Lines Matching refs:the
10 It provides for dynamic discovery of sensors in the system and the
11 ability to monitor the sensors and be informed when the sensor's
18 management software that can use the IPMI system.
20 This document describes how to use the IPMI driver for Linux. If you
21 are not familiar with IPMI itself, see the web site at
30 these are available in the 'Character Devices' menu then the IPMI
37 Kernel code (like the watchdog) can still use it. If you need access
42 properly provides the SMBIOS info for IPMI, the driver will detect it
45 manual), choose the 'IPMI SI handler' option. A driver also exists
46 for direct I2C access to the IPMI management controller. Some boards
49 figuring to see if it will work on your system if the SMBIOS/APCI
51 these enabled and let the drivers auto-detect what is present.
56 If you have a standard interface and the board manufacturer has done
57 their job correctly, the IPMI controller should be automatically
61 situation, you need to read the section below named 'The SI Driver' or
64 IPMI defines a standard watchdog timer. You can enable this with the
65 'IPMI Watchdog Timer' config option. If you compile the driver into
66 the kernel, then via a kernel command-line option you can have the
68 of other options, see the 'Watchdog' section below for more details.
69 Note that you can also have the watchdog continue to run if it is
70 closed (by default it is disabled on close). Go into the 'Watchdog
71 Cards' menu, enable 'Watchdog Timer Support', and enable the option
75 'IPMI Poweroff' to do this. The driver will auto-detect if the system
77 system doesn't support this option. This works on ATCA systems, the
81 If you want the driver to put an event into the event log on a panic,
82 enable the 'Generate a panic event to all BMCs on a panic' option. If
83 you want the whole panic string put into the event log using OEM
84 events, enable the 'Generate OEM events containing the panic string'
91 only need to take the pieces you need and you can use it in many
95 ipmi_msghandler - This is the central piece of software for the IPMI
97 IPMI users tie into this, and the IPMI physical interfaces (called
99 provides the kernelland interface for IPMI, but does not provide an
102 ipmi_devintf - This provides a userland IOCTL interface for the IPMI
103 driver, each open file for this device ties in to the message handler
110 ipmi_ssif - A driver for accessing BMCs on the SMBus. It uses the
112 over the SMBus.
115 timer. This driver implements the standard Linux watchdog timer
116 interface on top of the IPMI message handler.
118 ipmi_poweroff - Some systems support the ability to be turned off via
123 Note that the KCS-only interface has been removed. The af_ipmi driver
127 Much documentation for the interface is in the include files. The
130 net/af_ipmi.h - Contains the socket interface.
132 linux/ipmi.h - Contains the user interface and IOCTL interface for IPMI.
134 linux/ipmi_smi.h - Contains the interface for system management interfaces
144 to handle the different address types. The overlay is:
153 The addr_type determines what the address really is. The driver
164 and the type is IPMI_SYSTEM_INTERFACE_ADDR_TYPE. This is used for talking
165 straight to the BMC on the current card. The channel must be
168 Messages that are destined to go out on the IPMB bus use the
180 than one channel, it corresponds to the channel as defined in the IPMI
198 The driver takes care of adding/stripping the header information. The
199 data portion is just the data to be send (do NOT put addressing info
200 here) or the response. Note that the completion code of a response is
201 the first item in "data", it is not stripped out because that is how
202 all the messages are defined in the spec (and thus makes counting the
205 When using the IOCTL interface from userland, you must provide a block
206 of data for "data", fill it, and set data_len to the length of the
207 block of data, even when receiving messages. Otherwise the driver
208 will have no place to put the message.
210 Messages coming up from the message handler in kernelland will come in
217 /* The type of message as defined in the "Receive Types"
226 /* Call this when done with the message. It will presumably free
227 the message and do any other necessary cleanup. */
230 /* Place-holder for the data, don't make any assumptions about
231 the size or existence of this, since it may change. */
235 You should look at the receive type and handle the message
242 The upper layer of the interface provides the users with a consistent
243 view of the IPMI interfaces. It allows multiple SMI interfaces to be
245 and the user should not have to care what type of SMI is below them.
248 Creating the User
250 To user the message handler, you must first create a user using
254 so be careful using the callbacks. This also allows to you pass in a
255 piece of data, the handler_data, that will be passed back to you on
258 Once you are done, call ipmi_destroy_user() to get rid of the user.
260 From userland, opening the device automatically creates a user, and
261 closing the device automatically destroys the user.
266 To send a message from kernel-land, the ipmi_request() call does
267 pretty much all message handling. Most of the parameter are
269 the sequence number of messages. It is simply a long value that is
270 passed back when the response for the message is returned. You may
273 Responses come back in the function pointed to by the ipmi_recv_hndl
274 field of the "handler" that you passed in to ipmi_create_user().
276 look at the receive type, too.
278 From userland, you fill out an ipmi_req_t structure and use the
281 read() to get them, you must call the IPMICTL_RECEIVE_MSG with the
282 ipmi_recv_t structure to actually get the message. Remember that you
283 must supply a pointer to a block of data in the msg.data field, and
284 you must fill in the msg.data_len field with the size of the data.
