Re: [PATCH] HPET driver
From: Jeff Garzik
Date: Fri Jun 18 2004 - 18:09:10 EST
Linux Kernel Mailing List wrote:
ChangeSet 1.1817, 2004/06/18 07:57:53-07:00, Robert.Picco@xxxxxx
[PATCH] HPET driver
The driver supports the High Precision Event Timer. The driver has adopted
a similar API to the Real Time Clock driver. It can support any number of
HPET devices and the maximum number of timers per HPET device. For further
information look at the documentation in the patch.
Thanks to Venki at Intel for testing the driver on X86 hardware with HPET.
HPET documentation is available at http://www.intel.com/design/chipsets/datashts/252516.htm
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxx>
Was this posted on lkml, or simply snuck in?
If it was reviewed, I shall presume it was reviewed by a drunken monitor
lizard: It has serious security and crash problems.
This should NOT have been merged without changes. Please fix ASAP, or
revert and keep in -mm for a while.
diff -Nru a/arch/i386/kernel/time_hpet.c b/arch/i386/kernel/time_hpet.c
--- a/arch/i386/kernel/time_hpet.c 2004-06-18 09:16:23 -07:00
+++ b/arch/i386/kernel/time_hpet.c 2004-06-18 09:16:23 -07:00
@@ -21,6 +21,7 @@
#include <linux/config.h>
#include <asm/hpet.h>
+#include <linux/hpet.h>
unsigned long hpet_period; /* fsecs / HPET clock */
unsigned long hpet_tick; /* hpet clks count per tick */
@@ -135,6 +136,51 @@
hpet_writel(cfg, HPET_CFG);
use_hpet = 1;
+
+#ifdef CONFIG_HPET
+ {
+ struct hpet_data hd;
+ unsigned int ntimer;
+
+ memset(&hd, 0, sizeof (hd));
+
+ ntimer = hpet_readl(HPET_ID);
+ ntimer = (ntimer & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT;
+ ntimer++;
+
+ /*
+ * Register with driver.
+ * Timer0 and Timer1 is used by platform.
+ */
+ hd.hd_address = hpet_virt_address;
+ hd.hd_nirqs = ntimer;
+ hd.hd_flags = HPET_DATA_PLATFORM;
+#ifndef CONFIG_HPET_EMULATE_RTC
+ hd.hd_state = 0x1;
+#else
+ hd.hd_state = 0x3;
+#endif
don't use magic numbers
+ hd.hd_irq[0] = HPET_LEGACY_8254;
+ hd.hd_irq[1] = HPET_LEGACY_RTC;
+ if (ntimer > 2) {
+ struct hpet *hpet;
+ struct hpet_timer *timer;
+ int i;
+
+ hpet = (struct hpet *) hpet_virt_address;
+
+ for (i = 2, timer = &hpet->hpet_timers[2]; i < ntimer;
+ timer++, i++)
+ hd.hd_irq[i] = (timer->hpet_config &
+ Tn_INT_ROUTE_CNF_MASK) >>
+ Tn_INT_ROUTE_CNF_SHIFT;
+
+ }
+
+ hpet_alloc(&hd);
+ }
+#endif
+
#ifdef CONFIG_X86_LOCAL_APIC
wait_timer_tick = wait_hpet_tick;
#endif
diff -Nru a/drivers/char/hpet.c b/drivers/char/hpet.c
--- /dev/null Wed Dec 31 16:00:00 196900
+++ b/drivers/char/hpet.c 2004-06-18 09:16:23 -07:00
@@ -0,0 +1,1076 @@
+/*
+ * Intel & MS High Precision Event Timer Implementation.
+ * Contributors:
+ * Venki Pallipadi
+ * Bob Picco
+ */
+
+#include <linux/config.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/major.h>
+#include <linux/ioport.h>
+#include <linux/fcntl.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/spinlock.h>
+#include <linux/sysctl.h>
+#include <linux/wait.h>
+#include <linux/bcd.h>
+#include <linux/seq_file.h>
+
+#include <asm/current.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/bitops.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.
+ * http://www.intel.com/labs/platcomp/hpet/hpetspec.htm
+ */
+#define HPET_USER_FREQ (64)
+#define HPET_DRIFT (500)
+
+static u32 hpet_ntimer, hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
+
+/* A lock for concurrent access by app and isr hpet activity. */
+static spinlock_t hpet_lock = SPIN_LOCK_UNLOCKED;
+/* A lock for concurrent intermodule access to hpet and isr hpet activity. */
+static spinlock_t hpet_task_lock = SPIN_LOCK_UNLOCKED;
Shouldn't this lock be elsewhere, since HPET may be enabled but this
driver isn't?
