diff options
Diffstat (limited to 'drivers/char/mmtimer.c')
| -rw-r--r-- | drivers/char/mmtimer.c | 858 |
1 files changed, 858 insertions, 0 deletions
diff --git a/drivers/char/mmtimer.c b/drivers/char/mmtimer.c new file mode 100644 index 000000000..3d6c0671e --- /dev/null +++ b/drivers/char/mmtimer.c @@ -0,0 +1,858 @@ +/* + * 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 <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 */ + +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 = { + 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(const clockid_t clockid, const 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 +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 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 int sgi_clock_getres(const clockid_t which_clock, struct timespec *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); |