Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 227 insertions, 0 deletions

diff --git a/arch/loongarch/kernel/time.c b/arch/loongarch/kernel/time.c
new file mode 100644
index 0000000000..e7015f7b70
--- /dev/null
+++ b/arch/loongarch/kernel/time.c
@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Common time service routines for LoongArch machines.
+ *
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#include <linux/clockchips.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/sched_clock.h>
+#include <linux/spinlock.h>
+
+#include <asm/cpu-features.h>
+#include <asm/loongarch.h>
+#include <asm/time.h>
+
+u64 cpu_clock_freq;
+EXPORT_SYMBOL(cpu_clock_freq);
+u64 const_clock_freq;
+EXPORT_SYMBOL(const_clock_freq);
+
+static DEFINE_RAW_SPINLOCK(state_lock);
+static DEFINE_PER_CPU(struct clock_event_device, constant_clockevent_device);
+
+static void constant_event_handler(struct clock_event_device *dev)
+{
+}
+
+static irqreturn_t constant_timer_interrupt(int irq, void *data)
+{
+	int cpu = smp_processor_id();
+	struct clock_event_device *cd;
+
+	/* Clear Timer Interrupt */
+	write_csr_tintclear(CSR_TINTCLR_TI);
+	cd = &per_cpu(constant_clockevent_device, cpu);
+	cd->event_handler(cd);
+
+	return IRQ_HANDLED;
+}
+
+static int constant_set_state_oneshot(struct clock_event_device *evt)
+{
+	unsigned long timer_config;
+
+	raw_spin_lock(&state_lock);
+
+	timer_config = csr_read64(LOONGARCH_CSR_TCFG);
+	timer_config |= CSR_TCFG_EN;
+	timer_config &= ~CSR_TCFG_PERIOD;
+	csr_write64(timer_config, LOONGARCH_CSR_TCFG);
+
+	raw_spin_unlock(&state_lock);
+
+	return 0;
+}
+
+static int constant_set_state_periodic(struct clock_event_device *evt)
+{
+	unsigned long period;
+	unsigned long timer_config;
+
+	raw_spin_lock(&state_lock);
+
+	period = const_clock_freq / HZ;
+	timer_config = period & CSR_TCFG_VAL;
+	timer_config |= (CSR_TCFG_PERIOD | CSR_TCFG_EN);
+	csr_write64(timer_config, LOONGARCH_CSR_TCFG);
+
+	raw_spin_unlock(&state_lock);
+
+	return 0;
+}
+
+static int constant_set_state_shutdown(struct clock_event_device *evt)
+{
+	unsigned long timer_config;
+
+	raw_spin_lock(&state_lock);
+
+	timer_config = csr_read64(LOONGARCH_CSR_TCFG);
+	timer_config &= ~CSR_TCFG_EN;
+	csr_write64(timer_config, LOONGARCH_CSR_TCFG);
+
+	raw_spin_unlock(&state_lock);
+
+	return 0;
+}
+
+static int constant_timer_next_event(unsigned long delta, struct clock_event_device *evt)
+{
+	unsigned long timer_config;
+
+	delta &= CSR_TCFG_VAL;
+	timer_config = delta | CSR_TCFG_EN;
+	csr_write64(timer_config, LOONGARCH_CSR_TCFG);
+
+	return 0;
+}
+
+static unsigned long __init get_loops_per_jiffy(void)
+{
+	unsigned long lpj = (unsigned long)const_clock_freq;
+
+	do_div(lpj, HZ);
+
+	return lpj;
+}
+
+static long init_offset __nosavedata;
+
+void save_counter(void)
+{
+	init_offset = drdtime();
+}
+
+void sync_counter(void)
+{
+	/* Ensure counter begin at 0 */
+	csr_write64(init_offset, LOONGARCH_CSR_CNTC);
+}
+
+static int get_timer_irq(void)
+{
+	struct irq_domain *d = irq_find_matching_fwnode(cpuintc_handle, DOMAIN_BUS_ANY);
+
+	if (d)
+		return irq_create_mapping(d, INT_TI);
+
+	return -EINVAL;
+}
+
+int constant_clockevent_init(void)
+{
+	unsigned int cpu = smp_processor_id();
+	unsigned long min_delta = 0x600;
+	unsigned long max_delta = (1UL << 48) - 1;
+	struct clock_event_device *cd;
+	static int irq = 0, timer_irq_installed = 0;
+
+	if (!timer_irq_installed) {
+		irq = get_timer_irq();
+		if (irq < 0)
+			pr_err("Failed to map irq %d (timer)\n", irq);
+	}
+
+	cd = &per_cpu(constant_clockevent_device, cpu);
+
+	cd->name = "Constant";
+	cd->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_PERCPU;
+
+	cd->irq = irq;
+	cd->rating = 320;
+	cd->cpumask = cpumask_of(cpu);
+	cd->set_state_oneshot = constant_set_state_oneshot;
+	cd->set_state_oneshot_stopped = constant_set_state_shutdown;
+	cd->set_state_periodic = constant_set_state_periodic;
+	cd->set_state_shutdown = constant_set_state_shutdown;
+	cd->set_next_event = constant_timer_next_event;
+	cd->event_handler = constant_event_handler;
+
+	clockevents_config_and_register(cd, const_clock_freq, min_delta, max_delta);
+
+	if (timer_irq_installed)
+		return 0;
+
+	timer_irq_installed = 1;
+
+	sync_counter();
+
+	if (request_irq(irq, constant_timer_interrupt, IRQF_PERCPU | IRQF_TIMER, "timer", NULL))
+		pr_err("Failed to request irq %d (timer)\n", irq);
+
+	lpj_fine = get_loops_per_jiffy();
+	pr_info("Constant clock event device register\n");
+
+	return 0;
+}
+
+static u64 read_const_counter(struct clocksource *clk)
+{
+	return drdtime();
+}
+
+static noinstr u64 sched_clock_read(void)
+{
+	return drdtime();
+}
+
+static struct clocksource clocksource_const = {
+	.name = "Constant",
+	.rating = 400,
+	.read = read_const_counter,
+	.mask = CLOCKSOURCE_MASK(64),
+	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
+	.vdso_clock_mode = VDSO_CLOCKMODE_CPU,
+};
+
+int __init constant_clocksource_init(void)
+{
+	int res;
+	unsigned long freq = const_clock_freq;
+
+	res = clocksource_register_hz(&clocksource_const, freq);
+
+	sched_clock_register(sched_clock_read, 64, freq);
+
+	pr_info("Constant clock source device register\n");
+
+	return res;
+}
+
+void __init time_init(void)
+{
+	if (!cpu_has_cpucfg)
+		const_clock_freq = cpu_clock_freq;
+	else
+		const_clock_freq = calc_const_freq();
+
+	init_offset = -(drdtime() - csr_read64(LOONGARCH_CSR_CNTC));
+
+	constant_clockevent_init();
+	constant_clocksource_init();
+}