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Diffstat (limited to 'Documentation/acpi/apei/einj.txt')
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diff --git a/Documentation/acpi/apei/einj.txt b/Documentation/acpi/apei/einj.txt new file mode 100644 index 00000000..e20b6daa --- /dev/null +++ b/Documentation/acpi/apei/einj.txt @@ -0,0 +1,107 @@ + APEI Error INJection + ~~~~~~~~~~~~~~~~~~~~ + +EINJ provides a hardware error injection mechanism +It is very useful for debugging and testing of other APEI and RAS features. + +To use EINJ, make sure the following are 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. + +- 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. + +- error_type + This file is used to set the error type value. The error type value + is defined in "available_error_type" description. + +- error_inject + Write any integer to this file to trigger the error + injection. Before this, please specify all necessary error + parameters. + +- param1 + This file is used to set the first error parameter value. Effect of + parameter depends on error_type specified. + +- param2 + This file is used to set the second error parameter value. Effect of + parameter depends on error_type specified. + +- 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: + + 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. +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). + +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 0x8 > error_type # Choose correctable memory error +# echo 1 > error_inject # Inject now + + +For more information about EINJ, please refer to ACPI specification +version 4.0, section 17.5 and ACPI 5.0, section 18.6. |