1 files changed, 86 insertions, 139 deletions

diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index f6fd1d4398c6..42a3706e16a6 100644
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c
@@ -1,16 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  linux/arch/arm/kernel/smp_twd.c
  *
  *  Copyright (C) 2002 ARM Ltd.
  *  All Rights Reserved
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/clk.h>
+#include <linux/cpu.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/err.h>
@@ -22,9 +20,7 @@
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
 
-#include <asm/smp_plat.h>
 #include <asm/smp_twd.h>
-#include <asm/localtimer.h>
 
 /* set up by the platform code */
 static void __iomem *twd_base;
@@ -33,43 +29,46 @@ static struct clk *twd_clk;
 static unsigned long twd_timer_rate;
 static DEFINE_PER_CPU(bool, percpu_setup_called);
 
-static struct clock_event_device __percpu **twd_evt;
+static struct clock_event_device __percpu *twd_evt;
+static unsigned int twd_features =
+		CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
 static int twd_ppi;
 
-static void twd_set_mode(enum clock_event_mode mode,
-			struct clock_event_device *clk)
+static int twd_shutdown(struct clock_event_device *clk)
 {
-	unsigned long ctrl;
-
-	switch (mode) {
-	case CLOCK_EVT_MODE_PERIODIC:
-		ctrl = TWD_TIMER_CONTROL_ENABLE | TWD_TIMER_CONTROL_IT_ENABLE
-			| TWD_TIMER_CONTROL_PERIODIC;
-		__raw_writel(DIV_ROUND_CLOSEST(twd_timer_rate, HZ),
-			twd_base + TWD_TIMER_LOAD);
-		break;
-	case CLOCK_EVT_MODE_ONESHOT:
-		/* period set, and timer enabled in 'next_event' hook */
-		ctrl = TWD_TIMER_CONTROL_IT_ENABLE | TWD_TIMER_CONTROL_ONESHOT;
-		break;
-	case CLOCK_EVT_MODE_UNUSED:
-	case CLOCK_EVT_MODE_SHUTDOWN:
-	default:
-		ctrl = 0;
-	}
+	writel_relaxed(0, twd_base + TWD_TIMER_CONTROL);
+	return 0;
+}
+
+static int twd_set_oneshot(struct clock_event_device *clk)
+{
+	/* period set, and timer enabled in 'next_event' hook */
+	writel_relaxed(TWD_TIMER_CONTROL_IT_ENABLE | TWD_TIMER_CONTROL_ONESHOT,
+		       twd_base + TWD_TIMER_CONTROL);
+	return 0;
+}
 
-	__raw_writel(ctrl, twd_base + TWD_TIMER_CONTROL);
+static int twd_set_periodic(struct clock_event_device *clk)
+{
+	unsigned long ctrl = TWD_TIMER_CONTROL_ENABLE |
+			     TWD_TIMER_CONTROL_IT_ENABLE |
+			     TWD_TIMER_CONTROL_PERIODIC;
+
+	writel_relaxed(DIV_ROUND_CLOSEST(twd_timer_rate, HZ),
+		       twd_base + TWD_TIMER_LOAD);
+	writel_relaxed(ctrl, twd_base + TWD_TIMER_CONTROL);
+	return 0;
 }
 
 static int twd_set_next_event(unsigned long evt,
 			struct clock_event_device *unused)
 {
-	unsigned long ctrl = __raw_readl(twd_base + TWD_TIMER_CONTROL);
+	unsigned long ctrl = readl_relaxed(twd_base + TWD_TIMER_CONTROL);
 
 	ctrl |= TWD_TIMER_CONTROL_ENABLE;
 
