arm: arch_timer: move core to drivers/clocksource
The core functionality of the arch_timer driver is not directly tied to
anything under arch/arm, and can be split out.
This patch factors out the core of the arch_timer driver, so it can be
shared with other architectures. A couple of functions are added so
that architecture-specific code can interact with the driver without
needing to touch its internals.
The ARM_ARCH_TIMER config variable is moved out to
drivers/clocksource/Kconfig, existing uses in arch/arm are replaced with
HAVE_ARM_ARCH_TIMER, which selects it.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index 94f5033..36ebcf4 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -9,402 +9,52 @@
* published by the Free Software Foundation.
*/
#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/delay.h>
-#include <linux/device.h>
-#include <linux/smp.h>
-#include <linux/cpu.h>
-#include <linux/jiffies.h>
-#include <linux/clockchips.h>
-#include <linux/interrupt.h>
-#include <linux/of_irq.h>
-#include <linux/io.h>
+#include <linux/types.h>
#include <asm/delay.h>
-#include <asm/arch_timer.h>
#include <asm/sched_clock.h>
-static u32 arch_timer_rate;
+#include <clocksource/arm_arch_timer.h>
-enum ppi_nr {
- PHYS_SECURE_PPI,
- PHYS_NONSECURE_PPI,
- VIRT_PPI,
- HYP_PPI,
- MAX_TIMER_PPI
-};
+static unsigned long arch_timer_read_counter_long(void)
+{
+ return arch_timer_read_counter();
+}
-static int arch_timer_ppi[MAX_TIMER_PPI];
+static u32 arch_timer_read_counter_u32(void)
+{
+ return arch_timer_read_counter();
+}
-static struct clock_event_device __percpu *arch_timer_evt;
static struct delay_timer arch_delay_timer;
-static bool arch_timer_use_virtual = true;
-
-/*
- * Architected system timer support.
- */
-
-static irqreturn_t inline timer_handler(const int access,
- struct clock_event_device *evt)
+static void __init arch_timer_delay_timer_register(void)
{
- unsigned long ctrl;
- ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
- if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
- ctrl |= ARCH_TIMER_CTRL_IT_MASK;
- arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
- evt->event_handler(evt);
- return IRQ_HANDLED;
- }
-
- return IRQ_NONE;
-}
-
-static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id)
-{
- struct clock_event_device *evt = dev_id;
-
- return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt);
-}
-
-static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id)
-{
- struct clock_event_device *evt = dev_id;
-
- return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt);
-}
-
-static inline void timer_set_mode(const int access, int mode)
-{
- unsigned long ctrl;
- switch (mode) {
- case CLOCK_EVT_MODE_UNUSED:
- case CLOCK_EVT_MODE_SHUTDOWN:
- ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
- ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
- arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
- break;
- default:
- break;
- }
-}
-
-static void arch_timer_set_mode_virt(enum clock_event_mode mode,
- struct clock_event_device *clk)
-{
- timer_set_mode(ARCH_TIMER_VIRT_ACCESS, mode);
-}
-
-static void arch_timer_set_mode_phys(enum clock_event_mode mode,
- struct clock_event_device *clk)
-{
- timer_set_mode(ARCH_TIMER_PHYS_ACCESS, mode);
-}
-
-static inline void set_next_event(const int access, unsigned long evt)
-{
- unsigned long ctrl;
- ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
- ctrl |= ARCH_TIMER_CTRL_ENABLE;
- ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
- arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt);
- arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
-}
-
-static int arch_timer_set_next_event_virt(unsigned long evt,
- struct clock_event_device *unused)
-{
- set_next_event(ARCH_TIMER_VIRT_ACCESS, evt);
- return 0;
-}
-
