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authorIngo Molnar <mingo@elte.hu>2009-01-11 15:34:05 +0100
committerIngo Molnar <mingo@elte.hu>2009-01-11 15:34:05 +0100
commitd19b85db9d5c44a4c21dcb10d6fbadaa4425ab2a (patch)
tree250be7a5a29069f7d1f4524fa45ab0e988833025 /arch/xtensa/include/asm/delay.h
parent490dea45d00f01847ebebd007685d564aaf2cd98 (diff)
parentc59765042f53a79a7a65585042ff463b69cb248c (diff)
Merge commit 'v2.6.29-rc1' into timers/urgent
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 00000000000..e1d8c9e010c
--- /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
+