Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff
[linux-2.6.git] / drivers / char / mmtimer.c
index 3539b4a..1b05fa6 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
@@ -45,7 +45,7 @@ MODULE_LICENSE("GPL");
 /* name of the device, usually in /dev */
 #define MMTIMER_NAME "mmtimer"
 #define MMTIMER_DESC "SGI Altix RTC Timer"
-#define MMTIMER_VERSION "2.0"
+#define MMTIMER_VERSION "2.1"
 
 #define RTC_BITS 55 /* 55 bits for this implementation */
 
@@ -70,11 +70,6 @@ static struct file_operations mmtimer_fops = {
        .ioctl =        mmtimer_ioctl,
 };
 
-/*
- * Comparators and their associated info.  Shub has
- * three comparison registers.
- */
-
 /*
  * We only have comparison registers RTC1-4 currently available per
  * node.  RTC0 is used by SAL.
@@ -174,14 +169,10 @@ static void inline mmtimer_setup_int_2(u64 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.
- * mmtimer_setup will return the cycles that we were too late if the
- * initialization failed.
  */
 static int inline mmtimer_setup(int comparator, unsigned long expires)
 {
 
-       long diff;
-
        switch (comparator) {
        case 0:
                mmtimer_setup_int_0(expires);
@@ -194,17 +185,14 @@ static int inline mmtimer_setup(int comparator, unsigned long expires)
                break;
        }
        /* We might've missed our expiration time */
-        diff = rtc_time() - expires;
-       if (diff > 0) {
-               if (mmtimer_int_pending(comparator)) {
-                       /* We'll get an interrupt for this once we're done */
-                        return 0;
-               }
-               /* Looks like we missed it */
-               return diff;
-        }
+       if (rtc_time() < expires)
+               return 1;
 
-       return 0;
+       /*
+        * 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)
@@ -239,10 +227,7 @@ typedef struct mmtimer {
        struct tasklet_struct tasklet;
 } mmtimer_t;
 
-/*
- * Total number of comparators is comparators/node * MAX nodes/running kernel
- */
-static mmtimer_t timers[NUM_COMPARATORS*MAX_COMPACT_NODES];
+static mmtimer_t ** timers;
 
 /**
  * mmtimer_ioctl - ioctl interface for /dev/mmtimer
@@ -376,7 +361,7 @@ static int sgi_clock_period;
 static struct timespec sgi_clock_offset;
 static int sgi_clock_period;
 
-static int sgi_clock_get(struct timespec *tp)
+static int sgi_clock_get(clockid_t clockid, struct timespec *tp)
 {
        u64 nsec;
 
@@ -387,7 +372,7 @@ static int sgi_clock_get(struct timespec *tp)
        return 0;
 };
 
-static int sgi_clock_set(struct timespec *tp)
+static int sgi_clock_set(clockid_t clockid, struct timespec *tp)
 {
 
        u64 nsec;
@@ -418,19 +403,19 @@ static int inline reschedule_periodic_timer(mmtimer_t *x)
        int n;
        struct k_itimer *t = x->timer;
 
-       t->it_timer.magic = x->i;
+       t->it.mmtimer.clock = x->i;
        t->it_overrun--;
 
        n = 0;
        do {
 
-               t->it_timer.expires += t->it_incr << n;
+               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_timer.expires));
+       } while (!mmtimer_setup(x->i, t->it.mmtimer.expires));
 
        return 0;
 }
@@ -453,29 +438,29 @@ static irqreturn_t
 mmtimer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 {
        int i;
-       mmtimer_t *base = timers + cpuid_to_cnodeid(smp_processor_id()) *
-                                               NUM_COMPARATORS;
        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[i].lock);
-               if (base[i].cpu == smp_processor_id()) {
-                       if (base[i].timer)
-                               expires = base[i].timer->it_timer.expires;
+               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[i].tasklet);
+                               tasklet_schedule(&base->tasklet);
                                result = IRQ_HANDLED;
                        }
                }
-               spin_unlock(&base[i].lock);
+               spin_unlock(&base->lock);
                expires = 0;
        }
        return result;
@@ -497,13 +482,13 @@ void mmtimer_tasklet(unsigned long data) {
                goto out;
        t->it_overrun = 0;
 
