Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / metag / lib / delay.c

diff --git a/kernel/arch/metag/lib/delay.c b/kernel/arch/metag/lib/delay.c
new file mode 100644 (file)
index 0000000..0b308f4
--- /dev/null
+++ b/kernel/arch/metag/lib/delay.c
@@ -0,0 +1,56 @@
+/*
+ *     Precise Delay Loops for Meta
+ *
+ *     Copyright (C) 1993 Linus Torvalds
+ *     Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
+ *     Copyright (C) 2007,2009 Imagination Technologies Ltd.
+ *
+ */
+
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+
+#include <asm/core_reg.h>
+#include <asm/processor.h>
+
+/*
+ * TXTACTCYC is only 24 bits, so on chips with fast clocks it will wrap
+ * many times per-second. If it does wrap __delay will return prematurely,
+ * but this is only likely with large delay values.
+ *
+ * We also can't implement read_current_timer() with TXTACTCYC due to
+ * this wrapping behaviour.
+ */
+#define rdtimer(t) t = __core_reg_get(TXTACTCYC)
+
+void __delay(unsigned long loops)
+{
+       unsigned long bclock, now;
+
+       rdtimer(bclock);
+       do {
+               asm("NOP");
+               rdtimer(now);
+       } while ((now-bclock) < loops);
+}
+EXPORT_SYMBOL(__delay);
+
+inline void __const_udelay(unsigned long xloops)
+{
+       u64 loops = (u64)xloops * (u64)loops_per_jiffy * HZ;
+       __delay(loops >> 32);
+}
+EXPORT_SYMBOL(__const_udelay);
+
+void __udelay(unsigned long usecs)
+{
+       __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
+}
+EXPORT_SYMBOL(__udelay);
+
+void __ndelay(unsigned long nsecs)
+{
+       __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
+}
+EXPORT_SYMBOL(__ndelay);