-	__raw_writel(evt, twd_base + TWD_TIMER_COUNTER);
-	__raw_writel(ctrl, twd_base + TWD_TIMER_CONTROL);
+	writel_relaxed(evt, twd_base + TWD_TIMER_COUNTER);
+	writel_relaxed(ctrl, twd_base + TWD_TIMER_CONTROL);
 
 	return 0;
 }
@@ -82,22 +81,21 @@ static int twd_set_next_event(unsigned long evt,
  */
 static int twd_timer_ack(void)
 {
-	if (__raw_readl(twd_base + TWD_TIMER_INTSTAT)) {
-		__raw_writel(1, twd_base + TWD_TIMER_INTSTAT);
+	if (readl_relaxed(twd_base + TWD_TIMER_INTSTAT)) {
+		writel_relaxed(1, twd_base + TWD_TIMER_INTSTAT);
 		return 1;
 	}
 
 	return 0;
 }
 
-static void twd_timer_stop(struct clock_event_device *clk)
+static void twd_timer_stop(void)
 {
-	twd_set_mode(CLOCK_EVT_MODE_UNUSED, clk);
+	struct clock_event_device *clk = raw_cpu_ptr(twd_evt);
+
 	disable_percpu_irq(clk->irq);
 }
 
-#ifdef CONFIG_COMMON_CLK
-
 /*
  * Updates clockevent frequency when the cpu frequency changes.
  * Called on the cpu that is changing frequency with interrupts disabled.
@@ -106,7 +104,7 @@ static void twd_update_frequency(void *new_rate)
 {
 	twd_timer_rate = *((unsigned long *) new_rate);
 
-	clockevents_update_freq(*__this_cpu_ptr(twd_evt), twd_timer_rate);
+	clockevents_update_freq(raw_cpu_ptr(twd_evt), twd_timer_rate);
 }
 
 static int twd_rate_change(struct notifier_block *nb,
@@ -132,62 +130,14 @@ static struct notifier_block twd_clk_nb = {
 
 static int twd_clk_init(void)
 {
-	if (twd_evt && *__this_cpu_ptr(twd_evt) && !IS_ERR(twd_clk))
+	if (twd_evt && raw_cpu_ptr(twd_evt) && !IS_ERR(twd_clk))
 		return clk_notifier_register(twd_clk, &twd_clk_nb);
 
 	return 0;
 }
 core_initcall(twd_clk_init);
 
-#elif defined (CONFIG_CPU_FREQ)
-
-#include <linux/cpufreq.h>
-
-/*
- * Updates clockevent frequency when the cpu frequency changes.
- * Called on the cpu that is changing frequency with interrupts disabled.
- */
-static void twd_update_frequency(void *data)
-{
-	twd_timer_rate = clk_get_rate(twd_clk);
-
-	clockevents_update_freq(*__this_cpu_ptr(twd_evt), twd_timer_rate);
-}
-
-static int twd_cpufreq_transition(struct notifier_block *nb,
-	unsigned long state, void *data)
-{
-	struct cpufreq_freqs *freqs = data;
-
-	/*
-	 * The twd clock events must be reprogrammed to account for the new
-	 * frequency.  The timer is local to a cpu, so cross-call to the
-	 * changing cpu.
-	 */
-	if (state == CPUFREQ_POSTCHANGE || state == CPUFREQ_RESUMECHANGE)
-		smp_call_function_single(freqs->cpu, twd_update_frequency,
-			NULL, 1);
-
-	return NOTIFY_OK;
-}
-
-static struct notifier_block twd_cpufreq_nb = {
-	.notifier_call = twd_cpufreq_transition,
-};
-
-static int twd_cpufreq_init(void)
-{
-	if (twd_evt && *__this_cpu_ptr(twd_evt) && !IS_ERR(twd_clk))
-		return cpufreq_register_notifier(&twd_cpufreq_nb,
-			CPUFREQ_TRANSITION_NOTIFIER);
-
-	return 0;
-}
-core_initcall(twd_cpufreq_init);
-
-#endif
-
-static void __cpuinit twd_calibrate_rate(void)
+static void twd_calibrate_rate(void)
 {
 	unsigned long count;
 	u64 waitjiffies;
@@ -197,7 +147,7 @@ static void __cpuinit twd_calibrate_rate(void)
 	 * the timer ticks
 	 */
 	if (twd_timer_rate == 0) {
-		printk(KERN_INFO "Calibrating local timer... ");
+		pr_info("Calibrating local timer... ");
 
