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-rw-r--r--Documentation/00-INDEX2
-rw-r--r--Documentation/timers/00-INDEX10
-rw-r--r--Documentation/timers/hpet.txt (renamed from Documentation/hpet.txt)43
-rw-r--r--arch/x86/kernel/hpet.c6
-rw-r--r--arch/x86/kernel/quirks.c41
-rw-r--r--arch/x86/pci/fixup.c28
-rw-r--r--drivers/char/hpet.c155
-rw-r--r--include/linux/hpet.h14
8 files changed, 195 insertions, 104 deletions
diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX
index 5b5aba404aa..1427969275a 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 00000000000..397dc35e132
--- /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 6ad52d9dad6..e7c09abcfab 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 73deaffadd0..acf62fc233d 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/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index d1385881810..f6a11b9b1f9 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -354,9 +354,27 @@ static void ati_force_hpet_resume(void)
printk(KERN_DEBUG "Force enabled HPET at resume\n");
}
+static u32 ati_ixp4x0_rev(struct pci_dev *dev)
+{
+ u32 d;
+ u8 b;
+
+ pci_read_config_byte(dev, 0xac, &b);
+ b &= ~(1<<5);
+ pci_write_config_byte(dev, 0xac, b);
+ pci_read_config_dword(dev, 0x70, &d);
+ d |= 1<<8;
+ pci_write_config_dword(dev, 0x70, d);
+ pci_read_config_dword(dev, 0x8, &d);
+ d &= 0xff;
+ dev_printk(KERN_DEBUG, &dev->dev, "SB4X0 revision 0x%x\n", d);
+ return d;
+}
+
static void ati_force_enable_hpet(struct pci_dev *dev)
{
- u32 uninitialized_var(val);
+ u32 d, val;
+ u8 b;
if (hpet_address || force_hpet_address)
return;
@@ -366,14 +384,33 @@ static void ati_force_enable_hpet(struct pci_dev *dev)
return;
}
+ d = ati_ixp4x0_rev(dev);
+ if (d < 0x82)
+ return;
+
+ /* base address */
pci_write_config_dword(dev, 0x14, 0xfed00000);
pci_read_config_dword(dev, 0x14, &val);
+
+ /* enable interrupt */
+ outb(0x72, 0xcd6); b = inb(0xcd7);
+ b |= 0x1;
+ outb(0x72, 0xcd6); outb(b, 0xcd7);
+ outb(0x72, 0xcd6); b = inb(0xcd7);
+ if (!(b & 0x1))
+ return;
+ pci_read_config_dword(dev, 0x64, &d);
+ d |= (1<<10);
+ pci_write_config_dword(dev, 0x64, d);
+ pci_read_config_dword(dev, 0x64, &d);
+ if (!(d & (1<<10)))
+ return;
+
force_hpet_address = val;
force_hpet_resume_type = ATI_FORCE_HPET_RESUME;
dev_printk(KERN_DEBUG, &dev->dev, "Force enabled HPET at 0x%lx\n",
force_hpet_address);
cached_dev = dev;
- return;
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS,
ati_force_enable_hpet);
diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index 4bdaa590375..3c27a809393 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -511,3 +511,31 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_AMD, 0x1201, fam10h_pci_cfg_space_size);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_AMD, 0x1202, fam10h_pci_cfg_space_size);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_AMD, 0x1203, fam10h_pci_cfg_space_size);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_AMD, 0x1204, fam10h_pci_cfg_space_size);
+
+/*
+ * SB600: Disable BAR1 on device 14.0 to avoid HPET resources from
+ * confusing the PCI engine:
+ */
+static void sb600_disable_hpet_bar(struct pci_dev *dev)
+{
+ u8 val;
+
+ /*
+ * The SB600 and SB700 both share the same device
+ * ID, but the PM register 0x55 does something different
+ * for the SB700, so make sure we are dealing with the
+ * SB600 before touching the bit:
+ */
+
+ pci_read_config_byte(dev, 0x08, &val);
+
+ if (val < 0x2F) {
+ outb(0x55, 0xCD6);
+ val = inb(0xCD7);
+
+ /* Set bit 7 in PM register 0x55 */
+ outb(0x55, 0xCD6);
+ outb(val | 0x80, 0xCD7);
+ }
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_ATI, 0x4385, sb600_disable_hpet_bar);
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index b3f5dbc6d88..2908a0eb63a 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 2dc29ce6c8e..79f63a27bce 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 */
generated by cgit v1.2.3 (git 2.25.1) at 2025-01-09 22:32:49 +0000