctx)
> +{
> +       return simple_call_with_arg(ctx, OPTEE_MSG_CMD_STOP_ASYNC_NOTIF);
> +}
> diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> index 72685ee0d53f..2165bd11e6ac 100644
> --- a/drivers/tee/optee/optee_private.h
> +++ b/drivers/tee/optee/optee_private.h
> @@ -1,6 +1,6 @@
>  /* SPDX-License-Identifier: GPL-2.0-only */
>  /*
> - * Copyright (c) 2015-2021, Linaro Limited
> + * Copyright (c) 2015-2021, 2023 Linaro Limited
>   */
>
>  #ifndef OPTEE_PRIVATE_H
> @@ -325,6 +325,9 @@ void optee_rpc_cmd_free_suppl(struct tee_context *ctx, struct tee_shm *shm);
>  void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
>                    struct optee_msg_arg *arg);
>
> +int optee_do_bottom_half(struct tee_context *ctx);
> +int optee_stop_async_notif(struct tee_context *ctx);
> +
>  /*
>   * Small helpers
>   */
> diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
> index d5b28fd35d66..94e96803a722 100644
> --- a/drivers/tee/optee/smc_abi.c
> +++ b/drivers/tee/optee/smc_abi.c
> @@ -1,6 +1,6 @@
>  // SPDX-License-Identifier: GPL-2.0-only
>  /*
> - * Copyright (c) 2015-2021, Linaro Limited
> + * Copyright (c) 2015-2021, 2023 Linaro Limited
>   * Copyright (c) 2016, EPAM Systems
>   */
>
> @@ -965,34 +965,6 @@ static int optee_smc_do_call_with_arg(struct tee_context *ctx,
>         return rc;
>  }
>
> -static int simple_call_with_arg(struct tee_context *ctx, u32 cmd)
> -{
> -       struct optee_shm_arg_entry *entry;
> -       struct optee_msg_arg *msg_arg;
> -       struct tee_shm *shm;
> -       u_int offs;
> -
> -       msg_arg = optee_get_msg_arg(ctx, 0, &entry, &shm, &offs);
> -       if (IS_ERR(msg_arg))
> -               return PTR_ERR(msg_arg);
> -
> -       msg_arg->cmd = cmd;
> -       optee_smc_do_call_with_arg(ctx, shm, offs);
> -
> -       optee_free_msg_arg(ctx, entry, offs);
> -       return 0;
> -}
> -
> -static int optee_smc_do_bottom_half(struct tee_context *ctx)
> -{
> -       return simple_call_with_arg(ctx, OPTEE_MSG_CMD_DO_BOTTOM_HALF);
> -}
> -
> -static int optee_smc_stop_async_notif(struct tee_context *ctx)
> -{
> -       return simple_call_with_arg(ctx, OPTEE_MSG_CMD_STOP_ASYNC_NOTIF);
> -}
> -
>  /*
>   * 5. Asynchronous notification
>   */
> @@ -1048,7 +1020,7 @@ static irqreturn_t notif_irq_thread_fn(int irq, void *dev_id)
>  {
>         struct optee *optee = dev_id;
>
> -       optee_smc_do_bottom_half(optee->ctx);
> +       optee_do_bottom_half(optee->ctx);
>
>         return IRQ_HANDLED;
>  }
> @@ -1086,7 +1058,7 @@ static void notif_pcpu_irq_work_fn(struct work_struct *work)
>                                                    notif_pcpu_work);
>         struct optee *optee = container_of(optee_smc, struct optee, smc);
>
> -       optee_smc_do_bottom_half(optee->ctx);
> +       optee_do_bottom_half(optee->ctx);
>  }
>
>  static int init_pcpu_irq(struct optee *optee, u_int irq)
> @@ -1158,7 +1130,7 @@ static void uninit_pcpu_irq(struct optee *optee)
>  static void optee_smc_notif_uninit_irq(struct optee *optee)
>  {
>         if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_ASYNC_NOTIF) {
> -               optee_smc_stop_async_notif(optee->ctx);
> +               optee_stop_async_notif(optee->ctx);
>                 if (optee->smc.notif_irq) {
>                         if (irq_is_percpu_devid(optee->smc.notif_irq))
>                                 uninit_pcpu_irq(optee);
> --
> 2.34.1
>

[PATCH 2/2] optee: ffa_abi: add asynchronous notifications

[Jens Wiklander]

Adds support for asynchronous notifications from OP-TEE in secure world
when communicating via FF-A. In principle from OP-TEE and kernel driver
point of view this works in the same way as for the SMC ABI based
implementation.

The OP-TEE FF-A ABI is expanded in OPTEE_FFA_EXCHANGE_CAPABILITIES with
the capability OPTEE_FFA_SEC_CAP_ASYNC_NOTIF to indicate that OP-TEE
supports asynchronous notifications. OPTEE_FFA_ENABLE_ASYNC_NOTIF is
also added to tell that the driver has successfully initialized these
notifications.

Notification capability is negotiated while the driver is initialized.
If both sides supports these notifications then they are enabled.

The notification concept in this driver is merged with the FF-A concept,
the lower 64 values are reserved for FF-A as asynchronous notifications
while the synchronous notifications uses the higher values.

So a FF-A notification has to be allocated for each discrete
asynchronous notification value needed. Only one asynchronous
notification value is used at the moment, the "do bottom half"
notification.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
 drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
 drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
 drivers/tee/optee/optee_private.h |  4 +-
 3 files changed, 115 insertions(+), 8 deletions(-)

diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
index 0828240f27e6..e68acc42db65 100644
--- a/drivers/tee/optee/ffa_abi.c
+++ b/drivers/tee/optee/ffa_abi.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2021, Linaro Limited
+ * Copyright (c) 2021, 2023 Linaro Limited
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -692,7 +692,8 @@ static bool optee_ffa_api_is_compatbile(struct ffa_device *ffa_dev,
 static bool optee_ffa_exchange_caps(struct ffa_device *ffa_dev,
 				    const struct ffa_ops *ops,
 				    u32 *sec_caps,
-				    unsigned int *rpc_param_count)
+				    unsigned int *rpc_param_count,
+				    unsigned int *max_notif_value)
 {
 	struct ffa_send_direct_data data = { OPTEE_FFA_EXCHANGE_CAPABILITIES };
 	int rc;
@@ -709,10 +710,39 @@ static bool optee_ffa_exchange_caps(struct ffa_device *ffa_dev,
 
 	*rpc_param_count = (u8)data.data1;
 	*sec_caps = data.data2;
+	if (data.data3)
+		*max_notif_value = data.data3;
+	else
+		*max_notif_value = OPTEE_DEFAULT_MAX_NOTIF_VALUE;
 
 	return true;
 }
 
+static void notif_callback(int notify_id, void *cb_data)
+{
+	struct optee *optee = cb_data;
+
+	if (notify_id == optee->ffa.bottom_half_value)
+		optee_do_bottom_half(optee->ctx);
+	else
+		optee_notif_send(optee, notify_id);
+}
+
+static int enable_async_notif(struct optee *optee)
+{
+	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
+	struct ffa_send_direct_data data = {
+		.data0 = OPTEE_FFA_ENABLE_ASYNC_NOTIF,
+		.data1 = optee->ffa.bottom_half_value,
+	};
+	int rc;
+
+	rc = ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &data);
+	if (rc)
+		return rc;
+	return data.data0;
+}
+
 static void optee_ffa_get_version(struct tee_device *teedev,
 				  struct tee_ioctl_version_data *vers)
 {
@@ -775,7 +805,11 @@ static const struct optee_ops optee_ffa_ops = {
 static void optee_ffa_remove(struct ffa_device *ffa_dev)
 {
 	struct optee *optee = ffa_dev_get_drvdata(ffa_dev);
+	const struct ffa_notifier_ops *ops = ffa_dev->ops->notifier_ops;
+	u32 bottom_half_id = optee->ffa.bottom_half_value;
 