+struct hpet_dev {
+ struct hpets *hd_hpets;
+ struct hpet *hd_hpet;
+ struct hpet_timer *hd_timer;
+ unsigned long hd_ireqfreq;
+ 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;
+};
+
+struct hpets {
+ struct hpets *hp_next;
+ struct hpet *hp_hpet;
+ unsigned long hp_period;
+ unsigned long hp_delta;
+ unsigned int hp_ntimer;
+ unsigned int hp_which;
+ struct hpet_dev hp_dev[1];
+};
+
+static struct hpets *hpets;
+
+#define HPET_OPEN 0x0001
+#define HPET_IE 0x0002 /* interrupt enabled */
+#define HPET_PERIODIC 0x0004
+
+#if BITS_PER_LONG == 64
+#define write_counter(V, MC) writeq(V, MC)
+#define read_counter(MC) readq(MC)
+#else
+#define write_counter(V, MC) writel(V, MC)
+#define read_counter(MC) readl(MC)
+#endif
+
+#ifndef readq
+static unsigned long long __inline readq(void *addr)
+{
+ return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
+}
+#endif
+
+#ifndef writeq
+static void __inline writeq(unsigned long long v, void *addr)
+{
+ writel(v & 0xffffffff, addr);
+ writel(v >> 32, addr + 4);
+}
+#endif
don't define driver-local readq/writeq
+static irqreturn_t hpet_interrupt(int irq, void *data, struct pt_regs *regs)
+{
+ struct hpet_dev *devp;
+ unsigned long isr;
+
+ devp = data;
+
+ spin_lock(&hpet_lock);
+ devp->hd_irqdata++;
+
+ /*
+ * For non-periodic timers, increment the accumulator.
+ * This has the effect of treating non-periodic like periodic.
+ */
+ if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
+ unsigned long m, t;
+
+ t = devp->hd_ireqfreq;
+ m = read_counter(&devp->hd_hpet->hpet_mc);
+ write_counter(t + m + devp->hd_hpets->hp_delta,
+ &devp->hd_timer->hpet_compare);
+ }
+
+ isr = (1 << (devp - devp->hd_hpets->hp_dev));
+ writeq(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);
can the 'if' be moved outside the spinlock?
+ wake_up_interruptible(&devp->hd_waitqueue);
+
+ kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
shared interrupt: boom
+ return IRQ_HANDLED;
+}
+
+static int hpet_open(struct inode *inode, struct file *file)
+{
+ struct hpet_dev *devp;
+ struct hpets *hpetp;
+ int i;
+
+ spin_lock_irq(&hpet_lock);
+
+ 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)
+ continue;
+ else {
+ devp = &hpetp->hp_dev[i];
+ break;
+ }
+
+ if (!devp) {
+ spin_unlock_irq(&hpet_lock);
+ return -EBUSY;
+ }
+
+ file->private_data = devp;
+ devp->hd_irqdata = 0;
+ devp->hd_flags |= HPET_OPEN;
+ spin_unlock_irq(&hpet_lock);
+
+ return 0;
+}
security/bug: missing check for O_RDWR, no?
+static ssize_t
+hpet_read(struct file *file, char *buf, size_t count, loff_t * ppos)
+{
+ DECLARE_WAITQUEUE(wait, current);
+ unsigned long data;
+ ssize_t retval;
+ struct hpet_dev *devp;
+
+ devp = file->private_data;
+ if (!devp->hd_ireqfreq)
+ return -EIO;
+
+ if (count < sizeof(unsigned long))
+ return -EINVAL;
see comment below, re context switches
+ add_wait_queue(&devp->hd_waitqueue, &wait);
+
+ do {
+ __set_current_state(TASK_INTERRUPTIBLE);
+
+ spin_lock_irq(&hpet_lock);
+ data = devp->hd_irqdata;
+ devp->hd_irqdata = 0;
+ spin_unlock_irq(&hpet_lock);
+
+ if (data)
+ break;
+ else if (file->f_flags & O_NONBLOCK) {
+ retval = -EAGAIN;
+ goto out;
+ } else if (signal_pending(current)) {
+ retval = -ERESTARTSYS;
+ goto out;
+ }
+
+ schedule();
why munge the task state, if you're not going to schedule (such as
non-block)?
+ } while (1);
+
+ retval = put_user(data, (unsigned long *)buf);
+ if (!retval)
+ retval = sizeof(unsigned long);
If you don't process more than one datum per read(2), you wind up with a
lot of context switches
+ out:
+ current->state = TASK_RUNNING;
+ remove_wait_queue(&devp->hd_waitqueue, &wait);
+
+ return retval;
+}
+
+static unsigned int hpet_poll(struct file *file, poll_table * wait)
+{
+ unsigned long v;
+ struct hpet_dev *devp;
+
+ devp = file->private_data;
+
+ if (!devp->hd_ireqfreq)
+ return 0;
+
+ poll_wait(file, &devp->hd_waitqueue, wait);
+
+ spin_lock_irq(&hpet_lock);
+ v = devp->hd_irqdata;
+ spin_unlock_irq(&hpet_lock);
+
+ if (v != 0)
+ return POLLIN | POLLRDNORM;
+
+ return 0;
+}
I need to review ->poll hook again, but I thought this (via __pollwait)
just sets up the poll, not actually does the poll.
