async: Asynchronous function calls to speed up kernel boot

[safe/jmp/linux-2.6] / include / linux / clocksource.h

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 45b0c31..f88d32f 100644 (file)
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -12,11 +12,14 @@
 #include <linux/timex.h>
 #include <linux/time.h>
 #include <linux/list.h>
+#include <linux/cache.h>
+#include <linux/timer.h>
 #include <asm/div64.h>
 #include <asm/io.h>
 
 /* clocksource cycle base type */
 typedef u64 cycle_t;
+struct clocksource;
 
 /**
  * struct clocksource - hardware abstraction for a free running counter
@@ -42,38 +45,71 @@ typedef u64 cycle_t;
  * @read:              returns a cycle value
  * @mask:              bitmask for two's complement
  *                     subtraction of non 64 bit counters
- * @mult:              cycle to nanosecond multiplier
+ * @mult:              cycle to nanosecond multiplier (adjusted by NTP)
+ * @mult_orig:         cycle to nanosecond multiplier (unadjusted by NTP)
  * @shift:             cycle to nanosecond divisor (power of two)
- * @update_callback:   called when safe to alter clocksource values
  * @flags:             flags describing special properties
+ * @vread:             vsyscall based read
+ * @resume:            resume function for the clocksource, if necessary
  * @cycle_interval:    Used internally by timekeeping core, please ignore.
  * @xtime_interval:    Used internally by timekeeping core, please ignore.
  */
 struct clocksource {
+       /*
+        * First part of structure is read mostly
+        */
        char *name;
        struct list_head list;
        int rating;
        cycle_t (*read)(void);
        cycle_t mask;
        u32 mult;
+       u32 mult_orig;
        u32 shift;
-       int (*update_callback)(void);
        unsigned long flags;
+       cycle_t (*vread)(void);
+       void (*resume)(void);
+#ifdef CONFIG_IA64
+       void *fsys_mmio;        /* used by fsyscall asm code */
+#define CLKSRC_FSYS_MMIO_SET(mmio, addr)      ((mmio) = (addr))
+#else
+#define CLKSRC_FSYS_MMIO_SET(mmio, addr)      do { } while (0)
+#endif
 
        /* timekeeping specific data, ignore */
-       cycle_t cycle_last, cycle_interval;
-       u64 xtime_nsec, xtime_interval;
+       cycle_t cycle_interval;
+       u64     xtime_interval;
+       u32     raw_interval;
+       /*
+        * Second part is written at each timer interrupt
+        * Keep it in a different cache line to dirty no
+        * more than one cache line.
+        */
+       cycle_t cycle_last ____cacheline_aligned_in_smp;
+       u64 xtime_nsec;
        s64 error;
+       struct timespec raw_time;
+
+#ifdef CONFIG_CLOCKSOURCE_WATCHDOG
+       /* Watchdog related data, used by the framework */
+       struct list_head wd_list;
+       cycle_t wd_last;
+#endif
 };
 
+extern struct clocksource *clock;      /* current clocksource */
+
 /*
  * Clock source flags bits::
  */
-#define CLOCK_SOURCE_IS_CONTINUOUS     0x01
-#define CLOCK_SOURCE_MUST_VERIFY       0x02
+#define CLOCK_SOURCE_IS_CONTINUOUS             0x01
+#define CLOCK_SOURCE_MUST_VERIFY               0x02
+
+#define CLOCK_SOURCE_WATCHDOG                  0x10
+#define CLOCK_SOURCE_VALID_FOR_HRES            0x20
 
 /* simplify initialization of mask field */
-#define CLOCKSOURCE_MASK(bits) (cycle_t)(bits<64 ? ((1ULL<<bits)-1) : -1)
+#define CLOCKSOURCE_MASK(bits) (cycle_t)((bits) < 64 ? ((1ULL<<(bits))-1) : -1)
 
 /**
  * clocksource_khz2mult - calculates mult from khz and shift
@@ -169,23 +205,41 @@ static inline void clocksource_calculate_interval(struct clocksource *c,
 {
        u64 tmp;
 
-       /* XXX - All of this could use a whole lot of optimization */
+       /* Do the ns -> cycle conversion first, using original mult */
        tmp = length_nsec;
        tmp <<= c->shift;
-       tmp += c->mult/2;
-       do_div(tmp, c->mult);
+       tmp += c->mult_orig/2;
+       do_div(tmp, c->mult_orig);
 
        c->cycle_interval = (cycle_t)tmp;
        if (c->cycle_interval == 0)
                c->cycle_interval = 1;
 
+       /* Go back from cycles -> shifted ns, this time use ntp adjused mult */
        c->xtime_interval = (u64)c->cycle_interval * c->mult;
+       c->raw_interval = ((u64)c->cycle_interval * c->mult_orig) >> c->shift;
 }
 
 
 /* used to install a new clocksource */
 extern int clocksource_register(struct clocksource*);
+extern void clocksource_unregister(struct clocksource*);
+extern void clocksource_touch_watchdog(void);
 extern struct clocksource* clocksource_get_next(void);
 extern void clocksource_change_rating(struct clocksource *cs, int rating);
+extern void clocksource_resume(void);
+
+#ifdef CONFIG_GENERIC_TIME_VSYSCALL
+extern void update_vsyscall(struct timespec *ts, struct clocksource *c);
+extern void update_vsyscall_tz(void);
+#else
+static inline void update_vsyscall(struct timespec *ts, struct clocksource *c)
+{
+}
+
+static inline void update_vsyscall_tz(void)
+{
+}
+#endif
 
 #endif /* _LINUX_CLOCKSOURCE_H */