Merge tag 'v4.0.8' into xlnx_4.0.8-rt6

[zynq/linux.git] / arch / x86 / kernel / pvclock.c

diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
index 2f355d229a587771680b28080d92fd06f345d7e7..e5ecd20e72dd56d82447c94c17e6e85ae29eba90 100644 (file)
--- a/arch/x86/kernel/pvclock.c
+++ b/arch/x86/kernel/pvclock.c
@@ -141,7 +141,46 @@ void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock,
        set_normalized_timespec(ts, now.tv_sec, now.tv_nsec);
 }
 
+static struct pvclock_vsyscall_time_info *pvclock_vdso_info;
+
+static struct pvclock_vsyscall_time_info *
+pvclock_get_vsyscall_user_time_info(int cpu)
+{
+       if (!pvclock_vdso_info) {
+               BUG();
+               return NULL;
+       }
+
+       return &pvclock_vdso_info[cpu];
+}
+
+struct pvclock_vcpu_time_info *pvclock_get_vsyscall_time_info(int cpu)
+{
+       return &pvclock_get_vsyscall_user_time_info(cpu)->pvti;
+}
+
 #ifdef CONFIG_X86_64
+static int pvclock_task_migrate(struct notifier_block *nb, unsigned long l,
+                               void *v)
+{
+       struct task_migration_notifier *mn = v;
+       struct pvclock_vsyscall_time_info *pvti;
+
+       pvti = pvclock_get_vsyscall_user_time_info(mn->from_cpu);
+
+       /* this is NULL when pvclock vsyscall is not initialized */
+       if (unlikely(pvti == NULL))
+               return NOTIFY_DONE;
+
+       pvti->migrate_count++;
+
+       return NOTIFY_DONE;
+}
+
+static struct notifier_block pvclock_migrate = {
+       .notifier_call = pvclock_task_migrate,
+};
+
 /*
  * Initialize the generic pvclock vsyscall state.  This will allocate
  * a/some page(s) for the per-vcpu pvclock information, set up a
@@ -155,12 +194,17 @@ int __init pvclock_init_vsyscall(struct pvclock_vsyscall_time_info *i,
 
        WARN_ON (size != PVCLOCK_VSYSCALL_NR_PAGES*PAGE_SIZE);
 
+       pvclock_vdso_info = i;
+
        for (idx = 0; idx <= (PVCLOCK_FIXMAP_END-PVCLOCK_FIXMAP_BEGIN); idx++) {
                __set_fixmap(PVCLOCK_FIXMAP_BEGIN + idx,
                             __pa(i) + (idx*PAGE_SIZE),
                             PAGE_KERNEL_VVAR);
        }
 
+
+       register_task_migration_notifier(&pvclock_migrate);
+
        return 0;
 }
 #endif