X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=Documentation%2Fcputopology.txt;h=bd699da246666a503195ed0d8240fb531b90f746;hb=87f3b6b6fbcbfa715f0d0db3e7a63e65716a6d4e;hp=ff280e2e1613e808e4d7844376134dfa2bb1fc21;hpb=536ea4e4198eeaa5a73fb734ea675e621609bb7e;p=linux-2.6-omap-h63xx.git

diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt
index ff280e2e161..bd699da2466 100644
--- a/Documentation/cputopology.txt
+++ b/Documentation/cputopology.txt
@@ -1,5 +1,5 @@
 
-Export cpu topology info by sysfs. Items (attributes) are similar
+Export cpu topology info via sysfs. Items (attributes) are similar
 to /proc/cpuinfo.
 
 1) /sys/devices/system/cpu/cpuX/topology/physical_package_id:
@@ -12,11 +12,10 @@ represent the thread siblings to cpu X in the same core;
 represent the thread siblings to cpu X in the same physical package;
 
 To implement it in an architecture-neutral way, a new source file,
-driver/base/topology.c, is to export the 5 attributes.
+drivers/base/topology.c, is to export the 4 attributes.
 
-If one architecture wants to support this feature, it just needs to
-implement 4 defines, typically in file include/asm-XXX/topology.h.
-The 4 defines are:
+For an architecture to support this feature, it must define some of
+these macros in include/asm-XXX/topology.h:
 #define topology_physical_package_id(cpu)
 #define topology_core_id(cpu)
 #define topology_thread_siblings(cpu)
@@ -25,17 +24,10 @@ The 4 defines are:
 The type of **_id is int.
 The type of siblings is cpumask_t.
 
-To be consistent on all architectures, the 4 attributes should have
-deafult values if their values are unavailable. Below is the rule.
-1) physical_package_id: If cpu has no physical package id, -1 is the
-default value.
-2) core_id: If cpu doesn't support multi-core, its core id is 0.
-3) thread_siblings: Just include itself, if the cpu doesn't support
-HT/multi-thread.
-4) core_siblings: Just include itself, if the cpu doesn't support
-multi-core and HT/Multi-thread.
-
-So be careful when declaring the 4 defines in include/asm-XXX/topology.h.
-
-If an attribute isn't defined on an architecture, it won't be exported.
-
+To be consistent on all architectures, include/linux/topology.h
+provides default definitions for any of the above macros that are
+not defined by include/asm-XXX/topology.h:
+1) physical_package_id: -1
+2) core_id: 0
+3) thread_siblings: just the given CPU
+4) core_siblings: just the given CPU