x86: Add i8042 pre-detection hook to x86_platform_ops

Some x86 platforms like Intel MID platforms don't have i8042 controllers,
and i8042 driver's probe to some legacy IO ports may hang the MID
processor. With this hook, i8042 driver can runtime check and skip the
probe when the pretection fail which also saves some probe time

[ hpa note: this is currently a compile-time check, which breaks the
  i386 allyesconfig build.  This patch series thus does fix a regression. ]

Signed-off-by: Feng Tang <feng.tang@intel.com>
LKML-Reference: <1278342202-10973-2-git-send-email-feng.tang@intel.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index 519b54327d750f5e3580ed45cc68e78272c1ba81..baa579c8e03839cbb8d54fb7b2b4d3b7d700742c 100644 (file)
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -142,6 +142,7 @@ struct x86_cpuinit_ops {
  * @set_wallclock:             set time back to HW clock
  * @is_untracked_pat_range     exclude from PAT logic
  * @nmi_init                   enable NMI on cpus
+ * @i8042_detect               pre-detect if i8042 controller exists
  */
 struct x86_platform_ops {
        unsigned long (*calibrate_tsc)(void);
@@ -150,6 +151,7 @@ struct x86_platform_ops {
        void (*iommu_shutdown)(void);
        bool (*is_untracked_pat_range)(u64 start, u64 end);
        void (*nmi_init)(void);
+       int (*i8042_detect)(void);
 };
 
 extern struct x86_init_ops x86_init;

diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index ebfb8e4c9f224d30069485c5fa5f72838dd1dd95..cd6da6bf3ecaf7c24b9b9848c31d313c741d0f16 100644 (file)
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -86,6 +86,7 @@ struct x86_cpuinit_ops x86_cpuinit __cpuinitdata = {
 };
 
 static void default_nmi_init(void) { };
+static int default_i8042_detect(void) { return 1; };
 
 struct x86_platform_ops x86_platform = {
        .calibrate_tsc                  = native_calibrate_tsc,
@@ -93,7 +94,8 @@ struct x86_platform_ops x86_platform = {
        .set_wallclock                  = mach_set_rtc_mmss,
        .iommu_shutdown                 = iommu_shutdown_noop,
        .is_untracked_pat_range         = is_ISA_range,
-       .nmi_init                       = default_nmi_init
+       .nmi_init                       = default_nmi_init,
+       .i8042_detect                   = default_i8042_detect
 };
 
 EXPORT_SYMBOL_GPL(x86_platform);