+	if (bottom_half_id != U32_MAX)
+		ops->notify_relinquish(ffa_dev, bottom_half_id);
 	optee_remove_common(optee);
 
 	mutex_destroy(&optee->ffa.mutex);
@@ -784,9 +818,49 @@ static void optee_ffa_remove(struct ffa_device *ffa_dev)
 	kfree(optee);
 }
 
+static int optee_ffa_async_notif_init(struct ffa_device *ffa_dev,
+				      struct optee *optee)
+{
+	const struct ffa_notifier_ops *ops = ffa_dev->ops->notifier_ops;
+	bool is_per_vcpu = false;
+	u32 notif_id = 0;
+	int rc;
+
+	while (true) {
+		rc = ops->notify_request(ffa_dev, is_per_vcpu,
+					       notif_callback, optee,
+					       notif_id);
+		if (!rc)
+			break;
+		/*
+		 * -EACCES means that the notification ID was
+		 * already bound, try the next one as long as we
+		 * haven't reached the max. Any other error is a
+		 * permanent error, so skip asynchronous
+		 * notifications in that case.
+		 */
+		if (rc != -EACCES)
+			return rc;
+		notif_id++;
+		if (notif_id >= OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE)
+			return rc;
+	}
+	optee->ffa.bottom_half_value = notif_id;
+
+	rc = enable_async_notif(optee);
+	if (rc < 0) {
+		ops->notify_relinquish(ffa_dev, notif_id);
+		optee->ffa.bottom_half_value = U32_MAX;
+	}
+
+	return rc;
+}
+
 static int optee_ffa_probe(struct ffa_device *ffa_dev)
 {
+	const struct ffa_notifier_ops *notif_ops;
 	const struct ffa_ops *ffa_ops;
+	unsigned int max_notif_value;
 	unsigned int rpc_param_count;
 	struct tee_shm_pool *pool;
 	struct tee_device *teedev;
@@ -797,12 +871,13 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
 	int rc;
 
 	ffa_ops = ffa_dev->ops;
+	notif_ops = ffa_ops->notifier_ops;
 
 	if (!optee_ffa_api_is_compatbile(ffa_dev, ffa_ops))
 		return -EINVAL;
 
 	if (!optee_ffa_exchange_caps(ffa_dev, ffa_ops, &sec_caps,
-				     &rpc_param_count))
+				     &rpc_param_count, &max_notif_value))
 		return -EINVAL;
 	if (sec_caps & OPTEE_FFA_SEC_CAP_ARG_OFFSET)
 		arg_cache_flags |= OPTEE_SHM_ARG_SHARED;
@@ -820,6 +895,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
 
 	optee->ops = &optee_ffa_ops;
 	optee->ffa.ffa_dev = ffa_dev;
+	optee->ffa.bottom_half_value = U32_MAX;
 	optee->rpc_param_count = rpc_param_count;
 
 	teedev = tee_device_alloc(&optee_ffa_clnt_desc, NULL, optee->pool,
@@ -864,6 +940,12 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
 	rc = optee_notif_init(optee, OPTEE_DEFAULT_MAX_NOTIF_VALUE);
 	if (rc)
 		goto err_close_ctx;
+	if (sec_caps & OPTEE_FFA_SEC_CAP_ASYNC_NOTIF) {
+		rc = optee_ffa_async_notif_init(ffa_dev, optee);
+		if (rc < 0)
+			pr_err("Failed to initialize async notifications: %d",
+			       rc);
+	}
 
 	rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
 	if (rc)
@@ -874,6 +956,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
 
 err_unregister_devices:
 	optee_unregister_devices();
+	if (optee->ffa.bottom_half_value != U32_MAX)
+		notif_ops->notify_relinquish(ffa_dev,
+					     optee->ffa.bottom_half_value);
 	optee_notif_uninit(optee);
 err_close_ctx:
 	teedev_close_context(ctx);
diff --git a/drivers/tee/optee/optee_ffa.h b/drivers/tee/optee/optee_ffa.h
index 97266243deaa..fa14d931af8a 100644
--- a/drivers/tee/optee/optee_ffa.h
+++ b/drivers/tee/optee/optee_ffa.h
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: BSD-2-Clause */
 /*
- * Copyright (c) 2019-2021, Linaro Limited
+ * Copyright (c) 2019-2021, 2023 Linaro Limited
  */
 
 /*
@@ -73,7 +73,7 @@
  *
  * Call register usage:
  * w3:    Service ID, OPTEE_FFA_EXCHANGE_CAPABILITIES
- * w4-w7: Note used (MBZ)
+ * w4-w7: Not used (MBZ)
  *
  * Return register usage:
  * w3:    Error code, 0 on success
@@ -82,14 +82,16 @@
  *                   OPTEE_FFA_YIELDING_CALL_WITH_ARG.
  *        Bit[31:8]: Reserved (MBZ)
  * w5:	  Bitfield of secure world capabilities OPTEE_FFA_SEC_CAP_* below,
- *	  unused bits MBZ.
- * w6-w7: Not used (MBZ)
+ * w6:	  The maximum secure world notification number
+ * w7:	  Not used (MBZ)
  */
 /*
  * Secure world supports giving an offset into the argument shared memory
  * object, see also OPTEE_FFA_YIELDING_CALL_WITH_ARG
  */
 #define OPTEE_FFA_SEC_CAP_ARG_OFFSET	BIT(0)
+/* OP-TEE supports asynchronous notification via FF-A */
+#define OPTEE_FFA_SEC_CAP_ASYNC_NOTIF	BIT(1)
 
 #define OPTEE_FFA_EXCHANGE_CAPABILITIES OPTEE_FFA_BLOCKING_CALL(2)
 
@@ -108,6 +110,24 @@
  */
 #define OPTEE_FFA_UNREGISTER_SHM	OPTEE_FFA_BLOCKING_CALL(3)
 
+/*
+ * Inform OP-TEE that normal world is able to receive asynchronous
+ * notifications.
+ *
+ * Call register usage:
+ * w3:    Service ID, OPTEE_FFA_ENABLE_ASYNC_NOTIF
+ * w4:	  Notification value to request bottom half processing, should be
+ *	  less than OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE.
+ * w5-w7: Not used (MBZ)
+ *
+ * Return register usage:
+ * w3:    Error code, 0 on success
+ * w4-w7: Note used (MBZ)
+ */
+#define OPTEE_FFA_ENABLE_ASYNC_NOTIF	OPTEE_FFA_BLOCKING_CALL(5)
+
+#define OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE 64
+
 /*
  * Call with struct optee_msg_arg as argument in the supplied shared memory
  * with a zero internal offset and normal cached memory attributes.
diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
index 2165bd11e6ac..91f4ec45e388 100644
--- a/drivers/tee/optee/optee_private.h
+++ b/drivers/tee/optee/optee_private.h
@@ -129,12 +129,14 @@ struct optee_smc {
  * struct optee_ffa_data -  FFA communication struct
  * @ffa_dev		FFA device, contains the destination id, the id of
  *			OP-TEE in secure world
- * @ffa_ops		FFA operations
+ * @bottom_half_value	Notification ID used for bottom half signalling or
+ *			U32_MAX if unused
  * @mutex		Serializes access to @global_ids
  * @global_ids		FF-A shared memory global handle translation
  */
 struct optee_ffa {
 	struct ffa_device *ffa_dev;
+	u32 bottom_half_value;
 	/* Serializes access to @global_ids */
 	struct mutex mutex;
 	struct rhashtable global_ids;
-- 
2.34.1

