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+/*
+ * Copyright (c) 2011 Aeroflex Gaisler
+ *
+ * BSD license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+
+#ifndef _LINUX_JIFFIES_H
+#define _LINUX_JIFFIES_H
+
+#include <asm-leon/types.h>
+#include <asm-leon/clock.h>
+#include <asm-leon/linkage.h>
+
+/* Suppose we want to devide two numbers NOM and DEN: NOM/DEN, the we can
+ * improve accuracy by shifting LSH bits, hence calculating:
+ * (NOM << LSH) / DEN
+ * This however means trouble for large NOM, because (NOM << LSH) may no
+ * longer fit in 32 bits. The following way of calculating this gives us
+ * some slack, under the following conditions:
+ * - (NOM / DEN) fits in (32 - LSH) bits.
+ * - (NOM % DEN) fits in (32 - LSH) bits.
+ */
+#define SH_DIV(NOM,DEN,LSH) ( ((NOM / DEN) << LSH) \
+ + (((NOM % DEN) << LSH) + DEN / 2) / DEN)
+
+/* TICK_NSEC is the time between ticks in nsec assuming real ACTHZ */
+#define TICK_NSEC (SH_DIV (1000000UL * 1000, (HZ<<8), 8))
+
+/*
+ * The 64-bit value is not volatile - you MUST NOT read it
+ * without sampling the sequence number in xtime_lock.
+ */
+extern u64 jiffies_64;
+extern struct timespec xtime __attribute__ ((aligned (16)));
+#define jiffies (*((unsigned long *)(((unsigned long)(&jiffies_64))+4)))
+
+/*
+ * These inlines deal with timer wrapping correctly. You are
+ * strongly encouraged to use them
+ * 1. Because people otherwise forget
+ * 2. Because if the timer wrap changes in future you won't have to
+ * alter your driver code.
+ *
+ * time_after(a,b) returns true if the time a is after time b.
+ *
+ * Do this with "<0" and ">=0" to only test the sign of the result. A
+ * good compiler would generate better code (and a really good compiler
+ * wouldn't care). Gcc is currently neither.
+ */
+#define time_after(a,b) \
+ (typecheck(unsigned long, a) && \
+ typecheck(unsigned long, b) && \
+ ((long)(b) - (long)(a) < 0))
+#define time_before(a,b) time_after(b,a)
+
+#define time_after_eq(a,b) \
+ (typecheck(unsigned long, a) && \
+ typecheck(unsigned long, b) && \
+ ((long)(a) - (long)(b) >= 0))
+#define time_before_eq(a,b) time_after_eq(b,a)
+
+/*
+ * Have the 32 bit jiffies value wrap 5 minutes after boot
+ * so jiffies wrap bugs show up earlier.
+ */
+#define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ))
+
+static inline void
+set_normalized_timespec (struct timespec *ts, time_t sec, long nsec)
+{
+ while (nsec > NSEC_PER_SEC)
+ {
+ nsec -= NSEC_PER_SEC;
+ ++sec;
+ }
+ while (nsec < 0)
+ {
+ nsec += NSEC_PER_SEC;
+ --sec;
+ }
+ ts->tv_sec = sec;
+ ts->tv_nsec = nsec;
+}
+
+#endif