1 files changed, 293 insertions, 2 deletions

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 03d3655734b..31e9191b7e1 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -21,10 +21,19 @@
    NSEC = 10^-9 */
 #define FSEC_PER_NSEC			1000000L
 
+#define HPET_DEV_USED_BIT		2
+#define HPET_DEV_USED			(1 << HPET_DEV_USED_BIT)
+#define HPET_DEV_VALID			0x8
+#define HPET_DEV_FSB_CAP		0x1000
+#define HPET_DEV_PERI_CAP		0x2000
+
+#define EVT_TO_HPET_DEV(evt) container_of(evt, struct hpet_dev, evt)
+
 /*
  * HPET address is set in acpi/boot.c, when an ACPI entry exists
  */
 unsigned long				hpet_address;
+unsigned long				hpet_num_timers;
 static void __iomem			*hpet_virt_address;
 
 struct hpet_dev {
@@ -36,6 +45,10 @@ struct hpet_dev {
 	char				name[10];
 };
 
+static struct hpet_dev			*hpet_devs;
+
+static DEFINE_PER_CPU(struct hpet_dev *, cpu_hpet_dev);
+
 unsigned long hpet_readl(unsigned long a)
 {
 	return readl(hpet_virt_address + a);
@@ -145,6 +158,16 @@ static void hpet_reserve_platform_timers(unsigned long id)
 			Tn_INT_ROUTE_CNF_MASK) >> Tn_INT_ROUTE_CNF_SHIFT;
 	}
 
+	for (i = 0; i < nrtimers; i++) {
+		struct hpet_dev *hdev = &hpet_devs[i];
+
+		if (!(hdev->flags & HPET_DEV_VALID))
+			continue;
+
+		hd.hd_irq[hdev->num] = hdev->irq;
+		hpet_reserve_timer(&hd, hdev->num);
+	}
+
 	hpet_alloc(&hd);
 
 }
@@ -238,6 +261,8 @@ static void hpet_legacy_clockevent_register(void)
 	printk(KERN_DEBUG "hpet clockevent registered\n");
 }
 
+static int hpet_setup_msi_irq(unsigned int irq);
+
 static void hpet_set_mode(enum clock_event_mode mode,
 			  struct clock_event_device *evt, int timer)
 {
@@ -279,7 +304,15 @@ static void hpet_set_mode(enum clock_event_mode mode,
 		break;
 
 	case CLOCK_EVT_MODE_RESUME:
-		hpet_enable_legacy_int();
+		if (timer == 0) {
+			hpet_enable_legacy_int();
+		} else {
+			struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
+			hpet_setup_msi_irq(hdev->irq);
+			disable_irq(hdev->irq);
+			irq_set_affinity(hdev->irq, cpumask_of_cpu(hdev->cpu));
+			enable_irq(hdev->irq);
+		}
 		break;
 	}
 }
@@ -318,7 +351,7 @@ static int hpet_legacy_next_event(unsigned long delta,
 /*
  * HPET MSI Support
  */
-
+#ifdef CONFIG_PCI_MSI
 void hpet_msi_unmask(unsigned int irq)
 {
 	struct hpet_dev *hdev = get_irq_data(irq);
@@ -358,6 +391,253 @@ void hpet_msi_read(unsigned int irq, struct msi_msg *msg)
 	msg->address_hi = 0;
 }
 