 		/* Wait for a tick to start */
 		waitjiffies = get_jiffies_64() + 1;
@@ -209,26 +159,26 @@ static void __cpuinit twd_calibrate_rate(void)
 		waitjiffies += 5;
 
 				 /* enable, no interrupt or reload */
-		__raw_writel(0x1, twd_base + TWD_TIMER_CONTROL);
+		writel_relaxed(0x1, twd_base + TWD_TIMER_CONTROL);
 
 				 /* maximum value */
-		__raw_writel(0xFFFFFFFFU, twd_base + TWD_TIMER_COUNTER);
+		writel_relaxed(0xFFFFFFFFU, twd_base + TWD_TIMER_COUNTER);
 
 		while (get_jiffies_64() < waitjiffies)
 			udelay(10);
 
-		count = __raw_readl(twd_base + TWD_TIMER_COUNTER);
+		count = readl_relaxed(twd_base + TWD_TIMER_COUNTER);
 
 		twd_timer_rate = (0xFFFFFFFFU - count) * (HZ / 5);
 
-		printk("%lu.%02luMHz.\n", twd_timer_rate / 1000000,
+		pr_cont("%lu.%02luMHz.\n", twd_timer_rate / 1000000,
 			(twd_timer_rate / 10000) % 100);
 	}
 }
 
 static irqreturn_t twd_handler(int irq, void *dev_id)
 {
-	struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
+	struct clock_event_device *evt = dev_id;
 
 	if (twd_timer_ack()) {
 		evt->event_handler(evt);
@@ -265,9 +215,9 @@ static void twd_get_clock(struct device_node *np)
 /*
  * Setup the local clock events for a CPU.
  */
-static int __cpuinit twd_timer_setup(struct clock_event_device *clk)
+static void twd_timer_setup(void)
 {
-	struct clock_event_device **this_cpu_clk;
+	struct clock_event_device *clk = raw_cpu_ptr(twd_evt);
 	int cpu = smp_processor_id();
 
 	/*
@@ -275,10 +225,10 @@ static int __cpuinit twd_timer_setup(struct clock_event_device *clk)
 	 * bother with the below.
 	 */
 	if (per_cpu(percpu_setup_called, cpu)) {
-		__raw_writel(0, twd_base + TWD_TIMER_CONTROL);
-		clockevents_register_device(*__this_cpu_ptr(twd_evt));
+		writel_relaxed(0, twd_base + TWD_TIMER_CONTROL);
+		clockevents_register_device(clk);
 		enable_percpu_irq(clk->irq, 0);
-		return 0;
+		return;
 	}
 	per_cpu(percpu_setup_called, cpu) = true;
 
@@ -288,36 +238,41 @@ static int __cpuinit twd_timer_setup(struct clock_event_device *clk)
 	 * The following is done once per CPU the first time .setup() is
 	 * called.
 	 */
-	__raw_writel(0, twd_base + TWD_TIMER_CONTROL);
+	writel_relaxed(0, twd_base + TWD_TIMER_CONTROL);
 
 	clk->name = "local_timer";
-	clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
-			CLOCK_EVT_FEAT_C3STOP;
+	clk->features = twd_features;
 	clk->rating = 350;
-	clk->set_mode = twd_set_mode;
+	clk->set_state_shutdown = twd_shutdown;
+	clk->set_state_periodic = twd_set_periodic;
+	clk->set_state_oneshot = twd_set_oneshot;
+	clk->tick_resume = twd_shutdown;
 	clk->set_next_event = twd_set_next_event;
 	clk->irq = twd_ppi;
-
-	this_cpu_clk = __this_cpu_ptr(twd_evt);
-	*this_cpu_clk = clk;
+	clk->cpumask = cpumask_of(cpu);
 
 	clockevents_config_and_register(clk, twd_timer_rate,
 					0xf, 0xffffffff);
 	enable_percpu_irq(clk->irq, 0);
+}
 
