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Diffstat (limited to 'arch/sh/kernel/io_trapped.c')
-rw-r--r--arch/sh/kernel/io_trapped.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/sh/kernel/io_trapped.c b/arch/sh/kernel/io_trapped.c
index 39cd7f3aec7b..c22853b059ef 100644
--- a/arch/sh/kernel/io_trapped.c
+++ b/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;