* 2 of the License, or (at your option) any later version.
*/
-#include <linux/config.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
u64 tb_to_xs;
unsigned tb_to_us;
-#define TICKLEN_SCALE (SHIFT_SCALE - 10)
+#define TICKLEN_SCALE TICK_LENGTH_SHIFT
u64 last_tick_len; /* units are ns / 2^TICKLEN_SCALE */
u64 ticklen_to_xs; /* 0.64 fraction */
unsigned long ppc_proc_freq;
unsigned long ppc_tb_freq;
-u64 tb_last_jiffy __cacheline_aligned_in_smp;
-unsigned long tb_last_stamp;
-
-/*
- * Note that on ppc32 this only stores the bottom 32 bits of
- * the timebase value, but that's enough to tell when a jiffy
- * has passed.
- */
-DEFINE_PER_CPU(unsigned long, last_jiffy);
+static u64 tb_last_jiffy __cacheline_aligned_in_smp;
+static DEFINE_PER_CPU(u64, last_jiffy);
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
/*
/*
* This version of gettimeofday has microsecond resolution.
*/
-static inline void __do_gettimeofday(struct timeval *tv, u64 tb_val)
+static inline void __do_gettimeofday(struct timeval *tv)
{
unsigned long sec, usec;
u64 tb_ticks, xsec;
* without a divide (and in fact, without a multiply)
*/
temp_varp = do_gtod.varp;
- tb_ticks = tb_val - temp_varp->tb_orig_stamp;
+
+ /* Sampling the time base must be done after loading
+ * do_gtod.varp in order to avoid racing with update_gtod.
+ */
+ data_barrier(temp_varp);
+ tb_ticks = get_tb() - temp_varp->tb_orig_stamp;
temp_tb_to_xs = temp_varp->tb_to_xs;
temp_stamp_xsec = temp_varp->stamp_xsec;
xsec = temp_stamp_xsec + mulhdu(tb_ticks, temp_tb_to_xs);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
sec = xtime.tv_sec;
- nsec = xtime.tv_nsec + tb_ticks_since(tb_last_stamp);
+ nsec = xtime.tv_nsec + tb_ticks_since(tb_last_jiffy);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
usec = nsec / 1000;
while (usec >= 1000000) {
tv->tv_usec = usec;
return;
}
- __do_gettimeofday(tv, get_tb());
+ __do_gettimeofday(tv);
}
EXPORT_SYMBOL(do_gettimeofday);
int next_dec;
int cpu = smp_processor_id();
unsigned long ticks;
+ u64 tb_next_jiffy;
#ifdef CONFIG_PPC32
if (atomic_read(&ppc_n_lost_interrupts) != 0)
continue;
write_seqlock(&xtime_lock);
- tb_last_jiffy += tb_ticks_per_jiffy;
- tb_last_stamp = per_cpu(last_jiffy, cpu);
- do_timer(regs);
- timer_recalc_offset(tb_last_jiffy);
- timer_check_rtc();
+ tb_next_jiffy = tb_last_jiffy + tb_ticks_per_jiffy;
+ if (per_cpu(last_jiffy, cpu) >= tb_next_jiffy) {
+ tb_last_jiffy = tb_next_jiffy;
+ do_timer(regs);
+ timer_recalc_offset(tb_last_jiffy);
+ timer_check_rtc();
+ }
write_sequnlock(&xtime_lock);
}
int i;
unsigned long half = tb_ticks_per_jiffy / 2;
unsigned long offset = tb_ticks_per_jiffy / max_cpus;
- unsigned long previous_tb = per_cpu(last_jiffy, boot_cpuid);
+ u64 previous_tb = per_cpu(last_jiffy, boot_cpuid);
/* make sure tb > per_cpu(last_jiffy, cpu) for all cpus always */
previous_tb -= tb_ticks_per_jiffy;
* and therefore the (jiffies - wall_jiffies) computation
* has been removed.
*/
- tb_delta = tb_ticks_since(tb_last_stamp);
+ tb_delta = tb_ticks_since(tb_last_jiffy);
tb_delta = mulhdu(tb_delta, do_gtod.varp->tb_to_xs); /* in xsec */
new_nsec -= SCALE_XSEC(tb_delta, 1000000000);
EXPORT_SYMBOL(do_settimeofday);
-void __init generic_calibrate_decr(void)
+static int __init get_freq(char *name, int cells, unsigned long *val)
{
struct device_node *cpu;
- unsigned int *fp;
- int node_found;
+ const unsigned int *fp;
+ int found = 0;
- /*
- * The cpu node should have a timebase-frequency property
- * to tell us the rate at which the decrementer counts.
- */
+ /* The cpu node should have timebase and clock frequency properties */
cpu = of_find_node_by_type(NULL, "cpu");
- ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
- node_found = 0;
if (cpu) {
- fp = (unsigned int *)get_property(cpu, "timebase-frequency",
- NULL);
+ fp = get_property(cpu, name, NULL);
if (fp) {
- node_found = 1;
- ppc_tb_freq = *fp;
+ found = 1;
+ *val = 0;
+ while (cells--)
+ *val = (*val << 32) | *fp++;
}
+
+ of_node_put(cpu);
}
- if (!node_found)
+
+ return found;
+}
+
+void __init generic_calibrate_decr(void)
+{
+ ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
+
+ if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) &&
+ !get_freq("timebase-frequency", 1, &ppc_tb_freq)) {
+
printk(KERN_ERR "WARNING: Estimating decrementer frequency "
"(not found)\n");
+ }
- ppc_proc_freq = DEFAULT_PROC_FREQ;
- node_found = 0;
- if (cpu) {
- fp = (unsigned int *)get_property(cpu, "clock-frequency",
- NULL);
- if (fp) {
- node_found = 1;
- ppc_proc_freq = *fp;
- }
+ ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */
+
+ if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) &&
+ !get_freq("clock-frequency", 1, &ppc_proc_freq)) {
+
+ printk(KERN_ERR "WARNING: Estimating processor frequency "
+ "(not found)\n");
}
+
#ifdef CONFIG_BOOKE
/* Set the time base to zero */
mtspr(SPRN_TBWL, 0);
/* Enable decrementer interrupt */
mtspr(SPRN_TCR, TCR_DIE);
#endif
- if (!node_found)
- printk(KERN_ERR "WARNING: Estimating processor frequency "
- "(not found)\n");
-
- of_node_put(cpu);
}
unsigned long get_boot_time(void)
if (__USE_RTC()) {
/* 601 processor: dec counts down by 128 every 128ns */
ppc_tb_freq = 1000000000;
- tb_last_stamp = get_rtcl();
- tb_last_jiffy = tb_last_stamp;
+ tb_last_jiffy = get_rtcl();
} else {
/* Normal PowerPC with timebase register */
ppc_md.calibrate_decr();
ppc_tb_freq / 1000000, ppc_tb_freq % 1000000);
printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n",
ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
- tb_last_stamp = tb_last_jiffy = get_tb();
+ tb_last_jiffy = get_tb();
}
tb_ticks_per_jiffy = ppc_tb_freq / HZ;
do_gtod.varp = &do_gtod.vars[0];
do_gtod.var_idx = 0;
do_gtod.varp->tb_orig_stamp = tb_last_jiffy;
- __get_cpu_var(last_jiffy) = tb_last_stamp;
+ __get_cpu_var(last_jiffy) = tb_last_jiffy;
do_gtod.varp->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC;
do_gtod.tb_ticks_per_sec = tb_ticks_per_sec;
do_gtod.varp->tb_to_xs = tb_to_xs;