[PATCH v5 09/12] Documentation: PCI: convert endpoint/pci-endpoint.txt to reST

From: Changbin Du
Date: Mon May 13 2019 - 10:22:44 EST


This converts the plain text documentation to reStructuredText format and
add it to Sphinx TOC tree. No essential content change.

Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
Documentation/PCI/endpoint/index.rst | 10 ++
.../{pci-endpoint.txt => pci-endpoint.rst} | 96 +++++++++++--------
Documentation/PCI/index.rst | 1 +
3 files changed, 69 insertions(+), 38 deletions(-)
create mode 100644 Documentation/PCI/endpoint/index.rst
rename Documentation/PCI/endpoint/{pci-endpoint.txt => pci-endpoint.rst} (82%)

diff --git a/Documentation/PCI/endpoint/index.rst b/Documentation/PCI/endpoint/index.rst
new file mode 100644
index 000000000000..0db4f2fcd7f0
--- /dev/null
+++ b/Documentation/PCI/endpoint/index.rst
@@ -0,0 +1,10 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+======================
+PCI Endpoint Framework
+======================
+
+.. toctree::
+ :maxdepth: 2
+
+ pci-endpoint
diff --git a/Documentation/PCI/endpoint/pci-endpoint.txt b/Documentation/PCI/endpoint/pci-endpoint.rst
similarity index 82%
rename from Documentation/PCI/endpoint/pci-endpoint.txt
rename to Documentation/PCI/endpoint/pci-endpoint.rst
index e86a96b66a6a..693f3a2ad7a4 100644
--- a/Documentation/PCI/endpoint/pci-endpoint.txt
+++ b/Documentation/PCI/endpoint/pci-endpoint.rst
@@ -1,11 +1,17 @@
- PCI ENDPOINT FRAMEWORK
- Kishon Vijay Abraham I <kishon@xxxxxx>
+.. SPDX-License-Identifier: GPL-2.0
+
+======================
+PCI Endpoint Framework
+======================
+
+:Author: Kishon Vijay Abraham I <kishon@xxxxxx>

This document is a guide to use the PCI Endpoint Framework in order to create
endpoint controller driver, endpoint function driver, and using configfs
interface to bind the function driver to the controller driver.

-1. Introduction
+Introduction
+============

Linux has a comprehensive PCI subsystem to support PCI controllers that
operates in Root Complex mode. The subsystem has capability to scan PCI bus,
@@ -19,26 +25,30 @@ add endpoint mode support in Linux. This will help to run Linux in an
EP system which can have a wide variety of use cases from testing or
validation, co-processor accelerator, etc.

-2. PCI Endpoint Core
+PCI Endpoint Core
+=================

The PCI Endpoint Core layer comprises 3 components: the Endpoint Controller
library, the Endpoint Function library, and the configfs layer to bind the
endpoint function with the endpoint controller.

-2.1 PCI Endpoint Controller(EPC) Library
+PCI Endpoint Controller(EPC) Library
+------------------------------------

The EPC library provides APIs to be used by the controller that can operate
in endpoint mode. It also provides APIs to be used by function driver/library
in order to implement a particular endpoint function.

-2.1.1 APIs for the PCI controller Driver
+APIs for the PCI controller Driver
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This section lists the APIs that the PCI Endpoint core provides to be used
by the PCI controller driver.

-*) devm_pci_epc_create()/pci_epc_create()
+* devm_pci_epc_create()/pci_epc_create()

The PCI controller driver should implement the following ops:
+
* write_header: ops to populate configuration space header
* set_bar: ops to configure the BAR
* clear_bar: ops to reset the BAR
@@ -51,110 +61,116 @@ by the PCI controller driver.
The PCI controller driver can then create a new EPC device by invoking
devm_pci_epc_create()/pci_epc_create().

-*) devm_pci_epc_destroy()/pci_epc_destroy()
+* devm_pci_epc_destroy()/pci_epc_destroy()

The PCI controller driver can destroy the EPC device created by either
devm_pci_epc_create() or pci_epc_create() using devm_pci_epc_destroy() or
pci_epc_destroy().

-*) pci_epc_linkup()
+* pci_epc_linkup()

In order to notify all the function devices that the EPC device to which
they are linked has established a link with the host, the PCI controller
driver should invoke pci_epc_linkup().

-*) pci_epc_mem_init()
+* pci_epc_mem_init()

Initialize the pci_epc_mem structure used for allocating EPC addr space.

-*) pci_epc_mem_exit()
+* pci_epc_mem_exit()

Cleanup the pci_epc_mem structure allocated during pci_epc_mem_init().

-2.1.2 APIs for the PCI Endpoint Function Driver
+
+APIs for the PCI Endpoint Function Driver
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This section lists the APIs that the PCI Endpoint core provides to be used
by the PCI endpoint function driver.

-*) pci_epc_write_header()
+* pci_epc_write_header()

The PCI endpoint function driver should use pci_epc_write_header() to
write the standard configuration header to the endpoint controller.