Re: [PATCH 2/2] optee: ffa_abi: add asynchronous notifications

[Sumit Garg]

On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> Adds support for asynchronous notifications from OP-TEE in secure world
> when communicating via FF-A. In principle from OP-TEE and kernel driver
> point of view this works in the same way as for the SMC ABI based
> implementation.
>
> The OP-TEE FF-A ABI is expanded in OPTEE_FFA_EXCHANGE_CAPABILITIES with
> the capability OPTEE_FFA_SEC_CAP_ASYNC_NOTIF to indicate that OP-TEE
> supports asynchronous notifications. OPTEE_FFA_ENABLE_ASYNC_NOTIF is
> also added to tell that the driver has successfully initialized these
> notifications.
>
> Notification capability is negotiated while the driver is initialized.
> If both sides supports these notifications then they are enabled.
>
> The notification concept in this driver is merged with the FF-A concept,
> the lower 64 values are reserved for FF-A as asynchronous notifications
> while the synchronous notifications uses the higher values.

s/uses/use/

>
> So a FF-A notification has to be allocated for each discrete
> asynchronous notification value needed. Only one asynchronous
> notification value is used at the moment, the "do bottom half"
> notification.
>
> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> ---
>  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
>  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
>  drivers/tee/optee/optee_private.h |  4 +-
>  3 files changed, 115 insertions(+), 8 deletions(-)
>

Apart from nits below, feel free to add:

Reviewed-by: Sumit Garg <sumit.garg@linaro.org>

> diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> index 0828240f27e6..e68acc42db65 100644
> --- a/drivers/tee/optee/ffa_abi.c
> +++ b/drivers/tee/optee/ffa_abi.c
> @@ -1,6 +1,6 @@
>  // SPDX-License-Identifier: GPL-2.0-only
>  /*
> - * Copyright (c) 2021, Linaro Limited
> + * Copyright (c) 2021, 2023 Linaro Limited
>   */
>
>  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> @@ -692,7 +692,8 @@ static bool optee_ffa_api_is_compatbile(struct ffa_device *ffa_dev,
>  static bool optee_ffa_exchange_caps(struct ffa_device *ffa_dev,
>                                     const struct ffa_ops *ops,
>                                     u32 *sec_caps,
> -                                   unsigned int *rpc_param_count)
> +                                   unsigned int *rpc_param_count,
> +                                   unsigned int *max_notif_value)
>  {
>         struct ffa_send_direct_data data = { OPTEE_FFA_EXCHANGE_CAPABILITIES };
>         int rc;
> @@ -709,10 +710,39 @@ static bool optee_ffa_exchange_caps(struct ffa_device *ffa_dev,
>
>         *rpc_param_count = (u8)data.data1;
>         *sec_caps = data.data2;
> +       if (data.data3)
> +               *max_notif_value = data.data3;
> +       else
> +               *max_notif_value = OPTEE_DEFAULT_MAX_NOTIF_VALUE;
>
>         return true;
>  }
>
> +static void notif_callback(int notify_id, void *cb_data)
> +{
> +       struct optee *optee = cb_data;
> +
> +       if (notify_id == optee->ffa.bottom_half_value)
> +               optee_do_bottom_half(optee->ctx);
> +       else
> +               optee_notif_send(optee, notify_id);
> +}
> +
> +static int enable_async_notif(struct optee *optee)
> +{
> +       struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
> +       struct ffa_send_direct_data data = {
> +               .data0 = OPTEE_FFA_ENABLE_ASYNC_NOTIF,
> +               .data1 = optee->ffa.bottom_half_value,
> +       };
> +       int rc;
> +
> +       rc = ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &data);
> +       if (rc)
> +               return rc;
> +       return data.data0;
> +}
> +
>  static void optee_ffa_get_version(struct tee_device *teedev,
>                                   struct tee_ioctl_version_data *vers)
>  {
> @@ -775,7 +805,11 @@ static const struct optee_ops optee_ffa_ops = {
>  static void optee_ffa_remove(struct ffa_device *ffa_dev)
>  {
>         struct optee *optee = ffa_dev_get_drvdata(ffa_dev);
> +       const struct ffa_notifier_ops *ops = ffa_dev->ops->notifier_ops;
> +       u32 bottom_half_id = optee->ffa.bottom_half_value;
>
> +       if (bottom_half_id != U32_MAX)
> +               ops->notify_relinquish(ffa_dev, bottom_half_id);

nit: I would have preferred to keep common convention among FF-A calls
here being:

ffa_dev->ops->notifier_ops->notify_relinquish()

similar to:

ffa_dev->ops->msg_ops->sync_send_receive()

>         optee_remove_common(optee);
>
>         mutex_destroy(&optee->ffa.mutex);
> @@ -784,9 +818,49 @@ static void optee_ffa_remove(struct ffa_device *ffa_dev)
>         kfree(optee);
>  }
>
> +static int optee_ffa_async_notif_init(struct ffa_device *ffa_dev,
> +                                     struct optee *optee)
> +{
> +       const struct ffa_notifier_ops *ops = ffa_dev->ops->notifier_ops;
> +       bool is_per_vcpu = false;
> +       u32 notif_id = 0;
> +       int rc;
> +
> +       while (true) {
> +               rc = ops->notify_request(ffa_dev, is_per_vcpu,
> +                                              notif_callback, optee,
> +                                              notif_id);

Ditto.

> +               if (!rc)
> +                       break;
> +               /*
> +                * -EACCES means that the notification ID was
> +                * already bound, try the next one as long as we
> +                * haven't reached the max. Any other error is a
> +                * permanent error, so skip asynchronous
> +                * notifications in that case.
> +                */
> +               if (rc != -EACCES)
> +                       return rc;
> +               notif_id++;
> +               if (notif_id >= OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE)
> +                       return rc;
> +       }
> +       optee->ffa.bottom_half_value = notif_id;
> +
> +       rc = enable_async_notif(optee);
> +       if (rc < 0) {
> +               ops->notify_relinquish(ffa_dev, notif_id);

Ditto.

