diff options
Diffstat (limited to 'Documentation/rapidio')
| -rw-r--r-- | Documentation/rapidio/rapidio.txt | 216 | ||||
| -rw-r--r-- | Documentation/rapidio/sysfs.txt | 84 | ||||
| -rw-r--r-- | Documentation/rapidio/tsi721.txt | 49 |
3 files changed, 322 insertions, 27 deletions
diff --git a/Documentation/rapidio/rapidio.txt b/Documentation/rapidio/rapidio.txt index be70ee15f8c..28fbd877f85 100644 --- a/Documentation/rapidio/rapidio.txt +++ b/Documentation/rapidio/rapidio.txt @@ -73,39 +73,175 @@ 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 -rio_register_mport() for each available master port. After all active master -ports are registered with a RapidIO subsystem, the rio_init_mports() routine -is called to perform enumeration and discovery. +within the subsystem controller driver's initialization code calls function +rio_register_mport() for each available master port. + +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. -In the current PowerPC-based implementation a subsys_initcall() is specified to -perform controller initialization and mport registration. At the end it directly -calls rio_init_mports() to execute RapidIO enumeration and discovery. +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 ---------------------------- -When rio_init_mports() is called it scans a list of registered master ports and -calls an enumeration or discovery routine depending on the configured role of a -master port: host or agent. +4.1 Overview +------------ + +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: +simply to all available mports OR individually to the specified mport device. + +Depending on selected enumeration/discovery build configuration, there are +several methods to initiate an enumeration and/or discovery process: + + (a) Statically linked enumeration and discovery process can be started + automatically during kernel initialization time using corresponding module + parameters. This was the original method used since introduction of RapidIO + subsystem. Now this method relies on enumerator module parameter which is + 'rio-scan.scan' for existing basic enumeration/discovery method. + When automatic start of enumeration/discovery is used a user has to ensure + that all discovering endpoints are started before the enumerating endpoint + and are waiting for enumeration to be completed. + Configuration option CONFIG_RAPIDIO_DISC_TIMEOUT defines time that discovering + 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 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 + for a system startup compared to the option (a) above. After all participating + endpoints have been successfully booted, an enumeration process shall be + started first by issuing a user-space command, after an enumeration is + completed a discovery process can be started on all remaining endpoints. + + (c) Modular enumeration and discovery process can be started by a command from + user space. After an enumeration/discovery module is loaded, a network scan + process can be started by issuing a user-space command. + Similar to the option (b) above, an enumerator has to be started first. + + (d) Modular enumeration and discovery process can be started by a module + initialization routine. In this case an enumerating module shall be loaded + first. + +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. -The enumeration process is implemented according to the enumeration algorithm -outlined in the RapidIO Interconnect Specification: Annex I [1]. +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 +------------------------------------------------ + +Automatic enumeration/discovery start method is applicable only to built-in +enumeration/discovery RapidIO configuration selection. To enable automatic +enumeration/discovery start by existing basic enumerator method set use boot +command line parameter "rio-scan.scan=1". + +This configuration requires synchronized start of all RapidIO endpoints that +form a network which will be enumerated/discovered. Discovering endpoints have +to be started before an enumeration starts to ensure that all RapidIO +controllers have been initialized and are ready to be discovered. Configuration +parameter CONFIG_RAPIDIO_DISC_TIMEOUT defines time (in seconds) which +a discovering endpoint will wait for enumeration to be completed. + +When automatic enumeration/discovery start is selected, basic method's +initialization routine calls rio_init_mports() to perform enumeration or +discovery for all known mport devices. + +Depending on RapidIO network size and configuration this automatic +enumeration/discovery start method may be difficult to use due to the +requirement for synchronized start of all endpoints. + +4.3 User-space Start of Enumeration and Discovery +------------------------------------------------- + +User-space start of enumeration and discovery can be used with built-in and +modular build configurations. For user-space controlled start RapidIO subsystem +creates the sysfs write-only