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android_kernel_xiaomi_sm8350/drivers/char/hpet.c
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00

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/*
* Intel & MS High Precision Event Timer Implementation.
*
* Copyright (C) 2003 Intel Corporation
* Venki Pallipadi
* (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
* Bob Picco <robert.picco@hp.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#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 <linux/bitops.h>
#include <asm/current.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/io.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.
* http://www.intel.com/hardwaredesign/hpetspec.htm
*/
#define HPET_USER_FREQ (64)
#define HPET_DRIFT (500)
#define HPET_RANGE_SIZE 1024 /* from HPET spec */
static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
/* 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)
struct hpet_dev {
struct hpets *hd_hpets;
struct hpet __iomem *hd_hpet;
struct hpet_timer __iomem *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;
char hd_name[HPET_DEV_NAME];
};
struct hpets {
struct hpets *hp_next;
struct hpet __iomem *hp_hpet;
unsigned long hp_hpet_phys;
struct time_interpolator *hp_interpolator;
unsigned long long hp_tick_freq;
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
#define HPET_SHARED_IRQ 0x0008
#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 inline unsigned long long readq(void __iomem *addr)
{
return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
}
#endif
#ifndef writeq
static inline void writeq(unsigned long long v, void __iomem *addr)
{
writel(v & 0xffffffff, addr);
writel(v >> 32, addr + 4);
}
#endif
static irqreturn_t hpet_interrupt(int irq, void *data)
{
struct hpet_dev *devp;
unsigned long isr;
devp = data;
isr = 1 << (devp - devp->hd_hpets->hp_dev);
if ((devp->hd_flags & HPET_SHARED_IRQ) &&
!(isr & readl(&devp->hd_hpet->hpet_isr)))
return IRQ_NONE;
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);
}
if (devp->hd_flags & HPET_SHARED_IRQ)
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);
return IRQ_HANDLED;
}
static int hpet_open(struct inode *inode, struct file *file)
{
struct hpet_dev *devp;
struct hpets *hpetp;
int i;
if (file->f_mode & FMODE_WRITE)
return -EINVAL;
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;
}
static ssize_t
hpet_read(struct file *file, char __user *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;
add_wait_queue(&devp->hd_waitqueue, &wait);
for ( ; ; ) {
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();
}
retval = put_user(data, (unsigned long __user *)buf);
if (!retval)
retval = sizeof(unsigned long);
out:
__set_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;
}
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;
devp = file->private_data;
addr = devp->hd_hpets->hp_hpet_phys;
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",
__FUNCTION__);
return -EAGAIN;
}
return 0;
#else
return -ENOSYS;
#endif
}
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 __iomem *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);
file->private_data = NULL;
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 __iomem *timer;
struct hpet __iomem *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;
if (!devp->hd_ireqfreq)
return -EIO;
spin_lock_irq(&hpet_lock);
if (devp->hd_flags & HPET_IE) {
spin_unlock_irq(&hpet_lock);
return -EBUSY;
}
devp->hd_flags |= HPET_IE;
if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
devp->hd_flags |= HPET_SHARED_IRQ;
spin_unlock_irq(&hpet_lock);
irq = devp->hd_hdwirq;
if (irq) {
unsigned long irq_flags;
sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
irq_flags = devp->hd_flags & HPET_SHARED_IRQ
? IRQF_SHARED : IRQF_DISABLED;
if (request_irq(irq, hpet_interrupt, irq_flags,
devp->hd_name, (void *)devp)) {
printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
irq = 0;
}
}
if (irq == 0) {
spin_lock_irq(&hpet_lock);
devp->hd_flags ^= HPET_IE;
spin_unlock_irq(&hpet_lock);
return -EIO;
}
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);
}
if (devp->hd_flags & HPET_SHARED_IRQ) {
isr = 1 << (devp - devp->hd_hpets->hp_dev);
writel(isr, &hpet->hpet_isr);
}
writeq(g, &timer->hpet_config);
local_irq_restore(flags);
return 0;
}
/* converts Hz to number of timer ticks */
static inline unsigned long hpet_time_div(struct hpets *hpets,
unsigned long dis)
{
unsigned long long m;
m = hpets->hp_tick_freq + (dis >> 1);
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 __iomem *timer;
struct hpet __iomem *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;
case HPET_INFO:
{
struct hpet_info info;
if (devp->hd_ireqfreq)
info.hi_ireqfreq =
hpet_time_div(hpetp, devp->hd_ireqfreq);
else
info.hi_ireqfreq = 0;
info.hi_flags =
readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
info.hi_hpet = hpetp->hp_which;
info.hi_timer = devp - hpetp->hp_dev;
if (kernel)
memcpy((void *)arg, &info, sizeof(info));
else
if (copy_to_user((void __user *)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;
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;
case HPET_IRQFREQ:
if (!kernel && (arg > hpet_max_freq) &&
!capable(CAP_SYS_RESOURCE)) {
err = -EACCES;
break;
}
if (!arg) {
err = -EINVAL;
break;
}
devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
}
return err;
}
