Initial revision

1 files changed, 220 insertions, 0 deletions

diff --git a/c/src/lib/libcpu/hppa1.1/clock/clock.c b/c/src/lib/libcpu/hppa1.1/clock/clock.c
new file mode 100644
index 0000000000..62bb8e2826
--- /dev/null
+++ b/c/src/lib/libcpu/hppa1.1/clock/clock.c
@@ -0,0 +1,220 @@
+/*  Clock
+ *
+ *  This routine initializes the interval timer on the
+ *  PA-RISC CPU.  The tick frequency is specified by the bsp.
+ *
+ *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
+ *  On-Line Applications Research Corporation (OAR).
+ *  All rights assigned to U.S. Government, 1994.
+ *
+ *  This material may be reproduced by or for the U.S. Government pursuant
+ *  to the copyright license under the clause at DFARS 252.227-7013.  This
+ *  notice must appear in all copies of this file and its derivatives.
+ *
+ *  $Id$
+ */
+
+#include <bsp.h>
+#include <clockdrv.h>
+
+#include <stdlib.h>                     /* for atexit() */
+
+extern rtems_cpu_table           Cpu_table;             /* owned by BSP */
+
+typedef unsigned long long hppa_click_count_t;
+
+/*
+ * CPU_HPPA_CLICKS_PER_TICK is either a #define or an rtems_unsigned32
+ *   allocated and set by bsp_start()
+ */
+
+#ifndef CPU_HPPA_CLICKS_PER_TICK
+extern rtems_unsigned32 CPU_HPPA_CLICKS_PER_TICK;
+#endif
+
+volatile rtems_unsigned32 Clock_driver_ticks;
+rtems_unsigned32 Clock_isrs;              /* ISRs until next tick */
+
+rtems_unsigned32   most_recent_itimer_value;
+
+rtems_unsigned64   Clock_clicks;        /* running total of cycles */
+
+rtems_unsigned32   Clock_clicks_interrupt;
+
+rtems_device_driver Clock_initialize(
+  rtems_device_major_number major,
+  rtems_device_minor_number minor,
+  void *pargp,
+  rtems_id tid,
+  rtems_unsigned32 *rval
+)
+{
+    Install_clock(Clock_isr);
+}
+
+void
+ReInstall_clock(rtems_isr_entry new_clock_isr)
+{
+    rtems_unsigned32 isrlevel = 0;
+
+    rtems_interrupt_disable(isrlevel);
+    (void) set_vector(
+      new_clock_isr,
+      HPPA_INTERRUPT_EXTERNAL_INTERVAL_TIMER,
+      1
+    );
+    rtems_interrupt_enable(isrlevel);
+}
+
+/*
+ * read itimer and update Clock_clicks as appropriate
+ */
+
+rtems_unsigned32
+Clock_read_itimer()
+{
+    rtems_unsigned32 isrlevel;
+    rtems_unsigned32 itimer_value;
+    rtems_unsigned32 wrap_count;
+    rtems_unsigned32 recent_count;
+
+    rtems_interrupt_disable(isrlevel);
+
+    wrap_count = (Clock_clicks & 0xFFFFFFFF00000000ULL) >> 32;
+    recent_count = (rtems_unsigned32) Clock_clicks;
+
+    itimer_value = get_itimer();
+
+    if (itimer_value < recent_count)
+        wrap_count++;
+    Clock_clicks = (((rtems_unsigned64) wrap_count) << 32) + itimer_value;
+
+    rtems_interrupt_enable(isrlevel);
+
+    return itimer_value;
+}
+
+
+void Install_clock(rtems_isr_entry clock_isr)
+{
+    Clock_driver_ticks = 0;
+    Clock_clicks_interrupt = 0;
+    Clock_clicks = 0;
+
+    Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000;
+
+    if (BSP_Configuration.ticks_per_timeslice)
+    {
+        /*
+         * initialize the interval here
+         * First tick is set to right amount of time in the future
+         * Future ticks will be incremented over last value set
+         * in order to provide consistent clicks in the face of
+         * interrupt overhead
+         */
+
+        Clock_clicks_interrupt = Clock_read_itimer() + CPU_HPPA_CLICKS_PER_TICK;
+        set_itimer((rtems_unsigned32) Clock_clicks_interrupt);
+
+        (void) set_vector(clock_isr, HPPA_INTERRUPT_EXTERNAL_INTERVAL_TIMER, 1);
+    }
+    atexit(Clock_exit);
+}
+
+rtems_isr
+Clock_isr(rtems_vector_number vector)
+{
+    rtems_unsigned32 clicks_til_next_interrupt;
+    rtems_unsigned32 itimer_value;
+
+    /*
+     * setup for next interrupt; making sure the new value is reasonably
+     * in the future.... in case we lost out on an interrupt somehow
+     */
+
+    itimer_value = Clock_read_itimer();
+    Clock_clicks_interrupt += CPU_HPPA_CLICKS_PER_TICK;
+
+    /*
+     * how far away is next interrupt *really*
+     * It may be a long time; this subtraction works even if
+     * Clock_clicks_interrupt < Clock_clicks_low_order via
+     * the miracle of unsigned math.
+     */
+    clicks_til_next_interrupt = Clock_clicks_interrupt - itimer_value;
+
+    /*
+     * If it is too soon then bump it up.
+     * This should only happen if CPU_HPPA_CLICKS_PER_TICK is too small.
+     * But setting it low is useful for debug, so...
+     */
+
+    if (clicks_til_next_interrupt < 400)
+    {
+        Clock_clicks_interrupt = itimer_value + 1000;
+        /* XXX: count these! this should be rare */
+    }
+
+    /*
+     * If it is too late, that means we missed the interrupt somehow.
+     * Rather than wait 35-50s for a wrap, we just fudge it here.
+     */
+
+    if (clicks_til_next_interrupt > CPU_HPPA_CLICKS_PER_TICK)
+    {
+        Clock_clicks_interrupt = itimer_value + 1000;
+        /* XXX: count these! this should never happen :-) */
+    }
+
+    set_itimer((rtems_unsigned32) Clock_clicks_interrupt);
+
+    Clock_driver_ticks++;
+
+    if (Clock_isrs == 1)
+    {
+        rtems_clock_tick();
+        Clock_isrs = BSP_Configuration.microseconds_per_tick / 10000;
+        if (Clock_isrs == 0)
+            Clock_isrs = 1;
+    }
+    else
+        Clock_isrs--;
+}
+
+/*
+ * Called via atexit()
+ * Remove the clock interrupt handler by setting handler to NULL
+ */
+
+void
+Clock_exit(void)
+{
+    if ( BSP_Configuration.ticks_per_timeslice )
+    {
+        (void) set_vector(0, HPPA_INTERRUPT_EXTERNAL_INTERVAL_TIMER, 1);
+    }
+}
+
+/*
+ * spin delay for specified number of microseconds
+ * used by RTEMS delay macro
+ */
+
+void
+Clock_delay(rtems_unsigned32 microseconds)
+{
+    rtems_unsigned64 future_time;
+
+    (void) Clock_read_itimer();
+    future_time = Clock_clicks +
+      ((rtems_unsigned64) microseconds) *
+        Cpu_table.itimer_clicks_per_microsecond;
+
+    for (;;)
+    {
+        (void) Clock_read_itimer();
+        if (future_time <= Clock_clicks)
+            break;
+    }
+}
+