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Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/acpi/apei/einj.txt | 196 |
1 files changed, 122 insertions, 74 deletions
diff --git a/Documentation/acpi/apei/einj.txt b/Documentation/acpi/apei/einj.txt index f51861bcb07b..e550c8b98139 100644 --- a/Documentation/acpi/apei/einj.txt +++ b/Documentation/acpi/apei/einj.txt @@ -1,129 +1,177 @@ APEI Error INJection ~~~~~~~~~~~~~~~~~~~~ -EINJ provides a hardware error injection mechanism -It is very useful for debugging and testing of other APEI and RAS features. +EINJ provides a hardware error injection mechanism. It is very useful +for debugging and testing APEI and RAS features in general. -To use EINJ, make sure the following are enabled in your kernel +You need to check whether your BIOS supports EINJ first. For that, look +for early boot messages similar to this one: + +ACPI: EINJ 0x000000007370A000 000150 (v01 INTEL 00000001 INTL 00000001) + +which shows that the BIOS is exposing an EINJ table - it is the +mechanism through which the injection is done. + +Alternatively, look in /sys/firmware/acpi/tables for an "EINJ" file, +which is a different representation of the same thing. + +It doesn't necessarily mean that EINJ is not supported if those above +don't exist: before you give up, go into BIOS setup to see if the BIOS +has an option to enable error injection. Look for something called WHEA +or similar. Often, you need to enable an ACPI5 support option prior, in +order to see the APEI,EINJ,... functionality supported and exposed by +the BIOS menu. + +To use EINJ, make sure the following are options enabled in your kernel configuration: CONFIG_DEBUG_FS CONFIG_ACPI_APEI CONFIG_ACPI_APEI_EINJ -The user interface of EINJ is debug file system, under the -directory apei/einj. The following files are provided. +The EINJ user interface is in <debugfs mount point>/apei/einj. + +The following files belong to it: - available_error_type - Reading this file returns the error injection capability of the - platform, that is, which error types are supported. The error type - definition is as follow, the left field is the error type value, the - right field is error description. - - 0x00000001 Processor Correctable - 0x00000002 Processor Uncorrectable non-fatal - 0x00000004 Processor Uncorrectable fatal - 0x00000008 Memory Correctable - 0x00000010 Memory Uncorrectable non-fatal - 0x00000020 Memory Uncorrectable fatal - 0x00000040 PCI Express Correctable - 0x00000080 PCI Express Uncorrectable fatal - 0x00000100 PCI Express Uncorrectable non-fatal - 0x00000200 Platform Correctable - 0x00000400 Platform Uncorrectable non-fatal - 0x00000800 Platform Uncorrectable fatal - - The format of file contents are as above, except there are only the - available error type lines. + + This file shows which error types are supported: + + Error Type Value Error Description + ================ ================= + 0x00000001 Processor Correctable + 0x00000002 Processor Uncorrectable non-fatal + 0x00000004 Processor Uncorrectable fatal + 0x00000008 Memory Correctable + 0x00000010 Memory Uncorrectable non-fatal + 0x00000020 Memory Uncorrectable fatal + 0x00000040 PCI Express Correctable + 0x00000080 PCI Express Uncorrectable fatal + 0x00000100 PCI Express Uncorrectable non-fatal + 0x00000200 Platform Correctable + 0x00000400 Platform Uncorrectable non-fatal + 0x00000800 Platform Uncorrectable fatal + + The format of the file contents are as above, except present are only + the available error types. - error_type - This file is used to set the error type value. The error type value - is defined in "available_error_type" description. + + Set the value of the error type being injected. Possible error types + are defined in the file available_error_type above. - error_inject - Write any integer to this file to trigger the error - injection. Before this, please specify all necessary error - parameters. + + Write any integer to this file to trigger the error injection. Make + sure you have specified all necessary error parameters, i.e. this + write should be the last step when injecting errors. - flags - Present for kernel version 3.13 and above. Used to specify which - of param{1..4} are valid and should be used by BIOS during injection. - Value is a bitmask as specified in ACPI5.0 spec for the + + Present for kernel versions 3.13 and above. Used to specify which + of param{1..4} are valid and should be used by the firmware during + injection. Value is a bitmask as specified in ACPI5.0 spec for the SET_ERROR_TYPE_WITH_ADDRESS data structure: - Bit 0 - Processor APIC field valid (see param3 below) - Bit 1 - Memory address and mask valid (param1 and param2) - Bit 2 - PCIe (seg,bus,dev,fn) valid (param4 below) - If set to zero, legacy behaviour is used where the type of injection - specifies just one bit set, and param1 is multiplexed. + + Bit 0 - Processor APIC field valid (see param3 below). + Bit 1 - Memory address and mask valid (param1 and param2). + Bit 2 - PCIe (seg,bus,dev,fn) valid (see param4 below). + + If set to zero, legacy behavior is mimicked where the type of + injection specifies just one bit set, and param1 is multiplexed. - param1 - This file is used to set the first error parameter value. Effect of - parameter depends on error_type specified. For example, if error - type is memory related type, the param1 should be a valid physical - memory address. [Unless "flag" is set - see above] + + This file is used to set the first error parameter value. Its effect + depends on the error type specified in error_type. For example, if + error type is memory related type, the param1 should be a valid + physical memory address. [Unless "flag" is set - see above] - param2 - This file is used to set the second error parameter value. Effect of - parameter depends on error_type specified. For example, if