diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 2 | ||||
| -rw-r--r-- | arch/sh/kernel/io_trapped.c | 13 |
2 files changed, 15 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 240257dd423..8b2067ccead 100644 --- a/Documentation/kernel-parameters.txt +++ b/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/arch/sh/kernel/io_trapped.c b/arch/sh/kernel/io_trapped.c index 39cd7f3aec7..c22853b059e 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; |