Simplify clock interrupt handling on mips by using the new KPI - timer1clock()

and timer2clock().

Dynamically adjust the tick frequency depending on the value of 'hz'. Tested
with hz values of 100, 1000 and 2000.

1 files changed, 35 insertions, 70 deletions

diff --git a/sys/mips/mips/tick.c b/sys/mips/mips/tick.c
index 5931a5b..51270b4 100644
--- a/sys/mips/mips/tick.c
+++ b/sys/mips/mips/tick.c
@@ -58,19 +58,12 @@ struct timecounter *platform_timecounter;
 
 static uint64_t cycles_per_tick;
 static uint64_t cycles_per_usec;
-static uint64_t cycles_per_hz, cycles_per_stathz, cycles_per_profhz;
 
 static u_int32_t counter_upper = 0;
 static u_int32_t counter_lower_last = 0;
 
-struct clk_ticks {
-	u_long hard_ticks;
-	u_long stat_ticks;
-	u_long prof_ticks;
-	uint32_t compare_ticks;
-} __aligned(CACHE_LINE_SIZE);
-
-static struct clk_ticks pcpu_ticks[MAXCPU];
+static DPCPU_DEFINE(uint32_t, compare_ticks);
+static DPCPU_DEFINE(uint32_t, lost_ticks);
 
 /*
  * Device methods
@@ -150,22 +143,23 @@ mips_timer_init_params(uint64_t platform_counter_freq, int double_count)
 	if (double_count != 0)
 		counter_freq /= 2;
 
-	cycles_per_tick = counter_freq / 1000;
-	cycles_per_hz = counter_freq / hz;
-	cycles_per_stathz = counter_freq / stathz;
-	cycles_per_profhz = counter_freq / profhz;
+	if (hz >= 1500)
+		timer1hz = hz;
+	else if (hz >= 750)
+		timer1hz = hz * 2;
+	else
+		timer1hz = hz * 4;
+
+	cycles_per_tick = counter_freq / timer1hz;
 	cycles_per_usec = counter_freq / (1 * 1000 * 1000);
 	
 	counter_timecounter.tc_frequency = counter_freq;
-	printf("hz=%d cyl_per_tick:%jd cyl_per_usec:%jd freq:%jd "
-	       "cyl_per_hz:%jd cyl_per_stathz:%jd cyl_per_profhz:%jd\n",
+	printf("hz=%d timer1hz:%d cyl_per_tick:%jd cyl_per_usec:%jd freq:%jd\n",
 	       hz,
+	       timer1hz,
 	       cycles_per_tick,
 	       cycles_per_usec,
-	       counter_freq,
-	       cycles_per_hz,
-	       cycles_per_stathz,
-	       cycles_per_profhz);
+	       counter_freq);
 	set_cputicker(tick_ticker, counter_freq, 1);
 }
 
@@ -243,58 +237,59 @@ DELAY(int n)
 	}
 }
 
-#if 0 /* TARGET_OCTEON */
-int64_t wheel_run = 0;
-
-void octeon_led_run_wheel();
-
-#endif
 /*
  * Device section of file below
  */
 static int
 clock_intr(void *arg)
 {
-	struct clk_ticks *cpu_ticks;
 	struct trapframe *tf;
-	uint32_t count, compare, delta;
-
-	cpu_ticks = &pcpu_ticks[PCPU_GET(cpuid)];
+	uint32_t count, compare_last, compare_next, lost_ticks;
 
 	/*
 	 * Set next clock edge.
 	 */
 	count = mips_rd_count();
-	compare = cpu_ticks->compare_ticks;
-	cpu_ticks->compare_ticks = count + cycles_per_tick;
-	mips_wr_compare(cpu_ticks->compare_ticks);
+	compare_last = DPCPU_GET(compare_ticks);
+	compare_next = count + cycles_per_tick;
+	DPCPU_SET(compare_ticks, compare_next);
+	mips_wr_compare(compare_next);
+
 	critical_enter();
 	if (count < counter_lower_last) {
 		counter_upper++;
 		counter_lower_last = count;
 	}
+
 	/*
 	 * Magic.  Setting up with an arg of NULL means we get passed tf.
 	 */
 	tf = (struct trapframe *)arg;
 
-	delta = cycles_per_tick;
-
 	/*
 	 * Account for the "lost time" between when the timer interrupt fired
 	 * and when 'clock_intr' actually started executing.
 	 */
-	delta += count - compare;
+	lost_ticks = DPCPU_GET(lost_ticks);
+	lost_ticks += count - compare_last;
 
 	/*
 	 * If the COUNT and COMPARE registers are no longer in sync then make
-	 * up some reasonable value for the 'delta'.
+	 * up some reasonable value for the 'lost_ticks'.
 	 *
 	 * This could happen, for e.g., after we resume normal operations after
 	 * exiting the debugger.
 	 */
-	if (delta > cycles_per_hz)
-		delta = cycles_per_hz;
+	if (lost_ticks > 2 * cycles_per_tick)
+		lost_ticks = cycles_per_tick;
+
+	while (lost_ticks >= cycles_per_tick) {
+		timer1clock(TRAPF_USERMODE(tf), tf->pc);
+		timer2clock(TRAPF_USERMODE(tf), tf->pc);
+		lost_ticks -= cycles_per_tick;
+	}
+	DPCPU_SET(lost_ticks, lost_ticks);
+
 #ifdef KDTRACE_HOOKS
 	/*
 	 * If the DTrace hooks are configured and a callback function
@@ -305,39 +300,9 @@ clock_intr(void *arg)
 	if (cyclic_clock_func[cpu] != NULL)
 		(*cyclic_clock_func[cpu])(tf);
 #endif
-	/* Fire hardclock at hz. */
-	cpu_ticks->hard_ticks += delta;
-	if (cpu_ticks->hard_ticks >= cycles_per_hz) {
-	        cpu_ticks->hard_ticks -= cycles_per_hz;
-		if (PCPU_GET(cpuid) == 0)
-			hardclock(TRAPF_USERMODE(tf), tf->pc);
-		else
-			hardclock_cpu(TRAPF_USERMODE(tf));
-	}
-
-	/* Fire statclock at stathz. */
-	cpu_ticks->stat_ticks += delta;
-	if (cpu_ticks->stat_ticks >= cycles_per_stathz) {
-		cpu_ticks->stat_ticks -= cycles_per_stathz;
-		statclock(TRAPF_USERMODE(tf));
-	}
-
-	/* Fire profclock at profhz, but only when needed. */
-	cpu_ticks->prof_ticks += delta;
-	if (cpu_ticks->prof_ticks >= cycles_per_profhz) {
-		cpu_ticks->prof_ticks -= cycles_per_profhz;
-		if (profprocs != 0)
-			profclock(TRAPF_USERMODE(tf), tf->pc);
-	}
+	timer1clock(TRAPF_USERMODE(tf), tf->pc);
+	timer2clock(TRAPF_USERMODE(tf), tf->pc);
 	critical_exit();
-#if 0 /* TARGET_OCTEON */
-	/* Run the FreeBSD display once every hz ticks  */
-	wheel_run += cycles_per_tick;
-	if (wheel_run >= cycles_per_usec * 1000000ULL) {
-		wheel_run = 0;
-		octeon_led_run_wheel();
-	}
-#endif
 	return (FILTER_HANDLED);
 }