> +               optee->ffa.bottom_half_value = U32_MAX;
> +       }
> +
> +       return rc;
> +}
> +
>  static int optee_ffa_probe(struct ffa_device *ffa_dev)
>  {
> +       const struct ffa_notifier_ops *notif_ops;
>         const struct ffa_ops *ffa_ops;
> +       unsigned int max_notif_value;
>         unsigned int rpc_param_count;
>         struct tee_shm_pool *pool;
>         struct tee_device *teedev;
> @@ -797,12 +871,13 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
>         int rc;
>
>         ffa_ops = ffa_dev->ops;
> +       notif_ops = ffa_ops->notifier_ops;
>
>         if (!optee_ffa_api_is_compatbile(ffa_dev, ffa_ops))
>                 return -EINVAL;
>
>         if (!optee_ffa_exchange_caps(ffa_dev, ffa_ops, &sec_caps,
> -                                    &rpc_param_count))
> +                                    &rpc_param_count, &max_notif_value))
>                 return -EINVAL;
>         if (sec_caps & OPTEE_FFA_SEC_CAP_ARG_OFFSET)
>                 arg_cache_flags |= OPTEE_SHM_ARG_SHARED;
> @@ -820,6 +895,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
>
>         optee->ops = &optee_ffa_ops;
>         optee->ffa.ffa_dev = ffa_dev;
> +       optee->ffa.bottom_half_value = U32_MAX;
>         optee->rpc_param_count = rpc_param_count;
>
>         teedev = tee_device_alloc(&optee_ffa_clnt_desc, NULL, optee->pool,
> @@ -864,6 +940,12 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
>         rc = optee_notif_init(optee, OPTEE_DEFAULT_MAX_NOTIF_VALUE);
>         if (rc)
>                 goto err_close_ctx;
> +       if (sec_caps & OPTEE_FFA_SEC_CAP_ASYNC_NOTIF) {
> +               rc = optee_ffa_async_notif_init(ffa_dev, optee);
> +               if (rc < 0)
> +                       pr_err("Failed to initialize async notifications: %d",
> +                              rc);
> +       }
>
>         rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
>         if (rc)
> @@ -874,6 +956,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
>
>  err_unregister_devices:
>         optee_unregister_devices();
> +       if (optee->ffa.bottom_half_value != U32_MAX)
> +               notif_ops->notify_relinquish(ffa_dev,
> +                                            optee->ffa.bottom_half_value);
>         optee_notif_uninit(optee);
>  err_close_ctx:
>         teedev_close_context(ctx);
> diff --git a/drivers/tee/optee/optee_ffa.h b/drivers/tee/optee/optee_ffa.h
> index 97266243deaa..fa14d931af8a 100644
> --- a/drivers/tee/optee/optee_ffa.h
> +++ b/drivers/tee/optee/optee_ffa.h
> @@ -1,6 +1,6 @@
>  /* SPDX-License-Identifier: BSD-2-Clause */
>  /*
> - * Copyright (c) 2019-2021, Linaro Limited
> + * Copyright (c) 2019-2021, 2023 Linaro Limited
>   */
>
>  /*
> @@ -73,7 +73,7 @@
>   *
>   * Call register usage:
>   * w3:    Service ID, OPTEE_FFA_EXCHANGE_CAPABILITIES
> - * w4-w7: Note used (MBZ)
> + * w4-w7: Not used (MBZ)
>   *
>   * Return register usage:
>   * w3:    Error code, 0 on success
> @@ -82,14 +82,16 @@
>   *                   OPTEE_FFA_YIELDING_CALL_WITH_ARG.
>   *        Bit[31:8]: Reserved (MBZ)
>   * w5:   Bitfield of secure world capabilities OPTEE_FFA_SEC_CAP_* below,
> - *       unused bits MBZ.
> - * w6-w7: Not used (MBZ)
> + * w6:   The maximum secure world notification number
> + * w7:   Not used (MBZ)
>   */
>  /*
>   * Secure world supports giving an offset into the argument shared memory
>   * object, see also OPTEE_FFA_YIELDING_CALL_WITH_ARG
>   */
>  #define OPTEE_FFA_SEC_CAP_ARG_OFFSET   BIT(0)
> +/* OP-TEE supports asynchronous notification via FF-A */
> +#define OPTEE_FFA_SEC_CAP_ASYNC_NOTIF  BIT(1)
>
>  #define OPTEE_FFA_EXCHANGE_CAPABILITIES OPTEE_FFA_BLOCKING_CALL(2)
>
> @@ -108,6 +110,24 @@
>   */
>  #define OPTEE_FFA_UNREGISTER_SHM       OPTEE_FFA_BLOCKING_CALL(3)
>
> +/*
> + * Inform OP-TEE that normal world is able to receive asynchronous

s/that normal/that the normal/

-Sumit

> + * notifications.
> + *
> + * Call register usage:
> + * w3:    Service ID, OPTEE_FFA_ENABLE_ASYNC_NOTIF
> + * w4:   Notification value to request bottom half processing, should be
> + *       less than OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE.
> + * w5-w7: Not used (MBZ)
> + *
> + * Return register usage:
> + * w3:    Error code, 0 on success
> + * w4-w7: Note used (MBZ)
> + */
> +#define OPTEE_FFA_ENABLE_ASYNC_NOTIF   OPTEE_FFA_BLOCKING_CALL(5)
> +
> +#define OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE 64
> +
>  /*
>   * Call with struct optee_msg_arg as argument in the supplied shared memory
>   * with a zero internal offset and normal cached memory attributes.
> diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> index 2165bd11e6ac..91f4ec45e388 100644
> --- a/drivers/tee/optee/optee_private.h
> +++ b/drivers/tee/optee/optee_private.h
> @@ -129,12 +129,14 @@ struct optee_smc {
>   * struct optee_ffa_data -  FFA communication struct
>   * @ffa_dev            FFA device, contains the destination id, the id of
>   *                     OP-TEE in secure world
> - * @ffa_ops            FFA operations
> + * @bottom_half_value  Notification ID used for bottom half signalling or
> + *                     U32_MAX if unused
>   * @mutex              Serializes access to @global_ids
>   * @global_ids         FF-A shared memory global handle translation
>   */
>  struct optee_ffa {
>         struct ffa_device *ffa_dev;
> +       u32 bottom_half_value;
>         /* Serializes access to @global_ids */
>         struct mutex mutex;
>         struct rhashtable global_ids;
> --
> 2.34.1
>

Re: [PATCH 0/2] OP-TEE FF-A notifications

[Sumit Garg]

Hi Jens,

On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> Hi all,
>
> This patchset adds support for using FF-A notifications as a delivery
> mechanism of asynchronous notifications from OP-TEE running in the secure
> world. Support for asynchronous notifications via the SMC ABI was added in
> [1], here we add the counterpart needed when using the the FF-A ABI.
>
> Support for FF-A notifications is added with [2] and this patch set is based
> on Sudeeps tree at [3].

It's good to see FF-A notifications support coming through. The good
aspect here is that FF-A uses a common secure world SGI for
notifications and doesn't have to deal with platform specific reserved
SPI for notifications.

From OP-TEE point of view I think most of the secure SGI donation base
would be common, so can we switch the SMC ABI to use this donated
secure world SGI for notifications too?

-Sumit

>
> [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
>     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
>
> Thanks,
> Jens
>
> Jens Wiklander (2):
>   optee: provide optee_do_bottom_half() as a common function
>   optee: ffa_abi: add asynchronous notifications
>
>  drivers/tee/optee/call.c          | 31 ++++++++++-
>  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
>  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
>  drivers/tee/optee/optee_private.h |  9 ++-
>  drivers/tee/optee/smc_abi.c       | 36 ++----------
>  5 files changed, 153 insertions(+), 42 deletions(-)
>
>
> base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> --
> 2.34.1
>

Re: [PATCH 0/2] OP-TEE FF-A notifications

[Jens Wiklander]

Hi Sumit,

On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> Hi Jens,
> 
> On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> >
> > Hi all,
> >
> > This patchset adds support for using FF-A notifications as a delivery
> > mechanism of asynchronous notifications from OP-TEE running in the secure
> > world. Support for asynchronous notifications via the SMC ABI was added in
> > [1], here we add the counterpart needed when using the the FF-A ABI.
> >
> > Support for FF-A notifications is added with [2] and this patch set is based
> > on Sudeeps tree at [3].
> 
> It's good to see FF-A notifications support coming through. The good
> aspect here is that FF-A uses a common secure world SGI for
> notifications and doesn't have to deal with platform specific reserved
> SPI for notifications.
> 
> From OP-TEE point of view I think most of the secure SGI donation base
> would be common, so can we switch the SMC ABI to use this donated
> secure world SGI for notifications too?

