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mmtimer: Remove the SGI SN2 mmtimer driver

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This driver supports direct system clock access on the ancient SGI SN2
IA64 systems, and implement the only non-builtin k_clock instance.
Remove it as any remaining IA64 altix user will be running just as old
distros anyway.

Dimitri Sivanich stated: "Since this is SN2 specific, this can be removed."

Note that this does not affect the never uv_mmtimer driver for x86-based
Altix systems.

[ tglx: Added comment to CLOCK_SGI_CYCLE ]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Dimitri Sivanich <sivanich@hpe.com>
Link: http://lkml.kernel.org/r/20170526090311.3377-2-hch@lst.de
This commit is contained in:
Christoph Hellwig 2017-05-26 12:03:10 +03:00 committed by Thomas Gleixner
parent 08332893e3
commit 07903ada96
4 changed files with 5 additions and 869 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
drivers/char/Kconfig
View File

@ -539,15 +539,6 @@ config HANGCHECK_TIMER
out to lunch past a certain margin. It can reboot the system
or merely print a warning.
config MMTIMER
tristate "MMTIMER Memory mapped RTC for SGI Altix"
depends on IA64_GENERIC || IA64_SGI_SN2
depends on POSIX_TIMERS
default y
help
The mmtimer device allows direct userspace access to the
Altix system timer.
config UV_MMTIMER
tristate "UV_MMTIMER Memory mapped RTC for SGI UV"
depends on X86_UV

1
drivers/char/Makefile
View File

@ -10,7 +10,6 @@ obj-$(CONFIG_VIRTIO_CONSOLE) += virtio_console.o
obj-$(CONFIG_RAW_DRIVER) += raw.o
obj-$(CONFIG_SGI_SNSC) += snsc.o snsc_event.o
obj-$(CONFIG_MSPEC) += mspec.o
obj-$(CONFIG_MMTIMER) += mmtimer.o
obj-$(CONFIG_UV_MMTIMER) += uv_mmtimer.o
obj-$(CONFIG_IBM_BSR) += bsr.o
obj-$(CONFIG_SGI_MBCS) += mbcs.o

858
drivers/char/mmtimer.c
View File

@ -1,858 +0,0 @@
/*
* 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/fs.h>
#include <linux/mmtimer.h>
#include <linux/miscdevice.h>
#include <linux/posix-timers.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/math64.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/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 */
static struct k_clock sgi_clock;
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 DEFINE_MUTEX(mmtimer_mutex);
static long mmtimer_ioctl(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,
.unlocked_ioctl = mmtimer_ioctl,
.llseek = noop_llseek,
};
/*
* We only have comparison registers RTC1-4 currently available per
* node. RTC0 is used by SAL.
*/
/* Check for an RTC interrupt pending */
static int 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 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 mmtimer_setup_int_0(int cpu, 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(cpu) <<
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 mmtimer_setup_int_1(int cpu, 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(cpu) <<
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 mmtimer_setup_int_2(int cpu, 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(cpu) <<
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 mmtimer_setup(int cpu, int comparator, unsigned long expires,
u64 *set_completion_time)
{
switch (comparator) {
case 0:
mmtimer_setup_int_0(cpu, expires);
break;
case 1:
mmtimer_setup_int_1(cpu, expires);
break;
case 2:
mmtimer_setup_int_2(cpu, expires);
break;
}
/* We might've missed our expiration time */
*set_completion_time = rtc_time();
if (*set_completion_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 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 COMPARATOR 1 /* The comparator to use */
#define TIMER_OFF 0xbadcabLL /* Timer is not setup */
#define TIMER_SET 0 /* Comparator is set for this timer */
#define MMTIMER_INTERVAL_RETRY_INCREMENT_DEFAULT 40
/* There is one of these for each timer */
struct mmtimer {
struct rb_node list;
struct k_itimer *timer;
int cpu;
};
struct mmtimer_node {
spinlock_t lock ____cacheline_aligned;
struct rb_root timer_head;
struct rb_node *next;
struct tasklet_struct tasklet;
};
static struct mmtimer_node *timers;
static unsigned mmtimer_interval_retry_increment =
MMTIMER_INTERVAL_RETRY_INCREMENT_DEFAULT;
module_param(mmtimer_interval_retry_increment, uint, 0644);
MODULE_PARM_DESC(mmtimer_interval_retry_increment,
"RTC ticks to add to expiration on interval retry (default 40)");
/*
* Add a new mmtimer struct to the node's mmtimer list.
* This function assumes the struct mmtimer_node is locked.
*/
static void mmtimer_add_list(struct mmtimer *n)
{
int nodeid = n->timer->it.mmtimer.node;
unsigned long expires = n->timer->it.mmtimer.expires;
struct rb_node **link = &timers[nodeid].timer_head.rb_node;
struct rb_node *parent = NULL;
struct mmtimer *x;
/*
* Find the right place in the rbtree:
*/
while (*link) {
parent = *link;
x = rb_entry(parent, struct mmtimer, list);
if (expires < x->timer->it.mmtimer.expires)
link = &(*link)->rb_left;
else
link = &(*link)->rb_right;
}
/*
* Insert the timer to the rbtree and check whether it
* replaces the first pending timer
*/
rb_link_node(&n->list, parent, link);
rb_insert_color(&n->list, &timers[nodeid].timer_head);
if (!timers[nodeid].next || expires < rb_entry(timers[nodeid].next,
struct mmtimer, list)->timer->it.mmtimer.expires)
timers[nodeid].next = &n->list;
}
/*
* Set the comparator for the next timer.
* This function assumes the struct mmtimer_node is locked.
*/
static void mmtimer_set_next_timer(int nodeid)
{
struct mmtimer_node *n = &timers[nodeid];
struct mmtimer *x;
struct k_itimer *t;
u64 expires, exp, set_completion_time;
int i;
restart:
if (n->next == NULL)
return;
x = rb_entry(n->next, struct mmtimer, list);
t = x->timer;
if (!t->it.mmtimer.incr) {
/* Not an interval timer */
if (!mmtimer_setup(x->cpu, COMPARATOR,
