diff options
Diffstat (limited to 'Documentation/acpi/apei/einj.txt')
| -rw-r--r-- | Documentation/acpi/apei/einj.txt | 177 |
1 files changed, 0 insertions, 177 deletions
diff --git a/Documentation/acpi/apei/einj.txt b/Documentation/acpi/apei/einj.txt deleted file mode 100644 index e550c8b98139..000000000000 --- a/Documentation/acpi/apei/einj.txt +++ /dev/null @@ -1,177 +0,0 @@ - APEI Error INJection - ~~~~~~~~~~~~~~~~~~~~ - -EINJ provides a hardware error injection mechanism. It is very useful -for debugging and testing APEI and RAS features in general. - -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 EINJ user interface is in <debugfs mount point>/apei/einj. - -The following files belong to it: - -- available_error_type - - 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 - - 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. 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 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 (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. 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 - - 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 "flags" to specify the APIC id - -- param4 - Used when the 0x4 bit is set in "flags" to specify target PCIe device - -- notrigger - - 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 | - +-------------------------------------------------+ - -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 -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). - - -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 $((-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. |