linux/drivers/char/mmtimer.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

745 lines
18 KiB
C

/*
* Timer device implementation for SGI SN platforms.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2001-2006 Silicon Graphics, Inc. All rights reserved.
*
* This driver exports an API that should be supportable by any HPET or IA-PC
* multimedia timer. The code below is currently specific to the SGI Altix
* SHub RTC, however.
*
* 11/01/01 - jbarnes - initial revision
* 9/10/04 - Christoph Lameter - remove interrupt support for kernel inclusion
* 10/1/04 - Christoph Lameter - provide posix clock CLOCK_SGI_CYCLE
* 10/13/04 - Christoph Lameter, Dimitri Sivanich - provide timer interrupt
* support via the posix timer interface
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/ioctl.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/mmtimer.h>
#include <linux/miscdevice.h>
#include <linux/posix-timers.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <asm/sn/addrs.h>
#include <asm/sn/intr.h>
#include <asm/sn/shub_mmr.h>
#include <asm/sn/nodepda.h>
#include <asm/sn/shubio.h>
MODULE_AUTHOR("Jesse Barnes <jbarnes@sgi.com>");
MODULE_DESCRIPTION("SGI Altix RTC Timer");
MODULE_LICENSE("GPL");
/* name of the device, usually in /dev */
#define MMTIMER_NAME "mmtimer"
#define MMTIMER_DESC "SGI Altix RTC Timer"
#define MMTIMER_VERSION "2.1"
#define RTC_BITS 55 /* 55 bits for this implementation */
extern unsigned long sn_rtc_cycles_per_second;
#define RTC_COUNTER_ADDR ((long *)LOCAL_MMR_ADDR(SH_RTC))
#define rtc_time() (*RTC_COUNTER_ADDR)
static int mmtimer_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg);
static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma);
/*
* Period in femtoseconds (10^-15 s)
*/
static unsigned long mmtimer_femtoperiod = 0;
static const struct file_operations mmtimer_fops = {
.owner = THIS_MODULE,
.mmap = mmtimer_mmap,
.ioctl = mmtimer_ioctl,
};
/*
* We only have comparison registers RTC1-4 currently available per
* node. RTC0 is used by SAL.
*/
#define NUM_COMPARATORS 3
/* Check for an RTC interrupt pending */
static int inline mmtimer_int_pending(int comparator)
{
if (HUB_L((unsigned long *)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED)) &
SH_EVENT_OCCURRED_RTC1_INT_MASK << comparator)
return 1;
else
return 0;
}
/* Clear the RTC interrupt pending bit */
static void inline mmtimer_clr_int_pending(int comparator)
{
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED_ALIAS),
SH_EVENT_OCCURRED_RTC1_INT_MASK << comparator);
}
/* Setup timer on comparator RTC1 */
static void inline mmtimer_setup_int_0(u64 expires)
{
u64 val;
/* Disable interrupt */
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE), 0UL);
/* Initialize comparator value */
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPB), -1L);
/* Clear pending bit */
mmtimer_clr_int_pending(0);
val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC1_INT_CONFIG_IDX_SHFT) |
((u64)cpu_physical_id(smp_processor_id()) <<
SH_RTC1_INT_CONFIG_PID_SHFT);
/* Set configuration */
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_CONFIG), val);
/* Enable RTC interrupts */
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE), 1UL);
/* Initialize comparator value */
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPB), expires);
}
/* Setup timer on comparator RTC2 */
static void inline mmtimer_setup_int_1(u64 expires)
{
u64 val;
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE), 0UL);
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPC), -1L);
mmtimer_clr_int_pending(1);
val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC2_INT_CONFIG_IDX_SHFT) |
((u64)cpu_physical_id(smp_processor_id()) <<
SH_RTC2_INT_CONFIG_PID_SHFT);
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_CONFIG), val);
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE), 1UL);
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPC), expires);
}
/* Setup timer on comparator RTC3 */
static void inline mmtimer_setup_int_2(u64 expires)
{
u64 val;
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE), 0UL);
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPD), -1L);
mmtimer_clr_int_pending(2);
val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC3_INT_CONFIG_IDX_SHFT) |
((u64)cpu_physical_id(smp_processor_id()) <<
SH_RTC3_INT_CONFIG_PID_SHFT);
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_CONFIG), val);
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE), 1UL);
HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPD), expires);
}
/*
* This function must be called with interrupts disabled and preemption off
* in order to insure that the setup succeeds in a deterministic time frame.