The SMC ABI driver picks up the interrupt used for notification from
device-tree, so there's a chance that it just works if a donated SGI is
supplied instead. We'll need some changes in the secure world side of
OP-TEE, but they wouldn't affect the ABI.

Cheers,
Jens

> 
> -Sumit
> 
> >
> > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> >
> > Thanks,
> > Jens
> >
> > Jens Wiklander (2):
> >   optee: provide optee_do_bottom_half() as a common function
> >   optee: ffa_abi: add asynchronous notifications
> >
> >  drivers/tee/optee/call.c          | 31 ++++++++++-
> >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> >  drivers/tee/optee/optee_private.h |  9 ++-
> >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> >  5 files changed, 153 insertions(+), 42 deletions(-)
> >
> >
> > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > --
> > 2.34.1
> >

Re: [PATCH 0/2] OP-TEE FF-A notifications

[Sumit Garg]

On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> Hi Sumit,
>
> On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > Hi Jens,
> >
> > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > >
> > > Hi all,
> > >
> > > This patchset adds support for using FF-A notifications as a delivery
> > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > >
> > > Support for FF-A notifications is added with [2] and this patch set is based
> > > on Sudeeps tree at [3].
> >
> > It's good to see FF-A notifications support coming through. The good
> > aspect here is that FF-A uses a common secure world SGI for
> > notifications and doesn't have to deal with platform specific reserved
> > SPI for notifications.
> >
> > From OP-TEE point of view I think most of the secure SGI donation base
> > would be common, so can we switch the SMC ABI to use this donated
> > secure world SGI for notifications too?
>
> The SMC ABI driver picks up the interrupt used for notification from
> device-tree, so there's a chance that it just works if a donated SGI is
> supplied instead. We'll need some changes in the secure world side of
> OP-TEE, but they wouldn't affect the ABI.

AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
The FF-A driver explicitly creates that mapping here [1]. Moreover
it's better to detect it via an SMC call rather than hard coded via DT
as FF-A driver does.

So the ABI should dynamically detect if there is a donated SGI then
use it otherwise fallback to SPI/PPI detection via DT. This would make
the notifications feature platform agnostic and we can drop legacy DT
methods from optee-os entirely but still need to maintain them in the
kernel for backwards compatibility.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
[2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275

-Sumit

>
> Cheers,
> Jens
>
> >
> > -Sumit
> >
> > >
> > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > >
> > > Thanks,
> > > Jens
> > >
> > > Jens Wiklander (2):
> > >   optee: provide optee_do_bottom_half() as a common function
> > >   optee: ffa_abi: add asynchronous notifications
> > >
> > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > >  drivers/tee/optee/optee_private.h |  9 ++-
> > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > >
> > >
> > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > --
> > > 2.34.1
> > >

Re: [PATCH 0/2] OP-TEE FF-A notifications

[Jens Wiklander]

On Thu, Nov 02, 2023 at 05:46:55PM +0530, Sumit Garg wrote:
> On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> >
> > Hi Sumit,
> >
> > On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > > Hi Jens,
> > >
> > > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > >
> > > > Hi all,
> > > >
> > > > This patchset adds support for using FF-A notifications as a delivery
> > > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > > >
> > > > Support for FF-A notifications is added with [2] and this patch set is based
> > > > on Sudeeps tree at [3].
> > >
> > > It's good to see FF-A notifications support coming through. The good
> > > aspect here is that FF-A uses a common secure world SGI for
> > > notifications and doesn't have to deal with platform specific reserved
> > > SPI for notifications.
> > >
> > > From OP-TEE point of view I think most of the secure SGI donation base
> > > would be common, so can we switch the SMC ABI to use this donated
> > > secure world SGI for notifications too?
> >
> > The SMC ABI driver picks up the interrupt used for notification from
> > device-tree, so there's a chance that it just works if a donated SGI is
> > supplied instead. We'll need some changes in the secure world side of
> > OP-TEE, but they wouldn't affect the ABI.
> 
> AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
> The FF-A driver explicitly creates that mapping here [1].

That looks a lot like what platform_get_irq() does via of_irq_get().

> Moreover
> it's better to detect it via an SMC call rather than hard coded via DT
> as FF-A driver does.

Typo? I guess you mean that you prefer that way the FF-A driver does it
rather than having it set in the DT.

Assuming that you only care about "arm,gic-v3". The SGI will likely
always be the same so it shouldn't be too hard to keep the correct
configuration in DT.

> 
> So the ABI should dynamically detect if there is a donated SGI then
> use it otherwise fallback to SPI/PPI detection via DT. This would make
> the notifications feature platform agnostic and we can drop legacy DT
> methods from optee-os entirely but still need to maintain them in the
> kernel for backwards compatibility.

We care about compatibility in both directions so we'd need to keep it
in OP-TEE too, but perhaps under a config flag.

Thanks,
Jens

> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275
> 
> -Sumit
> 
> >
> > Cheers,
> > Jens
> >
> > >
> > > -Sumit
> > >
> > > >
> > > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > > >
> > > > Thanks,
> > > > Jens
> > > >
> > > > Jens Wiklander (2):
> > > >   optee: provide optee_do_bottom_half() as a common function
> > > >   optee: ffa_abi: add asynchronous notifications
> > > >
> > > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > > >  drivers/tee/optee/optee_private.h |  9 ++-
> > > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > > >
> > > >
> > > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > > --
> > > > 2.34.1
> > > >

Re: [PATCH 0/2] OP-TEE FF-A notifications

[Sumit Garg]

On Thu, 2 Nov 2023 at 18:46, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> On Thu, Nov 02, 2023 at 05:46:55PM +0530, Sumit Garg wrote:
> > On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > >
> > > Hi Sumit,
> > >
> > > On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > > > Hi Jens,
> > > >
> > > > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > >
> > > > > Hi all,
> > > > >
> > > > > This patchset adds support for using FF-A notifications as a delivery
> > > > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > > > >
> > > > > Support for FF-A notifications is added with [2] and this patch set is based
> > > > > on Sudeeps tree at [3].
> > > >
> > > > It's good to see FF-A notifications support coming through. The good
> > > > aspect here is that FF-A uses a common secure world SGI for
> > > > notifications and doesn't have to deal with platform specific reserved
> > > > SPI for notifications.
> > > >
> > > > From OP-TEE point of view I think most of the secure SGI donation base
> > > > would be common, so can we switch the SMC ABI to use this donated
> > > > secure world SGI for notifications too?
> > >
> > > The SMC ABI driver picks up the interrupt used for notification from
> > > device-tree, so there's a chance that it just works if a donated SGI is
> > > supplied instead. We'll need some changes in the secure world side of
> > > OP-TEE, but they wouldn't affect the ABI.
> >
> > AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
> > The FF-A driver explicitly creates that mapping here [1].
>
> That looks a lot like what platform_get_irq() does via of_irq_get().
>

There is GIC_SPI or GIC_PPI but nothing like GIC_SGI in DT bindings [1].

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/dt-bindings/interrupt-controller/arm-gic.h

> > Moreover
> > it's better to detect it via an SMC call rather than hard coded via DT
> > as FF-A driver does.
>
> Typo? I guess you mean that you prefer that way the FF-A driver does it
> rather than having it set in the DT.

Yeah sorry about that. We shouldn't use DT if OP-TEE features are discoverable.

>
> Assuming that you only care about "arm,gic-v3". The SGI will likely
> always be the same so it shouldn't be too hard to keep the correct
> configuration in DT.

See above, DT looks like it does not support SGI.

