diff options
Diffstat (limited to 'Documentation/IPMI.txt')
| -rw-r--r-- | Documentation/IPMI.txt | 118 |
1 files changed, 52 insertions, 66 deletions
diff --git a/Documentation/IPMI.txt b/Documentation/IPMI.txt index bc38283379f..f13c9132e9f 100644 --- a/Documentation/IPMI.txt +++ b/Documentation/IPMI.txt @@ -42,13 +42,7 @@ The driver interface depends on your hardware. If your system properly provides the SMBIOS info for IPMI, the driver will detect it and just work. If you have a board with a standard interface (These will generally be either "KCS", "SMIC", or "BT", consult your hardware -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 -information is wrong or not present. It is fairly safe to have both -these enabled and let the drivers auto-detect what is present. +manual), choose the 'IPMI SI handler' option. You should generally enable ACPI on your system, as systems with IPMI can have ACPI tables describing them. @@ -58,8 +52,7 @@ their job correctly, the IPMI controller should be automatically detected (via ACPI or SMBIOS tables) and should just work. Sadly, many boards do not have this information. The driver attempts standard defaults, but they may not work. If you fall into this -situation, you need to read the section below named 'The SI Driver' or -"The SMBus Driver" on how to hand-configure your system. +situation, you need to read the section below named 'The SI Driver'. IPMI defines a standard watchdog timer. You can enable this with the 'IPMI Watchdog Timer' config option. If you compile the driver into @@ -104,12 +97,7 @@ driver, each open file for this device ties in to the message handler as an IPMI user. ipmi_si - A driver for various system interfaces. This supports KCS, -SMIC, and BT interfaces. Unless you have an SMBus interface or your -own custom interface, you probably need to use this. - -ipmi_smb - A driver for accessing BMCs on the SMBus. It uses the -I2C kernel driver's SMBus interfaces to send and receive IPMI messages -over the SMBus. +SMIC, and BT interfaces. ipmi_watchdog - IPMI requires systems to have a very capable watchdog timer. This driver implements the standard Linux watchdog timer @@ -360,33 +348,40 @@ You can change this at module load time (for a module) with: modprobe ipmi_si.o type=<type1>,<type2>.... ports=<port1>,<port2>... addrs=<addr1>,<addr2>... - irqs=<irq1>,<irq2>... trydefaults=[0|1] + irqs=<irq1>,<irq2>... regspacings=<sp1>,<sp2>,... regsizes=<size1>,<size2>,... regshifts=<shift1>,<shift2>,... slave_addrs=<addr1>,<addr2>,... force_kipmid=<enable1>,<enable2>,... + kipmid_max_busy_us=<ustime1>,<ustime2>,... unload_when_empty=[0|1] + trydefaults=[0|1] trydmi=[0|1] tryacpi=[0|1] + tryplatform=[0|1] trypci=[0|1] -Each of these except si_trydefaults is a list, the first item for the +Each of these except try... items is a list, the first item for the first interface, second item for the second interface, etc. The si_type may be either "kcs", "smic", or "bt". If you leave it blank, it defaults to "kcs". -If you specify si_addrs as non-zero for an interface, the driver will +If you specify addrs as non-zero for an interface, the driver will use the memory address given as the address of the device. This overrides si_ports. -If you specify si_ports as non-zero for an interface, the driver will +If you specify ports as non-zero for an interface, the driver will use the I/O port given as the device address. -If you specify si_irqs as non-zero for an interface, the driver will +If you specify irqs as non-zero for an interface, the driver will attempt to use the given interrupt for the device. -si_trydefaults sets whether the standard IPMI interface at 0xca2 and +trydefaults sets whether the standard IPMI interface at 0xca2 and any interfaces specified by ACPE are tried. By default, the driver tries it, set this value to zero to turn this off. +The other try... items disable discovery by their corresponding +names. These are all enabled by default, set them to zero to disable +them. The tryplatform disables openfirmware. + The next three parameters have to do with register layout. The registers used by the interfaces may not appear at successive locations and they may not be in 8-bit registers. These parameters @@ -433,6 +428,7 @@ kernel command line as: ipmi_si.regshifts=<shift1>,<shift2>,... ipmi_si.slave_addrs=<addr1>,<addr2>,... ipmi_si.force_kipmid=<enable1>,<enable2>,... + ipmi_si.kipmid_max_busy_us=<ustime1>,<ustime2>,... It works the same as the module parameters of the same names. @@ -450,6 +446,16 @@ 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. +Unfortunately, this thread can use a lot of CPU depending on the +interface's performance. This can waste a lot of CPU and cause +various issues with detecting idle CPU and using extra power. To +avoid this, the kipmid_max_busy_us sets the maximum amount of time, in +microseconds, that kipmid will spin before sleeping for a tick. This +value sets a balance between performance and CPU waste and needs to be +tuned to your needs. Maybe, someday, auto-tuning will be added, but +that's not a simple thing and even the auto-tuning would need to be +tuned to the user's desired performance. + The driver supports a hot add and remove of interfaces. This way, interfaces can be added or removed after the kernel is up and running. This is done using /sys/modules/ipmi_si/parameters/hotmod, which is a @@ -470,56 +476,36 @@ for specifying an interface. Note that when removing an interface, only the first three parameters (si type, address type, and address) are used for the comparison. Any options are ignored for removing. -The SMBus Driver ----------------- - -The SMBus driver allows up to 4 SMBus devices to be configured in the -system. By default, the driver will register any SMBus interfaces it finds -in the I2C address range of 0x20 to 0x4f on any adapter. You can change this -at module load time (for a module) with: - - modprobe ipmi_smb.o - addr=<adapter1>,<i2caddr1>[,<adapter2>,<i2caddr2>[,...]] - dbg=<flags1>,<flags2>... - [defaultprobe=1] [dbg_probe=1] - -The addresses are specified in pairs, the first is the adapter ID and the -second is the I2C address on that adapter. - -The debug flags are bit flags for each BMC found, they are: -IPMI messages: 1, driver state: 2, timing: 4, I2C probe: 8 - -Setting smb_defaultprobe to zero disabled the default probing of SMBus -interfaces at address range 0x20 to 0x4f. This means that only the -BMCs specified on the smb_addr line will be detected. - -Setting smb_dbg_probe to 1 will enable debugging of the probing and -detection process for BMCs on the SMBusses. -Discovering the IPMI compliant BMC on the SMBus can cause devices -on the I2C bus to fail. The SMBus driver writes a "Get Device ID" IPMI -message as a block write to the I2C bus and waits for a response. -This action can be detrimental to some I2C devices. It is highly recommended -that the known I2c address be given to the SMBus driver in the smb_addr -parameter. The default address range will not be used when a smb_addr -parameter is provided. - -When compiled into the kernel, the addresses can be specified on the -kernel command line as: - - ipmb_smb.addr=<adapter1>,<i2caddr1>[,<adapter2>,<i2caddr2>[,...]] - ipmi_smb.dbg=<flags1>,<flags2>... - ipmi_smb.defaultprobe=0 ipmi_smb.dbg_probe=1 +Other Pieces +------------ -These are the same options as on the module command line. +Get the detailed info related with the IPMI device +-------------------------------------------------- + +Some users need more detailed information about a device, like where +the address came from or the raw base device for the IPMI interface. +You can use the IPMI smi_watcher to catch the IPMI interfaces as they +come or go, and to grab the information, you can use the function +ipmi_get_smi_info(), which returns the following structure: + +struct ipmi_smi_info { + enum ipmi_addr_src addr_src; + struct device *dev; + union { + struct { + void *acpi_handle; + } acpi_info; + } addr_info; +}; -Note that you might need some I2C changes if CONFIG_IPMI_PANIC_EVENT -is enabled along with this, so the I2C driver knows to run to -completion during sending a panic event. +Currently special info for only for SI_ACPI address sources is +returned. Others may be added as necessary. +Note that the dev pointer is included in the above structure, and +assuming ipmi_smi_get_info returns success, you must call put_device +on the dev pointer. -Other Pieces ------------- Watchdog -------- |