diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
---|---|---|
committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/m68k/include/asm/delay.h | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (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.h | 119 |
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) */ |