[tip:x86/urgent] x86/topology: Document cpu_llc_id

[tip-bot for Borislav Petkov]

Commit-ID:  dbf12ae564c022a741a6983b2bb4aeea5b8c0efd
Gitweb:     http://git.kernel.org/tip/dbf12ae564c022a741a6983b2bb4aeea5b8c0efd
Author:     Borislav Petkov <bp@xxxxxxxxx>
AuthorDate: Thu, 17 Nov 2016 10:45:57 +0100
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Mon, 19 Dec 2016 12:27:53 +0100

x86/topology: Document cpu_llc_id

It means different things on Intel and AMD so write it down so that
there's no confusion.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Yazen Ghannam <yazen.ghannam@xxxxxxx>
Link: http://lkml.kernel.org/r/20161117094557.jm6hwzdd52h7iwnj@xxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
 Documentation/x86/topology.txt | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/x86/topology.txt b/Documentation/x86/topology.txt
index 06afac2..f3e9d7e 100644
--- a/Documentation/x86/topology.txt
+++ b/Documentation/x86/topology.txt
@@ -63,6 +63,15 @@ The topology of a system is described in the units of:
     The maximum possible number of packages in the system. Helpful for per
     package facilities to preallocate per package information.
 
+  - cpu_llc_id:
+
+    A per-CPU variable containing:
+    - On Intel, the first APIC ID of the list of CPUs sharing the Last Level
+    Cache
+
+    - On AMD, the Node ID or Core Complex ID containing the Last Level
+    Cache. In general, it is a number identifying an LLC uniquely on the
+    system.
 
 * Cores: