Merge commit 'timers/auto-timers-next'

6 files changed, 128 insertions, 102 deletions

diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX
index 5b5aba404aac..1427969275a1 100644
--- a/Documentation/00-INDEX
+++ b/Documentation/00-INDEX
@@ -159,8 +159,6 @@ hayes-esp.txt
 	- info on using the Hayes ESP serial driver.
 highuid.txt
 	- notes on the change from 16 bit to 32 bit user/group IDs.
-hpet.txt
-	- High Precision Event Timer Driver for Linux.
 timers/
 	- info on the timer related topics
 hw_random.txt
diff --git a/Documentation/timers/00-INDEX b/Documentation/timers/00-INDEX
new file mode 100644
index 000000000000..397dc35e1323
--- /dev/null
+++ b/Documentation/timers/00-INDEX
@@ -0,0 +1,10 @@
+00-INDEX
+	- this file
+highres.txt
+	- High resolution timers and dynamic ticks design notes
+hpet.txt
+	- High Precision Event Timer Driver for Linux
+hrtimers.txt
+	- subsystem for high-resolution kernel timers
+timer_stats.txt
+	- timer usage statistics
diff --git a/Documentation/hpet.txt b/Documentation/timers/hpet.txt
index 6ad52d9dad6c..e7c09abcfab4 100644
--- a/Documentation/hpet.txt
+++ b/Documentation/timers/hpet.txt
@@ -1,21 +1,32 @@
 		High Precision Event Timer Driver for Linux
 
-The High Precision Event Timer (HPET) hardware is the future replacement
-for the 8254 and Real Time Clock (RTC) periodic timer functionality.
-Each HPET can have up to 32 timers.  It is possible to configure the
-first two timers as legacy replacements for 8254 and RTC periodic timers.
-A specification done by Intel and Microsoft can be found at
-<http://www.intel.com/technology/architecture/hpetspec.htm>.
+The High Precision Event Timer (HPET) hardware follows a specification
+by Intel and Microsoft which can be found at
+
+	http://www.intel.com/technology/architecture/hpetspec.htm
+
+Each HPET has one fixed-rate counter (at 10+ MHz, hence "High Precision")
+and up to 32 comparators.  Normally three or more comparators are provided,
+each of which can generate oneshot interupts and at least one of which has
+additional hardware to support periodic interrupts.  The comparators are
+also called "timers", which can be misleading since usually timers are
+independent of each other ... these share a counter, complicating resets.
+
+HPET devices can support two interrupt routing modes.  In one mode, the
+comparators are additional interrupt sources with no particular system
+role.  Many x86 BIOS writers don't route HPET interrupts at all, which
+prevents use of that mode.  They support the other "legacy replacement"
+mode where the first two comparators block interrupts from 8254 timers
+and from the RTC.
 
 The driver supports detection of HPET driver allocation and initialization
 of the HPET before the driver module_init routine is called.  This enables
 platform code which uses timer 0 or 1 as the main timer to intercept HPET
 initialization.  An example of this initialization can be found in
-arch/i386/kernel/time_hpet.c.
+arch/x86/kernel/hpet.c.
 
-The driver provides two APIs which are very similar to the API found in
-the rtc.c driver.  There is a user space API and a kernel space API.
-An example user space program is provided below.
+The driver provides a userspace API which resembles the API found in the
+RTC driver framework.  An example user space program is provided below.
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -286,15 +297,3 @@ out:
 
 	return;
 }
-
-The kernel API has three interfaces exported from the driver:
-
-	hpet_register(struct hpet_task *tp, int periodic)
-	hpet_unregister(struct hpet_task *tp)
-	hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
-
-The kernel module using this interface fills in the ht_func and ht_data
-members of the hpet_task structure before calling hpet_register.
-hpet_control simply vectors to the hpet_ioctl routine and has the same
-commands and respective arguments as the user API.  hpet_unregister
-is used to terminate usage of the HPET timer reserved by hpet_register.
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 59fd3b6b1303..f95c2471b94a 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -115,13 +115,17 @@ static void hpet_reserve_platform_timers(unsigned long id)
 	hd.hd_phys_address = hpet_address;
 	hd.hd_address = hpet;
 	hd.hd_nirqs = nrtimers;
-	hd.hd_flags = HPET_DATA_PLATFORM;
 	hpet_reserve_timer(&hd, 0);
 
