Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer and time updates from Thomas Gleixner:
 "A rather large update of timers, timekeeping & co

   - Core timekeeping code is year-2038 safe now for 32bit machines.
     Now we just need to fix all in kernel users and the gazillion of
     user space interfaces which rely on timespec/timeval :)

   - Better cache layout for the timekeeping internal data structures.

   - Proper nanosecond based interfaces for in kernel users.

   - Tree wide cleanup of code which wants nanoseconds but does hoops
     and loops to convert back and forth from timespecs.  Some of it
     definitely belongs into the ugly code museum.

   - Consolidation of the timekeeping interface zoo.

   - A fast NMI safe accessor to clock monotonic for tracing.  This is a
     long standing request to support correlated user/kernel space
     traces.  With proper NTP frequency correction it's also suitable
     for correlation of traces accross separate machines.

   - Checkpoint/restart support for timerfd.

   - A few NOHZ[_FULL] improvements in the [hr]timer code.

   - Code move from kernel to kernel/time of all time* related code.

   - New clocksource/event drivers from the ARM universe.  I'm really
     impressed that despite an architected timer in the newer chips SoC
     manufacturers insist on inventing new and differently broken SoC
     specific timers.

[ Ed. "Impressed"? I don't think that word means what you think it means ]

   - Another round of code move from arch to drivers.  Looks like most
     of the legacy mess in ARM regarding timers is sorted out except for
     a few obnoxious strongholds.

   - The usual updates and fixlets all over the place"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (114 commits)
  timekeeping: Fixup typo in update_vsyscall_old definition
  clocksource: document some basic timekeeping concepts
  timekeeping: Use cached ntp_tick_length when accumulating error
  timekeeping: Rework frequency adjustments to work better w/ nohz
  timekeeping: Minor fixup for timespec64->timespec assignment
  ftrace: Provide trace clocks monotonic
  timekeeping: Provide fast and NMI safe access to CLOCK_MONOTONIC
  seqcount: Add raw_write_seqcount_latch()
  seqcount: Provide raw_read_seqcount()
  timekeeping: Use tk_read_base as argument for timekeeping_get_ns()
  timekeeping: Create struct tk_read_base and use it in struct timekeeper
  timekeeping: Restructure the timekeeper some more
  clocksource: Get rid of cycle_last
  clocksource: Move cycle_last validation to core code
  clocksource: Make delta calculation a function
  wireless: ath9k: Get rid of timespec conversions
  drm: vmwgfx: Use nsec based interfaces
  drm: i915: Use nsec based interfaces
  timekeeping: Provide ktime_get_raw()
  hangcheck-timer: Use ktime_get_ns()
  ...

1 files changed, 21 insertions, 41 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b86d329b953a..ca3d760dd581 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1020,9 +1020,8 @@ struct pvclock_gtod_data {
                 u32     shift;
         } clock;
 
-        /* open coded 'struct timespec' */
-        u64             monotonic_time_snsec;
-        time_t          monotonic_time_sec;
+        u64             boot_ns;
+        u64             nsec_base;
 };
 
 static struct pvclock_gtod_data pvclock_gtod_data;
@@ -1030,27 +1029,21 @@ static struct pvclock_gtod_data pvclock_gtod_data;
 static void update_pvclock_gtod(struct timekeeper *tk)
 {
         struct pvclock_gtod_data *vdata = &pvclock_gtod_data;
+        u64 boot_ns;
+
+        boot_ns = ktime_to_ns(ktime_add(tk->tkr.base_mono, tk->offs_boot));
 
         write_seqcount_begin(&vdata->seq);
 
         /* copy pvclock gtod data */
-        vdata->clock.vclock_mode        = tk->clock->archdata.vclock_mode;
-        vdata->clock.cycle_last         = tk->clock->cycle_last;
-        vdata->clock.mask               = tk->clock->mask;
-        vdata->clock.mult               = tk->mult;
-        vdata->clock.shift              = tk->shift;
-
-        vdata->monotonic_time_sec       = tk->xtime_sec
-                                        + tk->wall_to_monotonic.tv_sec;
-        vdata->monotonic_time_snsec     = tk->xtime_nsec
-                                        + (tk->wall_to_monotonic.tv_nsec
-                                                << tk->shift);
-        while (vdata->monotonic_time_snsec >=
-                                        (((u64)NSEC_PER_SEC) << tk->shift)) {
-                vdata->monotonic_time_snsec -=
-                                        ((u64)NSEC_PER_SEC) << tk->shift;
-                vdata->monotonic_time_sec++;
-        }
+        vdata->clock.vclock_mode        = tk->tkr.clock->archdata.vclock_mode;
+        vdata->clock.cycle_last         = tk->tkr.cycle_last;
+        vdata->clock.mask               = tk->tkr.mask;
+        vdata->clock.mult               = tk->tkr.mult;
+        vdata->clock.shift              = tk->tkr.shift;
+
+        vdata->boot_ns                  = boot_ns;
+        vdata->nsec_base                = tk->tkr.xtime_nsec;
 
         write_seqcount_end(&vdata->seq);
 }
@@ -1145,11 +1138,7 @@ static void kvm_get_time_scale(uint32_t scaled_khz, uint32_t base_khz,
 
 static inline u64 get_kernel_ns(void)
 {
-        struct timespec ts;
-
-        ktime_get_ts(&ts);
-        monotonic_to_bootbased(&ts);
-        return timespec_to_ns(&ts);
+        return ktime_get_boot_ns();
 }
 
 #ifdef CONFIG_X86_64
@@ -1414,23 +1403,22 @@ static inline u64 vgettsc(cycle_t *cycle_now)
         return v * gtod->clock.mult;
 }
 
-static int do_monotonic(struct timespec *ts, cycle_t *cycle_now)
+static int do_monotonic_boot(s64 *t, cycle_t *cycle_now)
 {
+        struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
         unsigned long seq;
-        u64 ns;
         int mode;
-        struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
+        u64 ns;
 
-        ts->tv_nsec = 0;
         do {
                 seq = read_seqcount_begin(&gtod->seq);
                 mode = gtod->clock.vclock_mode;
-                ts->tv_sec = gtod->monotonic_time_sec;
-                ns = gtod->monotonic_time_snsec;
+                ns = gtod->nsec_base;
                 ns += vgettsc(cycle_now);
                 ns >>= gtod->clock.shift;
+                ns += gtod->boot_ns;
         } while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
-        timespec_add_ns(ts, ns);
+        *t = ns;
 
         return mode;
 }
@@ -1438,19 +1426,11 @@ static int do_monotonic(struct timespec *ts, cycle_t *cycle_now)
 /* returns true if host is using tsc clocksource */
 static bool kvm_get_time_and_clockread(s64 *kernel_ns, cycle_t *cycle_now)
 {
-        struct timespec ts;
-
         /* checked again under seqlock below */
         if (pvclock_gtod_data.clock.vclock_mode != VCLOCK_TSC)
                 return false;
 
-        if (do_monotonic(&ts, cycle_now) != VCLOCK_TSC)
-                return false;
-
-        monotonic_to_bootbased(&ts);
-        *kernel_ns = timespec_to_ns(&ts);
-
-        return true;
+        return do_monotonic_boot(kernel_ns, cycle_now) == VCLOCK_TSC;
 }
 #endif