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| author | Corey Minyard <minyard@acm.org> | 2021-09-30 17:06:48 -0500 |
|---|---|---|
| committer | Corey Minyard <cminyard@mvista.com> | 2021-10-05 06:54:17 -0500 |
| commit | ddf58738f502895c70a1e24cc3722ed045f7b811 (patch) | |
| tree | 67290dabeeab65af755da579546bb1980fb18d50 /Documentation/driver-api | |
| parent | 63c4eb347164845b380089012fe43992511c0ad3 (diff) | |
| download | linux-ddf58738f502895c70a1e24cc3722ed045f7b811.tar.bz2 | |
ipmi: Add docs for IPMB direct addressing
Describe the addressing mechanism and how to use it.
Signed-off-by: Corey Minyard <minyard@acm.org>
Tested-by: Andrew Manley <andrew.manley@sealingtech.com>
Reviewed-by: Andrew Manley <andrew.manley@sealingtech.com>
Diffstat (limited to 'Documentation/driver-api')
| -rw-r--r-- | Documentation/driver-api/ipmi.rst | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/Documentation/driver-api/ipmi.rst b/Documentation/driver-api/ipmi.rst index bc281f10ce4b..c9cb5669bc4c 100644 --- a/Documentation/driver-api/ipmi.rst +++ b/Documentation/driver-api/ipmi.rst @@ -166,8 +166,8 @@ and the type is IPMI_SYSTEM_INTERFACE_ADDR_TYPE. This is used for talking straight to the BMC on the current card. The channel must be IPMI_BMC_CHANNEL. -Messages that are destined to go out on the IPMB bus use the -IPMI_IPMB_ADDR_TYPE address type. The format is:: +Messages that are destined to go out on the IPMB bus going through the +BMC use the IPMI_IPMB_ADDR_TYPE address type. The format is:: struct ipmi_ipmb_addr { @@ -181,6 +181,23 @@ The "channel" here is generally zero, but some devices support more than one channel, it corresponds to the channel as defined in the IPMI spec. +There is also an IPMB direct address for a situation where the sender +is directly on an IPMB bus and doesn't have to go through the BMC. +You can send messages to a specific management controller (MC) on the +IPMB using the IPMI_IPMB_DIRECT_ADDR_TYPE with the following format:: + + struct ipmi_ipmb_direct_addr + { + int addr_type; + short channel; + unsigned char slave_addr; + unsigned char rq_lun; + unsigned char rs_lun; + }; + +The channel is always zero. You can also receive commands from other +MCs that you have registered to handle and respond to them, so you can +use this to implement a management controller on a bus.. Messages -------- @@ -348,6 +365,10 @@ user may be registered for each netfn/cmd/channel, but different users may register for different commands, or the same command if the channel bitmasks do not overlap. +To respond to a received command, set the response bit in the returned +netfn, use the address from the received message, and use the same +msgid that you got in the receive message. + From userland, equivalent IOCTLs are provided to do these functions. |