+static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
+{
+#ifdef CONFIG_HPET_NOMMAP
+ return -ENOSYS;
+#else
+ struct hpet_dev *devp;
+ unsigned long addr;
+
+ if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
+ return -EINVAL;
+
+ if (vma->vm_flags & VM_WRITE)
+ return -EPERM;
can this be prevented at open(2) time?
+ devp = file->private_data;
+ addr = (unsigned long)devp->hd_hpet;
locking/refcounting?
+ if (addr & (PAGE_SIZE - 1))
+ return -ENOSYS;
BUG() ?
+ vma->vm_flags |= VM_IO;
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+ addr = __pa(addr);
+
+ if (remap_page_range
+ (vma, vma->vm_start, addr, PAGE_SIZE, vma->vm_page_prot)) {
+ printk(KERN_ERR "remap_page_range failed in hpet.c\n");
+ return -EAGAIN;
+ }
+
+ return 0;
+#endif
+}
why not use ->nopage? And isn't VM_RESERVED needed?
+static int hpet_fasync(int fd, struct file *file, int on)
+{
+ struct hpet_dev *devp;
+
+ devp = file->private_data;
+
+ if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
+ return 0;
+ else
+ return -EIO;
+}
+
+static int hpet_release(struct inode *inode, struct file *file)
+{
+ struct hpet_dev *devp;
+ struct hpet_timer *timer;
+ int irq = 0;
+
+ devp = file->private_data;
+ timer = devp->hd_timer;
+
+ spin_lock_irq(&hpet_lock);
+
+ writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
+ &timer->hpet_config);
+
+ irq = devp->hd_irq;
+ devp->hd_irq = 0;
+
+ devp->hd_ireqfreq = 0;
+
+ if (devp->hd_flags & HPET_PERIODIC
+ && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
+ unsigned long v;
+
+ v = readq(&timer->hpet_config);
+ v ^= Tn_TYPE_CNF_MASK;
+ writeq(v, &timer->hpet_config);
+ }
+
+ devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
+ spin_unlock_irq(&hpet_lock);
+
+ if (irq)
+ free_irq(irq, devp);
+
+ if (file->f_flags & FASYNC)
+ hpet_fasync(-1, file, 0);
is this safe to do in ->release?
+ file->private_data = 0;
+ return 0;
+}
+
+static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
+
+static int
+hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct hpet_dev *devp;
+
+ devp = file->private_data;
+ return hpet_ioctl_common(devp, cmd, arg, 0);
+}
+
+static int hpet_ioctl_ieon(struct hpet_dev *devp)
+{
+ struct hpet_timer *timer;
+ struct hpet *hpet;
+ struct hpets *hpetp;
+ int irq;
+ unsigned long g, v, t, m;
+ unsigned long flags, isr;
+
+ timer = devp->hd_timer;
+ hpet = devp->hd_hpet;
+ hpetp = devp->hd_hpets;
+
+ v = readq(&timer->hpet_config);
+ spin_lock_irq(&hpet_lock);
+
+ if (devp->hd_flags & HPET_IE) {
+ spin_unlock_irq(&hpet_lock);
+ return -EBUSY;
+ }
+
+ devp->hd_flags |= HPET_IE;
+ spin_unlock_irq(&hpet_lock);
+
+ t = readq(&timer->hpet_config);
+ irq = devp->hd_hdwirq;
+
+ if (irq) {
+ char name[7];
+
+ sprintf(name, "hpet%d", (int)(devp - hpetp->hp_dev));
requesting irq in an ioctl is, um, unusual...
+ if (request_irq
+ (irq, hpet_interrupt, SA_INTERRUPT, name, (void *)devp)) {
+ printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
+ irq = 0;
+ }
+ }
SECURITY/OOPS: request_irq stores a C pointer to the device name.
having the device name on the stack is very bad news.
cat /proc/interrupts for an oops, or at least leaking kernel memory to
any user.