+static int twd_timer_starting_cpu(unsigned int cpu)
+{
+	twd_timer_setup();
 	return 0;
 }
 
-static struct local_timer_ops twd_lt_ops __cpuinitdata = {
-	.setup	= twd_timer_setup,
-	.stop	= twd_timer_stop,
-};
+static int twd_timer_dying_cpu(unsigned int cpu)
+{
+	twd_timer_stop();
+	return 0;
+}
 
 static int __init twd_local_timer_common_register(struct device_node *np)
 {
 	int err;
 
-	twd_evt = alloc_percpu(struct clock_event_device *);
+	twd_evt = alloc_percpu(struct clock_event_device);
 	if (!twd_evt) {
 		err = -ENOMEM;
 		goto out_free;
@@ -329,16 +284,26 @@ static int __init twd_local_timer_common_register(struct device_node *np)
 		goto out_free;
 	}
 
-	err = local_timer_register(&twd_lt_ops);
-	if (err)
-		goto out_irq;
+	cpuhp_setup_state_nocalls(CPUHP_AP_ARM_TWD_STARTING,
+				  "arm/timer/twd:starting",
+				  twd_timer_starting_cpu, twd_timer_dying_cpu);
 
 	twd_get_clock(np);
+	if (!of_property_read_bool(np, "always-on"))
+		twd_features |= CLOCK_EVT_FEAT_C3STOP;
+
+	/*
+	 * Immediately configure the timer on the boot CPU, unless we need
+	 * jiffies to be incrementing to calibrate the rate in which case
+	 * setup the timer in late_time_init.
+	 */
+	if (twd_timer_rate)
+		twd_timer_setup();
+	else
+		late_time_init = twd_timer_setup;
 
 	return 0;
 
-out_irq:
-	free_percpu_irq(twd_ppi, twd_evt);
 out_free:
 	iounmap(twd_base);
 	twd_base = NULL;
@@ -347,28 +312,10 @@ out_free:
 	return err;
 }
 
-int __init twd_local_timer_register(struct twd_local_timer *tlt)
-{
-	if (twd_base || twd_evt)
-		return -EBUSY;
-
-	twd_ppi	= tlt->res[1].start;
-
-	twd_base = ioremap(tlt->res[0].start, resource_size(&tlt->res[0]));
-	if (!twd_base)
-		return -ENOMEM;
-
-	return twd_local_timer_common_register(NULL);
-}
-
-#ifdef CONFIG_OF
-static void __init twd_local_timer_of_register(struct device_node *np)
+static int __init twd_local_timer_of_register(struct device_node *np)
 {
 	int err;
 
-	if (!is_smp() || !setup_max_cpus)
-		return;
-
 	twd_ppi = irq_of_parse_and_map(np, 0);
 	if (!twd_ppi) {
 		err = -EINVAL;
@@ -385,8 +332,8 @@ static void __init twd_local_timer_of_register(struct device_node *np)
 
 out:
 	WARN(err, "twd_local_timer_of_register failed (%d)\n", err);
+	return err;
 }
-CLOCKSOURCE_OF_DECLARE(arm_twd_a9, "arm,cortex-a9-twd-timer", twd_local_timer_of_register);
-CLOCKSOURCE_OF_DECLARE(arm_twd_a5, "arm,cortex-a5-twd-timer", twd_local_timer_of_register);
-CLOCKSOURCE_OF_DECLARE(arm_twd_11mp, "arm,arm11mp-twd-timer", twd_local_timer_of_register);
-#endif
+TIMER_OF_DECLARE(arm_twd_a9, "arm,cortex-a9-twd-timer", twd_local_timer_of_register);
+TIMER_OF_DECLARE(arm_twd_a5, "arm,cortex-a5-twd-timer", twd_local_timer_of_register);
+TIMER_OF_DECLARE(arm_twd_11mp, "arm,arm11mp-twd-timer", twd_local_timer_of_register);