* It will check if the interrupt setup succeeded.
*/
static int inline mmtimer_setup(int comparator, unsigned long expires)
{
switch (comparator) {
case 0:
mmtimer_setup_int_0(expires);
break;
case 1:
mmtimer_setup_int_1(expires);
break;
case 2:
mmtimer_setup_int_2(expires);
break;
}
/* We might've missed our expiration time */
if (rtc_time() < expires)
return 1;
/*
* If an interrupt is already pending then its okay
* if not then we failed
*/
return mmtimer_int_pending(comparator);
}
static int inline mmtimer_disable_int(long nasid, int comparator)
{
switch (comparator) {
case 0:
nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE),
0UL) : REMOTE_HUB_S(nasid, SH_RTC1_INT_ENABLE, 0UL);
break;
case 1:
nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE),
0UL) : REMOTE_HUB_S(nasid, SH_RTC2_INT_ENABLE, 0UL);
break;
case 2:
nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE),
0UL) : REMOTE_HUB_S(nasid, SH_RTC3_INT_ENABLE, 0UL);
break;
default:
return -EFAULT;
}
return 0;
}
#define TIMER_OFF 0xbadcabLL
/* There is one of these for each comparator */
typedef struct mmtimer {
spinlock_t lock ____cacheline_aligned;
struct k_itimer *timer;
int i;
int cpu;
struct tasklet_struct tasklet;
} mmtimer_t;
static mmtimer_t ** timers;
/**
* mmtimer_ioctl - ioctl interface for /dev/mmtimer
* @inode: inode of the device
* @file: file structure for the device
* @cmd: command to execute
* @arg: optional argument to command
*
* Executes the command specified by @cmd. Returns 0 for success, < 0 for
* failure.
*
* Valid commands:
*
* %MMTIMER_GETOFFSET - Should return the offset (relative to the start
* of the page where the registers are mapped) for the counter in question.
*
* %MMTIMER_GETRES - Returns the resolution of the clock in femto (10^-15)
* seconds
*
* %MMTIMER_GETFREQ - Copies the frequency of the clock in Hz to the address
* specified by @arg
*
* %MMTIMER_GETBITS - Returns the number of bits in the clock's counter
*
* %MMTIMER_MMAPAVAIL - Returns 1 if the registers can be mmap'd into userspace
*
* %MMTIMER_GETCOUNTER - Gets the current value in the counter and places it
* in the address specified by @arg.
*/
static int mmtimer_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
int ret = 0;
switch (cmd) {
case MMTIMER_GETOFFSET: /* offset of the counter */
/*
* SN RTC registers are on their own 64k page
*/
if(PAGE_SIZE <= (1 << 16))
ret = (((long)RTC_COUNTER_ADDR) & (PAGE_SIZE-1)) / 8;
else
ret = -ENOSYS;
break;
case MMTIMER_GETRES: /* resolution of the clock in 10^-15 s */
if(copy_to_user((unsigned long __user *)arg,
&mmtimer_femtoperiod, sizeof(unsigned long)))
return -EFAULT;
break;
case MMTIMER_GETFREQ: /* frequency in Hz */
if(copy_to_user((unsigned long __user *)arg,
&sn_rtc_cycles_per_second,
sizeof(unsigned long)))
return -EFAULT;
ret = 0;
break;
case MMTIMER_GETBITS: /* number of bits in the clock */
ret = RTC_BITS;
break;
case MMTIMER_MMAPAVAIL: /* can we mmap the clock into userspace? */
ret = (PAGE_SIZE <= (1 << 16)) ? 1 : 0;
break;
case MMTIMER_GETCOUNTER:
if(copy_to_user((unsigned long __user *)arg,
RTC_COUNTER_ADDR, sizeof(unsigned long)))
return -EFAULT;
break;
default:
ret = -ENOSYS;
break;
}
return ret;
}
/**
* mmtimer_mmap - maps the clock's registers into userspace
* @file: file structure for the device
* @vma: VMA to map the registers into
*
* Calls remap_pfn_range() to map the clock's registers into
* the calling process' address space.