+ if (irq == 0) {
+ spin_lock_irq(&hpet_lock);
+ devp->hd_flags ^= HPET_IE;
+ spin_unlock_irq(&hpet_lock);
+ return -EIO;
+ }
Don't set HPET_IE then unset it
+ devp->hd_irq = irq;
+ t = devp->hd_ireqfreq;
+ v = readq(&timer->hpet_config);
+ g = v | Tn_INT_ENB_CNF_MASK;
+
+ if (devp->hd_flags & HPET_PERIODIC) {
+ write_counter(t, &timer->hpet_compare);
+ g |= Tn_TYPE_CNF_MASK;
+ v |= Tn_TYPE_CNF_MASK;
+ writeq(v, &timer->hpet_config);
+ v |= Tn_VAL_SET_CNF_MASK;
+ writeq(v, &timer->hpet_config);
+ local_irq_save(flags);
+ m = read_counter(&hpet->hpet_mc);
+ write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
+ } else {
+ local_irq_save(flags);
+ m = read_counter(&hpet->hpet_mc);
+ write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
+ }
+
+ isr = (1 << (devp - hpets->hp_dev));
+ writeq(isr, &hpet->hpet_isr);
+ writeq(g, &timer->hpet_config);
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+static inline unsigned long hpet_time_div(unsigned long dis)
+{
+ unsigned long long m = 1000000000000000ULL;
+
+ do_div(m, dis);
+
+ return (unsigned long)m;
+}
+
+static int
+hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
+{
+ struct hpet_timer *timer;
+ struct hpet *hpet;
+ struct hpets *hpetp;
+ int err;
+ unsigned long v;
+
+ switch (cmd) {
+ case HPET_IE_OFF:
+ case HPET_INFO:
+ case HPET_EPI:
+ case HPET_DPI:
+ case HPET_IRQFREQ:
+ timer = devp->hd_timer;
+ hpet = devp->hd_hpet;
+ hpetp = devp->hd_hpets;
+ break;
+ case HPET_IE_ON:
+ return hpet_ioctl_ieon(devp);
+ default:
+ return -EINVAL;
+ }
+
+ err = 0;
+
+ switch (cmd) {
+ case HPET_IE_OFF:
+ if ((devp->hd_flags & HPET_IE) == 0)
+ break;
+ v = readq(&timer->hpet_config);
+ v &= ~Tn_INT_ENB_CNF_MASK;
+ writeq(v, &timer->hpet_config);
+ if (devp->hd_irq) {
+ free_irq(devp->hd_irq, devp);
+ devp->hd_irq = 0;
+ }
+ devp->hd_flags ^= HPET_IE;
+ break;
where did the spin-locking disappear to?
+ case HPET_INFO:
+ {
+ struct hpet_info info;
+
+ info.hi_ireqfreq = hpet_time_div(hpetp->hp_period *
+ devp->hd_ireqfreq);
+ info.hi_flags =
+ readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
+ info.hi_hpet = devp->hd_hpets->hp_which;
+ info.hi_timer = devp - devp->hd_hpets->hp_dev;
+ if (copy_to_user((void *)arg, &info, sizeof(info)))
+ err = -EFAULT;
+ break;
+ }
+ case HPET_EPI:
+ v = readq(&timer->hpet_config);
+ if ((v & Tn_PER_INT_CAP_MASK) == 0) {
+ err = -ENXIO;
+ break;
+ }
+ devp->hd_flags |= HPET_PERIODIC;
+ break;
locking?
+ case HPET_DPI:
+ v = readq(&timer->hpet_config);
+ if ((v & Tn_PER_INT_CAP_MASK) == 0) {
+ err = -ENXIO;
+ break;
+ }
+ if (devp->hd_flags & HPET_PERIODIC &&
+ readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
+ v = readq(&timer->hpet_config);
+ v ^= Tn_TYPE_CNF_MASK;
+ writeq(v, &timer->hpet_config);
+ }
+ devp->hd_flags &= ~HPET_PERIODIC;
+ break;
locking?
+ case HPET_IRQFREQ:
+ if (!kernel && (arg > hpet_max_freq) &&
+ !capable(CAP_SYS_RESOURCE)) {
+ err = -EACCES;
+ break;
+ }
+
+ if (arg & (arg - 1)) {
+ err = -EINVAL;
+ break;
+ }
+
+ devp->hd_ireqfreq = hpet_time_div(hpetp->hp_period * arg);
+ }
+
+ return err;
+}
+
+static struct file_operations hpet_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .read = hpet_read,
+ .poll = hpet_poll,
+ .ioctl = hpet_ioctl,
+ .open = hpet_open,
+ .release = hpet_release,
+ .fasync = hpet_fasync,
+ .mmap = hpet_mmap,
+};
+
+EXPORT_SYMBOL(hpet_alloc);
+EXPORT_SYMBOL(hpet_register);
+EXPORT_SYMBOL(hpet_unregister);
+EXPORT_SYMBOL(hpet_control);
+
+int hpet_register(struct hpet_task *tp, int periodic)
+{
+ unsigned int i;
+ u64 mask;
+ struct hpet_timer *timer;
+ struct hpet_dev *devp;
+ struct hpets *hpetp;
+
+ switch (periodic) {
+ case 1:
+ mask = Tn_PER_INT_CAP_MASK;
+ break;
+ case 0:
+ mask = 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ spin_lock_irq(&hpet_task_lock);
+ spin_lock(&hpet_lock);
+
+ for (devp = 0, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
+ for (timer = hpetp->hp_hpet->hpet_timers, i = 0;
+ i < hpetp->hp_ntimer; i++, timer++) {
+ if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK)
+ != mask)
+ continue;
+
+ devp = &hpetp->hp_dev[i];
+
+ if (devp->hd_flags & HPET_OPEN || devp->hd_task) {
+ devp = 0;
+ continue;
+ }
+
+ tp->ht_opaque = devp;
+ devp->hd_task = tp;
+ break;
+ }
+
+ spin_unlock(&hpet_lock);
+ spin_unlock_irq(&hpet_task_lock);
+
+ if (tp->ht_opaque)
+ return 0;
+ else
+ return -EBUSY;
+}
+
+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;
+}
locking?
+int hpet_unregister(struct hpet_task *tp)
+{
+ struct hpet_dev *devp;
+ struct hpet_timer *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 = 0;
+ spin_unlock(&hpet_lock);
+ spin_unlock_irq(&hpet_task_lock);
+
+ return 0;
+}
+
+int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
+{
+ struct hpet_dev *devp;
+ int err;
+
+ if ((err = hpet_tpcheck(tp)))
+ return err;
+
+ spin_lock_irq(&hpet_lock);
+ devp = tp->ht_opaque;
+ if (devp->hd_task != tp) {
+ spin_unlock_irq(&hpet_lock);
+ return -ENXIO;
+ }
+ spin_unlock_irq(&hpet_lock);
+ return hpet_ioctl_common(devp, cmd, arg, 1);
+}
+
+#ifdef CONFIG_TIME_INTERPOLATION
+
+static unsigned long hpet_offset, last_wall_hpet;
+static long hpet_nsecs_per_cycle, hpet_cycles_per_sec;
+
+static unsigned long hpet_getoffset(void)
+{
+ return hpet_offset + (read_counter(&hpets->hp_hpet->hpet_mc) -
+ last_wall_hpet) * hpet_nsecs_per_cycle;
+}
+
+static void hpet_update(long delta)
+{
+ unsigned long mc;
+ unsigned long offset;
+
+ mc = read_counter(&hpets->hp_hpet->hpet_mc);
+ offset = hpet_offset + (mc - last_wall_hpet) * hpet_nsecs_per_cycle;
+
+ if (delta < 0 || (unsigned long)delta < offset)
+ hpet_offset = offset - delta;
+ else
+ hpet_offset = 0;
+ last_wall_hpet = mc;
+}
+
+static void hpet_reset(void)
+{
+ hpet_offset = 0;
+ last_wall_hpet = read_counter(&hpets->hp_hpet->hpet_mc);
+}
+
+static struct time_interpolator hpet_interpolator = {
+ .get_offset = hpet_getoffset,
+ .update = hpet_update,
+ .reset = hpet_reset
+};
+
+#endif
+
+static ctl_table hpet_table[] = {
+ {
+ .ctl_name = 1,
+ .procname = "max-user-freq",
+ .data = &hpet_max_freq,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {.ctl_name = 0}
+};
+
+static ctl_table hpet_root[] = {
+ {
+ .ctl_name = 1,
+ .procname = "hpet",
+ .maxlen = 0,
+ .mode = 0555,
+ .child = hpet_table,
+ },
+ {.ctl_name = 0}
+};
+
+static ctl_table dev_root[] = {
+ {
+ .ctl_name = CTL_DEV,
+ .procname = "dev",
+ .maxlen = 0,
+ .mode = 0555,
+ .child = hpet_root,
+ },
+ {.ctl_name = 0}
+};
+
+static struct ctl_table_header *sysctl_header;
why is this not sysfs?
+static void *hpet_start(struct seq_file *s, loff_t * pos)
+{
+ struct hpets *hpetp;
+ loff_t n;
+
+ for (n = *pos, hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
+ if (!n--)
+ return hpetp;
+
+ return 0;
+}
+
+static void *hpet_next(struct seq_file *s, void *v, loff_t * pos)
+{
+ struct hpets *hpetp;
+
+ hpetp = v;
+ ++*pos;
+ return hpetp->hp_next;
+}
+
+static void hpet_stop(struct seq_file *s, void *v)
+{
+ return;
+}
+
+static int hpet_show(struct seq_file *s, void *v)
+{
+ struct hpets *hpetp;
+ struct hpet *hpet;
+ u64 cap, vendor, period;
+
+ hpetp = v;
+ hpet = hpetp->hp_hpet;
+
+ cap = readq(&hpet->hpet_cap);
+ period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
+ HPET_COUNTER_CLK_PERIOD_SHIFT;
+ vendor = (cap & HPET_VENDOR_ID_MASK) >> HPET_VENDOR_ID_SHIFT;
+
+ seq_printf(s,
+ "HPET%d period = %d 10**-15 vendor = 0x%x number timer = %d\n",
+ hpetp->hp_which, (u32) period, (u32) vendor,
+ hpetp->hp_ntimer);
+
+ return 0;
+}
+
+static struct seq_operations hpet_seq_ops = {
+ .start = hpet_start,
+ .next = hpet_next,
+ .stop = hpet_stop,
+ .show = hpet_show
+};
+
+static int hpet_proc_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &hpet_seq_ops);
+}
+
+static struct file_operations hpet_proc_fops = {
+ .open = hpet_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release
+};
why is this not sysfs?
+/*
+ * Adjustment for when arming the timer with
+ * initial conditions. That is, main counter
+ * ticks expired before interrupts are enabled.
