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

Ben Cheatham
2024-02-20T22:13:16Z

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 $dport_dev.
+
+For example, to inject a CXL.mem protocol correctable error into
+$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.
+
Special notes for injection into SGX enclaves:

There may be a separate BIOS setup option to enable SGX injection.
--
2.34.1