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| -rw-r--r-- | Documentation/PCI/endpoint/index.rst | 10 | ||||
| -rw-r--r-- | Documentation/PCI/endpoint/pci-endpoint.rst (renamed from Documentation/PCI/endpoint/pci-endpoint.txt) | 92 | ||||
| -rw-r--r-- | Documentation/PCI/index.rst | 1 |
3 files changed, 65 insertions, 38 deletions
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 index e86a96b66a6a..0e2311b5617b 100644 --- a/Documentation/PCI/endpoint/pci-endpoint.txt +++ b/Documentation/PCI/endpoint/pci-endpoint.rst @@ -1,11 +1,13 @@ - PCI ENDPOINT FRAMEWORK - Kishon Vijay Abraham I <kishon@ti.com> +.. SPDX-License-Identifier: GPL-2.0 + +:Author: Kishon Vijay Abraham I <kishon@ti.com> 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 +21,30 @@ 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 +57,116 @@ 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 +178,54 @@ 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 |