Merge branch 'for-arm-soc/arch-timers' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into next/virt

From Will Deacon:
This set of changes moves the arch-timer driver out from arch/arm/ and
into drivers/clocksource and unifies the new driver with the arm64 copy.

* 'for-arm-soc/arch-timers' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux:
  ARM: arch_timers: switch to physical timers if HYP mode is available
  Documentation: Add ARMv8 to arch_timer devicetree
  arm64: move from arm_generic to arm_arch_timer
  arm64: arm_generic: prevent reading stale time
  arm: arch_timer: move core to drivers/clocksource
  arm: arch_timer: add arch_counter_set_user_access
  arm: arch_timer: divorce from local_timer api
  arm: arch_timer: add isbs to register accessors
  arm: arch_timer: factor out register accessors
  arm: arch_timer: split cntfrq accessor
  arm: arch_timer: standardise counter reading
  arm: arch_timer: use u64/u32 for register data
  arm: arch_timer: remove redundant available check
  arm: arch_timer: balance device_node refcounting

Signed-off-by: Olof Johansson <olof@lixom.net>

1 files changed, 20 insertions, 484 deletions

diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index c8ef207..36ebcf4 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -9,516 +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/cputype.h>
 #include <asm/delay.h>
-#include <asm/localtimer.h>
-#include <asm/arch_timer.h>
-#include <asm/system_info.h>
 #include <asm/sched_clock.h>
 
-static unsigned long 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 int arch_timer_ppi[MAX_TIMER_PPI];
-
-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.
- */
-
-#define ARCH_TIMER_CTRL_ENABLE		(1 << 0)
-#define ARCH_TIMER_CTRL_IT_MASK		(1 << 1)
-#define ARCH_TIMER_CTRL_IT_STAT		(1 << 2)
-
-#define ARCH_TIMER_REG_CTRL		0
-#define ARCH_TIMER_REG_FREQ		1
-#define ARCH_TIMER_REG_TVAL		2
-
-#define ARCH_TIMER_PHYS_ACCESS		0
-#define ARCH_TIMER_VIRT_ACCESS		1
-
-/*
- * These register accessors are marked inline so the compiler can
- * nicely work out which register we want, and chuck away the rest of
- * the code. At least it does so with a recent GCC (4.6.3).
- */
-static inline void arch_timer_reg_write(const int access, const int reg, u32 val)
-{
-	if (access == ARCH_TIMER_PHYS_ACCESS) {
-		switch (reg) {
-		case ARCH_TIMER_REG_CTRL:
-			asm volatile("mcr p15, 0, %0, c14, c2, 1" : : "r" (val));
-			break;
-		case ARCH_TIMER_REG_TVAL:
-			asm volatile("mcr p15, 0, %0, c14, c2, 0" : : "r" (val));
-			break;
-		}
-	}
-
-	if (access == ARCH_TIMER_VIRT_ACCESS) {
-		switch (reg) {
-		case ARCH_TIMER_REG_CTRL:
-			asm volatile("mcr p15, 0, %0, c14, c3, 1" : : "r" (val));
-			break;
-		case ARCH_TIMER_REG_TVAL:
-			asm volatile("mcr p15, 0, %0, c14, c3, 0" : : "r" (val));
-			break;
-		}
-	}
-
-	isb();
-}
-
-static inline u32 arch_timer_reg_read(const int access, const int reg)
-{
-	u32 val = 0;
-
-	if (access == ARCH_TIMER_PHYS_ACCESS) {
-		switch (reg) {
-		case ARCH_TIMER_REG_CTRL:
-			asm volatile("mrc p15, 0, %0, c14, c2, 1" : "=r" (val));
-			break;
-		case ARCH_TIMER_REG_TVAL:
-			asm volatile("mrc p15, 0, %0, c14, c2, 0" : "=r" (val));
-			break;
-		case ARCH_TIMER_REG_FREQ:
-			asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (val));
-			break;
-		}
-	}
-
-	if (access == ARCH_TIMER_VIRT_ACCESS) {
-		switch (reg) {
-		case ARCH_TIMER_REG_CTRL:
-			asm volatile("mrc p15, 0, %0, c14, c3, 1" : "=r" (val));
-			break;
-		case ARCH_TIMER_REG_TVAL:
-			asm volatile("mrc p15, 0, %0, c14, c3, 0" : "=r" (val));
-			break;
-		}
-	}
-
-	return val;
-}
-
-static inline cycle_t arch_timer_counter_read(const int access)
-{
-	cycle_t cval = 0;
-
-	if (access == ARCH_TIMER_PHYS_ACCESS)
-		asm volatile("mrrc p15, 0, %Q0, %R0, c14" : "=r" (cval));
-
-	if (access == ARCH_TIMER_VIRT_ACCESS)
-		asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (cval));
-
-	return cval;
-}
-
-static inline cycle_t arch_counter_get_cntpct(void)
-{
-	return arch_timer_counter_read(ARCH_TIMER_PHYS_ACCESS);
-}
-
-static inline cycle_t arch_counter_get_cntvct(void)
-{
-	return arch_timer_counter_read(ARCH_TIMER_VIRT_ACCESS);
-}
-
-static irqreturn_t inline timer_handler(const int access,
-					struct clock_event_device *evt)
-{
-	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 = *(struct clock_event_device **)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 = *(struct clock_event_device **)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->set_mode(CLOCK_EVT_MODE_SHUTDOWN, NULL);
-
-	clockevents_config_and_register(clk, arch_timer_rate,
-					0xf, 0x7fffffff);
-
-	*__this_cpu_ptr(arch_timer_evt) = clk;
-
-	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);
-	}
-
-	return 0;
-}
-
-/* Is the optional system timer available? */
-static int local_timer_is_architected(void)
-{
-	return (cpu_architecture() >= CPU_ARCH_ARMv7) &&
-	       ((read_cpuid_ext(CPUID_EXT_PFR1) >> 16) & 0xf) == 1;
-}
-
-static int arch_timer_available(void)
-{
-	unsigned long freq;
-
-	if (!local_timer_is_architected())
-		return -ENXIO;
-
-	if (arch_timer_rate == 0) {
-		freq = arch_timer_reg_read(ARCH_TIMER_PHYS_ACCESS,
-					   ARCH_TIMER_REG_FREQ);
-
-		/* 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",
-		     arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100,
-		     arch_timer_use_virtual ? "virt" : "phys");
-	return 0;
-}
-
-static u32 notrace arch_counter_get_cntpct32(void)
-{
-	cycle_t cnt = arch_counter_get_cntpct();
-
-	/*
-	 * The sched_clock infrastructure only knows about counters
-	 * with at most 32bits. Forget about the upper 24 bits for the
-	 * time being...
-	 */
-	return (u32)cnt;
-}
-
-static u32 notrace arch_counter_get_cntvct32(void)
-{
-	cycle_t cnt = arch_counter_get_cntvct();
-
-	/*
-	 * The sched_clock infrastructure only knows about counters
-	 * with at most 32bits. Forget about the upper 24 bits for the
-	 * time being...
-	 */
-	return (u32)cnt;
-}
-
-static cycle_t arch_counter_read(struct clocksource *cs)
-{
-	/*
-	 * Always use the physical counter for the clocksource.
-	 * CNTHCTL.PL1PCTEN must be set to 1.
-	 */
-	return arch_counter_get_cntpct();
-}
-
-static unsigned long arch_timer_read_current_timer(void)
+static unsigned long arch_timer_read_counter_long(void)
 {
-	return arch_counter_get_cntpct();
+	return arch_timer_read_counter();
 }
 