>
> >
> > So the ABI should dynamically detect if there is a donated SGI then
> > use it otherwise fallback to SPI/PPI detection via DT. This would make
> > the notifications feature platform agnostic and we can drop legacy DT
> > methods from optee-os entirely but still need to maintain them in the
> > kernel for backwards compatibility.
>
> We care about compatibility in both directions so we'd need to keep it
> in OP-TEE too, but perhaps under a config flag.

Isn't it just supported on Qemu right now in OP-TEE? I hope dropping a
feature won't be a problem there compared with the maintenance burden.

-Sumit

>
> Thanks,
> Jens
>
> >
> > [1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
> > [2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275
> >
> > -Sumit
> >
> > >
> > > Cheers,
> > > Jens
> > >
> > > >
> > > > -Sumit
> > > >
> > > > >
> > > > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > > > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > > > >
> > > > > Thanks,
> > > > > Jens
> > > > >
> > > > > Jens Wiklander (2):
> > > > >   optee: provide optee_do_bottom_half() as a common function
> > > > >   optee: ffa_abi: add asynchronous notifications
> > > > >
> > > > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > > > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > > > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > > > >  drivers/tee/optee/optee_private.h |  9 ++-
> > > > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > > > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > > > >
> > > > >
> > > > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > > > --
> > > > > 2.34.1
> > > > >

Re: [PATCH 0/2] OP-TEE FF-A notifications

[Jens Wiklander]

On Thu, Nov 2, 2023 at 3:05 PM Sumit Garg <sumit.garg@linaro.org> wrote:
>
> On Thu, 2 Nov 2023 at 18:46, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> >
> > On Thu, Nov 02, 2023 at 05:46:55PM +0530, Sumit Garg wrote:
> > > On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > >
> > > > Hi Sumit,
> > > >
> > > > On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > > > > Hi Jens,
> > > > >
> > > > > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > > >
> > > > > > Hi all,
> > > > > >
> > > > > > This patchset adds support for using FF-A notifications as a delivery
> > > > > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > > > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > > > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > > > > >
> > > > > > Support for FF-A notifications is added with [2] and this patch set is based
> > > > > > on Sudeeps tree at [3].
> > > > >
> > > > > It's good to see FF-A notifications support coming through. The good
> > > > > aspect here is that FF-A uses a common secure world SGI for
> > > > > notifications and doesn't have to deal with platform specific reserved
> > > > > SPI for notifications.
> > > > >
> > > > > From OP-TEE point of view I think most of the secure SGI donation base
> > > > > would be common, so can we switch the SMC ABI to use this donated
> > > > > secure world SGI for notifications too?
> > > >
> > > > The SMC ABI driver picks up the interrupt used for notification from
> > > > device-tree, so there's a chance that it just works if a donated SGI is
> > > > supplied instead. We'll need some changes in the secure world side of
> > > > OP-TEE, but they wouldn't affect the ABI.
> > >
> > > AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
> > > The FF-A driver explicitly creates that mapping here [1].
> >
> > That looks a lot like what platform_get_irq() does via of_irq_get().
> >
>
> There is GIC_SPI or GIC_PPI but nothing like GIC_SGI in DT bindings [1].
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/dt-bindings/interrupt-controller/arm-gic.h
>
> > > Moreover
> > > it's better to detect it via an SMC call rather than hard coded via DT
> > > as FF-A driver does.
> >
> > Typo? I guess you mean that you prefer that way the FF-A driver does it
> > rather than having it set in the DT.
>
> Yeah sorry about that. We shouldn't use DT if OP-TEE features are discoverable.
>
> >
> > Assuming that you only care about "arm,gic-v3". The SGI will likely
> > always be the same so it shouldn't be too hard to keep the correct
> > configuration in DT.
>
> See above, DT looks like it does not support SGI.

You're right.

>
> >
> > >
> > > So the ABI should dynamically detect if there is a donated SGI then
> > > use it otherwise fallback to SPI/PPI detection via DT. This would make
> > > the notifications feature platform agnostic and we can drop legacy DT
> > > methods from optee-os entirely but still need to maintain them in the
> > > kernel for backwards compatibility.
> >
> > We care about compatibility in both directions so we'd need to keep it
> > in OP-TEE too, but perhaps under a config flag.
>
> Isn't it just supported on Qemu right now in OP-TEE? I hope dropping a
> feature won't be a problem there compared with the maintenance burden.

I'd rather not remove this since I believe it can support more
configurations (different interrupt controllers), but feel free to
propose a patch with the new ABI.

Cheers,
Jens

>
> -Sumit
>
> >
> > Thanks,
> > Jens
> >
> > >
> > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
> > > [2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275
> > >
> > > -Sumit
> > >
> > > >
> > > > Cheers,
> > > > Jens
> > > >
> > > > >
> > > > > -Sumit
> > > > >
> > > > > >
> > > > > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > > > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > > > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > > > > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > > > > >
> > > > > > Thanks,
> > > > > > Jens
> > > > > >
> > > > > > Jens Wiklander (2):
> > > > > >   optee: provide optee_do_bottom_half() as a common function
> > > > > >   optee: ffa_abi: add asynchronous notifications
> > > > > >
> > > > > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > > > > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > > > > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > > > > >  drivers/tee/optee/optee_private.h |  9 ++-
> > > > > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > > > > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > > > > >
> > > > > >
> > > > > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > > > > --
> > > > > > 2.34.1
> > > > > >

Re: [PATCH 0/2] OP-TEE FF-A notifications

[Sumit Garg]

On Fri, 3 Nov 2023 at 13:32, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> On Thu, Nov 2, 2023 at 3:05 PM Sumit Garg <sumit.garg@linaro.org> wrote:
> >
> > On Thu, 2 Nov 2023 at 18:46, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > >
> > > On Thu, Nov 02, 2023 at 05:46:55PM +0530, Sumit Garg wrote:
> > > > On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > >
> > > > > Hi Sumit,
> > > > >
> > > > > On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > > > > > Hi Jens,
> > > > > >
> > > > > > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > > > >
> > > > > > > Hi all,
> > > > > > >
> > > > > > > This patchset adds support for using FF-A notifications as a delivery
> > > > > > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > > > > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > > > > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > > > > > >
> > > > > > > Support for FF-A notifications is added with [2] and this patch set is based
> > > > > > > on Sudeeps tree at [3].
> > > > > >
> > > > > > It's good to see FF-A notifications support coming through. The good
> > > > > > aspect here is that FF-A uses a common secure world SGI for
> > > > > > notifications and doesn't have to deal with platform specific reserved
> > > > > > SPI for notifications.
> > > > > >
> > > > > > From OP-TEE point of view I think most of the secure SGI donation base
> > > > > > would be common, so can we switch the SMC ABI to use this donated
> > > > > > secure world SGI for notifications too?
> > > > >
> > > > > The SMC ABI driver picks up the interrupt used for notification from
> > > > > device-tree, so there's a chance that it just works if a donated SGI is
> > > > > supplied instead. We'll need some changes in the secure world side of
> > > > > OP-TEE, but they wouldn't affect the ABI.
> > > >
> > > > AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
> > > > The FF-A driver explicitly creates that mapping here [1].
> > >
> > > That looks a lot like what platform_get_irq() does via of_irq_get().
> > >
> >
> > There is GIC_SPI or GIC_PPI but nothing like GIC_SGI in DT bindings [1].
> >
> > [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/dt-bindings/interrupt-controller/arm-gic.h
> >
> > > > Moreover
> > > > it's better to detect it via an SMC call rather than hard coded via DT
> > > > as FF-A driver does.
> > >
> > > Typo? I guess you mean that you prefer that way the FF-A driver does it
> > > rather than having it set in the DT.
> >
> > Yeah sorry about that. We shouldn't use DT if OP-TEE features are discoverable.
> >
> > >
> > > Assuming that you only care about "arm,gic-v3". The SGI will likely
> > > always be the same so it shouldn't be too hard to keep the correct
> > > configuration in DT.
> >
> > See above, DT looks like it does not support SGI.
>
> You're right.
>
> >
> > >
> > > >
> > > > So the ABI should dynamically detect if there is a donated SGI then
> > > > use it otherwise fallback to SPI/PPI detection via DT. This would make
> > > > the notifications feature platform agnostic and we can drop legacy DT
> > > > methods from optee-os entirely but still need to maintain them in the
> > > > kernel for backwards compatibility.
> > >
> > > We care about compatibility in both directions so we'd need to keep it
> > > in OP-TEE too, but perhaps under a config flag.
> >
> > Isn't it just supported on Qemu right now in OP-TEE? I hope dropping a
> > feature won't be a problem there compared with the maintenance burden.
>
> I'd rather not remove this since I believe it can support more
> configurations (different interrupt controllers), but feel free to
> propose a patch with the new ABI.

