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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/powerpc/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/powerpc/include/asm/delay.h')
-rw-r--r-- | kernel/arch/powerpc/include/asm/delay.h | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/include/asm/delay.h b/kernel/arch/powerpc/include/asm/delay.h new file mode 100644 index 000000000..52e4d54da --- /dev/null +++ b/kernel/arch/powerpc/include/asm/delay.h @@ -0,0 +1,72 @@ +#ifndef _ASM_POWERPC_DELAY_H +#define _ASM_POWERPC_DELAY_H +#ifdef __KERNEL__ + +#include <asm/time.h> + +/* + * Copyright 1996, Paul Mackerras. + * Copyright (C) 2009 Freescale Semiconductor, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * PPC64 Support added by Dave Engebretsen, Todd Inglett, Mike Corrigan, + * Anton Blanchard. + */ + +extern void __delay(unsigned long loops); +extern void udelay(unsigned long usecs); + +/* + * On shared processor machines the generic implementation of mdelay can + * result in large errors. While each iteration of the loop inside mdelay + * is supposed to take 1ms, the hypervisor could sleep our partition for + * longer (eg 10ms). With the right timing these errors can add up. + * + * Since there is no 32bit overflow issue on 64bit kernels, just call + * udelay directly. + */ +#ifdef CONFIG_PPC64 +#define mdelay(n) udelay((n) * 1000) +#endif + +/** + * spin_event_timeout - spin until a condition gets true or a timeout elapses + * @condition: a C expression to evalate + * @timeout: timeout, in microseconds + * @delay: the number of microseconds to delay between each evaluation of + * @condition + * + * The process spins until the condition evaluates to true (non-zero) or the + * timeout elapses. The return value of this macro is the value of + * @condition when the loop terminates. This allows you to determine the cause + * of the loop terminates. If the return value is zero, then you know a + * timeout has occurred. + * + * This primary purpose of this macro is to poll on a hardware register + * until a status bit changes. The timeout ensures that the loop still + * terminates even if the bit never changes. The delay is for devices that + * need a delay in between successive reads. + * + * gcc will optimize out the if-statement if @delay is a constant. + */ +#define spin_event_timeout(condition, timeout, delay) \ +({ \ + typeof(condition) __ret; \ + unsigned long __loops = tb_ticks_per_usec * timeout; \ + unsigned long __start = get_tbl(); \ + while (!(__ret = (condition)) && (tb_ticks_since(__start) <= __loops)) \ + if (delay) \ + udelay(delay); \ + else \ + cpu_relax(); \ + if (!__ret) \ + __ret = (condition); \ + __ret; \ +}) + +#endif /* __KERNEL__ */ +#endif /* _ASM_POWERPC_DELAY_H */ |