+ */
+#define TICK_CALIBRATE (1000UL)
+
+static unsigned long __init hpet_calibrate(struct hpets *hpetp)
+{
+ struct hpet_timer *timer;
+ unsigned long t, m, count, i, flags, start;
+ struct hpet_dev *devp;
+ int j;
+ struct hpet *hpet;
+
+ for (timer = 0, j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer;
+ j++, devp++)
+ if ((devp->hd_flags & HPET_OPEN) == 0) {
+ timer = devp->hd_timer;
+ break;
+ }
+
+ if (!timer)
+ return 0;
+
+ hpet = hpets->hp_hpet;
+ t = read_counter(&timer->hpet_compare);
+
+ i = 0;
+ count = hpet_time_div(hpetp->hp_period * TICK_CALIBRATE);
+
+ local_irq_save(flags);
+
+ start = read_counter(&hpet->hpet_mc);
+
+ do {
+ m = read_counter(&hpet->hpet_mc);
+ write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
+ } while (i++, (m - start) < count);
+
+ local_irq_restore(flags);
+
+ return (m - start) / i;
+}
+
+int __init hpet_alloc(struct hpet_data *hdp)
+{
+ u64 cap, mcfg;
+ struct hpet_dev *devp;
+ u32 i, ntimer;
+ struct hpets *hpetp;
+ size_t siz;
+ struct hpet *hpet;
+ static struct hpets *last __initdata = (struct hpets *)0;
+
+ /*
+ * hpet_alloc can be called by platform dependent code.
+ * if platform dependent code has allocated the hpet
+ * ACPI also reports hpet, then we catch it here.
+ */
+ for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
+ if (hpetp->hp_hpet == (struct hpet *)(hdp->hd_address))
+ return 0;
+
+ siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
+ sizeof(struct hpet_dev));
+
+ hpetp = kmalloc(siz, GFP_KERNEL);
+
+ if (!hpetp)
+ return -ENOMEM;
+
+ memset(hpetp, 0, siz);
+
+ hpetp->hp_which = hpet_nhpet++;
+ hpetp->hp_hpet = (struct hpet *)hdp->hd_address;
+
+ hpetp->hp_ntimer = hdp->hd_nirqs;
+
+ for (i = 0; i < hdp->hd_nirqs; i++)
+ hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
+
+ hpet = hpetp->hp_hpet;
+
+ cap = readq(&hpet->hpet_cap);
+
+ ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
+
+ if (hpetp->hp_ntimer != ntimer) {
+ printk(KERN_WARNING "hpet: number irqs doesn't agree"
+ " with number of timers\n");
+ kfree(hpetp);
+ return -ENODEV;
+ }
+
+ if (last)
+ last->hp_next = hpetp;
+ else
+ hpets = hpetp;
+
+ last = hpetp;
+
+ hpetp->hp_period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
+ HPET_COUNTER_CLK_PERIOD_SHIFT;
+
+ mcfg = readq(&hpet->hpet_config);
+ if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
+ write_counter(0L, &hpet->hpet_mc);
+ mcfg |= HPET_ENABLE_CNF_MASK;
+ writeq(mcfg, &hpet->hpet_config);
+ }
+
+ for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer;
+ i++, hpet_ntimer++, devp++) {
+ unsigned long v;
+ struct hpet_timer *timer;
+
+ timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
+ v = readq(&timer->hpet_config);
+
+ devp->hd_hpets = hpetp;
+ devp->hd_hpet = hpet;
+ devp->hd_timer = timer;
+
+ /*
+ * If the timer was reserved by platform code,
+ * then make timer unavailable for opens.
+ */
+ if (hdp->hd_state & (1 << i)) {
+ devp->hd_flags = HPET_OPEN;
+ continue;
+ }
+
+ init_waitqueue_head(&devp->hd_waitqueue);
+ }
+
+ hpetp->hp_delta = hpet_calibrate(hpetp);
+
+ return 0;
+}
+static acpi_status __init hpet_resources(struct acpi_resource *res, void *data)
+{
+ struct hpet_data *hdp;
+ acpi_status status;
+ struct acpi_resource_address64 addr;
+ struct hpets *hpetp;
+
+ hdp = data;
+
+ status = acpi_resource_to_address64(res, &addr);
+
+ if (ACPI_SUCCESS(status)) {
+ unsigned long size;
+
+ size = addr.max_address_range - addr.min_address_range + 1;
+ hdp->hd_address =
+ (unsigned long)ioremap(addr.min_address_range, size);
+
+ for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
+ if (hpetp->hp_hpet == (struct hpet *)(hdp->hd_address))
+ return -EBUSY;
+ } else if (res->id == ACPI_RSTYPE_EXT_IRQ) {
+ struct acpi_resource_ext_irq *irqp;
+ int i;
+
+ irqp = &res->data.extended_irq;
+
+ if (irqp->number_of_interrupts > 0) {
+ hdp->hd_nirqs = irqp->number_of_interrupts;
+
+ for (i = 0; i < hdp->hd_nirqs; i++)
+#ifdef CONFIG_IA64
+ hdp->hd_irq[i] =
+ acpi_register_gsi(irqp->interrupts[i],
+ irqp->edge_level,
+ irqp->active_high_low);
+#else
+ hdp->hd_irq[i] = irqp->interrupts[i];
+#endif
+ }
+ }
+
+ return AE_OK;
+}
+static int __init hpet_acpi_add(struct acpi_device *device)
+{
+ acpi_status result;
+ struct hpet_data data;
+
+ memset(&data, 0, sizeof(data));
+
+ result =
+ acpi_walk_resources(device->handle, METHOD_NAME__CRS,
+ hpet_resources, &data);
+
+ if (ACPI_FAILURE(result))
+ return -ENODEV;
+
+ if (!data.hd_address || !data.hd_nirqs) {
+ printk("%s: no address or irqs in _CRS\n", __FUNCTION__);
+ return -ENODEV;
+ }
+
+ return hpet_alloc(&data);
+}
+static int __init hpet_acpi_remove(struct acpi_device *device, int type)
+{
+ return 0;
+}
+
+static struct acpi_driver hpet_acpi_driver __initdata = {
+ .name = "hpet",
+ .class = "",
+ .ids = "PNP0103",
+ .ops = {
+ .add = hpet_acpi_add,
+ .remove = hpet_acpi_remove,
+ },
+};
where is CONFIG_ACPI ifdef?