 #ifdef CONFIG_HPET_EMULATE_RTC
 	hpet_reserve_timer(&hd, 1);
 #endif
 
+	/*
+	 * NOTE that hd_irq[] reflects IOAPIC input pins (LEGACY_8254
+	 * is wrong for i8259!) not the output IRQ.  Many BIOS writers
+	 * don't bother configuring *any* comparator interrupts.
+	 */
 	hd.hd_irq[0] = HPET_LEGACY_8254;
 	hd.hd_irq[1] = HPET_LEGACY_RTC;
 
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index b3f5dbc6d880..2908a0eb63af 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -53,6 +53,11 @@
 
 #define HPET_RANGE_SIZE		1024	/* from HPET spec */
 
+
+/* WARNING -- don't get confused.  These macros are never used
+ * to write the (single) counter, and rarely to read it.
+ * They're badly named; to fix, someday.
+ */
 #if BITS_PER_LONG == 64
 #define	write_counter(V, MC)	writeq(V, MC)
 #define	read_counter(MC)	readq(MC)
@@ -77,7 +82,7 @@ static struct clocksource clocksource_hpet = {
         .rating         = 250,
         .read           = read_hpet,
         .mask           = CLOCKSOURCE_MASK(64),
-        .mult           = 0, /*to be caluclated*/
+	.mult		= 0, /* to be calculated */
         .shift          = 10,
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 };
@@ -86,8 +91,6 @@ static struct clocksource *hpet_clocksource;
 
 /* A lock for concurrent access by app and isr hpet activity. */
 static DEFINE_SPINLOCK(hpet_lock);
-/* A lock for concurrent intermodule access to hpet and isr hpet activity. */
-static DEFINE_SPINLOCK(hpet_task_lock);
 
 #define	HPET_DEV_NAME	(7)
 
@@ -99,7 +102,6 @@ struct hpet_dev {
 	unsigned long hd_irqdata;
 	wait_queue_head_t hd_waitqueue;
 	struct fasync_struct *hd_async_queue;
-	struct hpet_task *hd_task;
 	unsigned int hd_flags;
 	unsigned int hd_irq;
 	unsigned int hd_hdwirq;
@@ -173,11 +175,6 @@ static irqreturn_t hpet_interrupt(int irq, void *data)
 		writel(isr, &devp->hd_hpet->hpet_isr);
 	spin_unlock(&hpet_lock);
 
-	spin_lock(&hpet_task_lock);
-	if (devp->hd_task)
-		devp->hd_task->ht_func(devp->hd_task->ht_data);
-	spin_unlock(&hpet_task_lock);
-
 	wake_up_interruptible(&devp->hd_waitqueue);
 
 	kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
@@ -185,6 +182,67 @@ static irqreturn_t hpet_interrupt(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+static void hpet_timer_set_irq(struct hpet_dev *devp)
+{
+	unsigned long v;
+	int irq, gsi;
+	struct hpet_timer __iomem *timer;
+
+	spin_lock_irq(&hpet_lock);
+	if (devp->hd_hdwirq) {
+		spin_unlock_irq(&hpet_lock);
+		return;
+	}
+
+	timer = devp->hd_timer;
+
+	/* we prefer level triggered mode */
+	v = readl(&timer->hpet_config);
+	if (!(v & Tn_INT_TYPE_CNF_MASK)) {
+		v |= Tn_INT_TYPE_CNF_MASK;
+		writel(v, &timer->hpet_config);
+	}
+	spin_unlock_irq(&hpet_lock);
+
+	v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
+				 Tn_INT_ROUTE_CAP_SHIFT;
+
+	/*
+	 * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
+	 * legacy device. In IO APIC mode, we skip all the legacy IRQS.
+	 */
+	if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
+		v &= ~0xf3df;
+	else
+		v &= ~0xffff;
+
+	for (irq = find_first_bit(&v, HPET_MAX_IRQ); irq < HPET_MAX_IRQ;
+		irq = find_next_bit(&v, HPET_MAX_IRQ, 1 + irq)) {
+
+		if (irq >= NR_IRQS) {
+			irq = HPET_MAX_IRQ;
+			break;
+		}
+
+		gsi = acpi_register_gsi(irq, ACPI_LEVEL_SENSITIVE,
+					ACPI_ACTIVE_LOW);
+		if (gsi > 0)
+			break;
+
+		/* FIXME: Setup interrupt source table */
+	}
+
+	if (irq < HPET_MAX_IRQ) {
+		spin_lock_irq(&hpet_lock);
+		v = readl(&timer->hpet_config);
+		v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
+		writel(v, &timer->hpet_config);
+		devp->hd_hdwirq = gsi;
+		spin_unlock_irq(&hpet_lock);
+	}
+	return;
+}
+
 static int hpet_open(struct inode *inode, struct file *file)
 {
 	struct hpet_dev *devp;
@@ -199,8 +257,7 @@ static int hpet_open(struct inode *inode, struct file *file)
 
 	for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 		for (i = 0; i < hpetp->hp_ntimer; i++)
-			if (hpetp->hp_dev[i].hd_flags & HPET_OPEN
-			    || hpetp->hp_dev[i].hd_task)
+			if (hpetp->hp_dev[i].hd_flags & HPET_OPEN)
 				continue;
 			else {
 				devp = &hpetp->hp_dev[i];
@@ -219,6 +276,8 @@ static int hpet_open(struct inode *inode, struct file *file)
 	spin_unlock_irq(&hpet_lock);
 	unlock_kernel();
 
+	hpet_timer_set_irq(devp);
+
 	return 0;
 }
 
@@ -441,7 +500,11 @@ static int hpet_ioctl_ieon(struct hpet_dev *devp)
 	devp->hd_irq = irq;
 	t = devp->hd_ireqfreq;
 	v = readq(&timer->hpet_config);
-	g = v | Tn_INT_ENB_CNF_MASK;
+
+	/* 64-bit comparators are not yet supported through the ioctls,
+	 * so force this into 32-bit mode if it supports both modes
+	 */
+	g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK;
 
 	if (devp->hd_flags & HPET_PERIODIC) {
 		write_counter(t, &timer->hpet_compare);
@@ -451,6 +514,12 @@ static int hpet_ioctl_ieon(struct hpet_dev *devp)
 		v |= Tn_VAL_SET_CNF_MASK;
 		writeq(v, &timer->hpet_config);
 		local_irq_save(flags);
+
+		/* NOTE:  what we modify here is a hidden accumulator
+		 * register supported by periodic-capable comparators.
+		 * We never want to modify the (single) counter; that
+		 * would affect all the comparators.
+		 */
 		m = read_counter(&hpet->hpet_mc);
 		write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 	} else {
@@ -604,57 +673,6 @@ static int hpet_is_known(struct hpet_data *hdp)
 	return 0;
 }
 
