[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 6

The attached patches provides part 6 of an architecture implementation for the
Tensilica Xtensa CPU series.

Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 50 insertions, 0 deletions

diff --git a/include/asm-xtensa/delay.h b/include/asm-xtensa/delay.h
new file mode 100644
index 000000000000..6359c55e77a8
--- /dev/null
+++ b/include/asm-xtensa/delay.h
@@ -0,0 +1,50 @@
+/*
+ * include/asm-xtensa/delay.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2005 Tensilica Inc.
+ *
+ */
+
+#ifndef _XTENSA_DELAY_H
+#define _XTENSA_DELAY_H
+
+#include <linux/config.h>
+#include <asm/processor.h>
+#include <asm/param.h>
+
+extern unsigned long loops_per_jiffy;
+
+extern __inline__ void __delay(unsigned long loops)
+{
+  /* 2 cycles per loop. */
+  __asm__ __volatile__ ("1: addi %0, %0, -2; bgeui %0, 1, 1b"
+			: "=r" (loops) : "0" (loops));
+}
+
+static __inline__ u32 xtensa_get_ccount(void)
+{
+	u32 ccount;
+	asm volatile ("rsr %0, 234; # CCOUNT\n" : "=r" (ccount));
+	return ccount;
+}
+
+/* For SMP/NUMA systems, change boot_cpu_data to something like
+ * local_cpu_data->... where local_cpu_data points to the current
+ * cpu. */
+
+static __inline__ void udelay (unsigned long usecs)
+{
+	unsigned long start = xtensa_get_ccount();
+	unsigned long cycles = usecs * (loops_per_jiffy / (1000000UL / HZ));
+
+	/* Note: all variables are unsigned (can wrap around)! */
+	while (((unsigned long)xtensa_get_ccount()) - start < cycles)
+		;
+}
+
+#endif
+