285 This gives the receiver a place to actually put the message.
287 If the message cannot fit into the data you provide, you will get an
288 EMSGSIZE error and the driver will leave the data in the receive
289 queue. If you want to get it and have it truncate the message, us
290 the IPMICTL_RECEIVE_MSG_TRUNC ioctl.
292 When you send a command (which is defined by the lowest-order bit of
293 the netfn per the IPMI spec) on the IPMB bus, the driver will
294 automatically assign the sequence number to the command and save the
295 command. If the response is not receive in the IPMI-specified 5
296 seconds, it will generate a response automatically saying the command
302 that you should NEVER mess with the "done" field of a message, that is
303 required to properly clean up the message.
306 that lets you supply the smi and receive message. This is useful for
307 pieces of code that need to work even if the system is out of buffers
308 (the watchdog timer uses this, for instance). You supply your own
317 commands that other things on the IPMB bus have sent you). To receive
321 To receive events, you must call ipmi_set_gets_events() and set the
322 "val" to non-zero. Any events that have been received by the driver
323 since startup will immediately be delivered to the first user that
328 want to receive. Call ipmi_register_for_cmd() and supply the netfn
330 specify a bitmask of the channels you want to receive the command from
333 may register for different commands, or the same command if the
342 As mentioned before, multiple SMI interfaces may be registered to the
344 they register with the message handler. They are generally assigned
345 in the order they register, although if an SMI unregisters and then
348 The ipmi_smi.h defines the interface for management interfaces, see
356 in the system. By default, scan the ACPI tables for interfaces, and
357 if it doesn't find any the driver will attempt to register one KCS
358 interface at the spec-specified I/O port 0xca2 without interrupts.
373 Each of these except try... items is a list, the first item for the
374 first interface, second item for the second interface, etc.
379 If you specify addrs as non-zero for an interface, the driver will
380 use the memory address given as the address of the device. This
383 If you specify ports as non-zero for an interface, the driver will
384 use the I/O port given as the device address.
386 If you specify irqs as non-zero for an interface, the driver will
387 attempt to use the given interrupt for the device.
389 trydefaults sets whether the standard IPMI interface at 0xca2 and
390 any interfaces specified by ACPE are tried. By default, the driver
398 registers used by the interfaces may not appear at successive
400 allow the layout of the data in the registers to be more precisely
403 The regspacings parameter give the number of bytes between successive
404 register start addresses. For instance, if the regspacing is set to 4
405 and the start address is 0xca2, then the address for the second
408 The regsizes parameter gives the size of a register, in bytes. The
410 register. This parameter allows the read and write type to specified.
413 Since the register size may be larger than 32 bits, the IPMI data may not
414 be in the lower 8 bits. The regshifts parameter give the amount to shift
415 the data to get to the actual IPMI data.
417 The slave_addrs specifies the IPMI address of the local BMC. This is
418 usually 0x20 and the driver defaults to that, but in case it's not, it
419 can be specified when the driver starts up.
422 (if set to 0) the kernel IPMI daemon. Normally this is auto-detected
423 by the driver, but systems with broken interrupts might need an enable,
424 or users that don't want the daemon (don't need the performance, don't
425 want the CPU hit) can disable it.
427 If unload_when_empty is set to 1, the driver will be unloaded if it
428 doesn't find any interfaces or all the interfaces fail to work. The
429 default is one. Setting to 0 is useful with the hotmod, but is
432 When compiled into the kernel, the parameters can be specified on the
445 It works the same as the module parameters of the same names.
447 By default, the driver will attempt to detect any device specified by
448 ACPI, and if none of those then a KCS device at the spec-specified
449 0xca2. If you want to turn this off, set the "trydefaults" option to
453 SMIC interface, the IPMI driver will start a kernel thread for the
455 thread that constantly polls the IPMI driver while an IPMI operation
456 is in progress. The force_kipmid module parameter will all the user to
458 interrupts, the driver will run VERY slowly. Don't blame me,
461 Unfortunately, this thread can use a lot of CPU depending on the
464 avoid this, the kipmid_max_busy_us sets the maximum amount of time, in
468 that's not a simple thing and even the auto-tuning would need to be
469 tuned to the user's desired performance.
472 interfaces can be added or removed after the kernel is up and running.
475 has the format:
479 You can specify more than one interface on the line. The "opt"s are:
485 and these have the same meanings as discussed above. Note that you
486 can also use this on the kernel command line for a more compact format
488 only the first three parameters (si type, address type, and address)
489 are used for the comparison. Any options are ignored for removing.
494 The SMBus driver allows up to 4 SMBus devices to be configured in the
495 system. By default, the driver will only register with something it
506 The addresses are normal I2C addresses. The adapter is the string
507 name of the adapter, as shown in /sys/class/i2c-adapter/i2c-<n>/name.
508 It is *NOT* i2c-<n> itself. Also, the comparison is done ignoring
509 spaces, so if the name is "This is an I2C chip" you can say
516 Setting dbg_probe to 1 will enable debugging of the probing and
517 detection process for BMCs on the SMBusses.
