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From: Kishon Vijay Abraham I <kishon@ti.com>
To: Ohad Ben-Cohen <ohad@wizery.com>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Jon Mason <jdmason@kudzu.us>, Dave Jiang <dave.jiang@intel.com>,
	Allen Hubbe <allenbh@gmail.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Jason Wang <jasowang@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Stefan Hajnoczi <stefanha@redhat.com>,
	Stefano Garzarella <sgarzare@redhat.com>
Cc: <linux-doc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<linux-remoteproc@vger.kernel.org>, <linux-ntb@googlegroups.com>,
	<linux-pci@vger.kernel.org>, <kvm@vger.kernel.org>,
	<virtualization@lists.linux-foundation.org>,
	<netdev@vger.kernel.org>
Subject: [RFC PATCH 17/22] rpmsg.txt: Add Documentation to configure rpmsg using configfs
Date: Thu, 2 Jul 2020 13:51:38 +0530
Message-ID: <20200702082143.25259-18-kishon@ti.com> (raw)
In-Reply-To: <20200702082143.25259-1-kishon@ti.com>

Add Documentation on how rpmsg device can be created using
configfs required for vhost_rpmsg_bus.c

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 Documentation/rpmsg.txt | 56 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/Documentation/rpmsg.txt b/Documentation/rpmsg.txt
index 24b7a9e1a5f9..0e0a32b2cb66 100644
--- a/Documentation/rpmsg.txt
+++ b/Documentation/rpmsg.txt
@@ -339,3 +339,59 @@ by the bus, and can then start sending messages to the remote service.
 
 The plan is also to add static creation of rpmsg channels via the virtio
 config space, but it's not implemented yet.
+
+Configuring rpmsg using configfs
+================================
+
+Usually a rpmsg_device is created when the virtproc driver (virtio_rpmsg_bus.c)
+receives a name service notification from the remote core. However there could
+also be cases where the user should be given the ability to create rpmsg_device
+(like in the case of vhost_rpmsg_bus.c) where vhost_rpmsg_bus should be
+responsible for sending name service notification. For such cases, configfs
+provides an ability to the user for binding a rpmsg_client_driver with virtproc
+device in order to create rpmsg_device.
+
+Two configfs directories are added for configuring rpmsg
+::
+
+  # ls /sys/kernel/config/rpmsg/
+    channel   virtproc
+
+channel: Whenever a new rpmsg_driver is registered with rpmsg core, a new
+sub-directory will be created for each entry provided in rpmsg_device_id
+table of rpmsg_driver.
+
+For instance when rpmsg_sample_client is installed, it'll create the following
+entry in the mounted configfs directory
+::
+
+  # ls /sys/kernel/config/rpmsg/channel/
+    rpmsg-client-sample
+
+virtproc: A virtproc device can choose to add an entry in this directory.
+Virtproc device adds an entry if it has to allow user to control creation of
+rpmsg device. (e.g vhost_rpmsg_bus.c)
+::
+
+  # ls /sys/kernel/config/rpmsg/virtproc/
+    vhost0
+
+
+The first step in allowing the user to create rpmsg device is to create a
+sub-directory rpmsg-client-sample. For each rpmsg_device, the user would like
+to create, a separate subdirectory has to be created.
+::
+
+  # mkdir /sys/kernel/config/rpmsg/channel/rpmsg-client-sample/c1
+
+The next step is to link the created sub-directory with virtproc device to
+create rpmsg device.
+::
+
+  # ln -s /sys/kernel/config/rpmsg/channel/rpmsg-client-sample/c1 \
+        /sys/kernel/config/rpmsg/virtproc/vhost0
+
+This will create rpmsg_device. However the driver will not register the
+rpmsg device until it receives the VIRTIO_CONFIG_S_DRIVER_OK (in the case
+of vhost_rpmsg_bus.c) as it can access virtio buffers only after
+VIRTIO_CONFIG_S_DRIVER_OK is set.
-- 
2.17.1


  parent reply index

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-02  8:21 [RFC PATCH 00/22] Enhance VHOST to enable SoC-to-SoC communication Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 01/22] vhost: Make _feature_ bits a property of vhost device Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 02/22] vhost: Introduce standard Linux driver model in VHOST Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 03/22] vhost: Add ops for the VHOST driver to configure VHOST device Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 04/22] vringh: Add helpers to access vring in MMIO Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 05/22] vhost: Add MMIO helpers for operations on vhost virtqueue Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 06/22] vhost: Introduce configfs entry for configuring VHOST Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 07/22] virtio_pci: Use request_threaded_irq() instead of request_irq() Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 08/22] rpmsg: virtio_rpmsg_bus: Disable receive virtqueue callback when reading messages Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 09/22] rpmsg: Introduce configfs entry for configuring rpmsg Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 10/22] rpmsg: virtio_rpmsg_bus: Add Address Service Notification support Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 11/22] rpmsg: virtio_rpmsg_bus: Move generic rpmsg structure to rpmsg_internal.h Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 12/22] virtio: Add ops to allocate and free buffer Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 13/22] rpmsg: virtio_rpmsg_bus: Use virtio_alloc_buffer() and virtio_free_buffer() Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 14/22] rpmsg: Add VHOST based remote processor messaging bus Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 15/22] samples/rpmsg: Setup delayed work to send message Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 16/22] samples/rpmsg: Wait for address to be bound to rpdev for sending message Kishon Vijay Abraham I
2020-07-02  8:21 ` Kishon Vijay Abraham I [this message]
2020-07-02  8:21 ` [RFC PATCH 18/22] virtio_pci: Add VIRTIO driver for VHOST on Configurable PCIe Endpoint device Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 19/22] PCI: endpoint: Add EP function driver to provide VHOST interface Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 20/22] NTB: Add a new NTB client driver to implement VIRTIO functionality Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 21/22] NTB: Add a new NTB client driver to implement VHOST functionality Kishon Vijay Abraham I
2020-07-02  8:21 ` [RFC PATCH 22/22] NTB: Describe ntb_virtio and ntb_vhost client in the documentation Kishon Vijay Abraham I
2020-07-02  9:51 ` [RFC PATCH 00/22] Enhance VHOST to enable SoC-to-SoC communication Michael S. Tsirkin
2020-07-02 10:10   ` Jason Wang
2020-07-02 13:35     ` Kishon Vijay Abraham I
2020-07-03  7:16       ` Jason Wang
2020-07-06  9:32         ` Kishon Vijay Abraham I
2020-07-07  9:47           ` Jason Wang
2020-07-07 14:45             ` Kishon Vijay Abraham I
2020-07-08 11:22               ` Jason Wang
2020-07-08 13:13                 ` Kishon Vijay Abraham I
2020-07-09  6:26                   ` Jason Wang
2020-07-15 17:15                   ` Mathieu Poirier
2020-07-02 10:25   ` Kishon Vijay Abraham I
2020-07-02 17:31   ` Mathieu Poirier
2020-07-03  6:17     ` Kishon Vijay Abraham I

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