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authorChris Zankel <czankel@tensilica.com>2005-06-23 22:01:26 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-24 00:05:22 -0700
commit9a8fd5589902153a134111ed7a40f9cca1f83254 (patch)
tree6f7a06de25bdf0b2d94623794c2cbbc66b5a77f6 /include/asm-xtensa/delay.h
parent3f65ce4d141e435e54c20ed2379d983d362a2cb5 (diff)
[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>
Diffstat (limited to 'include/asm-xtensa/delay.h')
-rw-r--r--include/asm-xtensa/delay.h50
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
+