attribute file '/sys/bus/rapidio/scan'. To initiate +an enumeration or discovery process on specific mport device, a user needs to +write mport_ID (not RapidIO destination ID) into that file. The mport_ID is a +sequential number (0 ... RIO_MAX_MPORTS) assigned during mport device +registration. For example for machine with single RapidIO controller, mport_ID +for that controller always will be 0. + +To initiate RapidIO enumeration/discovery on all available mports a user may +write '-1' (or RIO_MPORT_ANY) into the scan attribute file. + +4.4 Basic Enumeration Method +---------------------------- + +This is an original enumeration/discovery method which is available since +first release of RapidIO subsystem code. The enumeration process is +implemented according to the enumeration algorithm outlined in the RapidIO +Interconnect Specification: Annex I [1]. + +This method can be configured as statically linked or loadable module. +The method's single parameter "scan" allows to trigger the enumeration/discovery +process from module initialization routine. + +This enumeration/discovery method can be started only once and does not support +unloading if it is built as a module. The enumeration process traverses the network using a recursive depth-first algorithm. When a new device is found, the enumerator takes ownership of that @@ -144,7 +280,7 @@ and the default device ID in order to access the device on the active port. After the host has completed enumeration of the entire network it releases devices by clearing device ID locks (calls rio_clear_locks()). For each endpoint -in the system, it sets the Master Enable bit in the Port General Control CSR +in the system, it sets the Discovered bit in the Port General Control CSR to indicate that enumeration is completed and agents are allowed to execute passive discovery of the network. @@ -160,7 +296,49 @@ time period. If this wait time period expires before enumeration is completed, an agent skips RapidIO discovery and continues with remaining kernel initialization. -5. References +4.5 Adding New Enumeration/Discovery Method +------------------------------------------- + +RapidIO subsystem code organization allows addition of new enumeration/discovery +methods as new configuration options without significant impact to the core +RapidIO code. + +A new enumeration/discovery method has to be attached to one or more mport +devices before an enumeration/discovery process can be started. Normally, +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. + +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. diff --git a/Documentation/rapidio/sysfs.txt b/Documentation/rapidio/sysfs.txt index 97f71ce575d..47ce9a5336e 100644 --- a/Documentation/rapidio/sysfs.txt +++ b/Documentation/rapidio/sysfs.txt @@ -2,8 +2,8 @@ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -1. Device Subdirectories ------------------------- +1. RapidIO Device Subdirectories +-------------------------------- For each RapidIO device, the RapidIO subsystem creates files in an individual subdirectory with the following name, /sys/bus/rapidio/devices/<device_name>. @@ -25,8 +25,8 @@ seen by the enumerating host (destID = 1): NOTE: An enumerating or discovering endpoint does not create a sysfs entry for itself, this is why an endpoint with destID=1 is not shown in the list. -2. Attributes Common for All Devices ------------------------------------- +2. Attributes Common for All RapidIO Devices +-------------------------------------------- Each device subdirectory contains the following informational read-only files: @@ -40,6 +40,7 @@ device_rev - returns the device revision level (see 4.1 for switch specific details) lprev - returns name of previous device (switch) on the path to the device that that owns this attribute + modalias - returns the device modalias In addition to the files listed above, each device has a binary attribute file that allows read/write access to the device configuration registers using @@ -51,16 +52,16 @@ This attribute is similar in behavior to the "config" attribute of PCI devices and provides an access to the RapidIO device registers using standard file read and write operations. -3. Endpoint Device Attributes ------------------------------ +3. RapidIO Endpoint Device Attributes +------------------------------------- Currently Linux RapidIO subsystem does not create any endpoint specific sysfs attributes. It is possible that RapidIO master port drivers and endpoint device drivers will add their device-specific sysfs attributes but such attributes are outside the scope of this document. -4. Switch Device Attributes ---------------------------- +4. RapidIO Switch Device Attributes +----------------------------------- RapidIO switches have additional attributes in sysfs. RapidIO subsystem supports common and device-specific sysfs attributes for switches. Because switches are @@ -88,3 +89,70 @@ that exports additional attributes. IDT_GEN2: errlog - reads contents of device error log until