linux/drivers/char/mmtimer.c

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/*
* 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>
Remove fs.h from mm.h Remove fs.h from mm.h. For this, 1) Uninline vma_wants_writenotify(). It's pretty huge anyway. 2) Add back fs.h or less bloated headers (err.h) to files that need it. As result, on x86_64 allyesconfig, fs.h dependencies cut down from 3929 files rebuilt down to 3444 (-12.3%). Cross-compile tested without regressions on my two usual configs and (sigh): alpha arm-mx1ads mips-bigsur powerpc-ebony alpha-allnoconfig arm-neponset mips-capcella powerpc-g5 alpha-defconfig arm-netwinder mips-cobalt powerpc-holly alpha-up arm-netx mips-db1000 powerpc-iseries arm arm-ns9xxx mips-db1100 powerpc-linkstation arm-assabet arm-omap_h2_1610 mips-db1200 powerpc-lite5200 arm-at91rm9200dk arm-onearm mips-db1500 powerpc-maple arm-at91rm9200ek arm-picotux200 mips-db1550 powerpc-mpc7448_hpc2 arm-at91sam9260ek arm-pleb mips-ddb5477 powerpc-mpc8272_ads arm-at91sam9261ek arm-pnx4008 mips-decstation powerpc-mpc8313_rdb arm-at91sam9263ek arm-pxa255-idp mips-e55 powerpc-mpc832x_mds arm-at91sam9rlek arm-realview mips-emma2rh powerpc-mpc832x_rdb arm-ateb9200 arm-realview-smp mips-excite powerpc-mpc834x_itx arm-badge4 arm-rpc mips-fulong powerpc-mpc834x_itxgp arm-carmeva arm-s3c2410 mips-ip22 powerpc-mpc834x_mds arm-cerfcube arm-shannon mips-ip27 powerpc-mpc836x_mds arm-clps7500 arm-shark mips-ip32 powerpc-mpc8540_ads arm-collie arm-simpad mips-jazz powerpc-mpc8544_ds arm-corgi arm-spitz mips-jmr3927 powerpc-mpc8560_ads arm-csb337 arm-trizeps4 mips-malta powerpc-mpc8568mds arm-csb637 arm-versatile mips-mipssim powerpc-mpc85xx_cds arm-ebsa110 i386 mips-mpc30x powerpc-mpc8641_hpcn arm-edb7211 i386-allnoconfig mips-msp71xx powerpc-mpc866_ads arm-em_x270 i386-defconfig mips-ocelot powerpc-mpc885_ads arm-ep93xx i386-up mips-pb1100 powerpc-pasemi arm-footbridge ia64 mips-pb1500 powerpc-pmac32 arm-fortunet ia64-allnoconfig mips-pb1550 powerpc-ppc64 arm-h3600 ia64-bigsur mips-pnx8550-jbs powerpc-prpmc2800 arm-h7201 ia64-defconfig mips-pnx8550-stb810 powerpc-ps3 arm-h7202 ia64-gensparse mips-qemu powerpc-pseries arm-hackkit ia64-sim mips-rbhma4200 powerpc-up arm-integrator ia64-sn2 mips-rbhma4500 s390 arm-iop13xx ia64-tiger mips-rm200 s390-allnoconfig arm-iop32x ia64-up mips-sb1250-swarm s390-defconfig arm-iop33x ia64-zx1 mips-sead s390-up arm-ixp2000 m68k mips-tb0219 sparc arm-ixp23xx m68k-amiga mips-tb0226 sparc-allnoconfig arm-ixp4xx m68k-apollo mips-tb0287 sparc-defconfig arm-jornada720 m68k-atari mips-workpad sparc-up arm-kafa m68k-bvme6000 mips-wrppmc sparc64 arm-kb9202 m68k-hp300 mips-yosemite sparc64-allnoconfig arm-ks8695 m68k-mac parisc sparc64-defconfig arm-lart m68k-mvme147 parisc-allnoconfig sparc64-up arm-lpd270 m68k-mvme16x parisc-defconfig um-x86_64 arm-lpd7a400 m68k-q40 parisc-up x86_64 arm-lpd7a404 m68k-sun3 powerpc x86_64-allnoconfig arm-lubbock m68k-sun3x powerpc-cell x86_64-defconfig arm-lusl7200 mips powerpc-celleb x86_64-up arm-mainstone mips-atlas powerpc-chrp32 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-29 22:36:13 +00:00
#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/smp_lock.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 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,
};
/*
* 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)
{
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 */
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 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 */
/* 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;
/*
* 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;
int o;
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)) {
/* Late setup, fire now */
tasklet_schedule(&n->tasklet);
}
return;
}
/* Interval timer */
o = 0;
while (!mmtimer_setup(x->cpu, COMPARATOR, t->it.mmtimer.expires)) {
unsigned long e, e1;
struct rb_node *next;
t->it.mmtimer.expires += t->it.mmtimer.incr << o;
t->it_overrun += 1 << o;
o++;
if (o > 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;
}
e = t->it.mmtimer.expires;
next = rb_next(&x->list);
if (next == NULL)
continue;
e1 = rb_entry(next, struct mmtimer, list)->
timer->it.mmtimer.expires;
if (e > e1) {
n->next = next;
rb_erase(&x->list, &n->timer_head);
mmtimer_add_list(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;
lock_kernel();
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;
}
unlock_kernel();
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 = ns_to_timespec(nsec);
tp->tv_sec += sgi_clock_offset.tv_sec;
return 0;
};
static int sgi_clock_set(clockid_t clockid, struct timespec *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
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 13:55:46 +00:00
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 = rb_entry(mn->next, struct mmtimer, list);
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 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;
}
cur_setting->it_interval = ns_to_timespec(timr->it.mmtimer.incr * sgi_clock_period);
cur_setting->it_value = ns_to_timespec((timr->it.mmtimer.expires - rtc_time()) * sgi_clock_period);
}
static int sgi_timer_set(struct k_itimer *timr, int flags,
struct itimerspec * new_setting,
struct itimerspec * 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 = timespec_to_ns(&new_setting->it_value);
period = timespec_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 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());
/* 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 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)
{
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 == NULL) {
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 = 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;
out3:
kfree(timers);
misc_deregister(&mmtimer_miscdev);
out2:
free_irq(SGI_MMTIMER_VECTOR, NULL);
out1:
return -1;
}
module_init(mmtimer_init);