bitkeeper revision 1.14.1.1 (3e397e7cPGmZK7y5LLOGYa43nTQMUw)

added time and accurate timer support
partially there for better scheduler (most of the infrastructure should be there)

4 files changed, 35 insertions, 67 deletions

diff --git a/xenolinux-2.4.16-sparse/arch/xeno/kernel/i386_ksyms.c b/xenolinux-2.4.16-sparse/arch/xeno/kernel/i386_ksyms.c
index 12db77164b..a35ef1cc8a 100644
--- a/xenolinux-2.4.16-sparse/arch/xeno/kernel/i386_ksyms.c
+++ b/xenolinux-2.4.16-sparse/arch/xeno/kernel/i386_ksyms.c
@@ -42,7 +42,7 @@ extern struct drive_info_struct drive_info;
 EXPORT_SYMBOL(drive_info);
 #endif
 
-extern unsigned long get_cmos_time(void);
+//extern unsigned long get_cmos_time(void);
 
 /* platform dependent support */
 EXPORT_SYMBOL(boot_cpu_data);
@@ -58,7 +58,7 @@ EXPORT_SYMBOL(probe_irq_mask);
 EXPORT_SYMBOL(kernel_thread);
 EXPORT_SYMBOL(pm_idle);
 EXPORT_SYMBOL(pm_power_off);
-EXPORT_SYMBOL(get_cmos_time);
+//EXPORT_SYMBOL(get_cmos_time);
 EXPORT_SYMBOL(apm_info);
 
 #ifdef CONFIG_DEBUG_IOVIRT
diff --git a/xenolinux-2.4.16-sparse/arch/xeno/kernel/process.c b/xenolinux-2.4.16-sparse/arch/xeno/kernel/process.c
index 9e26f3d65a..608049ece0 100644
--- a/xenolinux-2.4.16-sparse/arch/xeno/kernel/process.c
+++ b/xenolinux-2.4.16-sparse/arch/xeno/kernel/process.c
@@ -86,7 +86,7 @@ void cpu_idle (void)
 
     while (1) {
         while (!current->need_resched)
-            HYPERVISOR_yield();
+            HYPERVISOR_do_sched_op(NULL);
         schedule();
         check_pgt_cache();
     }
diff --git a/xenolinux-2.4.16-sparse/arch/xeno/kernel/time.c b/xenolinux-2.4.16-sparse/arch/xeno/kernel/time.c
index c728eb15e6..2557918c6d 100644
--- a/xenolinux-2.4.16-sparse/arch/xeno/kernel/time.c
+++ b/xenolinux-2.4.16-sparse/arch/xeno/kernel/time.c
@@ -102,47 +102,26 @@ static inline unsigned long ticks_to_us(unsigned long ticks)
     return(hi);
 }
 
-static inline unsigned long do_gettimeoffset(void)
+static long long get_s_time(void)
 {
-#if 0
-    register unsigned long eax, edx;
-
-    /* Read the Time Stamp Counter */
-
-    rdtsc(eax,edx);
-
-    /* .. relative to previous jiffy (32 bits is enough) */
-    eax -= last_tsc_low;	/* tsc_low delta */
-
-    /*
-     * Time offset = (tsc_low delta) * fast_gettimeoffset_quotient
-     *             = (tsc_low delta) * (usecs_per_clock)
-     *             = (tsc_low delta) * (usecs_per_jiffy / clocks_per_jiffy)
-     *
-     * Using a mull instead of a divl saves up to 31 clock cycles
-     * in the critical path.
-     */
-    
-    edx = ticks_to_us(eax);
-
-    /* our adjusted time offset in microseconds */
-    return delay_at_last_interrupt + edx;
-#else
-    /*
-     * We should keep a 'last_tsc_low' thing which incorporates 
-     * delay_at_last_interrupt, adjusted in timer_interrupt after
-     * do_timer_interrupt. It would look at change in xtime, and
-     * make appropriate adjustment to a last_tsc variable.
-     * 
-     * We'd be affected by rounding error in ticks_per_usec, and by
-     * processor clock drift (which should be no more than in an
-     * external interrupt source anyhow). 
-     * 
-     * Perhaps a bit rough and ready, but never mind!
-     */
-    return 0;
-#endif
+    u32 	  delta, low, pcc;
+	long long now;
+	long long incr;
+
+	/* read two values (pcc, now) "atomically" */
+again:
+    pcc = HYPERVISOR_shared_info->st_timestamp;
+    now = HYPERVISOR_shared_info->system_time;
+	if (HYPERVISOR_shared_info->st_timestamp != pcc) goto again;
+
+    /* only use bottom 32bits of TSC. This should be sufficient */
+	rdtscl(low);
+    delta = low - pcc;
+
+	incr = ((long long)(ticks_to_us(delta)*1000));
+    return now + incr; 
 }
+#define NOW()				((long long)get_s_time())
 
