--- /dev/null
+/*
+ * Copyright (c) 2000-2010 Apple Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+/*
+ * @OSF_COPYRIGHT@
+ */
+
+#include <platforms.h>
+#include <mach_kdb.h>
+
+#include <mach/mach_types.h>
+
+#include <architecture/i386/pio.h>
+#include <i386/machine_cpu.h>
+#include <i386/cpuid.h>
+#include <i386/cpu_threads.h>
+#include <i386/mp.h>
+#include <i386/machine_routines.h>
+#include <i386/pal_routines.h>
+#include <i386/proc_reg.h>
+#include <i386/misc_protos.h>
+#include <i386/lapic.h>
+#include <pexpert/pexpert.h>
+#include <machine/limits.h>
+#include <sys/kdebug.h>
+#include <i386/tsc.h>
+#include <i386/rtclock_protos.h>
+#include <i386/pal_routines.h>
+#include <kern/etimer.h>
+
+static uint64_t rtc_decrementer_min;
+static uint64_t rtc_decrementer_max;
+
+static uint64_t
+deadline_to_decrementer(
+ uint64_t deadline,
+ uint64_t now)
+{
+ uint64_t delta;
+
+ if (deadline <= now)
+ return rtc_decrementer_min;
+ else {
+ delta = deadline - now;
+ return MIN(MAX(rtc_decrementer_min,delta),rtc_decrementer_max);
+ }
+}
+
+static inline uint64_t
+_absolutetime_to_tsc(uint64_t ns)
+{
+ uint32_t generation;
+ uint64_t tsc;
+
+ do {
+ generation = pal_rtc_nanotime_info.generation;
+ tsc = tmrCvt(ns - pal_rtc_nanotime_info.ns_base, tscFCvtn2t)
+ + pal_rtc_nanotime_info.tsc_base;
+ } while (generation == 0 ||
+ generation != pal_rtc_nanotime_info.generation);
+
+ return tsc;
+}
+
+/*
+ * Regular local APIC timer case:
+ */
+static void
+rtc_lapic_config_timer(void)
+{
+ lapic_config_timer(TRUE, one_shot, divide_by_1);
+}
+static uint64_t
+rtc_lapic_set_timer(uint64_t deadline, uint64_t now)
+{
+ uint64_t count;
+ uint64_t set = 0;
+
+ if (deadline > 0) {
+ /*
+ * Convert delta to bus ticks
+ * - time now is not relevant
+ */
+ count = deadline_to_decrementer(deadline, now);
+ set = now + count;
+ lapic_set_timer_fast((uint32_t) tmrCvt(count, busFCvtn2t));
+ } else {
+ lapic_set_timer(FALSE, one_shot, divide_by_1, 0);
+ }
+ return set;
+}
+
+/*
+ * TSC-deadline timer case:
+ */
+static void
+rtc_lapic_config_tsc_deadline_timer(void)
+{
+ lapic_config_tsc_deadline_timer();
+}
+static uint64_t
+rtc_lapic_set_tsc_deadline_timer(uint64_t deadline, uint64_t now)
+{
+ uint64_t set = 0;
+
+ if (deadline > 0) {
+ /*
+ * Convert to TSC
+ */
+ set = now + deadline_to_decrementer(deadline, now);
+ lapic_set_tsc_deadline_timer(_absolutetime_to_tsc(set));
+ } else {
+ lapic_set_tsc_deadline_timer(0);
+ }
+
+ KERNEL_DEBUG_CONSTANT(
+ DECR_SET_TSC_DEADLINE | DBG_FUNC_NONE,
+ now, deadline,
+ rdtsc64(), lapic_get_tsc_deadline_timer(),
+ 0);
+
+ return set;
+}
+
+/*
+ * Definitions for timer operations table
+ */
+
+rtc_timer_t rtc_timer_lapic = {
+ rtc_lapic_config_timer,
+ rtc_lapic_set_timer
+};
+
+rtc_timer_t rtc_timer_tsc_deadline = {
+ rtc_lapic_config_tsc_deadline_timer,
+ rtc_lapic_set_tsc_deadline_timer
+};
+
+rtc_timer_t *rtc_timer = &rtc_timer_lapic; /* defaults to LAPIC timer */
+
+/*
+ * rtc_timer_init() is called at startup on the boot processor only.
+ */
+void
+rtc_timer_init(void)
+{
+ int TSC_deadline_timer = 0;
+
+ /* See whether we can use the local apic in TSC-deadline mode */
+ if ((cpuid_features() & CPUID_FEATURE_TSCTMR)) {
+ TSC_deadline_timer = 1;
+ PE_parse_boot_argn("TSC_deadline_timer", &TSC_deadline_timer,
+ sizeof(TSC_deadline_timer));
+ printf("TSC Deadline Timer supported %s enabled\n",
+ TSC_deadline_timer ? "and" : "but not");
+ }
+
+ if (TSC_deadline_timer) {
+ rtc_timer = &rtc_timer_tsc_deadline;
+ rtc_decrementer_max = UINT64_MAX; /* effectively none */
+ /*
+ * The min could be as low as 1nsec,
+ * but we're being conservative for now and making it the same
+ * as for the local apic timer.
+ */
+ rtc_decrementer_min = 1*NSEC_PER_USEC; /* 1 usec */
+ } else {
+ /*
+ * Compute the longest interval using LAPIC timer.
+ */
+ rtc_decrementer_max = tmrCvt(0x7fffffffULL, busFCvtt2n);
+ kprintf("maxDec: %lld\n", rtc_decrementer_max);
+ rtc_decrementer_min = 1*NSEC_PER_USEC; /* 1 usec */
+ }
+
+ /* Point LAPIC interrupts to hardclock() */
+ lapic_set_timer_func((i386_intr_func_t) rtclock_intr);
+}
projects / apple / xnu.git / blobdiff