t->it.mmtimer.expires,
&set_completion_time)) {
/* Late setup, fire now */
tasklet_schedule(&n->tasklet);
}
return;
}
/* Interval timer */
i = 0;
expires = exp = t->it.mmtimer.expires;
while (!mmtimer_setup(x->cpu, COMPARATOR, expires,
&set_completion_time)) {
int to;
i++;
expires = set_completion_time +
mmtimer_interval_retry_increment + (1 << i);
/* Calculate overruns as we go. */
to = ((u64)(expires - exp) / t->it.mmtimer.incr);
if (to) {
t->it_overrun += to;
t->it.mmtimer.expires += t->it.mmtimer.incr * to;
exp = t->it.mmtimer.expires;
}
if (i > 20) {
printk(KERN_ALERT "mmtimer: cannot reschedule timer\n");
t->it.mmtimer.clock = TIMER_OFF;
n->next = rb_next(&x->list);
rb_erase(&x->list, &n->timer_head);
kfree(x);
goto restart;
}
}
}
/**
* mmtimer_ioctl - ioctl interface for /dev/mmtimer
* @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 long mmtimer_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int ret = 0;
mutex_lock(&mmtimer_mutex);
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)))
ret = -EFAULT;
break;
case MMTIMER_GETFREQ: /* frequency in Hz */
if(copy_to_user((unsigned long __user *)arg,
&sn_rtc_cycles_per_second,
sizeof(unsigned long)))
ret = -EFAULT;
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)))
ret = -EFAULT;
break;
default:
ret = -ENOTTY;
break;
}
mutex_unlock(&mmtimer_mutex);
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 = {
.minor = SGI_MMTIMER,
.name = MMTIMER_NAME,
.fops = &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 timespec64 *tp)
{
u64 nsec;
nsec = rtc_time() * sgi_clock_period
+ sgi_clock_offset.tv_nsec;
*tp = ns_to_timespec64(nsec);
tp->tv_sec += sgi_clock_offset.tv_sec;
return 0;
};
static int sgi_clock_set(const clockid_t clockid, const struct timespec64 *tp)
{
u64 nsec;
u32 rem;
nsec = rtc_time() * sgi_clock_period;
sgi_clock_offset.tv_sec = tp->tv_sec - div_u64_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;
}
/**
* 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)
{
unsigned long expires = 0;
int result = IRQ_NONE;
unsigned indx = cpu_to_node(smp_processor_id());
struct mmtimer *base;
spin_lock(&timers[indx].lock);
base = rb_entry(timers[indx].next, struct mmtimer, list);
if (base == NULL) {
spin_unlock(&timers[indx].lock);
return result;
}
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(COMPARATOR) > 0) ||
(expires && (expires <= rtc_time()))) {
mmtimer_clr_int_pending(COMPARATOR);
tasklet_schedule(&timers[indx].tasklet);
result = IRQ_HANDLED;
}
}
spin_unlock(&timers[indx].lock);
return result;
}
static void mmtimer_tasklet(unsigned long data)
{
int nodeid = data;
struct mmtimer_node *mn = &timers[nodeid];
struct mmtimer *x;
struct k_itimer *t;
unsigned long flags;
/* Send signal and deal with periodic signals */
spin_lock_irqsave(&mn->lock, flags);
if (!mn->next)
goto out;
x = rb_entry(mn->next, struct mmtimer, list);
t = x->timer;
if (t->it.mmtimer.clock == TIMER_OFF)
goto out;
t->it_overrun = 0;
mn->next = rb_next(&x->list);
rb_erase(&x->list, &mn->timer_head);
if (posix_timer_event(t, 0) != 0)
t->it_overrun++;
if(t->it.mmtimer.incr) {
t->it.mmtimer.expires += t->it.mmtimer.incr;
mmtimer_add_list(x);
} else {
/* Ensure we don't false trigger in mmtimer_interrupt */
t->it.mmtimer.clock = TIMER_OFF;
t->it.mmtimer.expires = 0;
kfree(x);
}
/* Set comparator for next timer, if there is one */
mmtimer_set_next_timer(nodeid);
t->it_overrun_last = t->it_overrun;
out:
spin_unlock_irqrestore(&mn->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)
{
cnodeid_t nodeid = timr->it.mmtimer.node;
unsigned long irqflags;
spin_lock_irqsave(&timers[nodeid].lock, irqflags);
if (timr->it.mmtimer.clock != TIMER_OFF) {
unsigned long expires = timr->it.mmtimer.expires;
struct rb_node *n = timers[nodeid].timer_head.rb_node;
struct mmtimer *uninitialized_var(t);
int r = 0;
timr->it.mmtimer.clock = TIMER_OFF;
timr->it.mmtimer.expires = 0;
while (n) {
t = rb_entry(n, struct mmtimer, list);
if (t->timer == timr)
break;
if (expires < t->timer->it.mmtimer.expires)