static const 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,
};
static int hpet_is_known(struct hpet_data *hdp)
{
struct hpets *hpetp;
for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
return 1;
return 0;
}
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 __iomem *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;
}
tp->ht_opaque = NULL;
spin_lock_irq(&hpet_task_lock);
spin_lock(&hpet_lock);
for (devp = NULL, 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 = NULL;
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;
}
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;
}
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);
}
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;
static void hpet_register_interpolator(struct hpets *hpetp)
{
#ifdef CONFIG_TIME_INTERPOLATION
struct time_interpolator *ti;
ti = kzalloc(sizeof(*ti), GFP_KERNEL);
if (!ti)
return;
ti->source = TIME_SOURCE_MMIO64;
ti->shift = 10;
ti->addr = &hpetp->hp_hpet->hpet_mc;
ti->frequency = hpetp->hp_tick_freq;
ti->drift = HPET_DRIFT;
ti->mask = -1;
hpetp->hp_interpolator = ti;
register_time_interpolator(ti);
#endif
}
/*
* 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 hpet_calibrate(struct hpets *hpetp)
{
struct hpet_timer __iomem *timer = NULL;
unsigned long t, m, count, i, flags, start;
struct hpet_dev *devp;
int j;
struct hpet __iomem *hpet;
for (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 = hpetp->hp_hpet;
t = read_counter(&timer->hpet_compare);
i = 0;
count = hpet_time_div(hpetp, 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 hpet_alloc(struct hpet_data *hdp)
{
u64 cap, mcfg;
struct hpet_dev *devp;
u32 i, ntimer;
struct hpets *hpetp;
size_t siz;
struct hpet __iomem *hpet;
static struct hpets *last = NULL;
unsigned long period;
unsigned long long temp;
/*
* hpet_alloc can be called by platform dependent code.
* If platform dependent code has allocated the hpet that
* ACPI has also reported, then we catch it here.
*/
if (hpet_is_known(hdp)) {
printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
__FUNCTION__);
return 0;
}
siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
sizeof(struct hpet_dev));
hpetp = kzalloc(siz, GFP_KERNEL);
if (!hpetp)
return -ENOMEM;
hpetp->hp_which = hpet_nhpet++;
hpetp->hp_hpet = hdp->hd_address;
hpetp->hp_hpet_phys = hdp->hd_phys_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;
period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
temp += period >> 1; /* round */
do_div(temp, period);
hpetp->hp_tick_freq = temp; /* ticks per second */
printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
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_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);
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++, devp++) {
struct hpet_timer __iomem *timer;
timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
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);
hpet_register_interpolator(hpetp);
return 0;
}
static acpi_status hpet_resources(struct acpi_resource *res, void *data)
{
struct hpet_data *hdp;
acpi_status status;
struct acpi_resource_address64 addr;
hdp = data;
status = acpi_resource_to_address64(res, &addr);
if (ACPI_SUCCESS(status)) {
hdp->hd_phys_address = addr.minimum;
hdp->hd_address = ioremap(addr.minimum, addr.address_length);
if (hpet_is_known(hdp)) {
printk(KERN_DEBUG "%s: 0x%lx is busy\n",
__FUNCTION__, hdp->hd_phys_address);
iounmap(hdp->hd_address);
return -EBUSY;
}
} else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
struct acpi_resource_fixed_memory32 *fixmem32;
fixmem32 = &res->data.fixed_memory32;
if (!fixmem32)
return -EINVAL;
hdp->hd_phys_address = fixmem32->address;
hdp->hd_address = ioremap(fixmem32->address,
HPET_RANGE_SIZE);
if (hpet_is_known(hdp)) {
printk(KERN_DEBUG "%s: 0x%lx is busy\n",
__FUNCTION__, hdp->hd_phys_address);
iounmap(hdp->hd_address);
return -EBUSY;
}
} else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
struct acpi_resource_extended_irq *irqp;
int i, irq;
irqp = &res->data.extended_irq;
for (i = 0; i < irqp->interrupt_count; i++) {
irq = acpi_register_gsi(irqp->interrupts[i],
irqp->triggering, irqp->polarity);
if (irq < 0)
return AE_ERROR;
hdp->hd_irq[hdp->hd_nirqs] = irq;
hdp->hd_nirqs++;
}
}
return AE_OK;
}
static int 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 hpet_acpi_remove(struct acpi_device *device, int type)
{
/* XXX need to unregister interpolator, dealloc mem, etc */
return -EINVAL;
}
static struct acpi_driver hpet_acpi_driver = {
.name = "hpet",
.ids = "PNP0103",
.ops = {
.add = hpet_acpi_add,
.remove = hpet_acpi_remove,
},
};
static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
static int __init hpet_init(void)
{
int result;
result = misc_register(&hpet_misc);
if (result < 0)
return -ENODEV;
sysctl_header = register_sysctl_table(dev_root, 0);
result = acpi_bus_register_driver(&hpet_acpi_driver);
if (result < 0) {
if (sysctl_header)
unregister_sysctl_table(sysctl_header);
misc_deregister(&hpet_misc);
return result;
}
return 0;
}
static void __exit hpet_exit(void)
{
acpi_bus_unregister_driver(&hpet_acpi_driver);
if (sysctl_header)
unregister_sysctl_table(sysctl_header);
misc_deregister(&hpet_misc);
return;
}
module_init(hpet_init);
module_exit(hpet_exit);
MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
MODULE_LICENSE("GPL");
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