[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>

4 files changed, 31 insertions, 5 deletions

diff --git a/arch/i386/kernel/cpu/common.c b/arch/i386/kernel/cpu/common.c
index b9954248d0aa..d58e169fbdbb 100644
--- a/arch/i386/kernel/cpu/common.c
+++ b/arch/i386/kernel/cpu/common.c
@@ -432,6 +432,9 @@ void __init identify_cpu(struct cpuinfo_x86 *c)
 #ifdef CONFIG_X86_MCE
         mcheck_init(c);
 #endif
+        if (c == &boot_cpu_data)
+                sysenter_setup();
+        enable_sep_cpu();
 }
 
 #ifdef CONFIG_X86_HT
diff --git a/arch/i386/kernel/smp.c b/arch/i386/kernel/smp.c
index 35f521612b20..cec4bde67161 100644
--- a/arch/i386/kernel/smp.c
+++ b/arch/i386/kernel/smp.c
@@ -495,6 +495,16 @@ struct call_data_struct {
         int wait;
 };
 
+void lock_ipi_call_lock(void)
+{
+        spin_lock_irq(&call_lock);
+}
+
+void unlock_ipi_call_lock(void)
+{
+        spin_unlock_irq(&call_lock);
+}
+
 static struct call_data_struct * call_data;
 
 /*
diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index ad74a46e9ef0..c5517f332309 100644
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -449,7 +449,18 @@ static void __init start_secondary(void *unused)
          * the local TLBs too.
          */
         local_flush_tlb();
+
+        /*
+         * We need to hold call_lock, so there is no inconsistency
+         * between the time smp_call_function() determines number of
+         * IPI receipients, and the time when the determination is made
+         * for which cpus receive the IPI. Holding this
+         * lock helps us to not include this cpu in a currently in progress
+         * smp_call_function().
+         */
+        lock_ipi_call_lock();
         cpu_set(smp_processor_id(), cpu_online_map);
+        unlock_ipi_call_lock();
 
         /* We can take interrupts now: we're officially "up". */
         local_irq_enable();
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);