Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 167 insertions, 0 deletions

diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c
new file mode 100644
index 000000000..ed339d797
--- /dev/null
+++ b/arch/mips/kernel/time.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2001 MontaVista Software Inc.
+ * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
+ * Copyright (c) 2003, 2004  Maciej W. Rozycki
+ *
+ * Common time service routines for MIPS machines.
+ */
+#include <linux/bug.h>
+#include <linux/clockchips.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/param.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/export.h>
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
+
+#include <asm/cpu-features.h>
+#include <asm/cpu-type.h>
+#include <asm/div64.h>
+#include <asm/time.h>
+
+#ifdef CONFIG_CPU_FREQ
+
+static DEFINE_PER_CPU(unsigned long, pcp_lpj_ref);
+static DEFINE_PER_CPU(unsigned long, pcp_lpj_ref_freq);
+static unsigned long glb_lpj_ref;
+static unsigned long glb_lpj_ref_freq;
+
+static int cpufreq_callback(struct notifier_block *nb,
+			    unsigned long val, void *data)
+{
+	struct cpufreq_freqs *freq = data;
+	struct cpumask *cpus = freq->policy->cpus;
+	unsigned long lpj;
+	int cpu;
+
+	/*
+	 * Skip lpj numbers adjustment if the CPU-freq transition is safe for
+	 * the loops delay. (Is this possible?)
+	 */
+	if (freq->flags & CPUFREQ_CONST_LOOPS)
+		return NOTIFY_OK;
+
+	/* Save the initial values of the lpjes for future scaling. */
+	if (!glb_lpj_ref) {
+		glb_lpj_ref = boot_cpu_data.udelay_val;
+		glb_lpj_ref_freq = freq->old;
+
+		for_each_online_cpu(cpu) {
+			per_cpu(pcp_lpj_ref, cpu) =
+				cpu_data[cpu].udelay_val;
+			per_cpu(pcp_lpj_ref_freq, cpu) = freq->old;
+		}
+	}
+
+	/*
+	 * Adjust global lpj variable and per-CPU udelay_val number in
+	 * accordance with the new CPU frequency.
+	 */
+	if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
+	    (val == CPUFREQ_POSTCHANGE && freq->old > freq->new)) {
+		loops_per_jiffy = cpufreq_scale(glb_lpj_ref,
+						glb_lpj_ref_freq,
+						freq->new);
+
+		for_each_cpu(cpu, cpus) {
+			lpj = cpufreq_scale(per_cpu(pcp_lpj_ref, cpu),
+					    per_cpu(pcp_lpj_ref_freq, cpu),
+					    freq->new);
+			cpu_data[cpu].udelay_val = (unsigned int)lpj;
+		}
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block cpufreq_notifier = {
+	.notifier_call  = cpufreq_callback,
+};
+
+static int __init register_cpufreq_notifier(void)
+{
+	return cpufreq_register_notifier(&cpufreq_notifier,
+					 CPUFREQ_TRANSITION_NOTIFIER);
+}
+core_initcall(register_cpufreq_notifier);
+
+#endif /* CONFIG_CPU_FREQ */
+
+/*
+ * forward reference
+ */
+DEFINE_SPINLOCK(rtc_lock);
+EXPORT_SYMBOL(rtc_lock);
+
+static int null_perf_irq(void)
+{
+	return 0;
+}
+
+int (*perf_irq)(void) = null_perf_irq;
+
+EXPORT_SYMBOL(perf_irq);
+
+/*
+ * time_init() - it does the following things.
+ *
+ * 1) plat_time_init() -
+ *	a) (optional) set up RTC routines,
+ *	b) (optional) calibrate and set the mips_hpt_frequency
+ *	    (only needed if you intended to use cpu counter as timer interrupt
+ *	     source)
+ * 2) calculate a couple of cached variables for later usage
+ */
+
+unsigned int mips_hpt_frequency;
+EXPORT_SYMBOL_GPL(mips_hpt_frequency);
+
+static __init int cpu_has_mfc0_count_bug(void)
+{
+	switch (current_cpu_type()) {
+	case CPU_R4000PC:
+	case CPU_R4000SC:
+	case CPU_R4000MC:
+		/*
+		 * V3.0 is documented as suffering from the mfc0 from count bug.
+		 * Afaik this is the last version of the R4000.	 Later versions
+		 * were marketed as R4400.
+		 */
+		return 1;
+
+	case CPU_R4400PC:
+	case CPU_R4400SC:
+	case CPU_R4400MC:
+		/*
+		 * The published errata for the R4400 up to 3.0 say the CPU
+		 * has the mfc0 from count bug.  This seems the last version
+		 * produced.
+		 */
+		return 1;
+	}
+
+	return 0;
+}
+
+void __init time_init(void)
+{
+	plat_time_init();
+
+	/*
+	 * The use of the R4k timer as a clock event takes precedence;
+	 * if reading the Count register might interfere with the timer
+	 * interrupt, then we don't use the timer as a clock source.
+	 * We may still use the timer as a clock source though if the
+	 * timer interrupt isn't reliable; the interference doesn't
+	 * matter then, because we don't use the interrupt.
+	 */
+	if (mips_clockevent_init() != 0 || !cpu_has_mfc0_count_bug())
+		init_mips_clocksource();
+}