+static void hpet_msi_set_mode(enum clock_event_mode mode,
+				struct clock_event_device *evt)
+{
+	struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
+	hpet_set_mode(mode, evt, hdev->num);
+}
+
+static int hpet_msi_next_event(unsigned long delta,
+				struct clock_event_device *evt)
+{
+	struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
+	return hpet_next_event(delta, evt, hdev->num);
+}
+
+static int hpet_setup_msi_irq(unsigned int irq)
+{
+	if (arch_setup_hpet_msi(irq)) {
+		destroy_irq(irq);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int hpet_assign_irq(struct hpet_dev *dev)
+{
+	unsigned int irq;
+
+	irq = create_irq();
+	if (!irq)
+		return -EINVAL;
+
+	set_irq_data(irq, dev);
+
+	if (hpet_setup_msi_irq(irq))
+		return -EINVAL;
+
+	dev->irq = irq;
+	return 0;
+}
+
+static irqreturn_t hpet_interrupt_handler(int irq, void *data)
+{
+	struct hpet_dev *dev = (struct hpet_dev *)data;
+	struct clock_event_device *hevt = &dev->evt;
+
+	if (!hevt->event_handler) {
+		printk(KERN_INFO "Spurious HPET timer interrupt on HPET timer %d\n",
+				dev->num);
+		return IRQ_HANDLED;
+	}
+
+	hevt->event_handler(hevt);
+	return IRQ_HANDLED;
+}
+
+static int hpet_setup_irq(struct hpet_dev *dev)
+{
+
+	if (request_irq(dev->irq, hpet_interrupt_handler,
+			IRQF_SHARED|IRQF_NOBALANCING, dev->name, dev))
+		return -1;
+
+	disable_irq(dev->irq);
+	irq_set_affinity(dev->irq, cpumask_of_cpu(dev->cpu));
+	enable_irq(dev->irq);
+
+	return 0;
+}
+
+/* This should be called in specific @cpu */
+static void init_one_hpet_msi_clockevent(struct hpet_dev *hdev, int cpu)
+{
+	struct clock_event_device *evt = &hdev->evt;
+	uint64_t hpet_freq;
+
+	WARN_ON(cpu != smp_processor_id());
+	if (!(hdev->flags & HPET_DEV_VALID))
+		return;
+
+	if (hpet_setup_msi_irq(hdev->irq))
+		return;
+
+	hdev->cpu = cpu;
+	per_cpu(cpu_hpet_dev, cpu) = hdev;
+	evt->name = hdev->name;
+	hpet_setup_irq(hdev);
+	evt->irq = hdev->irq;
+
+	evt->rating = 110;
+	evt->features = CLOCK_EVT_FEAT_ONESHOT;
+	if (hdev->flags & HPET_DEV_PERI_CAP)
+		evt->features |= CLOCK_EVT_FEAT_PERIODIC;
+
+	evt->set_mode = hpet_msi_set_mode;
+	evt->set_next_event = hpet_msi_next_event;
+	evt->shift = 32;
+
+	/*
+	 * The period is a femto seconds value. We need to calculate the
+	 * scaled math multiplication factor for nanosecond to hpet tick
+	 * conversion.
+	 */
+	hpet_freq = 1000000000000000ULL;
+	do_div(hpet_freq, hpet_period);
+	evt->mult = div_sc((unsigned long) hpet_freq,
+				      NSEC_PER_SEC, evt->shift);
+	/* Calculate the max delta */
+	evt->max_delta_ns = clockevent_delta2ns(0x7FFFFFFF, evt);
+	/* 5 usec minimum reprogramming delta. */
+	evt->min_delta_ns = 5000;
+
+	evt->cpumask = cpumask_of_cpu(hdev->cpu);
+	clockevents_register_device(evt);
+}
+
+#ifdef CONFIG_HPET
+/* Reserve at least one timer for userspace (/dev/hpet) */
+#define RESERVE_TIMERS 1
+#else
+#define RESERVE_TIMERS 0
+#endif
+void hpet_msi_capability_lookup(unsigned int start_timer)
+{
+	unsigned int id;
+	unsigned int num_timers;
+	unsigned int num_timers_used = 0;
+	int i;
+
+	id = hpet_readl(HPET_ID);
+
+	num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
+	num_timers++; /* Value read out starts from 0 */
+
+	hpet_devs = kzalloc(sizeof(struct hpet_dev) * num_timers, GFP_KERNEL);