Having a second thought here, I think adding further ABIs (redundant
ABIs become maintenance burden overtime) don't make sense until we see
real users of notifications. Have you been able to discover real users
of this asynchronous notifications feature in OP-TEE?

-Sumit

>
> Cheers,
> Jens
>
> >
> > -Sumit
> >
> > >
> > > Thanks,
> > > Jens
> > >
> > > >
> > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
> > > > [2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275
> > > >
> > > > -Sumit
> > > >
> > > > >
> > > > > Cheers,
> > > > > Jens
> > > > >
> > > > > >
> > > > > > -Sumit
> > > > > >
> > > > > > >
> > > > > > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > > > > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > > > > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > > > > > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > > > > > >
> > > > > > > Thanks,
> > > > > > > Jens
> > > > > > >
> > > > > > > Jens Wiklander (2):
> > > > > > >   optee: provide optee_do_bottom_half() as a common function
> > > > > > >   optee: ffa_abi: add asynchronous notifications
> > > > > > >
> > > > > > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > > > > > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > > > > > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > > > > > >  drivers/tee/optee/optee_private.h |  9 ++-
> > > > > > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > > > > > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > > > > > >
> > > > > > >
> > > > > > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > > > > > --
> > > > > > > 2.34.1
> > > > > > >

Re: [PATCH 0/2] OP-TEE FF-A notifications

[Jens Wiklander]

On Fri, Nov 3, 2023 at 9:53 AM Sumit Garg <sumit.garg@linaro.org> wrote:
>
> On Fri, 3 Nov 2023 at 13:32, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> >
> > On Thu, Nov 2, 2023 at 3:05 PM Sumit Garg <sumit.garg@linaro.org> wrote:
> > >
> > > On Thu, 2 Nov 2023 at 18:46, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > >
> > > > On Thu, Nov 02, 2023 at 05:46:55PM +0530, Sumit Garg wrote:
> > > > > On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > > >
> > > > > > Hi Sumit,
> > > > > >
> > > > > > On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > > > > > > Hi Jens,
> > > > > > >
> > > > > > > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > > > > >
> > > > > > > > Hi all,
> > > > > > > >
> > > > > > > > This patchset adds support for using FF-A notifications as a delivery
> > > > > > > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > > > > > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > > > > > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > > > > > > >
> > > > > > > > Support for FF-A notifications is added with [2] and this patch set is based
> > > > > > > > on Sudeeps tree at [3].
> > > > > > >
> > > > > > > It's good to see FF-A notifications support coming through. The good
> > > > > > > aspect here is that FF-A uses a common secure world SGI for
> > > > > > > notifications and doesn't have to deal with platform specific reserved
> > > > > > > SPI for notifications.
> > > > > > >
> > > > > > > From OP-TEE point of view I think most of the secure SGI donation base
> > > > > > > would be common, so can we switch the SMC ABI to use this donated
> > > > > > > secure world SGI for notifications too?
> > > > > >
> > > > > > The SMC ABI driver picks up the interrupt used for notification from
> > > > > > device-tree, so there's a chance that it just works if a donated SGI is
> > > > > > supplied instead. We'll need some changes in the secure world side of
> > > > > > OP-TEE, but they wouldn't affect the ABI.
> > > > >
> > > > > AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
> > > > > The FF-A driver explicitly creates that mapping here [1].
> > > >
> > > > That looks a lot like what platform_get_irq() does via of_irq_get().
> > > >
> > >
> > > There is GIC_SPI or GIC_PPI but nothing like GIC_SGI in DT bindings [1].
> > >
> > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/dt-bindings/interrupt-controller/arm-gic.h
> > >
> > > > > Moreover
> > > > > it's better to detect it via an SMC call rather than hard coded via DT
> > > > > as FF-A driver does.
> > > >
> > > > Typo? I guess you mean that you prefer that way the FF-A driver does it
> > > > rather than having it set in the DT.
> > >
> > > Yeah sorry about that. We shouldn't use DT if OP-TEE features are discoverable.
> > >
> > > >
> > > > Assuming that you only care about "arm,gic-v3". The SGI will likely
> > > > always be the same so it shouldn't be too hard to keep the correct
> > > > configuration in DT.
> > >
> > > See above, DT looks like it does not support SGI.
> >
> > You're right.
> >
> > >
> > > >
> > > > >
> > > > > So the ABI should dynamically detect if there is a donated SGI then
> > > > > use it otherwise fallback to SPI/PPI detection via DT. This would make
> > > > > the notifications feature platform agnostic and we can drop legacy DT
> > > > > methods from optee-os entirely but still need to maintain them in the
> > > > > kernel for backwards compatibility.
> > > >
> > > > We care about compatibility in both directions so we'd need to keep it
> > > > in OP-TEE too, but perhaps under a config flag.
> > >
> > > Isn't it just supported on Qemu right now in OP-TEE? I hope dropping a
> > > feature won't be a problem there compared with the maintenance burden.
> >
> > I'd rather not remove this since I believe it can support more
> > configurations (different interrupt controllers), but feel free to
> > propose a patch with the new ABI.
>
> Having a second thought here, I think adding further ABIs (redundant
> ABIs become maintenance burden overtime) don't make sense until we see
> real users of notifications. Have you been able to discover real users
> of this asynchronous notifications feature in OP-TEE?

No, not upstream. There have been questions about a feature like this
from time to time in the past and I guess non-trivial interrupt
handling will soon need it.