it is empty. + + +5. RapidIO Bus Attributes +------------------------- + +RapidIO bus subdirectory /sys/bus/rapidio implements the following bus-specific +attribute: + + scan - allows to trigger enumeration discovery process from user space. This + is a write-only attribute. To initiate an enumeration or discovery + process on specific mport device, a user needs to write mport_ID (not + RapidIO destination ID) into this file. The mport_ID is a sequential + number (0 ... RIO_MAX_MPORTS) assigned to the mport device. + For example, for a machine with a single RapidIO controller, mport_ID + for that controller always will be 0. + To initiate RapidIO enumeration/discovery on all available mports + a user must write '-1' (or RIO_MPORT_ANY) into this attribute file. + + +6. RapidIO Bus Controllers/Ports +-------------------------------- + +On-chip RapidIO controllers and PCIe-to-RapidIO bridges (referenced as +"Master Port" or "mport") are presented in sysfs as the special class of +devices: "rapidio_port". + +The /sys/class/rapidio_port subdirectory contains individual subdirectories +named as "rapidioN" where N = mport ID registered with RapidIO subsystem. + +NOTE: An mport ID is not a RapidIO destination ID assigned to a given local +mport device. + +Each mport device subdirectory in addition to standard entries contains the +following device-specific attributes: + + port_destid - reports RapidIO destination ID assigned to the given RapidIO + mport device. If value 0xFFFFFFFF is returned this means that + no valid destination ID have been assigned to the mport (yet). + Normally, before enumeration/discovery have been executed only + fabric enumerating mports have a valid destination ID assigned + to them using "hdid=..." rapidio module parameter. + sys_size - reports RapidIO common transport system size: + 0 = small (8-bit destination ID, max. 256 devices), + 1 = large (16-bit destination ID, max. 65536 devices). + +After enumeration or discovery was performed for a given mport device, +the corresponding subdirectory will also contain subdirectories for each +child RapidIO device connected to the mport. Naming conventions for RapidIO +devices are described in Section 1 above. + +The example below shows mport device subdirectory with several child RapidIO +devices attached to it. + +[rio@rapidio ~]$ ls /sys/class/rapidio_port/rapidio0/ -l +total 0 +drwxr-xr-x 3 root root 0 Feb 11 15:10 00:e:0001 +drwxr-xr-x 3 root root 0 Feb 11 15:10 00:e:0004 +drwxr-xr-x 3 root root 0 Feb 11 15:10 00:e:0007 +drwxr-xr-x 3 root root 0 Feb 11 15:10 00:s:0002 +drwxr-xr-x 3 root root 0 Feb 11 15:10 00:s:0003 +drwxr-xr-x 3 root root 0 Feb 11 15:10 00:s:0005 +lrwxrwxrwx 1 root root 0 Feb 11 15:11 device -> ../../../0000:01:00.0 +-r--r--r-- 1 root root 4096 Feb 11 15:11 port_destid +drwxr-xr-x 2 root root 0 Feb 11 15:11 power +lrwxrwxrwx 1 root root 0 Feb 11 15:04 subsystem -> ../../../../../../class/rapidio_port +-r--r--r-- 1 root root 4096 Feb 11 15:11 sys_size +-rw-r--r-- 1 root root 4096 Feb 11 15:04 uevent diff --git a/Documentation/rapidio/tsi721.txt b/Documentation/rapidio/tsi721.txt new file mode 100644 index 00000000000..335f3c6087d --- /dev/null +++ b/Documentation/rapidio/tsi721.txt @@ -0,0 +1,49 @@ +RapidIO subsystem mport driver for IDT Tsi721 PCI Express-to-SRIO bridge. +========================================================================= + +I. Overview + +This driver implements all currently defined RapidIO mport callback functions. +It supports maintenance read and write operations, inbound and outbound RapidIO +doorbells, inbound maintenance port-writes and RapidIO messaging. + +To generate SRIO maintenance transactions this driver uses one of Tsi721 DMA +channels. This mechanism provides access to larger range of hop counts and +destination IDs without need for changes in outbound window translation. + +RapidIO messaging support uses dedicated messaging channels for each mailbox. +For inbound messages this driver uses destination ID matching to forward messages +into the corresponding message queue. Messaging callbacks are implemented to be +fully compatible with RIONET driver (Ethernet over RapidIO messaging services). + +II. Known problems + + None. + +III. To do + + Add DMA data transfers (non-messaging). + Add inbound region (SRIO-to-PCIe) mapping. + +IV. Version History + + 1.0.0 - Initial driver release. + +V. License +----------------------------------------------- + + Copyright(c) 2011 Integrated Device Technology, Inc. All rights reserved. + + This program is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by the Free + Software Foundation; either version 2 of the License, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, but WITHOUT + ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + more details. + + You should have received a copy of the GNU General Public License along with + this program; if not, write to the Free Software Foundation, Inc., + 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |