2 files changed, 49 insertions, 11 deletions

diff --git a/Documentation/acpi/apei/einj.txt b/Documentation/acpi/apei/einj.txt
index 5cc699ba5453..e7cc36397217 100644
--- a/Documentation/acpi/apei/einj.txt
+++ b/Documentation/acpi/apei/einj.txt
@@ -47,20 +47,53 @@ directory apei/einj. The following files are provided.
 
 - param1
   This file is used to set the first error parameter value. Effect of
-  parameter depends on error_type specified. For memory error, this is
-  physical memory address.  Only available if param_extension module
-  parameter is specified.
+  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. For memory error, this is
-  physical memory address mask.  Only available if param_extension
-  module parameter is specified.
+  parameter depends on error_type specified.
+
+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
 
-Injecting parameter support is a BIOS version specific extension, that
-is, it only works on some BIOS version.  If you want to use it, please
-make sure your BIOS version has the proper support and specify
-"param_extension=y" in module parameter.
 
 For more information about EINJ, please refer to ACPI specification
-version 4.0, section 17.5.
+version 4.0, section 17.5 and ACPI 5.0, section 18.6.
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index b29f3c416296..033d4e69b43b 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1059,6 +1059,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                         By default, super page will be supported if Intel IOMMU
                         has the capability. With this option, super page will
                         not be supported.
+
+        intel_idle.max_cstate=  [KNL,HW,ACPI,X86]
+                        0       disables intel_idle and fall back on acpi_idle.
+                        1 to 6  specify maximum depth of C-state.
+
         intremap=       [X86-64, Intel-IOMMU]
                         on      enable Interrupt Remapping (default)
                         off     disable Interrupt Remapping