fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / drivers / char / mmtimer.c
index 20aa170..c091603 100644 (file)
@@ -1,11 +1,11 @@
 /*
- * Intel Multimedia Timer device implementation for SGI SN platforms.
+ * 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) 2001-2004 Silicon Graphics, Inc.  All rights reserved.
+ * 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
@@ -13,6 +13,9 @@
  *
  * 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/init.h>
 #include <linux/errno.h>
 #include <linux/mm.h>
-#include <linux/devfs_fs_kernel.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/clksupport.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("Multimedia timer support");
+MODULE_DESCRIPTION("SGI Altix RTC Timer");
 MODULE_LICENSE("GPL");
 
 /* name of the device, usually in /dev */
 #define MMTIMER_NAME "mmtimer"
-#define MMTIMER_DESC "IA-PC Multimedia Timer"
-#define MMTIMER_VERSION "1.0"
+#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);
@@ -49,12 +63,171 @@ static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma);
  */
 static unsigned long mmtimer_femtoperiod = 0;
 
-static struct file_operations mmtimer_fops = {
+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
@@ -100,13 +273,13 @@ static int mmtimer_ioctl(struct inode *inode, struct file *file,
                break;
 
        case MMTIMER_GETRES: /* resolution of the clock in 10^-15 s */
-               if(copy_to_user((unsigned long *)arg, &mmtimer_femtoperiod,
-                               sizeof(unsigned long)))
+               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 *)arg,
+               if(copy_to_user((unsigned long __user *)arg,
                                &sn_rtc_cycles_per_second,
                                sizeof(unsigned long)))
                        return -EFAULT;
@@ -122,8 +295,8 @@ static int mmtimer_ioctl(struct inode *inode, struct file *file,
                break;
 
        case MMTIMER_GETCOUNTER:
-               if(copy_to_user((unsigned long *)arg, RTC_COUNTER_ADDR,
-                               sizeof(unsigned long)))
+               if(copy_to_user((unsigned long __user *)arg,
+                               RTC_COUNTER_ADDR, sizeof(unsigned long)))
                        return -EFAULT;
                break;
        default:
@@ -139,7 +312,7 @@ static int mmtimer_ioctl(struct inode *inode, struct file *file,
  * @file: file structure for the device
  * @vma: VMA to map the registers into
  *
- * Calls remap_page_range() to map the clock's 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)
@@ -155,16 +328,15 @@ static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma)
        if (PAGE_SIZE > (1 << 16))
                return -ENOSYS;
 
-       vma->vm_flags |= (VM_IO | VM_SHM | VM_LOCKED );
        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_page_range(vma, vma->vm_start, mmtimer_addr, PAGE_SIZE,
-                            vma->vm_page_prot)) {
-               printk(KERN_ERR "remap_page_range failed in mmtimer.c\n");
+       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;
        }
 
@@ -177,6 +349,318 @@ static struct miscdevice mmtimer_miscdev = {
        &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
  *
@@ -184,8 +668,11 @@ static struct miscdevice mmtimer_miscdev = {
  */
 static int __init mmtimer_init(void)
 {
+       unsigned i;
+       cnodeid_t node, maxn = -1;
+
        if (!ia64_platform_is("sn2"))
-               return -1;
+               return 0;
 
        /*
         * Sanity check the cycles/sec variable
@@ -193,23 +680,78 @@ static int __init mmtimer_init(void)
        if (sn_rtc_cycles_per_second < 100000) {
                printk(KERN_ERR "%s: unable to determine clock frequency\n",
                       MMTIMER_NAME);
-               return -1;
+               goto out1;
        }
 
        mmtimer_femtoperiod = ((unsigned long)1E15 + sn_rtc_cycles_per_second /
                               2) / sn_rtc_cycles_per_second;
 
-       strcpy(mmtimer_miscdev.devfs_name, MMTIMER_NAME);
+       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);
-               return -1;
+               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 = kmalloc(sizeof(mmtimer_t *)*maxn, GFP_KERNEL);
+       if (timers == NULL) {
+               printk(KERN_ERR "%s: failed to allocate memory for device\n",
+                               MMTIMER_NAME);
+               goto out3;
        }
 
+       memset(timers,0,(sizeof(mmtimer_t *)*maxn));
+
+       /* 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);
+                       goto out4;
+               }
+               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;
+
+out4:
+       for_each_online_node(node) {
+               kfree(timers[node]);
+       }
+out3:
+       misc_deregister(&mmtimer_miscdev);
+out2:
+       free_irq(SGI_MMTIMER_VECTOR, NULL);
+out1:
+       return -1;
 }
 
 module_init(mmtimer_init);