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Diffstat (limited to 'Documentation/rapidio/rapidio.txt')
| -rw-r--r-- | Documentation/rapidio/rapidio.txt | 98 |
1 files changed, 85 insertions, 13 deletions
diff --git a/Documentation/rapidio/rapidio.txt b/Documentation/rapidio/rapidio.txt index a9c16c979da..717f5aa388b 100644 --- a/Documentation/rapidio/rapidio.txt +++ b/Documentation/rapidio/rapidio.txt @@ -73,28 +73,44 @@ data structure. This structure includes lists of all devices and local master ports that form the same network. It also contains a pointer to the default master port that is used to communicate with devices within the network. +2.5 Device Drivers + +RapidIO device-specific drivers follow Linux Kernel Driver Model and are +intended to support specific RapidIO devices attached to the RapidIO network. + +2.6 Subsystem Interfaces + +RapidIO interconnect specification defines features that may be used to provide +one or more common service layers for all participating RapidIO devices. These +common services may act separately from device-specific drivers or be used by +device-specific drivers. Example of such service provider is the RIONET driver +which implements Ethernet-over-RapidIO interface. Because only one driver can be +registered for a device, all common RapidIO services have to be registered as +subsystem interfaces. This allows to have multiple common services attached to +the same device without blocking attachment of a device-specific driver. + 3. Subsystem Initialization --------------------------- In order to initialize the RapidIO subsystem, a platform must initialize and register at least one master port within the RapidIO network. To register mport -within the subsystem controller driver initialization code calls function +within the subsystem controller driver's initialization code calls function rio_register_mport() for each available master port. -RapidIO subsystem uses subsys_initcall() or device_initcall() to perform -controller initialization (depending on controller device type). - After all active master ports are registered with a RapidIO subsystem, an enumeration and/or discovery routine may be called automatically or by user-space command. +RapidIO subsystem can be configured to be built as a statically linked or +modular component of the kernel (see details below). + 4. Enumeration and Discovery ---------------------------- 4.1 Overview ------------ -RapidIO subsystem configuration options allow users to specify enumeration and +RapidIO subsystem configuration options allow users to build enumeration and discovery methods as statically linked components or loadable modules. An enumeration/discovery method implementation and available input parameters define how any given method can be attached to available RapidIO mports: @@ -115,8 +131,8 @@ several methods to initiate an enumeration and/or discovery process: endpoint waits for enumeration to be completed. If the specified timeout expires the discovery process is terminated without obtaining RapidIO network information. NOTE: a timed out discovery process may be restarted later using - a user-space command as it is described later if the given endpoint was - enumerated successfully. + a user-space command as it is described below (if the given endpoint was + enumerated successfully). (b) Statically linked enumeration and discovery process can be started by a command from user space. This initiation method provides more flexibility @@ -138,15 +154,42 @@ When a network scan process is started it calls an enumeration or discovery routine depending on the configured role of a master port: host or agent. Enumeration is performed by a master port if it is configured as a host port by -assigning a host device ID greater than or equal to zero. A host device ID is -assigned to a master port through the kernel command line parameter "riohdid=", -or can be configured in a platform-specific manner. If the host device ID for -a specific master port is set to -1, the discovery process will be performed -for it. +assigning a host destination ID greater than or equal to zero. The host +destination ID can be assigned to a master port using various methods depending +on RapidIO subsystem build configuration: + + (a) For a statically linked RapidIO subsystem core use command line parameter + "rapidio.hdid=" with a list of destination ID assignments in order of mport + device registration. For example, in a system with two RapidIO controllers + the command line parameter "rapidio.hdid=-1,7" will result in assignment of + the host destination ID=7 to the second RapidIO controller, while the first + one will be assigned destination ID=-1. + + (b) If the RapidIO subsystem core is built as a loadable module, in addition + to the method shown above, the host destination ID(s) can be specified using + traditional methods of passing module parameter "hdid=" during its loading: + - from command line: "modprobe rapidio hdid=-1,7", or + - from modprobe configuration file using configuration command "options", + like in this example: "options rapidio hdid=-1,7". An example of modprobe + configuration file is provided in the section below. + + NOTES: + (i) if "hdid=" parameter is omitted all available mport will be assigned + destination ID = -1; + (ii) the "hdid=" parameter in systems with multiple mports can have + destination ID assignments omitted from the end of list (default = -1). + +If the host device ID for a specific master port is set to -1, the discovery +process will be performed for it. The enumeration and discovery routines use RapidIO maintenance transactions to access the configuration space of devices. +NOTE: If RapidIO switch-specific device drivers are built as loadable modules +they must be loaded before enumeration/discovery process starts. +This requirement is cased by the fact that enumeration/discovery methods invoke +vendor-specific callbacks on early stages. + 4.2 Automatic Start of Enumeration and Discovery ------------------------------------------------ @@ -266,7 +309,36 @@ method's module initialization routine calls rio_register_scan() to attach an enumerator to a specified mport device (or devices). The basic enumerator implementation demonstrates this process. -5. References +4.6 Using Loadable RapidIO Switch Drivers +----------------------------------------- + +In the case when RapidIO switch drivers are built as loadable modules a user +must ensure that they are loaded before the enumeration/discovery starts. +This process can be automated by specifying pre- or post- dependencies in the +RapidIO-specific modprobe configuration file as shown in the example below. + + File /etc/modprobe.d/rapidio.conf: + ---------------------------------- + + # Configure RapidIO subsystem modules + + # Set enumerator host destination ID (overrides kernel command line option) + options rapidio hdid=-1,2 + + # Load RapidIO switch drivers immediately after rapidio core module was loaded + softdep rapidio post: idt_gen2 idtcps tsi57x + + # OR : + + # Load RapidIO switch drivers just before rio-scan enumerator module is loaded + softdep rio-scan pre: idt_gen2 idtcps tsi57x + + -------------------------- + +NOTE: In the example above, one of "softdep" commands must be removed or +commented out to keep required module loading sequence. + +A. References ------------- [1] RapidIO Trade Association. RapidIO Interconnect Specifications. |