-       if (tasklist_lock.write_lock || posix_timer_event(t, 0) != 0) {
+       if (posix_timer_event(t, 0) != 0) {
 
                // printk(KERN_WARNING "mmtimer: cannot deliver signal.\n");
 
                t->it_overrun++;
        }
-       if(t->it_incr) {
+       if(t->it.mmtimer.incr) {
                /* Periodic timer */
                if (reschedule_periodic_timer(x)) {
                        printk(KERN_WARNING "mmtimer: unable to reschedule\n");
@@ -511,7 +496,7 @@ void mmtimer_tasklet(unsigned long data) {
                }
        } else {
                /* Ensure we don't false trigger in mmtimer_interrupt */
-               t->it_timer.expires = 0;
+               t->it.mmtimer.expires = 0;
        }
        t->it_overrun_last = t->it_overrun;
 out:
@@ -522,7 +507,7 @@ out:
 static int sgi_timer_create(struct k_itimer *timer)
 {
        /* Insure that a newly created timer is off */
-       timer->it_timer.magic = TIMER_OFF;
+       timer->it.mmtimer.clock = TIMER_OFF;
        return 0;
 }
 
@@ -533,17 +518,17 @@ static int sgi_timer_create(struct k_itimer *timer)
  */
 static int sgi_timer_del(struct k_itimer *timr)
 {
-       int i = timr->it_timer.magic;
-       cnodeid_t nodeid = timr->it_timer.data;
-       mmtimer_t *t = timers + nodeid * NUM_COMPARATORS +i;
+       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_timer.magic = TIMER_OFF;
-               timr->it_timer.expires = 0;
+               timr->it.mmtimer.clock = TIMER_OFF;
+               timr->it.mmtimer.expires = 0;
                spin_unlock_irqrestore(&t->lock, irqflags);
        }
        return 0;
@@ -556,7 +541,7 @@ static int sgi_timer_del(struct k_itimer *timr)
 static void sgi_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
 {
 
-       if (timr->it_timer.magic == TIMER_OFF) {
+       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;
@@ -564,8 +549,8 @@ static void sgi_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
                return;
        }
 
-       ns_to_timespec(cur_setting->it_interval, timr->it_incr * sgi_clock_period);
-       ns_to_timespec(cur_setting->it_value, (timr->it_timer.expires - rtc_time())* sgi_clock_period);
+       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;
 }
 
@@ -594,9 +579,15 @@ static int sgi_timer_set(struct k_itimer *timr, int flags,
 
        if (flags & TIMER_ABSTIME) {
                struct timespec n;
+               unsigned long now;
 
                getnstimeofday(&n);
-               when -= timespec_to_ns(n);
+               now = timespec_to_ns(n);
+               if (when > now)
+                       when -= now;
+               else
+                       /* Fire the timer immediately */
+                       when = 0;
        }
 
        /*
@@ -614,12 +605,12 @@ static int sgi_timer_set(struct k_itimer *timr, int flags,
         */
        preempt_disable();
 
-       nodeid =  cpuid_to_cnodeid(smp_processor_id());
-       base = timers + nodeid * NUM_COMPARATORS;
+       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++) {
-               if (!base[i].timer && !base[i].tasklet.state) {
+               base = timers[nodeid] + i;
+               if (!base->timer && !base->tasklet.state) {
                        break;
                }
        }
@@ -629,33 +620,33 @@ retry:
                return -EBUSY;
        }
 
-       spin_lock_irqsave(&base[i].lock, irqflags);
+       spin_lock_irqsave(&base->lock, irqflags);
 