-static int arch_timer_set_next_event_phys(unsigned long evt,
- struct clock_event_device *unused)
-{
- set_next_event(ARCH_TIMER_PHYS_ACCESS, evt);
- return 0;
-}
-
-static int __cpuinit arch_timer_setup(struct clock_event_device *clk)
-{
- clk->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP;
- clk->name = "arch_sys_timer";
- clk->rating = 450;
- if (arch_timer_use_virtual) {
- clk->irq = arch_timer_ppi[VIRT_PPI];
- clk->set_mode = arch_timer_set_mode_virt;
- clk->set_next_event = arch_timer_set_next_event_virt;
- } else {
- clk->irq = arch_timer_ppi[PHYS_SECURE_PPI];
- clk->set_mode = arch_timer_set_mode_phys;
- clk->set_next_event = arch_timer_set_next_event_phys;
- }
-
- clk->cpumask = cpumask_of(smp_processor_id());
-
- clk->set_mode(CLOCK_EVT_MODE_SHUTDOWN, NULL);
-
- clockevents_config_and_register(clk, arch_timer_rate,
- 0xf, 0x7fffffff);
-
- if (arch_timer_use_virtual)
- enable_percpu_irq(arch_timer_ppi[VIRT_PPI], 0);
- else {
- enable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI], 0);
- if (arch_timer_ppi[PHYS_NONSECURE_PPI])
- enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0);
- }
-
- arch_counter_set_user_access();
-
- return 0;
-}
-
-static int arch_timer_available(void)
-{
- u32 freq;
-
- if (arch_timer_rate == 0) {
- freq = arch_timer_get_cntfrq();
-
- /* Check the timer frequency. */
- if (freq == 0) {
- pr_warn("Architected timer frequency not available\n");
- return -EINVAL;
- }
-
- arch_timer_rate = freq;
- }
-
- pr_info_once("Architected local timer running at %lu.%02luMHz (%s).\n",
- (unsigned long)arch_timer_rate / 1000000,
- (unsigned long)(arch_timer_rate / 10000) % 100,
- arch_timer_use_virtual ? "virt" : "phys");
- return 0;
-}
-
-/*
- * Some external users of arch_timer_read_counter (e.g. sched_clock) may try to
- * call it before it has been initialised. Rather than incur a performance
- * penalty checking for initialisation, provide a default implementation that
- * won't lead to time appearing to jump backwards.
- */
-static u64 arch_timer_read_zero(void)
-{
- return 0;
-}
-
-u64 (*arch_timer_read_counter)(void) = arch_timer_read_zero;
-
-static u32 arch_timer_read_counter32(void)
-{
- return arch_timer_read_counter();
-}
-
-static cycle_t arch_counter_read(struct clocksource *cs)
-{
- return arch_timer_read_counter();
-}
-
-static unsigned long arch_timer_read_current_timer(void)
-{
- return arch_timer_read_counter();
-}
-
-static cycle_t arch_counter_read_cc(const struct cyclecounter *cc)
-{
- return arch_timer_read_counter();
-}
-
-static struct clocksource clocksource_counter = {
- .name = "arch_sys_counter",
- .rating = 400,
- .read = arch_counter_read,
- .mask = CLOCKSOURCE_MASK(56),
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
-static struct cyclecounter cyclecounter = {
- .read = arch_counter_read_cc,
- .mask = CLOCKSOURCE_MASK(56),
-};
-
-static struct timecounter timecounter;
-
-struct timecounter *arch_timer_get_timecounter(void)
-{
- return &timecounter;
-}
-
-static void __cpuinit arch_timer_stop(struct clock_event_device *clk)
-{
- pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n",
- clk->irq, smp_processor_id());
-
- if (arch_timer_use_virtual)
- disable_percpu_irq(arch_timer_ppi[VIRT_PPI]);
- else {
- disable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI]);
- if (arch_timer_ppi[PHYS_NONSECURE_PPI])
- disable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI]);
- }
-
- clk->set_mode(CLOCK_EVT_MODE_UNUSED, clk);
-}
-
-static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- struct clock_event_device *evt = this_cpu_ptr(arch_timer_evt);
-
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_STARTING:
- arch_timer_setup(evt);
- break;
- case CPU_DYING:
- arch_timer_stop(evt);
- break;
- }
-
- return NOTIFY_OK;
-}
-
-static struct notifier_block arch_timer_cpu_nb __cpuinitdata = {