*/
static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma)
{
unsigned long mmtimer_addr;
if (vma->vm_end - vma->vm_start != PAGE_SIZE)
return -EINVAL;
if (vma->vm_flags & VM_WRITE)
return -EPERM;
if (PAGE_SIZE > (1 << 16))
return -ENOSYS;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
mmtimer_addr = __pa(RTC_COUNTER_ADDR);
mmtimer_addr &= ~(PAGE_SIZE - 1);
mmtimer_addr &= 0xfffffffffffffffUL;
if (remap_pfn_range(vma, vma->vm_start, mmtimer_addr >> PAGE_SHIFT,
PAGE_SIZE, vma->vm_page_prot)) {
printk(KERN_ERR "remap_pfn_range failed in mmtimer.c\n");
return -EAGAIN;
}
return 0;
}
static struct miscdevice mmtimer_miscdev = {
SGI_MMTIMER,
MMTIMER_NAME,
&mmtimer_fops
};
static struct timespec sgi_clock_offset;
static int sgi_clock_period;
/*
* Posix Timer Interface
*/
static struct timespec sgi_clock_offset;
static int sgi_clock_period;
static int sgi_clock_get(clockid_t clockid, struct timespec *tp)
{
u64 nsec;
nsec = rtc_time() * sgi_clock_period
+ sgi_clock_offset.tv_nsec;
tp->tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &tp->tv_nsec)
+ sgi_clock_offset.tv_sec;
return 0;
};
static int sgi_clock_set(clockid_t clockid, struct timespec *tp)
{
u64 nsec;
u64 rem;
nsec = rtc_time() * sgi_clock_period;
sgi_clock_offset.tv_sec = tp->tv_sec - div_long_long_rem(nsec, NSEC_PER_SEC, &rem);
if (rem <= tp->tv_nsec)
sgi_clock_offset.tv_nsec = tp->tv_sec - rem;
else {
sgi_clock_offset.tv_nsec = tp->tv_sec + NSEC_PER_SEC - rem;
sgi_clock_offset.tv_sec--;
}
return 0;
}
/*
* Schedule the next periodic interrupt. This function will attempt
* to schedule a periodic interrupt later if necessary. If the scheduling
* of an interrupt fails then the time to skip is lengthened
* exponentially in order to ensure that the next interrupt
* can be properly scheduled..
*/
static int inline reschedule_periodic_timer(mmtimer_t *x)
{
int n;
struct k_itimer *t = x->timer;
t->it.mmtimer.clock = x->i;
t->it_overrun--;
n = 0;
do {
t->it.mmtimer.expires += t->it.mmtimer.incr << n;
t->it_overrun += 1 << n;
n++;
if (n > 20)
return 1;
} while (!mmtimer_setup(x->i, t->it.mmtimer.expires));
return 0;
}
/**
* mmtimer_interrupt - timer interrupt handler
* @irq: irq received
* @dev_id: device the irq came from
*
* Called when one of the comarators matches the counter, This
* routine will send signals to processes that have requested
* them.
*
* This interrupt is run in an interrupt context
* by the SHUB. It is therefore safe to locally access SHub
* registers.
