ACPI, APEI, EINJ: Changes to the ACPI/APEI/EINJ debugfs interface

When I added support for ACPI5 I made the assumption that
injected processor errors would just need to know the APICID,
memory errors just the address and mask, and PCIe errors just the
segment/bus/device/function. So I had the code check the type of injection
and multiplex the "param1" value appropriately.

This was not a good assumption :-(

There are injection scenarios where we need to specify more than one of
these items. E.g. injecting a cache error we need to specify an APICID
of the cpu that owns the cache, and also an address (so that we can trip
the error by accessing the address).

Add a "flags" file to give the user direct access to specify which items
are valid in the ACPI SET_ERROR_TYPE_WITH_ADDRESS structure. Also add
new files param3 and param4 to hold all these values.

For backwards compatability with old injection scripts we maintain the
old behaviour if flags remains set at zero (or is reset to 0).

Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 18 insertions, 1 deletions

diff --git a/Documentation/acpi/apei/einj.txt b/Documentation/acpi/apei/einj.txt
index a58b63da1a36..f51861bcb07b 100644
--- a/Documentation/acpi/apei/einj.txt
+++ b/Documentation/acpi/apei/einj.txt
@@ -45,11 +45,22 @@ directory apei/einj. The following files are provided.
   injection. Before this, please specify all necessary error
   parameters.
 
+- flags
+  Present for kernel version 3.13 and above. Used to specify which
+  of param{1..4} are valid and should be used by BIOS during injection.
+  Value is a bitmask as specified in ACPI5.0 spec for the
+  SET_ERROR_TYPE_WITH_ADDRESS data structure:
+        Bit 0 - Processor APIC field valid (see param3 below)
+        Bit 1 - Memory address and mask valid (param1 and param2)
+        Bit 2 - PCIe (seg,bus,dev,fn) valid (param4 below)
+  If set to zero, legacy behaviour is used where the type of injection
+  specifies just one bit set, and param1 is multiplexed.
+
 - param1
   This file is used to set the first error parameter value. Effect of
   parameter depends on error_type specified. For example, if error
   type is memory related type, the param1 should be a valid physical
-  memory address.
+  memory address. [Unless "flag" is set - see above]
 
 - param2
   This file is used to set the second error parameter value. Effect of
@@ -58,6 +69,12 @@ directory apei/einj. The following files are provided.
   address mask. Linux requires page or narrower granularity, say,
   0xfffffffffffff000.
 
+- param3
+  Used when the 0x1 bit is set in "flag" to specify the APIC id
+
+- param4
+  Used when the 0x4 bit is set in "flag" to specify target PCIe device
+
 - notrigger
   The EINJ mechanism is a two step process. First inject the error, then
   perform some actions to trigger it. Setting "notrigger" to 1 skips the