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authorLinus Torvalds <torvalds@linux-foundation.org>2009-01-07 11:56:29 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-07 11:56:29 -0800
commit52fefcec97c25b15887e6a9a885ca54e7f7c0928 (patch)
tree4898112a7fb30c20a9da3aefe9fdc7fdebda57a6 /arch/xtensa/include/asm/delay.h
parenta0e280e0f33f6c859a235fb69a875ed8f3420388 (diff)
parent5fee325e7d2bcbebf1cb38b4ff3a7aa3744c43e3 (diff)
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Merge git://git.kernel.org/pub/scm/linux/kernel/git/czankel/xtensa-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/czankel/xtensa-2.6: xtensa: Update platform files to reflect new location of the header files. xtensa: switch to packed struct unaligned access implementation xtensa: Add xt2000 support files. xtensa: move headers files to arch/xtensa/include xtensa: use the new byteorder headers
Diffstat (limited to 'arch/xtensa/include/asm/delay.h')
-rw-r--r--arch/xtensa/include/asm/delay.h49
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/delay.h b/arch/xtensa/include/asm/delay.h
new file mode 100644
index 0000000..e1d8c9e
--- /dev/null
+++ b/arch/xtensa/include/asm/delay.h
@@ -0,0 +1,49 @@
+/*
+ * 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 <asm/processor.h>
+#include <asm/param.h>
+
+extern unsigned long loops_per_jiffy;
+
+static inline void __delay(unsigned long loops)
+{
+ /* 2 cycles per loop. */
+ __asm__ __volatile__ ("1: addi %0, %0, -2; bgeui %0, 2, 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
+