*/
static irqreturn_t
mmtimer_interrupt(int irq, void *dev_id)
{
int i;
unsigned long expires = 0;
int result = IRQ_NONE;
unsigned indx = cpu_to_node(smp_processor_id());
/*
* Do this once for each comparison register
*/
for (i = 0; i < NUM_COMPARATORS; i++) {
mmtimer_t *base = timers[indx] + i;
/* Make sure this doesn't get reused before tasklet_sched */
spin_lock(&base->lock);
if (base->cpu == smp_processor_id()) {
if (base->timer)
expires = base->timer->it.mmtimer.expires;
/* expires test won't work with shared irqs */
if ((mmtimer_int_pending(i) > 0) ||
(expires && (expires < rtc_time()))) {
mmtimer_clr_int_pending(i);
tasklet_schedule(&base->tasklet);
result = IRQ_HANDLED;
}
}
spin_unlock(&base->lock);
expires = 0;
}
return result;
}
void mmtimer_tasklet(unsigned long data) {
mmtimer_t *x = (mmtimer_t *)data;
struct k_itimer *t = x->timer;
unsigned long flags;
if (t == NULL)
return;
/* Send signal and deal with periodic signals */
spin_lock_irqsave(&t->it_lock, flags);
spin_lock(&x->lock);
/* If timer was deleted between interrupt and here, leave */
if (t != x->timer)
goto out;
t->it_overrun = 0;
if (posix_timer_event(t, 0) != 0) {
// printk(KERN_WARNING "mmtimer: cannot deliver signal.\n");
t->it_overrun++;
}
if(t->it.mmtimer.incr) {
/* Periodic timer */
if (reschedule_periodic_timer(x)) {
printk(KERN_WARNING "mmtimer: unable to reschedule\n");
x->timer = NULL;
}
} else {
/* Ensure we don't false trigger in mmtimer_interrupt */
t->it.mmtimer.expires = 0;
}
t->it_overrun_last = t->it_overrun;
out:
spin_unlock(&x->lock);
spin_unlock_irqrestore(&t->it_lock, flags);
}
static int sgi_timer_create(struct k_itimer *timer)
{
/* Insure that a newly created timer is off */
timer->it.mmtimer.clock = TIMER_OFF;
return 0;
}
/* This does not really delete a timer. It just insures
* that the timer is not active
*
* Assumption: it_lock is already held with irq's disabled
*/
static int sgi_timer_del(struct k_itimer *timr)
{
int i = timr->it.mmtimer.clock;
cnodeid_t nodeid = timr->it.mmtimer.node;
mmtimer_t *t = timers[nodeid] + i;
unsigned long irqflags;
if (i != TIMER_OFF) {
spin_lock_irqsave(&t->lock, irqflags);
mmtimer_disable_int(cnodeid_to_nasid(nodeid),i);
t->timer = NULL;
timr->it.mmtimer.clock = TIMER_OFF;
timr->it.mmtimer.expires = 0;
spin_unlock_irqrestore(&t->lock, irqflags);
}
return 0;
}
#define timespec_to_ns(x) ((x).tv_nsec + (x).tv_sec * NSEC_PER_SEC)
#define ns_to_timespec(ts, nsec) (ts).tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &(ts).tv_nsec)
/* Assumption: it_lock is already held with irq's disabled */
static void sgi_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
{
if (timr->it.mmtimer.clock == TIMER_OFF) {
cur_setting->it_interval.tv_nsec = 0;
cur_setting->it_interval.tv_sec = 0;
cur_setting->it_value.tv_nsec = 0;
cur_setting->it_value.tv_sec =0;
return;
}
ns_to_timespec(cur_setting->it_interval, timr->it.mmtimer.incr * sgi_clock_period);
ns_to_timespec(cur_setting->it_value, (timr->it.mmtimer.expires - rtc_time())* sgi_clock_period);
return;
}
static int sgi_timer_set(struct k_itimer *timr, int flags,
struct itimerspec * new_setting,
struct itimerspec * old_setting)
{
int i;
unsigned long when, period, irqflags;
int err = 0;
cnodeid_t nodeid;
mmtimer_t *base;
if (old_setting)
sgi_timer_get(timr, old_setting);
sgi_timer_del(timr);
when = timespec_to_ns(new_setting->it_value);
period = timespec_to_ns(new_setting->it_interval);
if (when == 0)
/* Clear timer */
return 0;
if (flags & TIMER_ABSTIME) {
struct timespec n;
unsigned long now;
getnstimeofday(&n);
now = timespec_to_ns(n);
if (when > now)
when -= now;
else
/* Fire the timer immediately */
when = 0;
}
/*
* Convert to sgi clock period. Need to keep rtc_time() as near as possible
* to getnstimeofday() in order to be as faithful as possible to the time
* specified.
*/
when = (when + sgi_clock_period - 1) / sgi_clock_period + rtc_time();
period = (period + sgi_clock_period - 1) / sgi_clock_period;
/*
* We are allocating a local SHub comparator. If we would be moved to another
* cpu then another SHub may be local to us. Prohibit that by switching off
* preemption.
