Re: [PATCH v13 4/4] EINJ, Documentation: Update EINJ kernel doc

Dan Williams
2024-02-21T20:27:42Z

Ben Cheatham wrote:
> Update EINJ kernel document to include how to inject CXL protocol error
> types, build the kernel to include CXL error types, and give an example
> injection.
>
> Signed-off-by: Ben Cheatham <Benjamin.Cheatham@amd.com>
> ---
> .../firmware-guide/acpi/apei/einj.rst | 21 +++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/Documentation/firmware-guide/acpi/apei/einj.rst b/Documentation/firmware-guide/acpi/apei/einj.rst
> index d6b61d22f525..23741ec0de75 100644
> --- a/Documentation/firmware-guide/acpi/apei/einj.rst
> +++ b/Documentation/firmware-guide/acpi/apei/einj.rst
> @@ -181,6 +181,27 @@ You should see something like this in dmesg::
> [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)
>
> +CXL error types are supported from ACPI 6.5 onwards (given a CXL port
> +is present). These error types are not available in the legacy interface
> +at /sys/kernel/debug/apei/einj, and are instead at /sys/kernel/debug/cxl/.
> +There is a file under debug/cxl called "einj_type" that is analogous to
> +available_error_type under debug/cxl. There is also a "einj_inject" file
> +in each $dport_dev directory under debug/cxl that will inject a given error
> +into the dport represented by $dport_dev.

Follow the style of the current document and document the files in a
section following this one:

---
The EINJ user interface is in <debugfs mount point>/apei/einj.

The following files belong to it:
---

> +
> +For example, to inject a CXL.mem protocol correctable error into
> +$dport_dev=pci0000:0c::
> +
> + # cd /sys/kernel/debug/cxl/
> + # cat einj_type # See which error can be injected
> + 0x00008000 CXL.mem Protocol Correctable
> + 0x00010000 CXL.mem Protocol Uncorrectable non-fatal
> + 0x00020000 CXL.mem Protocol Uncorrectable fatal
> + # cd 0000:e0:01.1 # Navigate to dport to inject into
> + # echo 0x8000 > einj_inject # Inject error
> +
> +To use CXL error types, ``CONFIG_ACPI_APEI_CXL_EINJ`` will need to be enabled.

Config symbols are already communicated in this list:

---
To use EINJ, make sure the following are options enabled in your kernel
configuration::

CONFIG_DEBUG_FS
CONFIG_ACPI_APEI
CONFIG_ACPI_APEI_EINJ
---

...so just add something like:

---
diff --git a/Documentation/firmware-guide/acpi/apei/einj.rst b/Documentation/firmware-guide/acpi/apei/e>
index d6b61d22f525..3bfd86f50c61 100644
--- a/Documentation/firmware-guide/acpi/apei/einj.rst
+++ b/Documentation/firmware-guide/acpi/apei/einj.rst
@@ -32,6 +32,10 @@ configuration::
CONFIG_ACPI_APEI
CONFIG_ACPI_APEI_EINJ

+...and optionally to enable CXL protocol error injection set:
+
+ CONFIG_ACPI_APEI_EINJ_CXL
+
The EINJ user interface is in <debugfs mount point>/apei/einj.

The following files belong to it:
---

...just to make it look like the document was written by a single
author.