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authorMiod Vallat <miod@cvs.openbsd.org>2006-03-18 12:03:34 +0000
committerMiod Vallat <miod@cvs.openbsd.org>2006-03-18 12:03:34 +0000
commit8bb18eeb467dfaa682ca767de6cd88e515d5ce85 (patch)
tree81347d07035b366855ef3dda533a1406b29a97d8
parente2c7839de4c287ef03b800699e067f0935331ecd (diff)
Switch to a rpcc-based delay() implementation. From NetBSD.
-rw-r--r--sys/arch/alpha/alpha/machdep.c43
1 files changed, 32 insertions, 11 deletions
diff --git a/sys/arch/alpha/alpha/machdep.c b/sys/arch/alpha/alpha/machdep.c
index ef445300b07..3218de778d5 100644
--- a/sys/arch/alpha/alpha/machdep.c
+++ b/sys/arch/alpha/alpha/machdep.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: machdep.c,v 1.97 2006/03/15 21:03:33 deraadt Exp $ */
+/* $OpenBSD: machdep.c,v 1.98 2006/03/18 12:03:33 miod Exp $ */
/* $NetBSD: machdep.c,v 1.210 2000/06/01 17:12:38 thorpej Exp $ */
/*-
@@ -2044,18 +2044,39 @@ void
delay(n)
unsigned long n;
{
- long N = cycles_per_usec * (n);
+ unsigned long pcc0, pcc1, curcycle, cycles, usec;
- /*
- * XXX Should be written to use RPCC?
- */
+ if (n == 0)
+ return;
+
+ pcc0 = alpha_rpcc() & 0xffffffffUL;
+ cycles = 0;
+ usec = 0;
+
+ while (usec <= n) {
+ /*
+ * Get the next CPU cycle count - assumes that we can not
+ * have had more than one 32 bit overflow.
+ */
+ pcc1 = alpha_rpcc() & 0xffffffffUL;
+ if (pcc1 < pcc0)
+ curcycle = (pcc1 + 0x100000000UL) - pcc0;
+ else
+ curcycle = pcc1 - pcc0;
- __asm __volatile(
- "# The 2 corresponds to the insn count\n"
- "1: subq %2, %1, %0 \n"
- " bgt %0, 1b"
- : "=r" (N)
- : "i" (2), "0" (N));
+ /*
+ * We now have the number of processor cycles since we
+ * last checked. Add the current cycle count to the
+ * running total. If it's over cycles_per_usec, increment
+ * the usec counter.
+ */
+ cycles += curcycle;
+ while (cycles > cycles_per_usec) {
+ usec++;
+ cycles -= cycles_per_usec;
+ }
+ pcc0 = pcc1;
+ }
}
#if defined(COMPAT_OSF1)