*/
preempt_disable();
nodeid = cpu_to_node(smp_processor_id());
retry:
/* Don't use an allocated timer, or a deleted one that's pending */
for(i = 0; i< NUM_COMPARATORS; i++) {
base = timers[nodeid] + i;
if (!base->timer && !base->tasklet.state) {
break;
}
}
if (i == NUM_COMPARATORS) {
preempt_enable();
return -EBUSY;
}
spin_lock_irqsave(&base->lock, irqflags);
if (base->timer || base->tasklet.state != 0) {
spin_unlock_irqrestore(&base->lock, irqflags);
goto retry;
}
base->timer = timr;
base->cpu = smp_processor_id();
timr->it.mmtimer.clock = i;
timr->it.mmtimer.node = nodeid;
timr->it.mmtimer.incr = period;
timr->it.mmtimer.expires = when;
if (period == 0) {
if (!mmtimer_setup(i, when)) {
mmtimer_disable_int(-1, i);
posix_timer_event(timr, 0);
timr->it.mmtimer.expires = 0;
}
} else {
timr->it.mmtimer.expires -= period;
if (reschedule_periodic_timer(base))
err = -EINVAL;
}
spin_unlock_irqrestore(&base->lock, irqflags);
preempt_enable();
return err;
}
static struct k_clock sgi_clock = {
.res = 0,
.clock_set = sgi_clock_set,
.clock_get = sgi_clock_get,
.timer_create = sgi_timer_create,
.nsleep = do_posix_clock_nonanosleep,
.timer_set = sgi_timer_set,
.timer_del = sgi_timer_del,
.timer_get = sgi_timer_get
};
/**
* mmtimer_init - device initialization routine
*
* Does initial setup for the mmtimer device.
*/
static int __init mmtimer_init(void)
{
unsigned i;
cnodeid_t node, maxn = -1;
if (!ia64_platform_is("sn2"))
return 0;
/*
* Sanity check the cycles/sec variable
*/
if (sn_rtc_cycles_per_second < 100000) {
printk(KERN_ERR "%s: unable to determine clock frequency\n",
MMTIMER_NAME);
return -1;
}
mmtimer_femtoperiod = ((unsigned long)1E15 + sn_rtc_cycles_per_second /
2) / sn_rtc_cycles_per_second;
if (request_irq(SGI_MMTIMER_VECTOR, mmtimer_interrupt, IRQF_PERCPU, MMTIMER_NAME, NULL)) {
printk(KERN_WARNING "%s: unable to allocate interrupt.",
MMTIMER_NAME);
return -1;
}
if (misc_register(&mmtimer_miscdev)) {
printk(KERN_ERR "%s: failed to register device\n",
MMTIMER_NAME);
return -1;
}
/* Get max numbered node, calculate slots needed */
for_each_online_node(node) {
maxn = node;
}
maxn++;
/* Allocate list of node ptrs to mmtimer_t's */
timers = kmalloc(sizeof(mmtimer_t *)*maxn, GFP_KERNEL);
if (timers == NULL) {
printk(KERN_ERR "%s: failed to allocate memory for device\n",
MMTIMER_NAME);
return -1;
}
/* Allocate mmtimer_t's for each online node */
for_each_online_node(node) {
timers[node] = kmalloc_node(sizeof(mmtimer_t)*NUM_COMPARATORS, GFP_KERNEL, node);
if (timers[node] == NULL) {
printk(KERN_ERR "%s: failed to allocate memory for device\n",
MMTIMER_NAME);
return -1;
}
for (i=0; i< NUM_COMPARATORS; i++) {
mmtimer_t * base = timers[node] + i;
spin_lock_init(&base->lock);
base->timer = NULL;
base->cpu = 0;
base->i = i;
tasklet_init(&base->tasklet, mmtimer_tasklet,
(unsigned long) (base));
}
}
sgi_clock_period = sgi_clock.res = NSEC_PER_SEC / sn_rtc_cycles_per_second;
register_posix_clock(CLOCK_SGI_CYCLE, &sgi_clock);
printk(KERN_INFO "%s: v%s, %ld MHz\n", MMTIMER_DESC, MMTIMER_VERSION,
sn_rtc_cycles_per_second/(unsigned long)1E6);
return 0;
}
module_init(mmtimer_init);