Re: [PATCH v5 3/3] ACPI, APEI, EINJ: Update EINJ documentation

[Ben Cheatham <benjamin.cheatham@amd.com>]

On 9/26/23 6:05 AM, Jonathan Cameron wrote:
> On Mon, 25 Sep 2023 15:01:27 -0500
> Ben Cheatham <Benjamin.Cheatham@amd.com> wrote:
> 
>> Update EINJ documentation to include CXL errors in available_error_types
>> table and usage of the types.
>>
>> Also fix a formatting error in the param4 file description that caused
>> the description to be on the same line as the bullet point.
>>
>> Signed-off-by: Ben Cheatham <Benjamin.Cheatham@amd.com>
> A trivial comment inline.
> 
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
>> ---
>>  .../firmware-guide/acpi/apei/einj.rst         | 25 ++++++++++++++++---
>>  1 file changed, 21 insertions(+), 4 deletions(-)
>>
>> diff --git a/Documentation/firmware-guide/acpi/apei/einj.rst b/Documentation/firmware-guide/acpi/apei/einj.rst
>> index d6b61d22f525..c6f28118c48b 100644
>> --- a/Documentation/firmware-guide/acpi/apei/einj.rst
>> +++ b/Documentation/firmware-guide/acpi/apei/einj.rst
>> @@ -32,6 +32,9 @@ configuration::
>>    CONFIG_ACPI_APEI
>>    CONFIG_ACPI_APEI_EINJ
>>  
>> +To use CXL error types ``CONFIG_CXL_ACPI`` needs to be set to the same
>> +value as ``CONFIG_ACPI_APEI_EINJ`` (either "y" or "m").
>> +
>>  The EINJ user interface is in <debugfs mount point>/apei/einj.
>>  
>>  The following files belong to it:
>> @@ -40,9 +43,9 @@ The following files belong to it:
>>  
>>    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
>> @@ -55,7 +58,13 @@ The following files belong to it:
>>    0x00000200        Platform Correctable
>>    0x00000400        Platform Uncorrectable non-fatal
>>    0x00000800        Platform Uncorrectable fatal
>> -  ================  ===================================
>> +  0x00001000        CXL.cache Protocol Correctable
>> +  0x00002000        CXL.cache Protocol Uncorrectable non-fatal
>> +  0x00004000        CXL.cache Protocol Uncorrectable fatal
>> +  0x00008000        CXL.mem Protocol Correctable
>> +  0x00010000        CXL.mem Protocol Uncorrectable non-fatal
>> +  0x00020000        CXL.mem Protocol Uncorrectable fatal
>> +  ================  =========================================
>>  
>>    The format of the file contents are as above, except present are only
>>    the available error types.
>> @@ -106,6 +115,7 @@ The following files belong to it:
>>    Used when the 0x1 bit is set in "flags" to specify the APIC id
>>  
>>  - param4
>> +
> 
> #Unrelated change.  Probably reasonable but should be separate patch really.
> 

I'll take that out.

Thanks,
Ben

>>    Used when the 0x4 bit is set in "flags" to specify target PCIe device
>>  
>>  - notrigger
>> @@ -159,6 +169,13 @@ 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).
>>  
>> +CXL error types are supported from ACPI 6.5 onwards. To use these error
>> +types you need the MMIO address of a CXL 1.1 downstream port. You can
>> +find the address of dportY in /sys/bus/cxl/devices/portX/dportY/cxl_rcrb_addr
>> +(it's possible that the dport is under the CXL root, in that case the
>> +path would be /sys/us/cxl/devices/rootX/dportY/cxl_rcrb_addr).
>> +From there, write the address to param1 and continue as you would for a
>> +memory error type.
>>  
>>  An error injection example::
>>  
>> @@ -201,4 +218,4 @@ The following sequence can be used:
>>    7) Read from the virtual address. This will trigger the error
>>  
>>  For more information about EINJ, please refer to ACPI specification
>> -version 4.0, section 17.5 and ACPI 5.0, section 18.6.
>> +version 4.0, section 17.5 and ACPI 6.5, section 18.6.
>