From 42eb9640b7616b14e924da5a36778846a495f571 Mon Sep 17 00:00:00 2001
From: Paul Mundt <lethal@linux-sh.org>
Date: Thu, 2 Apr 2009 12:31:16 +0900
Subject: [PATCH] --- yaml --- r: 141823 b: refs/heads/master c:
 eeee7853c4ffaf5b9eb58f39708e3c78f66cee15 h: refs/heads/master i:   141821:
 0f62b8fd6e1b39e35859fd6a50a62e8a45453a0c   141819:
 e5bbf2c8f7a6b21c43fd02268949a1fd93fe11e5   141815:
 86c7af1ad588900e6642f45286d00c650e5cb8c9   141807:
 7e56de99b326a91bb3d9861956a77aa0281d2da6   141791:
 e672dffe59281b431c60799733aa7c37bf1ead14   141759:
 0a380593c288020aec2bea9e0df360290ead979c   141695:
 0b9502b07915d0f484f3fa551f1b1d8dfe779c29   141567:
 314dd180f9e9f20e95c4d79586ef45145192008b   141311:
 b9f0a2a9a55e27e85fa43af27ba7b2eba7599985 v: v3

---
 [refs]                                    |  2 +-
 trunk/Documentation/kernel-parameters.txt |  2 ++
 trunk/arch/sh/kernel/io_trapped.c         | 13 +++++++++++++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index dca906ac3856..a852500e3989 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 8dafc34616282c1fd79d42a4353ee5322767d720
+refs/heads/master: eeee7853c4ffaf5b9eb58f39708e3c78f66cee15
diff --git a/trunk/Documentation/kernel-parameters.txt b/trunk/Documentation/kernel-parameters.txt
index 240257dd4238..8b2067cceadc 100644
--- a/trunk/Documentation/kernel-parameters.txt
+++ b/trunk/Documentation/kernel-parameters.txt
@@ -1544,6 +1544,8 @@ and is between 256 and 4096 characters. It is defined in the file
 			Valid arguments: on, off
 			Default: on
 
+	noiotrap	[SH] Disables trapped I/O port accesses.
+
 	noirqdebug	[X86-32] Disables the code which attempts to detect and
 			disable unhandled interrupt sources.
 
diff --git a/trunk/arch/sh/kernel/io_trapped.c b/trunk/arch/sh/kernel/io_trapped.c
index 39cd7f3aec7b..c22853b059ef 100644
--- a/trunk/arch/sh/kernel/io_trapped.c
+++ b/trunk/arch/sh/kernel/io_trapped.c
@@ -14,6 +14,7 @@
 #include <linux/bitops.h>
 #include <linux/vmalloc.h>
 #include <linux/module.h>
+#include <linux/init.h>
 #include <asm/system.h>
 #include <asm/mmu_context.h>
 #include <asm/uaccess.h>
@@ -32,6 +33,15 @@ EXPORT_SYMBOL_GPL(trapped_mem);
 #endif
 static DEFINE_SPINLOCK(trapped_lock);
 
+static int trapped_io_disable __read_mostly;
+
+static int __init trapped_io_setup(char *__unused)
+{
+	trapped_io_disable = 1;
+	return 1;
+}
+__setup("noiotrap", trapped_io_setup);
+
 int register_trapped_io(struct trapped_io *tiop)
 {
 	struct resource *res;
@@ -39,6 +49,9 @@ int register_trapped_io(struct trapped_io *tiop)
 	struct page *pages[TRAPPED_PAGES_MAX];
 	int k, n;
 
+	if (unlikely(trapped_io_disable))
+		return 0;
+
 	/* structure must be page aligned */
 	if ((unsigned long)tiop & (PAGE_SIZE - 1))
 		goto bad;