Merge branch 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  clocksource: convert mips to generic i8253 clocksource
  clocksource: convert x86 to generic i8253 clocksource
  clocksource: convert footbridge to generic i8253 clocksource
  clocksource: add common i8253 PIT clocksource
  blackfin: convert to clocksource_register_hz
  mips: convert to clocksource_register_hz/khz
  sparc: convert to clocksource_register_hz/khz
  alpha: convert to clocksource_register_hz
  microblaze: convert to clocksource_register_hz/khz
  ia64: convert to clocksource_register_hz/khz
  x86: Convert remaining x86 clocksources to clocksource_register_hz/khz
  Make clocksource name const
This commit is contained in:
Linus Torvalds
2011-05-19 17:44:13 -07:00
38 changed files with 157 additions and 355 deletions

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@ -51,8 +51,7 @@ void __init txx9_clocksource_init(unsigned long baseaddr,
{
struct txx9_tmr_reg __iomem *tmrptr;
clocksource_set_clock(&txx9_clocksource.cs, TIMER_CLK(imbusclk));
clocksource_register(&txx9_clocksource.cs);
clocksource_register_hz(&txx9_clocksource.cs, TIMER_CLK(imbusclk));
tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
__raw_writel(TCR_BASE, &tmrptr->tcr);

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@ -49,6 +49,5 @@ void __init sb1480_clocksource_init(void)
plldiv = G_BCM1480_SYS_PLL_DIV(__raw_readq(IOADDR(A_SCD_SYSTEM_CFG)));
zbbus = ((plldiv >> 1) * 50000000) + ((plldiv & 1) * 25000000);
clocksource_set_clock(cs, zbbus);
clocksource_register(cs);
clocksource_register_hz(cs, zbbus);
}

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@ -59,7 +59,5 @@ void __init dec_ioasic_clocksource_init(void)
printk(KERN_INFO "I/O ASIC clock frequency %dHz\n", freq);
clocksource_dec.rating = 200 + freq / 10000000;
clocksource_set_clock(&clocksource_dec, freq);
clocksource_register(&clocksource_dec);
clocksource_register_hz(&clocksource_dec, freq);
}

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@ -78,9 +78,7 @@ static void __init powertv_c0_hpt_clocksource_init(void)
clocksource_mips.rating = 200 + mips_hpt_frequency / 10000000;
clocksource_set_clock(&clocksource_mips, mips_hpt_frequency);
clocksource_register(&clocksource_mips);
clocksource_register_hz(&clocksource_mips, mips_hpt_frequency);
}
/**
@ -130,43 +128,16 @@ static struct clocksource clocksource_tim_c = {
/**
* powertv_tim_c_clocksource_init - set up a clock source for the TIM_C clock
*
* The hard part here is coming up with a constant k and shift s such that
* the 48-bit TIM_C value multiplied by k doesn't overflow and that value,
* when shifted right by s, yields the corresponding number of nanoseconds.
* We know that TIM_C counts at 27 MHz/8, so each cycle corresponds to
* 1 / (27,000,000/8) seconds. Multiply that by a billion and you get the
* number of nanoseconds. Since the TIM_C value has 48 bits and the math is
* done in 64 bits, avoiding an overflow means that k must be less than
* 64 - 48 = 16 bits.
* 1 / (27,000,000/8) seconds.
*/
static void __init powertv_tim_c_clocksource_init(void)
{
int prescale;
unsigned long dividend;
unsigned long k;
int s;
const int max_k_bits = (64 - 48) - 1;
const unsigned long billion = 1000000000;
const unsigned long counts_per_second = 27000000 / 8;
prescale = BITS_PER_LONG - ilog2(billion) - 1;
dividend = billion << prescale;
k = dividend / counts_per_second;
s = ilog2(k) - max_k_bits;
if (s < 0)
s = prescale;
else {
k >>= s;
s += prescale;
}
clocksource_tim_c.mult = k;
clocksource_tim_c.shift = s;
clocksource_tim_c.rating = 200;
clocksource_register(&clocksource_tim_c);
clocksource_register_hz(&clocksource_tim_c, counts_per_second);
tim_c = (struct tim_c *) asic_reg_addr(tim_ch);
}

