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Add RapidIO documentation files as it was discussed earlier (see thread http://marc.info/?l=linux-kernel&m=129202338918062&w=2) Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
91 lines
3.9 KiB
Plaintext
91 lines
3.9 KiB
Plaintext
RapidIO sysfs Files
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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1. Device Subdirectories
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------------------------
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For each RapidIO device, the RapidIO subsystem creates files in an individual
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subdirectory with the following name, /sys/bus/rapidio/devices/<device_name>.
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The format of device_name is "nn:d:iiii", where:
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nn - two-digit hexadecimal ID of RapidIO network where the device resides
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d - device typr: 'e' - for endpoint or 's' - for switch
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iiii - four-digit device destID for endpoints, or switchID for switches
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For example, below is a list of device directories that represents a typical
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RapidIO network with one switch, one host, and two agent endpoints, as it is
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seen by the enumerating host (destID = 1):
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/sys/bus/rapidio/devices/00:e:0000
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/sys/bus/rapidio/devices/00:e:0002
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/sys/bus/rapidio/devices/00:s:0001
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NOTE: An enumerating or discovering endpoint does not create a sysfs entry for
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itself, this is why an endpoint with destID=1 is not shown in the list.
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2. Attributes Common for All Devices
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------------------------------------
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Each device subdirectory contains the following informational read-only files:
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did - returns the device identifier
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vid - returns the device vendor identifier
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device_rev - returns the device revision level
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asm_did - returns identifier for the assembly containing the device
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asm_rev - returns revision level of the assembly containing the device
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asm_vid - returns vendor identifier of the assembly containing the device
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destid - returns device destination ID assigned by the enumeration routine
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(see 4.1 for switch specific details)
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lprev - returns name of previous device (switch) on the path to the device
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that that owns this attribute
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In addition to the files listed above, each device has a binary attribute file
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that allows read/write access to the device configuration registers using
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the RapidIO maintenance transactions:
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config - reads from and writes to the device configuration registers.
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This attribute is similar in behavior to the "config" attribute of PCI devices
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and provides an access to the RapidIO device registers using standard file read
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and write operations.
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3. Endpoint Device Attributes
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-----------------------------
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Currently Linux RapidIO subsystem does not create any endpoint specific sysfs
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attributes. It is possible that RapidIO master port drivers and endpoint device
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drivers will add their device-specific sysfs attributes but such attributes are
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outside the scope of this document.
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4. Switch Device Attributes
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---------------------------
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RapidIO switches have additional attributes in sysfs. RapidIO subsystem supports
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common and device-specific sysfs attributes for switches. Because switches are
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integrated into the RapidIO subsystem, it offers a method to create
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device-specific sysfs attributes by specifying a callback function that may be
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set by the switch initialization routine during enumeration or discovery process.
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4.1 Common Switch Attributes
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routes - reports switch routing information in "destID port" format. This
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attribute reports only valid routing table entries, one line for
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each entry.
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destid - device destination ID that defines a route to the switch
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hopcount - number of hops on the path to the switch
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lnext - returns names of devices linked to the switch except one of a device
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linked to the ingress port (reported as "lprev"). This is an array
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names with number of lines equal to number of ports in switch. If
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a switch port has no attached device, returns "null" instead of
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a device name.
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4.2 Device-specific Switch Attributes
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Device-specific switch attributes are listed for each RapidIO switch driver
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that exports additional attributes.
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IDT_GEN2:
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errlog - reads contents of device error log until it is empty.
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