---

yaml --- r: 141823 b: refs/heads/master c: eeee785 h: refs/heads/master i: 141821: 0f62b8f 141819: e5bbf2c 141815: 86c7af1 141807: 7e56de9 141791: e672dff 141759: 0a38059 141695: 0b9502b 141567: 314dd18 141311: b9f0a2a v: v3
git-mirror · Apr 2, 2009 · 42eb964 · 42eb964
1 parent e23bf0e
commit 42eb964
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Showing 3 changed files with 16 additions and 1 deletion.
diff --git 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
@@ -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
@@ -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>
@@ -32,13 +33,25 @@ 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;
 	unsigned long len = 0, flags = 0;
 	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;