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path: root/drivers/char/hpet.c
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Diffstat (limited to 'drivers/char/hpet.c')
-rw-r--r--drivers/char/hpet.c100
1 files changed, 60 insertions, 40 deletions
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 55b8667f739..d5d4cd82b9f 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -14,7 +14,6 @@
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/kernel.h>
-#include <linux/smp_lock.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/major.h>
@@ -35,16 +34,12 @@
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/io.h>
-
+#include <linux/acpi.h>
+#include <linux/hpet.h>
#include <asm/current.h>
-#include <asm/system.h>
#include <asm/irq.h>
#include <asm/div64.h>
-#include <linux/acpi.h>
-#include <acpi/acpi_bus.h>
-#include <linux/hpet.h>
-
/*
* The High Precision Event Timer driver.
* This driver is closely modelled after the rtc.c driver.
@@ -85,8 +80,6 @@ static struct clocksource clocksource_hpet = {
.rating = 250,
.read = read_hpet,
.mask = CLOCKSOURCE_MASK(64),
- .mult = 0, /* to be calculated */
- .shift = 10,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static struct clocksource *hpet_clocksource;
@@ -166,11 +159,32 @@ static irqreturn_t hpet_interrupt(int irq, void *data)
* This has the effect of treating non-periodic like periodic.
*/
if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
- unsigned long m, t;
+ unsigned long m, t, mc, base, k;
+ struct hpet __iomem *hpet = devp->hd_hpet;
+ struct hpets *hpetp = devp->hd_hpets;
t = devp->hd_ireqfreq;
m = read_counter(&devp->hd_timer->hpet_compare);
- write_counter(t + m, &devp->hd_timer->hpet_compare);
+ mc = read_counter(&hpet->hpet_mc);
+ /* The time for the next interrupt would logically be t + m,
+ * however, if we are very unlucky and the interrupt is delayed
+ * for longer than t then we will completely miss the next
+ * interrupt if we set t + m and an application will hang.
+ * Therefore we need to make a more complex computation assuming
+ * that there exists a k for which the following is true:
+ * k * t + base < mc + delta
+ * (k + 1) * t + base > mc + delta
+ * where t is the interval in hpet ticks for the given freq,
+ * base is the theoretical start value 0 < base < t,
+ * mc is the main counter value at the time of the interrupt,
+ * delta is the time it takes to write the a value to the
+ * comparator.
+ * k may then be computed as (mc - base + delta) / t .
+ */
+ base = mc % t;
+ k = (mc - base + hpetp->hp_delta) / t;
+ write_counter(t * (k + 1) + base,
+ &devp->hd_timer->hpet_compare);
}
if (devp->hd_flags & HPET_SHARED_IRQ)
@@ -350,14 +364,28 @@ static unsigned int hpet_poll(struct file *file, poll_table * wait)
return 0;
}
+#ifdef CONFIG_HPET_MMAP
+#ifdef CONFIG_HPET_MMAP_DEFAULT
+static int hpet_mmap_enabled = 1;
+#else
+static int hpet_mmap_enabled = 0;
+#endif
+
+static __init int hpet_mmap_enable(char *str)
+{
+ get_option(&str, &hpet_mmap_enabled);
+ pr_info("HPET mmap %s\n", hpet_mmap_enabled ? "enabled" : "disabled");
+ return 1;
+}
+__setup("hpet_mmap", hpet_mmap_enable);
+
static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
{
-#ifdef CONFIG_HPET_MMAP
struct hpet_dev *devp;
unsigned long addr;
- if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
- return -EINVAL;
+ if (!hpet_mmap_enabled)
+ return -EACCES;
devp = file->private_data;
addr = devp->hd_hpets->hp_hpet_phys;
@@ -365,21 +393,15 @@ static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
if (addr & (PAGE_SIZE - 1))
return -ENOSYS;