+static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
+
+static int __init hpet_init(void)
+{
+ struct proc_dir_entry *entry;
+
+ (void)acpi_bus_register_driver(&hpet_acpi_driver);
+
+ if (hpets) {
+ if (misc_register(&hpet_misc))
+ return -ENODEV;
+
+ entry = create_proc_entry("driver/hpet", 0, 0);
+
+ if (entry)
+ entry->proc_fops = &hpet_proc_fops;
+
+ sysctl_header = register_sysctl_table(dev_root, 0);
+
+#ifdef CONFIG_TIME_INTERPOLATION
+ {
+ struct hpet *hpet;
+
+ hpet = hpets->hp_hpet;
+ hpet_cycles_per_sec = hpet_time_div(hpets->hp_period);
+ hpet_interpolator.frequency = hpet_cycles_per_sec;
+ hpet_interpolator.drift = hpet_cycles_per_sec *
+ HPET_DRIFT / 1000000;
+ hpet_nsecs_per_cycle = 1000000000 / hpet_cycles_per_sec;
+ register_time_interpolator(&hpet_interpolator);
+ }
+#endif
+ return 0;
+ } else
+ return -ENODEV;
+}
+
+static void __exit hpet_exit(void)
+{
+ acpi_bus_unregister_driver(&hpet_acpi_driver);
+
+ if (hpets) {
+ unregister_sysctl_table(sysctl_header);
+ remove_proc_entry("driver/hpet", NULL);
+ }
+
+ return;
+}
+
+module_init(hpet_init);
+module_exit(hpet_exit);
+MODULE_AUTHOR("Bob Picco <Robert.Picco@xxxxxx>");
+MODULE_LICENSE("GPL");
diff -Nru a/drivers/char/rtc.c b/drivers/char/rtc.c
--- a/drivers/char/rtc.c 2004-06-18 09:16:23 -07:00
+++ b/drivers/char/rtc.c 2004-06-18 09:16:23 -07:00
@@ -97,6 +97,11 @@
static int rtc_irq = PCI_IRQ_NONE;
#endif
+#ifdef CONFIG_HPET_RTC_IRQ
+#undef RTC_IRQ
+#define RTC_IRQ 0
+#endif
+
#ifdef RTC_IRQ
static int rtc_has_irq = 1;
#endif
diff -Nru a/include/asm-i386/hpet.h b/include/asm-i386/hpet.h
--- a/include/asm-i386/hpet.h 2004-06-18 09:16:23 -07:00
+++ b/include/asm-i386/hpet.h 2004-06-18 09:16:23 -07:00
@@ -57,9 +57,12 @@
#define HPET_ID_LEGSUP 0x00008000
#define HPET_ID_NUMBER 0x00001f00
#define HPET_ID_REV 0x000000ff
+#define HPET_ID_NUMBER_SHIFT 8
#define HPET_CFG_ENABLE 0x001
#define HPET_CFG_LEGACY 0x002
+#define HPET_LEGACY_8254 2
+#define HPET_LEGACY_RTC 8
#define HPET_TN_ENABLE 0x004
#define HPET_TN_PERIODIC 0x008
diff -Nru a/include/linux/hpet.h b/include/linux/hpet.h
--- /dev/null Wed Dec 31 16:00:00 196900
+++ b/include/linux/hpet.h 2004-06-18 09:16:23 -07:00
@@ -0,0 +1,133 @@
+#ifndef __HPET__
+#define __HPET__ 1
+
+/*
+ * Offsets into HPET Registers
+ */
+
+struct hpet {
+ u64 hpet_cap; /* capabilities */
+ u64 res0; /* reserved */
+ u64 hpet_config; /* configuration */
+ u64 res1; /* reserved */
+ u64 hpet_isr; /* interrupt status reg */
+ u64 res2[25]; /* reserved */
+ union { /* main counter */
+ u64 _hpet_mc64;
+ u32 _hpet_mc32;
+ unsigned long _hpet_mc;
+ } _u0;
+ u64 res3; /* reserved */
+ struct hpet_timer {
+ u64 hpet_config; /* configuration/cap */
+ union { /* timer compare register */
+ u64 _hpet_hc64;
+ u32 _hpet_hc32;
+ unsigned long _hpet_compare;
+ } _u1;
+ u64 hpet_fsb[2]; /* FSB route */
+ } hpet_timers[1];
+};
+
+#define hpet_mc _u0._hpet_mc
+#define hpet_compare _u1._hpet_compare