519 The slave_addrs specifies the IPMI address of the local BMC. This is
520 usually 0x20 and the driver defaults to that, but in case it's not, it
521 can be specified when the driver starts up.
523 Discovering the IPMI compliant BMC on the SMBus can cause devices on
524 the I2C bus to fail. The SMBus driver writes a "Get Device ID" IPMI
525 message as a block write to the I2C bus and waits for a response.
527 recommended that the known I2C address be given to the SMBus driver in
528 the smb_addr parameter unless you have DMI or ACPI data to tell the
531 When compiled into the kernel, the addresses can be specified on the
540 These are the same options as on the module command line.
543 this driver cannod to IPMI panic events, extend the watchdog at panic
545 patches and driver modifications. You can get those at the openipmi
548 The driver supports a hot add and remove of interfaces through the I2C
554 Get the detailed info related with the IPMI device
558 the address came from or the raw base device for the IPMI interface.
559 You can use the IPMI smi_watcher to catch the IPMI interfaces as they
560 come or go, and to grab the information, you can use the function
561 ipmi_get_smi_info(), which returns the following structure:
576 Note that the dev pointer is included in the above structure, and
578 on the dev pointer.
584 A watchdog timer is provided that implements the Linux-standard
592 ifnum_to_use specifies which interface the watchdog timer should use.
593 The default is -1, which means to pick the first one registered.
595 The timeout is the number of seconds to the action, and the pretimeout
596 is the amount of seconds before the reset that the pre-timeout panic will
598 that the pretimeout is the time before the final timeout. So if the
599 timeout is 50 seconds and the pretimeout is 10 seconds, then the pretimeout
600 will occur in 40 second (10 seconds before the timeout). The panic_wdt_timeout
601 is the value of timeout which is set on kernel panic, in order to let actions
605 specifies what to do when the timer times out, and defaults to
608 The preaction may be "pre_smi" for an indication through the SMI
609 interface, "pre_int" for an indication through the SMI with an
611 the driver is informed of the pretimeout.
614 "preop_panic" to set the preoperation to panic, or "preop_give_data"
615 to provide data to read from the watchdog device when the pretimeout
620 on the device when the pretimeout occurs. Select and fasync work on
621 the device, as well.
623 If start_now is set to 1, the watchdog timer will start running as
624 soon as the driver is loaded.
626 If nowayout is set to 1, the watchdog timer will not stop when the
628 if the CONFIG_WATCHDOG_NOWAYOUT option is enabled, or false if not.
630 When compiled into the kernel, the kernel command line is available
631 for configuring the watchdog:
641 The options are the same as the module parameter options.
644 gets a pre-action. During a panic or a reboot, the watchdog will
645 start a 120 timer if it is running to make sure the reboot occurs.
647 Note that if you use the NMI preaction for the watchdog, you MUST NOT
648 use the nmi watchdog. There is no reasonable way to tell if an NMI
649 comes from the IPMI controller, so it must assume that if it gets an
653 Once you open the watchdog timer, you must write a 'V' character to the
654 device to close it, or the timer will not stop. This is a new semantic
655 for the driver, but makes it consistent with the rest of the watchdog
662 The OpenIPMI driver supports the ability to put semi-custom and custom
663 events in the system event log if a panic occurs. if you enable the
666 the 'Generate OEM events containing the panic string' option, you will
667 also get a bunch of OEM events holding the panic string.
670 The field settings of the events are:
674 * Sensor #: The first byte of the panic string (0 if no panic string)
679 See the IPMI spec for the details of the event layout. This event is
680 always sent to the local management controller. It will handle routing
681 the message to the right place
683 Other OEM events have the following format:
684 Record ID (bytes 0-1): Set by the SEL.
686 byte 3: The slave address of the card saving the panic
688 The rest of the bytes (11 bytes) are the panic string. If the panic string
692 Because you cannot send OEM events using the standard interface, this
693 function will attempt to find an SEL and add the events there. It
694 will first query the capabilities of the local management controller.
695 If it has an SEL, then they will be stored in the SEL of the local
696 management controller. If not, and the local management controller is
697 an event generator, the event receiver from the local management
698 controller will be queried and the events sent to the SEL on that
699 device. Otherwise, the events go nowhere since there is nowhere to
706 If the poweroff capability is selected, the IPMI driver will install
707 a shutdown function into the standard poweroff function pointer. This
708 is in the ipmi_poweroff module. When the system requests a powerdown,
709 it will send the proper IPMI commands to do this. This is supported on
714 the system off, then power it on in a few seconds). Setting
715 ipmi_poweroff.poweroff_control=x will do the same thing on the kernel
716 command line. The parameter is also available via the proc filesystem
717 in /proc/sys/dev/ipmi/poweroff_powercycle. Note that if the system
718 does not support power cycling, it will always do the power off.
720 The "ifnum_to_use" parameter specifies which interface the poweroff
721 code should use. The default is -1, which means to pick the first one
724 Note that if you have ACPI enabled, the system will prefer using ACPI to