- vma->vm_flags |= VM_IO;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-
- if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
- PAGE_SIZE, vma->vm_page_prot)) {
- printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
- __func__);
- return -EAGAIN;
- }
-
- return 0;
+ return vm_iomap_memory(vma, addr, PAGE_SIZE);
+}
#else
+static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
+{
return -ENOSYS;
-#endif
}
+#endif
static int hpet_fasync(int fd, struct file *file, int on)
{
@@ -481,8 +503,7 @@ static int hpet_ioctl_ieon(struct hpet_dev *devp)
}
sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
- irq_flags = devp->hd_flags & HPET_SHARED_IRQ
- ? IRQF_SHARED : IRQF_DISABLED;
+ irq_flags = devp->hd_flags & HPET_SHARED_IRQ ? IRQF_SHARED : 0;
if (request_irq(irq, hpet_interrupt, irq_flags,
devp->hd_name, (void *)devp)) {
printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
@@ -720,7 +741,7 @@ static int hpet_is_known(struct hpet_data *hdp)
return 0;
}
-static ctl_table hpet_table[] = {
+static struct ctl_table hpet_table[] = {
{
.procname = "max-user-freq",
.data = &hpet_max_freq,
@@ -731,7 +752,7 @@ static ctl_table hpet_table[] = {
{}
};
-static ctl_table hpet_root[] = {
+static struct ctl_table hpet_root[] = {
{
.procname = "hpet",
.maxlen = 0,
@@ -741,7 +762,7 @@ static ctl_table hpet_root[] = {
{}
};
-static ctl_table dev_root[] = {
+static struct ctl_table dev_root[] = {
{
.procname = "dev",
.maxlen = 0,
@@ -799,7 +820,7 @@ static unsigned long __hpet_calibrate(struct hpets *hpetp)
static unsigned long hpet_calibrate(struct hpets *hpetp)
{
- unsigned long ret = -1;
+ unsigned long ret = ~0UL;
unsigned long tmp;
/*
@@ -889,8 +910,8 @@ int hpet_alloc(struct hpet_data *hdp)
hpetp->hp_which, hdp->hd_phys_address,
hpetp->hp_ntimer > 1 ? "s" : "");
for (i = 0; i < hpetp->hp_ntimer; i++)
- printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
- printk("\n");
+ printk(KERN_CONT "%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
+ printk(KERN_CONT "\n");
temp = hpetp->hp_tick_freq;
remainder = do_div(temp, 1000000);
@@ -934,10 +955,8 @@ int hpet_alloc(struct hpet_data *hdp)
#ifdef CONFIG_IA64
if (!hpet_clocksource) {
hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
- CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr);
- clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq,
- clocksource_hpet.shift);
- clocksource_register(&clocksource_hpet);
+ clocksource_hpet.archdata.fsys_mmio = hpet_mctr;
+ clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq);
hpetp->hp_clocksource = &clocksource_hpet;
hpet_clocksource = &clocksource_hpet;
}
@@ -968,8 +987,6 @@ static acpi_status hpet_resources(struct acpi_resource *res, void *data)
struct acpi_resource_fixed_memory32 *fixmem32;
fixmem32 = &res->data.fixed_memory32;
- if (!fixmem32)
- return AE_NO_MEMORY;
hdp->hd_phys_address = fixmem32->address;
hdp->hd_address = ioremap(fixmem32->address,
@@ -986,6 +1003,9 @@ static acpi_status hpet_resources(struct acpi_resource *res, void *data)
irqp = &res->data.extended_irq;
for (i = 0; i < irqp->interrupt_count; i++) {
+ if (hdp->hd_nirqs >= HPET_MAX_TIMERS)
+ break;
+
irq = acpi_register_gsi(NULL, irqp->interrupts[i],
irqp->triggering, irqp->polarity);
if (irq < 0)
@@ -1023,7 +1043,7 @@ static int hpet_acpi_add(struct acpi_device *device)
return hpet_alloc(&data);
}
-static int hpet_acpi_remove(struct acpi_device *device, int type)
+static int hpet_acpi_remove(struct acpi_device *device)
{
/* XXX need to unregister clocksource, dealloc mem, etc */
return -EINVAL;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-03 18:32:17 +0000