+
+#define HPET_MAX_TIMERS (32)
+
+/*
+ * HPET general capabilities register
+ */
+
+#define HPET_COUNTER_CLK_PERIOD_MASK (0xffffffff00000000ULL)
+#define HPET_COUNTER_CLK_PERIOD_SHIFT (32UL)
+#define HPET_VENDOR_ID_MASK (0x00000000ffff0000ULL)
+#define HPET_VENDOR_ID_SHIFT (16ULL)
+#define HPET_LEG_RT_CAP_MASK (0x8000)
+#define HPET_COUNTER_SIZE_MASK (0x2000)
+#define HPET_NUM_TIM_CAP_MASK (0x1f00)
+#define HPET_NUM_TIM_CAP_SHIFT (8ULL)
+
+/*
+ * HPET general configuration register
+ */
+
+#define HPET_LEG_RT_CNF_MASK (2UL)
+#define HPET_ENABLE_CNF_MASK (1UL)
+
+/*
+ * HPET interrupt status register
+ */
+
+#define HPET_ISR_CLEAR(HPET, TIMER) \
+ (HPET)->hpet_isr |= (1UL << TIMER)
+
+/*
+ * Timer configuration register
+ */
+
+#define Tn_INT_ROUTE_CAP_MASK (0xffffffff00000000ULL)
+#define Tn_INI_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)
+#define Tn_FSB_EN_CNF_SHIFT (14)
+#define Tn_INT_ROUTE_CNF_MASK (0x3e00UL)
+#define Tn_INT_ROUTE_CNF_SHIFT (9)
+#define Tn_32MODE_CNF_MASK (0x0100UL)
+#define Tn_VAL_SET_CNF_MASK (0x0040UL)
+#define Tn_SIZE_CAP_MASK (0x0020UL)
+#define Tn_PER_INT_CAP_MASK (0x0010UL)
+#define Tn_TYPE_CNF_MASK (0x0008UL)
+#define Tn_INT_ENB_CNF_MASK (0x0004UL)
+#define Tn_INT_TYPE_CNF_MASK (0x0002UL)
+
+/*
+ * Timer FSB Interrupt Route Register
+ */
+
+#define Tn_FSB_INT_ADDR_MASK (0xffffffff00000000ULL)
+#define Tn_FSB_INT_ADDR_SHIFT (32UL)
+#define Tn_FSB_INT_VAL_MASK (0x00000000ffffffffULL)
+
+struct hpet_info {
+ unsigned long hi_ireqfreq; /* Hz */
+ unsigned long hi_flags; /* information */
+ unsigned short hi_hpet;
+ unsigned short hi_timer;
+};
+
+#define HPET_INFO_PERIODIC 0x0001 /* timer is periodic */
+
+#define HPET_IE_ON _IO('h', 0x01) /* interrupt on */
+#define HPET_IE_OFF _IO('h', 0x02) /* interrupt off */
+#define HPET_INFO _IOR('h', 0x03, struct hpet_info)
+#define HPET_EPI _IO('h', 0x04) /* enable periodic */
+#define HPET_DPI _IO('h', 0x05) /* disable periodic */
+#define HPET_IRQFREQ _IOW('h', 0x6, unsigned long) /* IRQFREQ usec */
+
+/*
+ * exported interfaces
+ */
+
+struct hpet_task {
+ void (*ht_func) (void *);
+ void *ht_data;
+ void *ht_opaque;
+};
+
+struct hpet_data {
+ unsigned long 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 */
+
+int hpet_alloc(struct hpet_data *);
+int hpet_register(struct hpet_task *, int);
+int hpet_unregister(struct hpet_task *);
+int hpet_control(struct hpet_task *, unsigned int, unsigned long);
+
+#endif /* !__HPET__ */
diff -Nru a/include/linux/miscdevice.h b/include/linux/miscdevice.h
--- a/include/linux/miscdevice.h 2004-06-18 09:16:23 -07:00
+++ b/include/linux/miscdevice.h 2004-06-18 09:16:23 -07:00
@@ -33,6 +33,7 @@
#define SGI_STREAMS_KEYBOARD 150
/* drivers/sgi/char/usema.c */
#define SGI_USEMACLONE 151
+#define HPET_MINOR 152
Is this officially allocated by LANANA?
Where is the devices.txt update?
Jeff
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