x86: various changes and cleanups to in_p/out_p delay details

various changes to the in_p/out_p delay details:

- add the io_delay=none method
- make each method selectable from the kernel config
- simplify the delay code a bit by getting rid of an indirect function call
- add the /proc/sys/kernel/io_delay_type sysctl
- change 'io_delay=standard|alternate' to io_delay=0x80 and io_delay=0xed
- make the io delay config not depend on CONFIG_DEBUG_KERNEL

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: "David P. Reed" <dpreed@reed.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 4bc8e48434a7..357b68ba23ec 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -53,6 +53,7 @@
 #ifdef CONFIG_X86
 #include <asm/nmi.h>
 #include <asm/stacktrace.h>
+#include <asm/io.h>
 #endif
 
 static int deprecated_sysctl_warning(struct __sysctl_args *args);
@@ -727,6 +728,14 @@ static struct ctl_table kern_table[] = {
                 .mode           = 0644,
                 .proc_handler   = &proc_dointvec,
         },
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "io_delay_type",
+                .data           = &io_delay_type,
+                .maxlen         = sizeof(int),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec,
+        },
 #endif
 #if defined(CONFIG_MMU)
         {