x86: pvclock: generic pvclock vsyscall initialization

Originally from Jeremy Fitzhardinge.

Introduce generic, non hypervisor specific, pvclock initialization
routines.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/x86/include/asm/clocksource.h b/arch/x86/include/asm/clocksource.h
index 0bdbbb3b9ce70545337d86b68c269867d6075384..16a57f4ed64de83d8e4321cbbd497d76b01239a7 100644 (file)
--- a/arch/x86/include/asm/clocksource.h
+++ b/arch/x86/include/asm/clocksource.h
@@ -8,6 +8,7 @@
 #define VCLOCK_NONE 0  /* No vDSO clock available.     */
 #define VCLOCK_TSC  1  /* vDSO should use vread_tsc.   */
 #define VCLOCK_HPET 2  /* vDSO should use vread_hpet.  */
+#define VCLOCK_PVCLOCK 3 /* vDSO should use vread_pvclock. */
 
 struct arch_clocksource_data {
        int vclock_mode;

diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
index 4da3c0c4c9741c38efd6418ec081404bb43d8fef..a09c28571064d7d4d148dc34f7f86b3bcb319abb 100644 (file)
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -19,6 +19,7 @@
 #include <asm/acpi.h>
 #include <asm/apicdef.h>
 #include <asm/page.h>
+#include <asm/pvclock.h>
 #ifdef CONFIG_X86_32
 #include <linux/threads.h>
 #include <asm/kmap_types.h>
@@ -80,6 +81,10 @@ enum fixed_addresses {
                            + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
        VVAR_PAGE,
        VSYSCALL_HPET,
+#endif
+#ifdef CONFIG_PARAVIRT_CLOCK
+       PVCLOCK_FIXMAP_BEGIN,
+       PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1,
 #endif
        FIX_DBGP_BASE,
        FIX_EARLYCON_MEM_BASE,

diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
index 63f91679af733d7e86db34163ed95668d7bdd701..109a9dd5d454f197414e2449617cf9cb73ab1220 100644 (file)
--- a/arch/x86/include/asm/pvclock.h
+++ b/arch/x86/include/asm/pvclock.h
@@ -91,4 +91,16 @@ unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src,
        return version;
 }
 
+struct pvclock_vsyscall_time_info {
+       struct pvclock_vcpu_time_info pvti;
+       u32 migrate_count;
+} __attribute__((__aligned__(SMP_CACHE_BYTES)));
+
+#define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info)
+#define PVCLOCK_VSYSCALL_NR_PAGES (((NR_CPUS-1)/(PAGE_SIZE/PVTI_SIZE))+1)
+
+int __init pvclock_init_vsyscall(struct pvclock_vsyscall_time_info *i,
+                                int size);
+struct pvclock_vcpu_time_info *pvclock_get_vsyscall_time_info(int cpu);
+
 #endif /* _ASM_X86_PVCLOCK_H */

diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
index c8fb043a8695793f6907cb6c5c789aff3f2274ec..85c39590c1a4b79d4384ddfddfb1cd82428f1ea2 100644 (file)
--- a/arch/x86/kernel/pvclock.c
+++ b/arch/x86/kernel/pvclock.c
@@ -17,6 +17,11 @@
 
 #include <linux/kernel.h>
 #include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/sched.h>
+#include <linux/gfp.h>
+#include <linux/bootmem.h>
+#include <asm/fixmap.h>
 #include <asm/pvclock.h>
 
 static u8 valid_flags __read_mostly = 0;
@@ -122,3 +127,71 @@ 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
+ * fixmap mapping for the page(s)
+ */
+
+int __init pvclock_init_vsyscall(struct pvclock_vsyscall_time_info *i,
+                                int size)
+{
+       int idx;
+
+       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_symbol(i) + (idx*PAGE_SIZE),
+                            PAGE_KERNEL_VVAR);
+       }
+
+
+       register_task_migration_notifier(&pvclock_migrate);
+
+       return 0;
+}
+#endif