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@ -30,9 +30,7 @@ int __init init_r4k_clocksource(void)
/* Calculate a somewhat reasonable rating value */
clocksource_mips.rating = 200 + mips_hpt_frequency / 10000000;
clocksource_set_clock(&clocksource_mips, mips_hpt_frequency);
clocksource_register(&clocksource_mips);
clocksource_register_hz(&clocksource_mips, mips_hpt_frequency);
return 0;
}

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@ -65,6 +65,5 @@ void __init sb1250_clocksource_init(void)
IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM,
R_SCD_TIMER_CFG)));
clocksource_set_clock(cs, V_SCD_TIMER_FREQ);
clocksource_register(cs);
clocksource_register_hz(cs, V_SCD_TIMER_FREQ);
}

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@ -125,87 +125,11 @@ void __init setup_pit_timer(void)
setup_irq(0, &irq0);
}
/*
* Since the PIT overflows every tick, its not very useful
* to just read by itself. So use jiffies to emulate a free
* running counter:
*/
static cycle_t pit_read(struct clocksource *cs)
{
unsigned long flags;
int count;
u32 jifs;
static int old_count;
static u32 old_jifs;
raw_spin_lock_irqsave(&i8253_lock, flags);
/*
* Although our caller may have the read side of xtime_lock,
* this is now a seqlock, and we are cheating in this routine
* by having side effects on state that we cannot undo if
* there is a collision on the seqlock and our caller has to
* retry. (Namely, old_jifs and old_count.) So we must treat
* jiffies as volatile despite the lock. We read jiffies
* before latching the timer count to guarantee that although
* the jiffies value might be older than the count (that is,
* the counter may underflow between the last point where
* jiffies was incremented and the point where we latch the
* count), it cannot be newer.
*/
jifs = jiffies;
outb_p(0x00, PIT_MODE); /* latch the count ASAP */
count = inb_p(PIT_CH0); /* read the latched count */
count |= inb_p(PIT_CH0) << 8;
/* VIA686a test code... reset the latch if count > max + 1 */
if (count > LATCH) {
outb_p(0x34, PIT_MODE);
outb_p(LATCH & 0xff, PIT_CH0);
outb(LATCH >> 8, PIT_CH0);
count = LATCH - 1;
}
/*
* It's possible for count to appear to go the wrong way for a
* couple of reasons:
*
* 1. The timer counter underflows, but we haven't handled the
* resulting interrupt and incremented jiffies yet.
* 2. Hardware problem with the timer, not giving us continuous time,
* the counter does small "jumps" upwards on some Pentium systems,
* (see c't 95/10 page 335 for Neptun bug.)
*
* Previous attempts to handle these cases intelligently were
* buggy, so we just do the simple thing now.
*/
if (count > old_count && jifs == old_jifs) {
count = old_count;
}
old_count = count;
old_jifs = jifs;
raw_spin_unlock_irqrestore(&i8253_lock, flags);
count = (LATCH - 1) - count;
return (cycle_t)(jifs * LATCH) + count;
}
static struct clocksource clocksource_pit = {
.name = "pit",
.rating = 110,
.read = pit_read,
.mask = CLOCKSOURCE_MASK(32),
.mult = 0,
.shift = 20,
};
static int __init init_pit_clocksource(void)
{
if (num_possible_cpus() > 1) /* PIT does not scale! */
return 0;
clocksource_pit.mult = clocksource_hz2mult(CLOCK_TICK_RATE, 20);
return clocksource_register(&clocksource_pit);
return clocksource_i8253_init();
}
arch_initcall(init_pit_clocksource);