+++ /dev/null
-/*
- * arch/ubicom32/kernel/time.c
- * Initialize the timer list and start the appropriate timers.
- *
- * (C) Copyright 2009, Ubicom, Inc.
- * Copyright (C) 1991, 1992, 1995 Linus Torvalds
- *
- * This file is part of the Ubicom32 Linux Kernel Port.
- *
- * The Ubicom32 Linux Kernel Port is free software: you can redistribute
- * it and/or modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation, either version 2 of the
- * License, or (at your option) any later version.
- *
- * The Ubicom32 Linux Kernel Port is distributed in the hope that it
- * will be useful, but WITHOUT ANY WARRANTY; without even the implied
- * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
- * the GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with the Ubicom32 Linux Kernel Port. If not,
- * see <http://www.gnu.org/licenses/>.
- *
- * Ubicom32 implementation derived from (with many thanks):
- * arch/m68knommu
- * arch/blackfin
- * arch/parisc
- */
-
-#include <linux/profile.h>
-#include <linux/smp.h>
-#include <asm/ip5000.h>
-#include <asm/machdep.h>
-
-/*
- * A bitmap of the timers on the processor indicates
- * that the timer is free or in-use.
- */
-static unsigned int timers;
-
-/*
- * timer_set()
- * Init the specified compare register to go off <n> cycles from now.
- */
-void timer_set(int timervector, unsigned int cycles)
-{
- int idx = UBICOM32_VECTOR_TO_TIMER_INDEX(timervector);
- UBICOM32_IO_TIMER->syscom[idx] =
- UBICOM32_IO_TIMER->sysval + cycles;
- ldsr_enable_vector(timervector);
-}
-
-/*
- * timer_reset()
- * Set/reset the timer to go off again.
- *
- * Because sysval is a continuous timer, this function is able
- * to ensure that we do not have clock sku by using the previous
- * value in syscom to set the next value for syscom.
- *
- * Returns the number of ticks that transpired since the last event.
- */
-int timer_reset(int timervector, unsigned int cycles)
-{
- /*
- * Reset the timer in the LDSR thread to go off appropriately.
- *
- * Use the previous value of the timer to calculate the new stop
- * time. This allows us to account for it taking an
- * indeterminate amount of time to get here.
- */
- const int timer_index = UBICOM32_VECTOR_TO_TIMER_INDEX(timervector);
- unsigned int prev = UBICOM32_IO_TIMER->syscom[timer_index];
- unsigned int next = prev + cycles;
- int scratchpad3;
- int diff;
- int ticks = 1;
-
- /*
- * If the difference is negative, we have missed at least one
- * timer tick.
- *
- * TODO: Decide if we want to "ignore" time (as done below) or
- * if we want to process time (unevenly) by calling timer_tick()
- * lost_ticks times.
- */
- while (1) {
- /*
- * Set our future time first.
- */
- UBICOM32_IO_TIMER->syscom[timer_index] = next;
-
- /*
- * Then check if we are really set time in the futrue.
- */
- diff = (int)next - (int)UBICOM32_IO_TIMER->sysval;
- if (diff >= 0) {
- break;
- }
-
- /*
- * Oops, we are too slow. Playing catch up.
- *
- * If the debugger is connected the there is a good
- * chance that we lost time because we were in a
- * break-point, so in this case we do not print out
- * diagnostics.
- */
- asm volatile ("move.4 %0, scratchpad3"
- : "=r" (scratchpad3));
- if ((scratchpad3 & 0x1) == 0) {
- /*
- * No debugger attached, print to the console
- */
- printk(KERN_EMERG "diff: %d, timer has lost %u "
- "ticks [rounded up]\n",
- -diff,
- (unsigned int)((-diff + cycles - 1) / cycles));
- }
-
- do {
- next += cycles;
- diff = (int)next - (int)UBICOM32_IO_TIMER->sysval;
- ticks++;
- } while (diff < 0);
- }
- return ticks;
-}
-
-/*
- * sched_clock()
- * Returns current time in nano-second units.
- *
- * Notes:
- * 1) This is an override for the weak alias in
- * kernel/sched_clock.c.
- * 2) Do not use xtime_lock as this function is
- * sometimes called with xtime_lock held.
- * 3) We use a retry algorithm to ensure that
- * we get a consistent value.
- * 4) sched_clock must be overwritten if IRQ tracing
- * is enabled because the default implementation uses
- * the xtime_lock sequence while holding xtime_lock.
- */
-unsigned long long sched_clock(void)
-{
- unsigned long long my_jiffies;
- unsigned long jiffies_top;
- unsigned long jiffies_bottom;
-
- do {
- jiffies_top = jiffies_64 >> 32;
- jiffies_bottom = jiffies_64 & 0xffffffff;
- } while (unlikely(jiffies_top != (unsigned long)(jiffies_64 >> 32)));
-
- my_jiffies = ((unsigned long long)jiffies_top << 32) | (jiffies_bottom);
- return (my_jiffies - INITIAL_JIFFIES) * (NSEC_PER_SEC / HZ);
-}
-
-/*
- * timer_free()
- * Free a hardware timer.
- */
-void timer_free(int interrupt)
-{
- unsigned int bit = interrupt - TIMER_INT(0);
-
- /*
- * The timer had not been allocated.
- */
- BUG_ON(timers & (1 << bit));
- timers |= (1 << bit);
-}
-
-/*
- * timer_alloc()
- * Allocate a hardware timer.
- */
-int timer_alloc(void)
-{
- unsigned int bit = find_first_bit((unsigned long *)&timers, 32);
- if (!bit) {
- printk(KERN_WARNING "no more free timers\n");
- return -1;
- }
-
- timers &= ~(1 << bit);
- return bit + TIMER_INT(0);
-}
-
-/*
- * time_init()
- * Time init function.
- */
-void time_init(void)
-{
- /*
- * Find the processor node and determine what timers are
- * available for us.
- */
- timers = processor_timers();
- if (timers == 0) {
- printk(KERN_WARNING "no timers are available for Linux\n");
- return;
- }
-
-#ifdef CONFIG_GENERIC_CLOCKEVENTS
- timer_device_init();
-#else
- timer_tick_init();
-#endif
-}
projects / openwrt / svn-archive / archive.git / blobdiff