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Diffstat (limited to 'Documentation/driver-api/ipmi.rst')
| -rw-r--r-- | Documentation/driver-api/ipmi.rst | 91 |
1 files changed, 74 insertions, 17 deletions
diff --git a/Documentation/driver-api/ipmi.rst b/Documentation/driver-api/ipmi.rst index bc281f10ce4b..f52ab2df2569 100644 --- a/Documentation/driver-api/ipmi.rst +++ b/Documentation/driver-api/ipmi.rst @@ -45,7 +45,7 @@ manual), choose the 'IPMI SI handler' option. A driver also exists for direct I2C access to the IPMI management controller. Some boards support this, but it is unknown if it will work on every board. For this, choose 'IPMI SMBus handler', but be ready to try to do some -figuring to see if it will work on your system if the SMBIOS/APCI +figuring to see if it will work on your system if the SMBIOS/ACPI information is wrong or not present. It is fairly safe to have both these enabled and let the drivers auto-detect what is present. @@ -63,7 +63,7 @@ situation, you need to read the section below named 'The SI Driver' or IPMI defines a standard watchdog timer. You can enable this with the 'IPMI Watchdog Timer' config option. If you compile the driver into the kernel, then via a kernel command-line option you can have the -watchdog timer start as soon as it initializes. It also have a lot +watchdog timer start as soon as it initializes. It also has a lot of other options, see the 'Watchdog' section below for more details. Note that you can also have the watchdog continue to run if it is closed (by default it is disabled on close). Go into the 'Watchdog @@ -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 -------- @@ -263,10 +280,8 @@ Creating the User To use the message handler, you must first create a user using ipmi_create_user. The interface number specifies which SMI you want to connect to, and you must supply callback functions to be called -when data comes in. The callback function can run at interrupt level, -so be careful using the callbacks. This also allows to you pass in a -piece of data, the handler_data, that will be passed back to you on -all calls. +when data comes in. This also allows to you pass in a piece of data, +the handler_data, that will be passed back to you on all calls. Once you are done, call ipmi_destroy_user() to get rid of the user. @@ -286,8 +301,7 @@ use it for anything you like. Responses come back in the function pointed to by the ipmi_recv_hndl field of the "handler" that you passed in to ipmi_create_user(). -Remember again, these may be running at interrupt level. Remember to -look at the receive type, too. +Remember to look at the receive type, too. From userland, you fill out an ipmi_req_t structure and use the IPMICTL_SEND_COMMAND ioctl. For incoming stuff, you can use select() @@ -300,13 +314,13 @@ This gives the receiver a place to actually put the message. If the message cannot fit into the data you provide, you will get an EMSGSIZE error and the driver will leave the data in the receive -queue. If you want to get it and have it truncate the message, us +queue. If you want to get it and have it truncate the message, use the IPMICTL_RECEIVE_MSG_TRUNC ioctl. When you send a command (which is defined by the lowest-order bit of the netfn per the IPMI spec) on the IPMB bus, the driver will automatically assign the sequence number to the command and save the -command. If the response is not receive in the IPMI-specified 5 +command. If the response is not received in the IPMI-specified 5 seconds, it will generate a response automatically saying the command timed out. If an unsolicited response comes in (if it was after 5 seconds, for instance), that response will be ignored. @@ -348,6 +362,10 @@ 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 received message. + From userland, equivalent IOCTLs are provided to do these functions. @@ -419,7 +437,7 @@ register would be 0xca6. This defaults to 1. The regsizes parameter gives the size of a register, in bytes. The data used by IPMI is 8-bits wide, but it may be inside a larger -register. This parameter allows the read and write type to specified. +register. This parameter allows the read and write type to be specified. It may be 1, 2, 4, or 8. The default is 1. Since the register size may be larger than 32 bits, the IPMI data may not @@ -460,8 +478,8 @@ If your IPMI interface does not support interrupts and is a KCS or SMIC interface, the IPMI driver will start a kernel thread for the interface to help speed things up. This is a low-priority kernel thread that constantly polls the IPMI driver while an IPMI operation -is in progress. The force_kipmid module parameter will all the user to -force this thread on or off. If you force it off and don't have +is in progress. The force_kipmid module parameter will allow the user +to force this thread on or off. If you force it off and don't have interrupts, the driver will run VERY slowly. Don't blame me, these interfaces suck. @@ -519,7 +537,7 @@ at module load time (for a module) with:: alerts_broken The addresses are normal I2C addresses. The adapter is the string -name of the adapter, as shown in /sys/class/i2c-adapter/i2c-<n>/name. +name of the adapter, as shown in /sys/bus/i2c/devices/i2c-<n>/name. It is *NOT* i2c-<n> itself. Also, the comparison is done ignoring spaces, so if the name is "This is an I2C chip" you can say adapter_name=ThisisanI2cchip. This is because it's hard to pass in @@ -562,7 +580,7 @@ kernel command line as:: These are the same options as on the module command line. The I2C driver does not support non-blocking access or polling, so -this driver cannod to IPMI panic events, extend the watchdog at panic +this driver cannot do IPMI panic events, extend the watchdog at panic time, or other panic-related IPMI functions without special kernel patches and driver modifications. You can get those at the openipmi web page. @@ -570,6 +588,45 @@ web page. The driver supports a hot add and remove of interfaces through the I2C sysfs interface. +The IPMI IPMB Driver +-------------------- + +This driver is for supporting a system that sits on an IPMB bus; it +allows the interface to look like a normal IPMI interface. Sending +system interface addressed messages to it will cause the message to go +to the registered BMC on the system (default at IPMI address 0x20). + +It also allows you to directly address other MCs on the bus using the +ipmb direct addressing. You can receive commands from other MCs on +the bus and they will be handled through the normal received command +mechanism described above. + +Parameters are:: + + ipmi_ipmb.bmcaddr=<address to use for system interface addresses messages> + ipmi_ipmb.retry_time_ms=<Time between retries on IPMB> + ipmi_ipmb.max_retries=<Number of times to retry a message> + +Loading the module will not result in the driver automatically +starting unless there is device tree information setting it up. If +you want to instantiate one of these by hand, do:: + + echo ipmi-ipmb <addr> > /sys/class/i2c-dev/i2c-<n>/device/new_device + +Note that the address you give here is the I2C address, not the IPMI +address. So if you want your MC address to be 0x60, you put 0x30 +here. See the I2C driver info for more details. + +Command bridging to other IPMB buses through this interface does not +work. The receive message queue is not implemented, by design. There +is only one receive message queue on a BMC, and that is meant for the +host drivers, not something on the IPMB bus. + +A BMC may have multiple IPMB buses, which bus your device sits on +depends on how the system is wired. You can fetch the channels with +"ipmitool channel info <n>" where <n> is the channel, with the +channels being 0-7 and try the IPMB channels. + Other Pieces ------------ |