[RFC PATCH v2 8/8] ACPI: APEI: EINJ: Update the documentation for EINJv2 support

[Zaid Alali <zaidal@os.amperecomputing.com>]

Add documentation for the updated ACPI specs for EINJv2(1)(2)

(1)https://bugzilla.tianocore.org/show_bug.cgi?id=4615
(2)https://bugzilla.tianocore.org/attachment.cgi?id=1446

Signed-off-by: Zaid Alali <zaidal@os.amperecomputing.com>
---
 .../firmware-guide/acpi/apei/einj.rst         | 51 +++++++++++++++++--
 1 file changed, 48 insertions(+), 3 deletions(-)

diff --git a/Documentation/firmware-guide/acpi/apei/einj.rst b/Documentation/firmware-guide/acpi/apei/einj.rst
index c52b9da08fa9..f2751cee9698 100644
--- a/Documentation/firmware-guide/acpi/apei/einj.rst
+++ b/Documentation/firmware-guide/acpi/apei/einj.rst
@@ -61,8 +61,18 @@ The following files belong to it:
   0x00000800        Platform Uncorrectable fatal
   ================  ===================================
 
+  ================  ===================================
+  Error Type Value      Error Description
+  ================  ===================================
+  0x00000001        EINJV2 Processor Error
+  0x00000002        EINJV2 Memory Error
+  0x00000004        EINJV2 PCI Express Error
+  ================  ===================================
+
   The format of the file contents are as above, except present are only
-  the available error types.
+  the available error types. The available Error types are discovered by
+  calling GET_ERROR_TYPE command, and if bit 30 is set in the returned
+  value, then EINJv2 is supported by the system.
 
 - error_type
 
@@ -85,9 +95,11 @@ The following files belong to it:
     Bit 0
       Processor APIC field valid (see param3 below).
     Bit 1
-      Memory address and mask valid (param1 and param2).
+      Memory address and range valid (param1 and param2).
     Bit 2
       PCIe (seg,bus,dev,fn) valid (see param4 below).
+    Bit 3
+      EINJv2 extension structure is valid
 
   If set to zero, legacy behavior is mimicked where the type of
   injection specifies just one bit set, and param1 is multiplexed.
@@ -110,6 +122,7 @@ The following files belong to it:
   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
@@ -122,6 +135,18 @@ The following files belong to it:
   this actually works depends on what operations the BIOS actually
   includes in the trigger phase.
 
+- einjv2_component_count
+
+  The value from this file is used to set the "Component Array Count"
+  field of EINJv2 Extension Structure.
+
+- einjv2_component_array
+
+  The contents of this file are used to set the "Component Array" field
+  of the EINJv2 Extension Structure. The expected format is hex values
+  for component id and syndrome separated by space, and multiple
+  components are separated by new line.
+
 CXL error types are supported from ACPI 6.5 onwards (given a CXL port
 is present). The EINJ user interface for CXL error types is at
 <debugfs mount point>/cxl. The following files belong to it:
@@ -139,7 +164,6 @@ is present). The EINJ user interface for CXL error types is at
   under <debugfs mount point>/apei/einj, while CXL 1.1/1.0 port injections
   must use this file.
 
-
 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
@@ -194,6 +218,27 @@ An error injection example::
   # echo 0x8 > error_type			# Choose correctable memory error
   # echo 1 > error_inject			# Inject now
 
+An EINJv2 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
+  ==================
+  0x00000001        EINJV2 Processor Error
+  0x00000002        EINJV2 Memory Error
+
+  # echo 0x12345000 > param1            	# Set memory address for injection
+  # echo 0xfffffffffffff000 > param2            # Range - anywhere in this page
+  # comp_arr="0x1 0x2				# Fill in the component array
+    >0x1 0x4
+    >0x2 0x4"
+  # echo "$comp_arr" > einjv2_component_array
+  # echo 0x2 > error_type                       # Choose EINJv2 memory error
+  # echo 0xa > flags				# set flags to indicate EINJv2
+  # echo 1 > error_inject                       # Inject now
+
 You should see something like this in dmesg::
 
   [22715.830801] EDAC sbridge MC3: HANDLING MCE MEMORY ERROR
-- 
2.34.1