n = n->rb_left;
else
n = n->rb_right;
}
if (!n) {
spin_unlock_irqrestore(&timers[nodeid].lock, irqflags);
return 0;
}
if (timers[nodeid].next == n) {
timers[nodeid].next = rb_next(n);
r = 1;
}
rb_erase(n, &timers[nodeid].timer_head);
kfree(t);
if (r) {
mmtimer_disable_int(cnodeid_to_nasid(nodeid),
COMPARATOR);
mmtimer_set_next_timer(nodeid);
}
}
spin_unlock_irqrestore(&timers[nodeid].lock, irqflags);
return 0;
}
/* Assumption: it_lock is already held with irq's disabled */
static void sgi_timer_get(struct k_itimer *timr, struct itimerspec64 *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;
}
cur_setting->it_interval = ns_to_timespec64(timr->it.mmtimer.incr * sgi_clock_period);
cur_setting->it_value = ns_to_timespec64((timr->it.mmtimer.expires - rtc_time()) * sgi_clock_period);
}
static int sgi_timer_set(struct k_itimer *timr, int flags,
struct itimerspec64 *new_setting,
struct itimerspec64 *old_setting)
{
unsigned long when, period, irqflags;
int err = 0;
cnodeid_t nodeid;
struct mmtimer *base;
struct rb_node *n;
if (old_setting)
sgi_timer_get(timr, old_setting);
sgi_timer_del(timr);
when = timespec64_to_ns(&new_setting->it_value);
period = timespec64_to_ns(&new_setting->it_interval);
if (when == 0)
/* Clear timer */
return 0;
base = kmalloc(sizeof(struct mmtimer), GFP_KERNEL);
if (base == NULL)
return -ENOMEM;
if (flags & TIMER_ABSTIME) {
struct timespec64 n;
unsigned long now;
getnstimeofday64(&n);
now = timespec64_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());
/* Lock the node timer structure */
spin_lock_irqsave(&timers[nodeid].lock, irqflags);
base->timer = timr;
base->cpu = smp_processor_id();
timr->it.mmtimer.clock = TIMER_SET;
timr->it.mmtimer.node = nodeid;
timr->it.mmtimer.incr = period;
timr->it.mmtimer.expires = when;
n = timers[nodeid].next;
/* Add the new struct mmtimer to node's timer list */
mmtimer_add_list(base);
if (timers[nodeid].next == n) {
/* No need to reprogram comparator for now */
spin_unlock_irqrestore(&timers[nodeid].lock, irqflags);
preempt_enable();
return err;
}
/* We need to reprogram the comparator */
if (n)
mmtimer_disable_int(cnodeid_to_nasid(nodeid), COMPARATOR);
mmtimer_set_next_timer(nodeid);
/* Unlock the node timer structure */
spin_unlock_irqrestore(&timers[nodeid].lock, irqflags);
preempt_enable();
return err;
}
static int sgi_clock_getres(const clockid_t which_clock, struct timespec64 *tp)
{
tp->tv_sec = 0;
tp->tv_nsec = sgi_clock_period;
return 0;
}
static struct k_clock sgi_clock = {
.clock_set = sgi_clock_set,
.clock_get = sgi_clock_get,
.clock_getres = sgi_clock_getres,
.timer_create = sgi_timer_create,
.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)
{
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);
goto out1;
}
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);
goto out1;
}
if (misc_register(&mmtimer_miscdev)) {
printk(KERN_ERR "%s: failed to register device\n",
MMTIMER_NAME);
goto out2;
}
/* 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 = kzalloc(sizeof(struct mmtimer_node)*maxn, GFP_KERNEL);
if (!timers) {
printk(KERN_ERR "%s: failed to allocate memory for device\n",
MMTIMER_NAME);
goto out3;
}
/* Initialize struct mmtimer's for each online node */
for_each_online_node(node) {
spin_lock_init(&timers[node].lock);
tasklet_init(&timers[node].tasklet, mmtimer_tasklet,
(unsigned long) node);
}
sgi_clock_period = NSEC_PER_SEC / sn_rtc_cycles_per_second;
posix_timers_register_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;
out3:
misc_deregister(&mmtimer_miscdev);
out2:
free_irq(SGI_MMTIMER_VECTOR, NULL);
out1:
return -1;
}
module_init(mmtimer_init);

6
include/uapi/linux/time.h
View File

@ -54,7 +54,11 @@ struct itimerval {
#define CLOCK_BOOTTIME 7
#define CLOCK_REALTIME_ALARM 8
#define CLOCK_BOOTTIME_ALARM 9
#define CLOCK_SGI_CYCLE 10 /* Hardware specific */
/*
* The driver implementing this got removed. The clock ID is kept as a
* place holder. Do not reuse!
*/
#define CLOCK_SGI_CYCLE 10
#define CLOCK_TAI 11
#define MAX_CLOCKS 16