svn commit: r220545 - head/sys/x86/isa

[Jung-uk Kim]

Author: jkim
Date: Mon Apr 11 19:27:44 2011
New Revision: 220545
URL: http://svn.freebsd.org/changeset/base/220545

Log:
  Merge two similar functions to reduce duplication.

Modified:
  head/sys/x86/isa/clock.c

Modified: head/sys/x86/isa/clock.c
==============================================================================
--- head/sys/x86/isa/clock.c    Mon Apr 11 17:49:26 2011        (r220544)
+++ head/sys/x86/isa/clock.c    Mon Apr 11 19:27:44 2011        (r220545)
@@ -246,40 +246,50 @@ getit(void)
 }
 
 #ifndef DELAYDEBUG
-static __inline void
-delay_tsc(int n, uint64_t freq)
+static u_int
+get_tsc(__unused struct timecounter *tc)
 {
-       uint64_t start, end, now;
 
-       sched_pin();
-       start = rdtsc();
-       end = start + (freq * n) / 1000000;
-       do {
-               cpu_spinwait();
-               now = rdtsc();
-       } while (now < end || (now > start && end < start));
-       sched_unpin();
+       return (rdtsc());
 }
 
-static __inline void
-delay_timecounter(struct timecounter *tc, int n)
+static __inline int
+delay_tc(int n)
 {
-       uint64_t end, now;
+       struct timecounter *tc;
+       timecounter_get_t *func;
+       uint64_t end, freq, now;
        u_int last, mask, u;
 
-       mask = tc->tc_counter_mask;
-       last = tc->tc_get_timecount(tc) & mask;
-       end = tc->tc_frequency * n / 1000000;
+       tc = timecounter;
+       freq = atomic_load_acq_64(&tsc_freq);
+       if (freq != 0) {
+               func = get_tsc;
+               mask = ~0u;
+       } else {
+               if (tc->tc_quality <= 0)
+                       return (0);
+               func = tc->tc_get_timecount;
+               mask = tc->tc_counter_mask;
+               freq = tc->tc_frequency;
+       }
        now = 0;
+       end = freq * n / 1000000;
+       if (func == get_tsc)
+               sched_pin();
+       last = func(tc) & mask;
        do {
                cpu_spinwait();
-               u = tc->tc_get_timecount(tc) & mask;
+               u = func(tc) & mask;
                if (u < last)
                        now += mask - last + u + 1;
                else
                        now += u - last;
                last = u;
        } while (now < end);
+       if (func == get_tsc)
+               sched_unpin();
+       return (1);
 }
 #endif
 
@@ -306,19 +316,8 @@ DELAY(int n)
        if (state == 1)
                printf("DELAY(%d)...", n);
 #else
-       struct timecounter *tc;
-       uint64_t freq;
-
-       freq = atomic_load_acq_64(&tsc_freq);
-       if (freq != 0) {
-               delay_tsc(n, freq);
+       if (delay_tc(n))
                return;
-       }
-       tc = timecounter;
-       if (tc->tc_quality > 0) {
-               delay_timecounter(tc, n);
-               return;
-       }
 #endif
        /*
         * Read the counter first, so that the rest of the setup overhead is
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