-static cycle_t arch_counter_read_cc(const struct cyclecounter *cc)
+static u32 arch_timer_read_counter_u32(void)
 {
-	/*
-	 * Always use the physical counter for the clocksource.
-	 * CNTHCTL.PL1PCTEN must be set to 1.
-	 */
-	return arch_counter_get_cntpct();
+	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 struct local_timer_ops arch_timer_ops __cpuinitdata = {
-	.setup	= arch_timer_setup,
-	.stop	= arch_timer_stop,
-};
-
-static struct clock_event_device arch_timer_global_evt;
+static struct delay_timer arch_delay_timer;
 
-static int __init arch_timer_register(void)
+static void __init arch_timer_delay_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 = local_timer_register(&arch_timer_ops);
-	if (err) {
-		/*
-		 * We couldn't register as a local timer (could be
-		 * because we're on a UP platform, or because some
-		 * other local timer is already present...). Try as a
-		 * global timer instead.
-		 */
-		arch_timer_global_evt.cpumask = cpumask_of(0);
-		err = arch_timer_setup(&arch_timer_global_evt);
-	}
-	if (err)
-		goto out_free_irq;
-
 	/* 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;
-
-	np = of_find_matching_node(NULL, arch_timer_of_match);
-	if (!np) {
-		pr_err("arch_timer: can't find DT node\n");
-		return -ENODEV;
-	}
-
-	/* Try to determine the frequency from the device tree or CNTFRQ */
-	if (!of_property_read_u32(np, "clock-frequency", &freq))
-		arch_timer_rate = freq;
-
-	for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
-		arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
+	int ret;
 
-	/*
-	 * 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;
+	ret = arch_timer_init();
+	if (ret)
+		return ret;
 
-		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;
-		}
-	}
+	arch_timer_delay_timer_register();
 
-	return arch_timer_register();
+	return 0;
 }
 
 int __init arch_timer_sched_clock_init(void)
 {
-	u32 (*cnt32)(void);
-	int err;
-
-	err = arch_timer_available();
-	if (err)
-		return err;
-
-	if (arch_timer_use_virtual)
-		cnt32 = arch_counter_get_cntvct32;
-	else
-		cnt32 = arch_counter_get_cntpct32;
+	if (arch_timer_get_rate() == 0)
+		return -ENXIO;
 
-	setup_sched_clock(cnt32, 32, arch_timer_rate);
+	setup_sched_clock(arch_timer_read_counter_u32,
+			  32, arch_timer_get_rate());
 	return 0;
 }