-static inline int hpet_tpcheck(struct hpet_task *tp)
-{
-	struct hpet_dev *devp;
-	struct hpets *hpetp;
-
-	devp = tp->ht_opaque;
-
-	if (!devp)
-		return -ENXIO;
-
-	for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
-		if (devp >= hpetp->hp_dev
-		    && devp < (hpetp->hp_dev + hpetp->hp_ntimer)
-		    && devp->hd_hpet == hpetp->hp_hpet)
-			return 0;
-
-	return -ENXIO;
-}
-
-#if 0
-int hpet_unregister(struct hpet_task *tp)
-{
-	struct hpet_dev *devp;
-	struct hpet_timer __iomem *timer;
-	int err;
-
-	if ((err = hpet_tpcheck(tp)))
-		return err;
-
-	spin_lock_irq(&hpet_task_lock);
-	spin_lock(&hpet_lock);
-
-	devp = tp->ht_opaque;
-	if (devp->hd_task != tp) {
-		spin_unlock(&hpet_lock);
-		spin_unlock_irq(&hpet_task_lock);
-		return -ENXIO;
-	}
-
-	timer = devp->hd_timer;
-	writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
-	       &timer->hpet_config);
-	devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC);
-	devp->hd_task = NULL;
-	spin_unlock(&hpet_lock);
-	spin_unlock_irq(&hpet_task_lock);
-
-	return 0;
-}
-#endif  /*  0  */
-
 static ctl_table hpet_table[] = {
 	{
 	 .ctl_name = CTL_UNNUMBERED,
@@ -746,6 +764,7 @@ int hpet_alloc(struct hpet_data *hdp)
 	static struct hpets *last = NULL;
 	unsigned long period;
 	unsigned long long temp;
+	u32 remainder;
 
 	/*
 	 * hpet_alloc can be called by platform dependent code.
@@ -809,9 +828,13 @@ int hpet_alloc(struct hpet_data *hdp)
 		printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
 	printk("\n");
 
-	printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n",
-	       hpetp->hp_which, hpetp->hp_ntimer,
-	       cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, hpetp->hp_tick_freq);
+	temp = hpetp->hp_tick_freq;
+	remainder = do_div(temp, 1000000);
+	printk(KERN_INFO
+		"hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n",
+		hpetp->hp_which, hpetp->hp_ntimer,
+		cap & HPET_COUNTER_SIZE_MASK ? 64 : 32,
+		(unsigned) temp, remainder);
 
 	mcfg = readq(&hpet->hpet_config);
 	if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
diff --git a/include/linux/hpet.h b/include/linux/hpet.h
index 2dc29ce6c8e4..79f63a27bcef 100644
--- a/include/linux/hpet.h
+++ b/include/linux/hpet.h
@@ -37,6 +37,7 @@ struct hpet {
 #define	hpet_compare	_u1._hpet_compare
 
 #define	HPET_MAX_TIMERS	(32)
+#define	HPET_MAX_IRQ	(32)
 
 /*
  * HPET general capabilities register
@@ -64,7 +65,7 @@ struct hpet {
  */
 
 #define	Tn_INT_ROUTE_CAP_MASK		(0xffffffff00000000ULL)
-#define	Tn_INI_ROUTE_CAP_SHIFT		(32UL)
+#define	Tn_INT_ROUTE_CAP_SHIFT		(32UL)
 #define	Tn_FSB_INT_DELCAP_MASK		(0x8000UL)
 #define	Tn_FSB_INT_DELCAP_SHIFT		(15)
 #define	Tn_FSB_EN_CNF_MASK		(0x4000UL)
@@ -91,23 +92,14 @@ struct hpet {
  * exported interfaces
  */
 
-struct hpet_task {
-	void (*ht_func) (void *);
-	void *ht_data;
-	void *ht_opaque;
-};
-
 struct hpet_data {
 	unsigned long hd_phys_address;
 	void __iomem *hd_address;
 	unsigned short hd_nirqs;
-	unsigned short hd_flags;
 	unsigned int hd_state;	/* timer allocated */
 	unsigned int hd_irq[HPET_MAX_TIMERS];
 };
 
-#define	HPET_DATA_PLATFORM	0x0001	/* platform call to hpet_alloc */
-
 static inline void hpet_reserve_timer(struct hpet_data *hd, int timer)
 {
 	hd->hd_state |= (1 << timer);
@@ -125,7 +117,7 @@ struct hpet_info {
 	unsigned short hi_timer;
 };
 
-#define	HPET_INFO_PERIODIC	0x0001	/* timer is periodic */
+#define HPET_INFO_PERIODIC	0x0010	/* periodic-capable comparator */
 
 #define	HPET_IE_ON	_IO('h', 0x01)	/* interrupt on */
 #define	HPET_IE_OFF	_IO('h', 0x02)	/* interrupt off */