error - type is memory related type, the param2 should be a physical memory - address mask. Linux requires page or narrower granularity, say, - 0xfffffffffffff000. + + Same use as param1 above. For example, if error type is of memory + related type, then param2 should be a physical memory address mask. + Linux requires page or narrower granularity, say, 0xfffffffffffff000. - param3 - Used when the 0x1 bit is set in "flag" to specify the APIC id + + Used when the 0x1 bit is set in "flags" to specify the APIC id - param4 - Used when the 0x4 bit is set in "flag" to specify target PCIe device + Used when the 0x4 bit is set in "flags" to specify target PCIe device - notrigger - The EINJ mechanism is a two step process. First inject the error, then - perform some actions to trigger it. Setting "notrigger" to 1 skips the - trigger phase, which *may* allow the user to cause the error in some other - context by a simple access to the cpu, memory location, or device that is - the target of the error injection. Whether this actually works depends - on what operations the BIOS actually includes in the trigger phase. - -BIOS versions based in the ACPI 4.0 specification have limited options -to control where the errors are injected. Your BIOS may support an -extension (enabled with the param_extension=1 module parameter, or -boot command line einj.param_extension=1). This allows the address -and mask for memory injections to be specified by the param1 and -param2 files in apei/einj. - -BIOS versions using the ACPI 5.0 specification have more control over -the target of the injection. For processor related errors (type 0x1, -0x2 and 0x4) the APICID of the target should be provided using the -param1 file in apei/einj. For memory errors (type 0x8, 0x10 and 0x20) -the address is set using param1 with a mask in param2 (0x0 is equivalent -to all ones). For PCI express errors (type 0x40, 0x80 and 0x100) the -segment, bus, device and function are specified using param1: + + The error injection mechanism is a two-step process. First inject the + error, then perform some actions to trigger it. Setting "notrigger" + to 1 skips the trigger phase, which *may* allow the user to cause the + error in some other context by a simple access to the CPU, memory + location, or device that is the target of the error injection. Whether + this actually works depends on what operations the BIOS actually + includes in the trigger phase. + +BIOS versions based on the ACPI 4.0 specification have limited options +in controlling where the errors are injected. Your BIOS may support an +extension (enabled with the param_extension=1 module parameter, or boot +command line einj.param_extension=1). This allows the address and mask +for memory injections to be specified by the param1 and param2 files in +apei/einj. + +BIOS versions based on the ACPI 5.0 specification have more control over +the target of the injection. For processor-related errors (type 0x1, 0x2 +and 0x4), you can set flags to 0x3 (param3 for bit 0, and param1 and +param2 for bit 1) so that you have more information added to the error +signature being injected. The actual data passed is this: + + memory_address = param1; + memory_address_range = param2; + apicid = param3; + pcie_sbdf = param4; + +For memory errors (type 0x8, 0x10 and 0x20) the address is set using +param1 with a mask in param2 (0x0 is equivalent to all ones). For PCI +express errors (type 0x40, 0x80 and 0x100) the segment, bus, device and +function are specified using param1: 31 24 23 16 15 11 10 8 7 0 +-------------------------------------------------+ | segment | bus | device | function | reserved | +-------------------------------------------------+ -An ACPI 5.0 BIOS may also allow vendor specific errors to be injected. +Anyway, you get the idea, if there's doubt just take a look at the code +in drivers/acpi/apei/einj.c. + +An ACPI 5.0 BIOS may also allow vendor-specific errors to be injected. In this case a file named vendor will contain identifying information from the BIOS that hopefully will allow an application wishing to use -the vendor specific extension to tell that they are running on a BIOS +the vendor-specific extension to tell that they are running on a BIOS that supports it. All vendor extensions have the 0x80000000 bit set in error_type. A file vendor_flags controls the interpretation of param1 and param2 (1 = PROCESSOR, 2 = MEMORY, 4 = PCI). See your BIOS vendor documentation for details (and expect changes to this API if vendors creativity in using this feature expands beyond our expectations). -Example: + +An error injection example: + # cd /sys/kernel/debug/apei/einj # cat available_error_type # See which errors can be injected 0x00000002 Processor Uncorrectable non-fatal 0x00000008 Memory Correctable 0x00000010 Memory Uncorrectable non-fatal # echo 0x12345000 > param1 # Set memory address for injection -# echo 0xfffffffffffff000 > param2 # Mask - anywhere in this page +# echo $((-1 << 12)) > param2 # Mask 0xfffffffffffff000 - anywhere in this page # echo 0x8 > error_type # Choose correctable memory error # echo 1 > error_inject # Inject now +You should see something like this in dmesg: + +[22715.830801] EDAC sbridge MC3: HANDLING MCE MEMORY ERROR +[22715.834759] EDAC sbridge MC3: CPU 0: Machine Check Event: 0 Bank 7: 8c00004000010090 +[22715.834759] EDAC sbridge MC3: TSC 0 +[22715.834759] EDAC sbridge MC3: ADDR 12345000 EDAC sbridge MC3: MISC 144780c86 +[22715.834759] EDAC sbridge MC3: PROCESSOR 0:306e7 TIME 1422553404 SOCKET 0 APIC 0 +[22716.616173] EDAC MC3: 1 CE memory read error on CPU_SrcID#0_Channel#0_DIMM#0 (channel:0 slot:0 page:0x12345 offset:0x0 grain:32 syndrome:0x0 - area:DRAM err_code:0001:0090 socket:0 channel_mask:1 rank:0) For more information about EINJ, please refer to ACPI specification version 4.0, section 17.5 and ACPI 5.0, section 18.6. |