-       if (base[i].timer || base[i].tasklet.state != 0) {
-               spin_unlock_irqrestore(&base[i].lock, irqflags);
+       if (base->timer || base->tasklet.state != 0) {
+               spin_unlock_irqrestore(&base->lock, irqflags);
                goto retry;
        }
-       base[i].timer = timr;
-       base[i].cpu = smp_processor_id();
+       base->timer = timr;
+       base->cpu = smp_processor_id();
 
-       timr->it_timer.magic = i;
-       timr->it_timer.data = nodeid;
-       timr->it_incr = period;
-       timr->it_timer.expires = when;
+       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)) {
+               if (!mmtimer_setup(i, when)) {
                        mmtimer_disable_int(-1, i);
                        posix_timer_event(timr, 0);
-                       timr->it_timer.expires = 0;
+                       timr->it.mmtimer.expires = 0;
                }
        } else {
-               timr->it_timer.expires -= period;
-               if (reschedule_periodic_timer(base+i))
+               timr->it.mmtimer.expires -= period;
+               if (reschedule_periodic_timer(base))
                        err = -EINVAL;
        }
 
-       spin_unlock_irqrestore(&base[i].lock, irqflags);
+       spin_unlock_irqrestore(&base->lock, irqflags);
 
        preempt_enable();
 
@@ -681,9 +672,10 @@ static struct k_clock sgi_clock = {
 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
@@ -697,14 +689,6 @@ static int __init mmtimer_init(void)
        mmtimer_femtoperiod = ((unsigned long)1E15 + sn_rtc_cycles_per_second /
                               2) / sn_rtc_cycles_per_second;
 
-       for (i=0; i< NUM_COMPARATORS*MAX_COMPACT_NODES; i++) {
-               spin_lock_init(&timers[i].lock);
-               timers[i].timer = NULL;
-               timers[i].cpu = 0;
-               timers[i].i = i % NUM_COMPARATORS;
-               tasklet_init(&timers[i].tasklet, mmtimer_tasklet, (unsigned long) (timers+i));
-       }
-
        if (request_irq(SGI_MMTIMER_VECTOR, mmtimer_interrupt, SA_PERCPU_IRQ, MMTIMER_NAME, NULL)) {
                printk(KERN_WARNING "%s: unable to allocate interrupt.",
                        MMTIMER_NAME);
@@ -718,6 +702,40 @@ static int __init mmtimer_init(void)
                return -1;
        }
 
+       /* Get max numbered node, calculate slots needed */
+       for_each_online_node(node) {
+               maxn = node;
+       }
+       maxn++;
+
+       /* Allocate list of node ptrs to mmtimer_t's */
+       timers = kmalloc(sizeof(mmtimer_t *)*maxn, GFP_KERNEL);
+       if (timers == NULL) {
+               printk(KERN_ERR "%s: failed to allocate memory for device\n",
+                               MMTIMER_NAME);
+               return -1;
+       }
+
+       /* Allocate mmtimer_t's for each online node */
+       for_each_online_node(node) {
+               timers[node] = kmalloc_node(sizeof(mmtimer_t)*NUM_COMPARATORS, GFP_KERNEL, node);
+               if (timers[node] == NULL) {
+                       printk(KERN_ERR "%s: failed to allocate memory for device\n",
+                               MMTIMER_NAME);
+                       return -1;
+               }
+               for (i=0; i< NUM_COMPARATORS; i++) {
+                       mmtimer_t * base = timers[node] + i;
+
+                       spin_lock_init(&base->lock);
+                       base->timer = NULL;
+                       base->cpu = 0;
+                       base->i = i;
+                       tasklet_init(&base->tasklet, mmtimer_tasklet,
+                               (unsigned long) (base));
+               }
+       }
+
        sgi_clock_period = sgi_clock.res = NSEC_PER_SEC / sn_rtc_cycles_per_second;
        register_posix_clock(CLOCK_SGI_CYCLE, &sgi_clock);