Cheers,
Jens

>
> -Sumit
>
> >
> > Cheers,
> > Jens
> >
> > >
> > > -Sumit
> > >
> > > >
> > > > Thanks,
> > > > Jens
> > > >
> > > > >
> > > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
> > > > > [2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275
> > > > >
> > > > > -Sumit
> > > > >
> > > > > >
> > > > > > Cheers,
> > > > > > Jens
> > > > > >
> > > > > > >
> > > > > > > -Sumit
> > > > > > >
> > > > > > > >
> > > > > > > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > > > > > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > > > > > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > > > > > > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > > > > > > >
> > > > > > > > Thanks,
> > > > > > > > Jens
> > > > > > > >
> > > > > > > > Jens Wiklander (2):
> > > > > > > >   optee: provide optee_do_bottom_half() as a common function
> > > > > > > >   optee: ffa_abi: add asynchronous notifications
> > > > > > > >
> > > > > > > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > > > > > > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > > > > > > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > > > > > > >  drivers/tee/optee/optee_private.h |  9 ++-
> > > > > > > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > > > > > > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > > > > > > >
> > > > > > > >
> > > > > > > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > > > > > > --
> > > > > > > > 2.34.1
> > > > > > > >

Re: [PATCH 0/2] OP-TEE FF-A notifications

[Sumit Garg]

On Mon, 6 Nov 2023 at 14:09, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> On Fri, Nov 3, 2023 at 9:53 AM Sumit Garg <sumit.garg@linaro.org> wrote:
> >
> > On Fri, 3 Nov 2023 at 13:32, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > >
> > > On Thu, Nov 2, 2023 at 3:05 PM Sumit Garg <sumit.garg@linaro.org> wrote:
> > > >
> > > > On Thu, 2 Nov 2023 at 18:46, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > >
> > > > > On Thu, Nov 02, 2023 at 05:46:55PM +0530, Sumit Garg wrote:
> > > > > > On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > > > >
> > > > > > > Hi Sumit,
> > > > > > >
> > > > > > > On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > > > > > > > Hi Jens,
> > > > > > > >
> > > > > > > > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > > > > > >
> > > > > > > > > Hi all,
> > > > > > > > >
> > > > > > > > > This patchset adds support for using FF-A notifications as a delivery
> > > > > > > > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > > > > > > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > > > > > > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > > > > > > > >
> > > > > > > > > Support for FF-A notifications is added with [2] and this patch set is based
> > > > > > > > > on Sudeeps tree at [3].
> > > > > > > >
> > > > > > > > It's good to see FF-A notifications support coming through. The good
> > > > > > > > aspect here is that FF-A uses a common secure world SGI for
> > > > > > > > notifications and doesn't have to deal with platform specific reserved
> > > > > > > > SPI for notifications.
> > > > > > > >
> > > > > > > > From OP-TEE point of view I think most of the secure SGI donation base
> > > > > > > > would be common, so can we switch the SMC ABI to use this donated
> > > > > > > > secure world SGI for notifications too?
> > > > > > >
> > > > > > > The SMC ABI driver picks up the interrupt used for notification from
> > > > > > > device-tree, so there's a chance that it just works if a donated SGI is
> > > > > > > supplied instead. We'll need some changes in the secure world side of
> > > > > > > OP-TEE, but they wouldn't affect the ABI.
> > > > > >
> > > > > > AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
> > > > > > The FF-A driver explicitly creates that mapping here [1].
> > > > >
> > > > > That looks a lot like what platform_get_irq() does via of_irq_get().
> > > > >
> > > >
> > > > There is GIC_SPI or GIC_PPI but nothing like GIC_SGI in DT bindings [1].
> > > >
> > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/dt-bindings/interrupt-controller/arm-gic.h
> > > >
> > > > > > Moreover
> > > > > > it's better to detect it via an SMC call rather than hard coded via DT
> > > > > > as FF-A driver does.
> > > > >
> > > > > Typo? I guess you mean that you prefer that way the FF-A driver does it
> > > > > rather than having it set in the DT.
> > > >
> > > > Yeah sorry about that. We shouldn't use DT if OP-TEE features are discoverable.
> > > >
> > > > >
> > > > > Assuming that you only care about "arm,gic-v3". The SGI will likely
> > > > > always be the same so it shouldn't be too hard to keep the correct
> > > > > configuration in DT.
> > > >
> > > > See above, DT looks like it does not support SGI.
> > >
> > > You're right.
> > >
> > > >
> > > > >
> > > > > >
> > > > > > So the ABI should dynamically detect if there is a donated SGI then
> > > > > > use it otherwise fallback to SPI/PPI detection via DT. This would make
> > > > > > the notifications feature platform agnostic and we can drop legacy DT
> > > > > > methods from optee-os entirely but still need to maintain them in the
> > > > > > kernel for backwards compatibility.
> > > > >
> > > > > We care about compatibility in both directions so we'd need to keep it
> > > > > in OP-TEE too, but perhaps under a config flag.
> > > >
> > > > Isn't it just supported on Qemu right now in OP-TEE? I hope dropping a
> > > > feature won't be a problem there compared with the maintenance burden.
> > >
> > > I'd rather not remove this since I believe it can support more
> > > configurations (different interrupt controllers), but feel free to
> > > propose a patch with the new ABI.
> >
> > Having a second thought here, I think adding further ABIs (redundant
> > ABIs become maintenance burden overtime) don't make sense until we see
> > real users of notifications. Have you been able to discover real users
> > of this asynchronous notifications feature in OP-TEE?
>
> No, not upstream. There have been questions about a feature like this
> from time to time in the past and I guess non-trivial interrupt
> handling will soon need it.

Okay let's keep the way it is today unless we really need support for SGIs too.

-Sumit

>
> Cheers,
> Jens
>
> >
> > -Sumit
> >
> > >
> > > Cheers,
> > > Jens
> > >
> > > >
> > > > -Sumit
> > > >
> > > > >
> > > > > Thanks,
> > > > > Jens
> > > > >
> > > > > >
> > > > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
> > > > > > [2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275
> > > > > >
> > > > > > -Sumit
> > > > > >
> > > > > > >
> > > > > > > Cheers,
> > > > > > > Jens
> > > > > > >
> > > > > > > >
> > > > > > > > -Sumit
> > > > > > > >
> > > > > > > > >
> > > > > > > > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > > > > > > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > > > > > > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > > > > > > > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > > > > > > > >
> > > > > > > > > Thanks,
> > > > > > > > > Jens
> > > > > > > > >
> > > > > > > > > Jens Wiklander (2):
> > > > > > > > >   optee: provide optee_do_bottom_half() as a common function
> > > > > > > > >   optee: ffa_abi: add asynchronous notifications
> > > > > > > > >
> > > > > > > > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > > > > > > > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > > > > > > > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > > > > > > > >  drivers/tee/optee/optee_private.h |  9 ++-
> > > > > > > > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > > > > > > > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > > > > > > > --
> > > > > > > > > 2.34.1
> > > > > > > > >

Re: [PATCH 0/2] OP-TEE FF-A notifications

[Sudeep Holla]

On Thu, Oct 26, 2023 at 10:04:07AM +0200, Jens Wiklander wrote:
> Hi all,
> 
> This patchset adds support for using FF-A notifications as a delivery
> mechanism of asynchronous notifications from OP-TEE running in the secure
> world. Support for asynchronous notifications via the SMC ABI was added in
> [1], here we add the counterpart needed when using the the FF-A ABI.
> 
> Support for FF-A notifications is added with [2] and this patch set is based
> on Sudeeps tree at [3].
> 
> [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
>     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> 

FWIW:

Tested-by: Sudeep Holla <sudeep.holla@arm.com>

-- 
Regards,
Sudeep

Re: [PATCH 0/2] OP-TEE FF-A notifications

[Jens Wiklander]

On Tue, Nov 7, 2023 at 12:48 PM Sudeep Holla <sudeep.holla@arm.com> wrote:
>
> On Thu, Oct 26, 2023 at 10:04:07AM +0200, Jens Wiklander wrote:
> > Hi all,
> >
> > This patchset adds support for using FF-A notifications as a delivery
> > mechanism of asynchronous notifications from OP-TEE running in the secure
> > world. Support for asynchronous notifications via the SMC ABI was added in
> > [1], here we add the counterpart needed when using the the FF-A ABI.
> >
> > Support for FF-A notifications is added with [2] and this patch set is based
> > on Sudeeps tree at [3].
> >
> > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> >
>
> FWIW:
>
> Tested-by: Sudeep Holla <sudeep.holla@arm.com>

Thanks, much appreciated.

Cheers,
Jens

>
> --
> Regards,
> Sudeep