-*) pci_epc_set_bar()
+* pci_epc_set_bar()

The PCI endpoint function driver should use pci_epc_set_bar() to configure
the Base Address Register in order for the host to assign PCI addr space.
Register space of the function driver is usually configured
using this API.

-*) pci_epc_clear_bar()
+* pci_epc_clear_bar()

The PCI endpoint function driver should use pci_epc_clear_bar() to reset
the BAR.

-*) pci_epc_raise_irq()
+* pci_epc_raise_irq()

The PCI endpoint function driver should use pci_epc_raise_irq() to raise
Legacy Interrupt, MSI or MSI-X Interrupt.

-*) pci_epc_mem_alloc_addr()
+* pci_epc_mem_alloc_addr()

The PCI endpoint function driver should use pci_epc_mem_alloc_addr(), to
allocate memory address from EPC addr space which is required to access
RC's buffer

-*) pci_epc_mem_free_addr()
+* pci_epc_mem_free_addr()

The PCI endpoint function driver should use pci_epc_mem_free_addr() to
free the memory space allocated using pci_epc_mem_alloc_addr().

-2.1.3 Other APIs
+Other APIs
+~~~~~~~~~~

There are other APIs provided by the EPC library. These are used for binding
the EPF device with EPC device. pci-ep-cfs.c can be used as reference for
using these APIs.

-*) pci_epc_get()
+* pci_epc_get()

Get a reference to the PCI endpoint controller based on the device name of
the controller.

-*) pci_epc_put()
+* pci_epc_put()

Release the reference to the PCI endpoint controller obtained using
pci_epc_get()

-*) pci_epc_add_epf()
+* pci_epc_add_epf()

Add a PCI endpoint function to a PCI endpoint controller. A PCIe device
can have up to 8 functions according to the specification.

-*) pci_epc_remove_epf()
+* pci_epc_remove_epf()

Remove the PCI endpoint function from PCI endpoint controller.

-*) pci_epc_start()
+* pci_epc_start()

The PCI endpoint function driver should invoke pci_epc_start() once it
has configured the endpoint function and wants to start the PCI link.

-*) pci_epc_stop()
+* pci_epc_stop()

The PCI endpoint function driver should invoke pci_epc_stop() to stop
the PCI LINK.

-2.2 PCI Endpoint Function(EPF) Library
+
+PCI Endpoint Function(EPF) Library
+----------------------------------

The EPF library provides APIs to be used by the function driver and the EPC
library to provide endpoint mode functionality.

-2.2.1 APIs for the PCI Endpoint Function Driver
+APIs for the PCI Endpoint Function Driver
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This section lists the APIs that the PCI Endpoint core provides to be used
by the PCI endpoint function driver.

-*) pci_epf_register_driver()
+* pci_epf_register_driver()

The PCI Endpoint Function driver should implement the following ops:
* bind: ops to perform when a EPC device has been bound to EPF device
@@ -166,50 +182,54 @@ by the PCI endpoint function driver.
The PCI Function driver can then register the PCI EPF driver by using
pci_epf_register_driver().

-*) pci_epf_unregister_driver()
+* pci_epf_unregister_driver()

The PCI Function driver can unregister the PCI EPF driver by using
pci_epf_unregister_driver().

-*) pci_epf_alloc_space()
+* pci_epf_alloc_space()

The PCI Function driver can allocate space for a particular BAR using
pci_epf_alloc_space().

-*) pci_epf_free_space()
+* pci_epf_free_space()

The PCI Function driver can free the allocated space
(using pci_epf_alloc_space) by invoking pci_epf_free_space().

-2.2.2 APIs for the PCI Endpoint Controller Library
+APIs for the PCI Endpoint Controller Library
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
This section lists the APIs that the PCI Endpoint core provides to be used
by the PCI endpoint controller library.

-*) pci_epf_linkup()
+* pci_epf_linkup()

The PCI endpoint controller library invokes pci_epf_linkup() when the
EPC device has established the connection to the host.

-2.2.2 Other APIs
+Other APIs
+~~~~~~~~~~
+
There are other APIs provided by the EPF library. These are used to notify
the function driver when the EPF device is bound to the EPC device.
pci-ep-cfs.c can be used as reference for using these APIs.

-*) pci_epf_create()
+* pci_epf_create()

Create a new PCI EPF device by passing the name of the PCI EPF device.
This name will be used to bind the the EPF device to a EPF driver.

-*) pci_epf_destroy()
+* pci_epf_destroy()

Destroy the created PCI EPF device.

-*) pci_epf_bind()
+* pci_epf_bind()

pci_epf_bind() should be invoked when the EPF device has been bound to
a EPC device.

-*) pci_epf_unbind()
+* pci_epf_unbind()

pci_epf_unbind() should be invoked when the binding between EPC device
and EPF device is lost.
diff --git a/Documentation/PCI/index.rst b/Documentation/PCI/index.rst
index f54b65b1ca5f..f4c6121868c3 100644
--- a/Documentation/PCI/index.rst
+++ b/Documentation/PCI/index.rst
@@ -15,3 +15,4 @@ Linux PCI Bus Subsystem
acpi-info
pci-error-recovery
pcieaer-howto
+ endpoint/index
--
2.20.1