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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/m68k/include/asm/delay.h
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/m68k/include/asm/delay.h')
-rw-r--r--kernel/arch/m68k/include/asm/delay.h119
1 files changed, 119 insertions, 0 deletions
diff --git a/kernel/arch/m68k/include/asm/delay.h b/kernel/arch/m68k/include/asm/delay.h
new file mode 100644
index 000000000..d28fa8fe2
--- /dev/null
+++ b/kernel/arch/m68k/include/asm/delay.h
@@ -0,0 +1,119 @@
+#ifndef _M68K_DELAY_H
+#define _M68K_DELAY_H
+
+#include <asm/param.h>
+
+/*
+ * Copyright (C) 1994 Hamish Macdonald
+ * Copyright (C) 2004 Greg Ungerer <gerg@uclinux.com>
+ *
+ * Delay routines, using a pre-computed "loops_per_jiffy" value.
+ */
+
+#if defined(CONFIG_COLDFIRE)
+/*
+ * The ColdFire runs the delay loop at significantly different speeds
+ * depending upon long word alignment or not. We'll pad it to
+ * long word alignment which is the faster version.
+ * The 0x4a8e is of course a 'tstl %fp' instruction. This is better
+ * than using a NOP (0x4e71) instruction because it executes in one
+ * cycle not three and doesn't allow for an arbitrary delay waiting
+ * for bus cycles to finish. Also fp/a6 isn't likely to cause a
+ * stall waiting for the register to become valid if such is added
+ * to the coldfire at some stage.
+ */
+#define DELAY_ALIGN ".balignw 4, 0x4a8e\n\t"
+#else
+/*
+ * No instruction alignment required for other m68k types.
+ */
+#define DELAY_ALIGN
+#endif
+
+static inline void __delay(unsigned long loops)
+{
+ __asm__ __volatile__ (
+ DELAY_ALIGN
+ "1: subql #1,%0\n\t"
+ "jcc 1b"
+ : "=d" (loops)
+ : "0" (loops));
+}
+
+extern void __bad_udelay(void);
+
+
+#ifdef CONFIG_CPU_HAS_NO_MULDIV64
+/*
+ * The simpler m68k and ColdFire processors do not have a 32*32->64
+ * multiply instruction. So we need to handle them a little differently.
+ * We use a bit of shifting and a single 32*32->32 multiply to get close.
+ * This is a macro so that the const version can factor out the first
+ * multiply and shift.
+ */
+#define HZSCALE (268435456 / (1000000 / HZ))
+
+#define __const_udelay(u) \
+ __delay(((((u) * HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6)
+
+#else
+
+static inline void __xdelay(unsigned long xloops)
+{
+ unsigned long tmp;
+
+ __asm__ ("mulul %2,%0:%1"
+ : "=d" (xloops), "=d" (tmp)
+ : "d" (xloops), "1" (loops_per_jiffy));
+ __delay(xloops * HZ);
+}
+
+/*
+ * The definition of __const_udelay is specifically made a macro so that
+ * the const factor (4295 = 2**32 / 1000000) can be optimized out when
+ * the delay is a const.
+ */
+#define __const_udelay(n) (__xdelay((n) * 4295))
+
+#endif
+
+static inline void __udelay(unsigned long usecs)
+{
+ __const_udelay(usecs);
+}
+
+/*
+ * Use only for very small delays ( < 1 msec). Should probably use a
+ * lookup table, really, as the multiplications take much too long with
+ * short delays. This is a "reasonable" implementation, though (and the
+ * first constant multiplications gets optimized away if the delay is
+ * a constant)
+ */
+#define udelay(n) (__builtin_constant_p(n) ? \
+ ((n) > 20000 ? __bad_udelay() : __const_udelay(n)) : __udelay(n))
+
+/*
+ * nanosecond delay:
+ *
+ * ((((HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6) is the number of loops
+ * per microsecond
+ *
+ * 1000 / ((((HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6) is the number of
+ * nanoseconds per loop
+ *
+ * So n / ( 1000 / ((((HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6) ) would
+ * be the number of loops for n nanoseconds
+ */
+
+/*
+ * The simpler m68k and ColdFire processors do not have a 32*32->64
+ * multiply instruction. So we need to handle them a little differently.
+ * We use a bit of shifting and a single 32*32->32 multiply to get close.
+ * This is a macro so that the const version can factor out the first
+ * multiply and shift.
+ */
+#define HZSCALE (268435456 / (1000000 / HZ))
+
+#define ndelay(n) __delay(DIV_ROUND_UP((n) * ((((HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6), 1000));
+
+#endif /* defined(_M68K_DELAY_H) */