 /*
  * This version of gettimeofday has microsecond resolution
@@ -151,15 +130,15 @@ static inline unsigned long do_gettimeoffset(void)
 void do_gettimeofday(struct timeval *tv)
 {
     unsigned long flags;
-    unsigned long usec, sec, lost;
+    unsigned long usec, sec;
 
     read_lock_irqsave(&xtime_lock, flags);
-    usec = do_gettimeoffset();
-    lost = jiffies - wall_jiffies;
-    if ( lost != 0 ) usec += lost * (1000000 / HZ);
-    sec = xtime.tv_sec;
-    usec += xtime.tv_usec;
-    read_unlock_irqrestore(&xtime_lock, flags);
+
+	usec  = ((unsigned long)(NOW()-HYPERVISOR_shared_info->wc_timestamp))/1000;
+	sec   = HYPERVISOR_shared_info->tv_sec;
+	usec += HYPERVISOR_shared_info->tv_usec;
+
+	read_unlock_irqrestore(&xtime_lock, flags);
 
     while ( usec >= 1000000 ) 
     {
@@ -173,6 +152,8 @@ void do_gettimeofday(struct timeval *tv)
 
 void do_settimeofday(struct timeval *tv)
 {
+/* XXX RN: shoudl do something special here for dom0 */
+#if 0
     write_lock_irq(&xtime_lock);
     /*
      * This is revolting. We need to set "xtime" correctly. However, the
@@ -195,6 +176,7 @@ void do_settimeofday(struct timeval *tv)
     time_maxerror = NTP_PHASE_LIMIT;
     time_esterror = NTP_PHASE_LIMIT;
     write_unlock_irq(&xtime_lock);
+#endif
 }
 
 
@@ -235,19 +217,6 @@ static struct irqaction irq_timer = {
 };
 
 
-unsigned long get_cmos_time(void)
-{
-    unsigned long secs = HYPERVISOR_shared_info->rtc_time;
-    unsigned long diff;
-
-    rdtscl(diff);
-    diff -= (unsigned long)HYPERVISOR_shared_info->rtc_timestamp;
-
-    secs += ticks_to_us(diff);
-
-    return(secs + ticks_to_secs(diff));
-}
-
 
 /* Return 2^32 * (1 / (TSC clocks per usec)) for do_fast_gettimeoffset(). */
 static unsigned long __init calibrate_tsc(void)
@@ -268,7 +237,6 @@ void __init time_init(void)
     unsigned long long alarm;
 	
     fast_gettimeoffset_quotient = calibrate_tsc();
-    do_get_fast_time = do_gettimeofday;
 
     /* report CPU clock rate in Hz.
      * The formula is (10^6 * 2^32) / (2^32 * 1 / (clocks/us)) =
@@ -299,6 +267,5 @@ void __init time_init(void)
     HYPERVISOR_shared_info->domain_timeout = ~0ULL;
     clear_bit(_EVENT_TIMER, &HYPERVISOR_shared_info->events);
 
-    xtime.tv_sec = get_cmos_time();
-    xtime.tv_usec = 0;
+	do_gettimeofday(&xtime);
 }
diff --git a/xenolinux-2.4.16-sparse/include/asm-xeno/hypervisor.h b/xenolinux-2.4.16-sparse/include/asm-xeno/hypervisor.h
index 839feed153..0d0940c9bb 100644
--- a/xenolinux-2.4.16-sparse/include/asm-xeno/hypervisor.h
+++ b/xenolinux-2.4.16-sparse/include/asm-xeno/hypervisor.h
@@ -203,12 +203,13 @@ static inline int HYPERVISOR_fpu_taskswitch(void)
     return ret;
 }
 
-static inline int HYPERVISOR_yield(void)
+static inline int HYPERVISOR_do_sched_op(void *sched_op)
 {
     int ret;
     __asm__ __volatile__ (
         TRAP_INSTR
-        : "=a" (ret) : "0" (__HYPERVISOR_yield) );
+        : "=a" (ret) : "0" (__HYPERVISOR_sched_op),
+        "b" (sched_op) );
 
     return ret;
 }