[PATCH] sep initializing rework

Make SEP init per-cpu, so it is hotplug safe.

Signed-off-by: Li Shaohua<shaohua.li@intel.com>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 7 insertions, 5 deletions

diff --git a/arch/i386/kernel/sysenter.c b/arch/i386/kernel/sysenter.c
index 960d8bd137d0..0bada1870bdf 100644
--- a/arch/i386/kernel/sysenter.c
+++ b/arch/i386/kernel/sysenter.c
@@ -21,11 +21,16 @@
 
 extern asmlinkage void sysenter_entry(void);
 
-void enable_sep_cpu(void *info)
+void enable_sep_cpu(void)
 {
         int cpu = get_cpu();
         struct tss_struct *tss = &per_cpu(init_tss, cpu);
 
+        if (!boot_cpu_has(X86_FEATURE_SEP)) {
+                put_cpu();
+                return;
+        }
+
         tss->ss1 = __KERNEL_CS;
         tss->esp1 = sizeof(struct tss_struct) + (unsigned long) tss;
         wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
@@ -41,7 +46,7 @@ void enable_sep_cpu(void *info)
 extern const char vsyscall_int80_start, vsyscall_int80_end;
 extern const char vsyscall_sysenter_start, vsyscall_sysenter_end;
 
-static int __init sysenter_setup(void)
+int __init sysenter_setup(void)
 {
         void *page = (void *)get_zeroed_page(GFP_ATOMIC);
 
@@ -58,8 +63,5 @@ static int __init sysenter_setup(void)
                &vsyscall_sysenter_start,
                &vsyscall_sysenter_end - &vsyscall_sysenter_start);
 
-        on_each_cpu(enable_sep_cpu, NULL, 1, 1);
         return 0;
 }
-
-__initcall(sysenter_setup);