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authorSebastian Huber <sebastian.huber@embedded-brains.de>2018-04-20 12:08:42 +0200
committerSebastian Huber <sebastian.huber@embedded-brains.de>2018-04-20 13:52:19 +0200
commite0dd8a5ad830798bc8082b03b8c42c32fb9660e0 (patch)
treed147bfc4d670fcdfbd2e2d2e75eb209f92e07df1 /bsps/mips/csb350
parentbsps: Move startup files to bsps (diff)
downloadrtems-e0dd8a5ad830798bc8082b03b8c42c32fb9660e0.tar.bz2
bsps: Move benchmark timer to bsps
This patch is a part of the BSP source reorganization. Update #3285.
Diffstat (limited to 'bsps/mips/csb350')
-rw-r--r--bsps/mips/csb350/btimer/btimer.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/bsps/mips/csb350/btimer/btimer.c b/bsps/mips/csb350/btimer/btimer.c
new file mode 100644
index 0000000000..30dbfe836b
--- /dev/null
+++ b/bsps/mips/csb350/btimer/btimer.c
@@ -0,0 +1,57 @@
+/*
+ * This file implements a benchmark timer using the count/compare
+ * CP0 registers.
+ *
+ * Copyright (c) 2005 by Cogent Computer Systems
+ * Written by Jay Monkman <jtm@lopingdog.com>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#include <assert.h>
+
+#include <bsp.h>
+#include <rtems/btimer.h>
+
+bool benchmark_timer_find_average_overhead;
+uint32_t tstart;
+
+void benchmark_timer_initialize(void)
+{
+ __asm__ volatile ("mfc0 %0, $9\n" : "=r" (tstart));
+ /* tick time in picooseconds */
+}
+
+#define AVG_OVERHEAD 0 /* It typically takes N instructions */
+ /* to start/stop the timer. */
+#define LEAST_VALID 1 /* Don't trust a value lower than this */
+ /* tx39 simulator can count instructions. :) */
+
+benchmark_timer_t benchmark_timer_read(void)
+{
+ uint32_t total;
+ uint32_t cnt;
+
+ __asm__ volatile ("mfc0 %0, $9\n" : "=r" (cnt));
+
+ total = cnt - tstart;
+ total = (total * 1000) / 396; /* convert to nanoseconds */
+
+
+ if ( benchmark_timer_find_average_overhead == true )
+ return total; /* in one microsecond units */
+
+ if ( total < LEAST_VALID )
+ return 0; /* below timer resolution */
+
+ return total - AVG_OVERHEAD;
+}
+
+void benchmark_timer_disable_subtracting_average_overhead(
+ bool find_flag
+)
+{
+ benchmark_timer_find_average_overhead = find_flag;
+}