Documentation/PCI/pciebus-howto.rst

15 and provides information on how to enable the service drivers to
38 and handled by corresponding service drivers.
46 services. To maintain a clean and simple solution each service
47 may have its own software service driver. In this case several
48 service drivers will compete for a single PCI-PCI Bridge device.
49 For example, if the PCI Express Root Port native hotplug service
51 kernel therefore does not load other service drivers for that Root
52 Port. In other words, it is impossible to have multiple service
56 To enable multiple service drivers running simultaneously requires
58 PCI Express Ports and distributes all provided service requests
59 to the corresponding service drivers as required. Some key
62   - Allow multiple service drivers to run simultaneously on
65   - Allow service drivers implemented in an independent
68   - Allow one service driver to run on multiple PCI-PCI Bridge
72     device to requested service drivers.
74 Configuring the PCI Express Port Bus Driver vs. Service Drivers
85 Enabling Service Driver Support
89 All service drivers are PCI device drivers. As discussed above, it is
90 impossible to load any service driver once the kernel has loaded the
92 Model requires some minimal changes on existing service drivers that
93 imposes no impact on the functionality of existing service drivers.
95 A service driver is required to use the two APIs shown below to
96 register its service with the PCI Express Port Bus driver (see
97 section 5.2.1 & 5.2.2). It is important that a service driver
101 the PCI Express Port Bus driver from loading a service driver.
110 service driver should always calls pcie_port_service_register at
111 module init. Note that after service driver being loaded, calls
122 pci_unregister_driver. It's always called by service driver when a
128 Below is sample service driver code to initialize the port service
151 Below is a sample code for registering/unregistering a service
179 Since all service drivers of a PCI-PCI Bridge Port device are
187 mode until they are disabled again.  Since service drivers of the same
189 service driver enables or disables MSI/MSI-X mode it may result
192 To avoid this situation all service drivers are not permitted to
195 transparent to service drivers. Service drivers need to know only
197 is passed in when the PCI Express Port Bus driver probes each service
198 driver. Service drivers should use (struct pcie_device*)dev->irq to
205 Service drivers for PCI Express Power Management (PME), Advanced
209 that all service drivers will be well behaved and not overwrite
210 other service driver's configuration settings.
215 Each service driver runs its PCI config operations on its own
217 that is shared between many drivers including the service drivers.