+	if (!hpet_devs)
+		return;
+
+	hpet_num_timers = num_timers;
+
+	for (i = start_timer; i < num_timers - RESERVE_TIMERS; i++) {
+		struct hpet_dev *hdev = &hpet_devs[num_timers_used];
+		unsigned long cfg = hpet_readl(HPET_Tn_CFG(i));
+
+		/* Only consider HPET timer with MSI support */
+		if (!(cfg & HPET_TN_FSB_CAP))
+			continue;
+
+		hdev->flags = 0;
+		if (cfg & HPET_TN_PERIODIC_CAP)
+			hdev->flags |= HPET_DEV_PERI_CAP;
+		hdev->num = i;
+
+		sprintf(hdev->name, "hpet%d", i);
+		if (hpet_assign_irq(hdev))
+			continue;
+
+		hdev->flags |= HPET_DEV_FSB_CAP;
+		hdev->flags |= HPET_DEV_VALID;
+		num_timers_used++;
+		if (num_timers_used == num_possible_cpus())
+			break;
+	}
+
+	printk(KERN_INFO "HPET: %d timers in total, %d timers will be used for per-cpu timer\n",
+		num_timers, num_timers_used);
+}
+
+static struct hpet_dev *hpet_get_unused_timer(void)
+{
+	int i;
+
+	if (!hpet_devs)
+		return NULL;
+
+	for (i = 0; i < hpet_num_timers; i++) {
+		struct hpet_dev *hdev = &hpet_devs[i];
+
+		if (!(hdev->flags & HPET_DEV_VALID))
+			continue;
+		if (test_and_set_bit(HPET_DEV_USED_BIT,
+			(unsigned long *)&hdev->flags))
+			continue;
+		return hdev;
+	}
+	return NULL;
+}
+
+struct hpet_work_struct {
+	struct delayed_work work;
+	struct completion complete;
+};
+
+static void hpet_work(struct work_struct *w)
+{
+	struct hpet_dev *hdev;
+	int cpu = smp_processor_id();
+	struct hpet_work_struct *hpet_work;
+
+	hpet_work = container_of(w, struct hpet_work_struct, work.work);
+
+	hdev = hpet_get_unused_timer();
+	if (hdev)
+		init_one_hpet_msi_clockevent(hdev, cpu);
+
+	complete(&hpet_work->complete);
+}
+
+static int hpet_cpuhp_notify(struct notifier_block *n,
+		unsigned long action, void *hcpu)
+{
+	unsigned long cpu = (unsigned long)hcpu;
+	struct hpet_work_struct work;
+	struct hpet_dev *hdev = per_cpu(cpu_hpet_dev, cpu);
+
+	switch (action & 0xf) {
+	case CPU_ONLINE:
+		INIT_DELAYED_WORK(&work.work, hpet_work);
+		init_completion(&work.complete);
+		/* FIXME: add schedule_work_on() */
+		schedule_delayed_work_on(cpu, &work.work, 0);
+		wait_for_completion(&work.complete);
+		break;
+	case CPU_DEAD:
+		if (hdev) {
+			free_irq(hdev->irq, hdev);
+			hdev->flags &= ~HPET_DEV_USED;
+			per_cpu(cpu_hpet_dev, cpu) = NULL;
+		}
+		break;
+	}
+	return NOTIFY_OK;
+}
+#else
+
+void hpet_msi_capability_lookup(unsigned int start_timer)
+{
+	return;
+}
+
+static int hpet_cpuhp_notify(struct notifier_block *n,
+		unsigned long action, void *hcpu)
+{
+	return NOTIFY_OK;
+}
+
+#endif
+
 /*
  * Clock source related code
  */
@@ -493,8 +773,10 @@ int __init hpet_enable(void)
 
 	if (id & HPET_ID_LEGSUP) {
 		hpet_legacy_clockevent_register();
+		hpet_msi_capability_lookup(2);
 		return 1;
 	}
+	hpet_msi_capability_lookup(0);
 	return 0;
 
 out_nohpet:
@@ -511,6 +793,8 @@ out_nohpet:
  */
 static __init int hpet_late_init(void)
 {
+	int cpu;
+
 	if (boot_hpet_disable)
 		return -ENODEV;
 
@@ -526,6 +810,13 @@ static __init int hpet_late_init(void)
 
 	hpet_reserve_platform_timers(hpet_readl(HPET_ID));
 
+	for_each_online_cpu(cpu) {
+		hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu);
+	}
+
+	/* This notifier should be called after workqueue is ready */
+	hotcpu_notifier(hpet_cpuhp_notify, -20);
+
 	return 0;
 }
 fs_initcall(hpet_late_init);