- .notifier_call = arch_timer_cpu_notify,
-};
-
-static int __init arch_timer_register(void)
-{
- int err;
- int ppi;
-
- err = arch_timer_available();
- if (err)
- goto out;
-
- arch_timer_evt = alloc_percpu(struct clock_event_device);
- if (!arch_timer_evt) {
- err = -ENOMEM;
- goto out;
- }
-
- clocksource_register_hz(&clocksource_counter, arch_timer_rate);
- cyclecounter.mult = clocksource_counter.mult;
- cyclecounter.shift = clocksource_counter.shift;
- timecounter_init(&timecounter, &cyclecounter,
- arch_counter_get_cntpct());
-
- if (arch_timer_use_virtual) {
- ppi = arch_timer_ppi[VIRT_PPI];
- err = request_percpu_irq(ppi, arch_timer_handler_virt,
- "arch_timer", arch_timer_evt);
- } else {
- ppi = arch_timer_ppi[PHYS_SECURE_PPI];
- err = request_percpu_irq(ppi, arch_timer_handler_phys,
- "arch_timer", arch_timer_evt);
- if (!err && arch_timer_ppi[PHYS_NONSECURE_PPI]) {
- ppi = arch_timer_ppi[PHYS_NONSECURE_PPI];
- err = request_percpu_irq(ppi, arch_timer_handler_phys,
- "arch_timer", arch_timer_evt);
- if (err)
- free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
- arch_timer_evt);
- }
- }
-
- if (err) {
- pr_err("arch_timer: can't register interrupt %d (%d)\n",
- ppi, err);
- goto out_free;
- }
-
- err = register_cpu_notifier(&arch_timer_cpu_nb);
- if (err)
- goto out_free_irq;
-
- /* Immediately configure the timer on the boot CPU */
- arch_timer_setup(this_cpu_ptr(arch_timer_evt));
-
/* Use the architected timer for the delay loop. */
- arch_delay_timer.read_current_timer = &arch_timer_read_current_timer;
- arch_delay_timer.freq = arch_timer_rate;
+ arch_delay_timer.read_current_timer = arch_timer_read_counter_long;
+ arch_delay_timer.freq = arch_timer_get_rate();
register_current_timer_delay(&arch_delay_timer);
- return 0;
-
-out_free_irq:
- if (arch_timer_use_virtual)
- free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt);
- else {
- free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
- arch_timer_evt);
- if (arch_timer_ppi[PHYS_NONSECURE_PPI])
- free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI],
- arch_timer_evt);
- }
-
-out_free:
- free_percpu(arch_timer_evt);
-out:
- return err;
}
-static const struct of_device_id arch_timer_of_match[] __initconst = {
- { .compatible = "arm,armv7-timer", },
- {},
-};
-
int __init arch_timer_of_register(void)
{
- struct device_node *np;
- u32 freq;
- int i;
+ int ret;
- np = of_find_matching_node(NULL, arch_timer_of_match);
- if (!np) {
- pr_err("arch_timer: can't find DT node\n");
- return -ENODEV;
- }
+ ret = arch_timer_init();
+ if (ret)
+ return ret;
- /* Try to determine the frequency from the device tree or CNTFRQ */
- if (!of_property_read_u32(np, "clock-frequency", &freq))
- arch_timer_rate = freq;
+ arch_timer_delay_timer_register();
- for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
- arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
-
- of_node_put(np);
-
- /*
- * If no interrupt provided for virtual timer, we'll have to
- * stick to the physical timer. It'd better be accessible...
- */
- if (!arch_timer_ppi[VIRT_PPI]) {
- arch_timer_use_virtual = false;
-
- if (!arch_timer_ppi[PHYS_SECURE_PPI] ||
- !arch_timer_ppi[PHYS_NONSECURE_PPI]) {
- pr_warn("arch_timer: No interrupt available, giving up\n");
- return -EINVAL;
- }
- }
-
- if (arch_timer_use_virtual)
- arch_timer_read_counter = arch_counter_get_cntvct;
- else
- arch_timer_read_counter = arch_counter_get_cntpct;
-
- return arch_timer_register();
+ return 0;
}
int __init arch_timer_sched_clock_init(void)
{
- int err;
+ if (arch_timer_get_rate() == 0)
+ return -ENXIO;
- err = arch_timer_available();
- if (err)
- return err;
-
- setup_sched_clock(arch_timer_read_counter32,
- 32, arch_timer_rate);
+ setup_sched_clock(arch_timer_read_counter_u32,
+ 32, arch_timer_get_rate());
return 0;
}