[kernel] r15877 - in dists/sid/linux-2.6/debian: . patches/features/sh4 patches/series

[Aurelien Jarno]

Author: aurel32
Date: Tue Jun 15 12:36:19 2010
New Revision: 15877

Log:
* [sh4] optimize runtime disabling of trapped I/O.

Added:
   dists/sid/linux-2.6/debian/patches/features/sh4/
   dists/sid/linux-2.6/debian/patches/features/sh4/sh-optimize-runtime-disabling-of-trapped-IO.patch
Modified:
   dists/sid/linux-2.6/debian/changelog
   dists/sid/linux-2.6/debian/patches/series/16

Modified: dists/sid/linux-2.6/debian/changelog
==============================================================================
--- dists/sid/linux-2.6/debian/changelog	Tue Jun 15 11:12:23 2010	(r15876)
+++ dists/sid/linux-2.6/debian/changelog	Tue Jun 15 12:36:19 2010	(r15877)
@@ -28,6 +28,7 @@
 
   [ Aurelien Jarno ]
   * [sh4] fix sh_tmu clocksource following recent nohz changes.
+  * [sh4] optimize runtime disabling of trapped I/O. 
   * [mips] backport mips/swarm: fix M3 TLB exception handler.
 
   [ Moritz Muehlenhoff ]

Added: dists/sid/linux-2.6/debian/patches/features/sh4/sh-optimize-runtime-disabling-of-trapped-IO.patch
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ dists/sid/linux-2.6/debian/patches/features/sh4/sh-optimize-runtime-disabling-of-trapped-IO.patch	Tue Jun 15 12:36:19 2010	(r15877)
@@ -0,0 +1,28 @@
+commit 08b36c4a02b5a9db609fc6d93b9c41d7fa75713c
+Author: Paul Mundt <lethal at linux-sh.org>
+Date:   Wed Jan 27 21:56:57 2010 +0900
+
+    sh: Optimize runtime disabling of trapped I/O.
+    
+    Presently trapped I/O is only registered if it's not explicitly disabled
+    for the platforms that select it openly. From the fault path this runs
+    through an address lookup before figuring out that nothing matches and
+    falls back through the error path, but we can forego the lookup
+    completely by testing if it's been explicitly disabled. This provides a
+    measurable speedup for things like qemu that rely on runtime disabling.
+    
+    Signed-off-by: Paul Mundt <lethal at linux-sh.org>
+
+diff --git a/arch/sh/kernel/io_trapped.c b/arch/sh/kernel/io_trapped.c
+index 16b83cc..4a8bb4e 100644
+--- a/arch/sh/kernel/io_trapped.c
++++ b/arch/sh/kernel/io_trapped.c
+@@ -271,6 +271,8 @@ int handle_trapped_io(struct pt_regs *regs, unsigned long address)
+ 	insn_size_t instruction;
+ 	int tmp;
+ 
++	if (trapped_io_disable)
++		return 0;
+ 	if (!lookup_tiop(address))
+ 		return 0;
+ 

Modified: dists/sid/linux-2.6/debian/patches/series/16
==============================================================================
--- dists/sid/linux-2.6/debian/patches/series/16	Tue Jun 15 11:12:23 2010	(r15876)
+++ dists/sid/linux-2.6/debian/patches/series/16	Tue Jun 15 12:36:19 2010	(r15877)
@@ -137,3 +137,4 @@
 + features/arm/hp-t5325.patch
 + bugfix/mips/mips-Set-io_map_base-for-several-PCI-bridges-lacking.patch
 - bugfix/all/vlan-macvlan-propagate-transmission-state-to-upper-layer.patch
++ features/sh4/sh-optimize-runtime-disabling-of-trapped-IO.patch