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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/s390/lib/delay.c | |
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/s390/lib/delay.c')
-rw-r--r-- | kernel/arch/s390/lib/delay.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/kernel/arch/s390/lib/delay.c b/kernel/arch/s390/lib/delay.c new file mode 100644 index 000000000..16dc42d83 --- /dev/null +++ b/kernel/arch/s390/lib/delay.c @@ -0,0 +1,129 @@ +/* + * Precise Delay Loops for S390 + * + * Copyright IBM Corp. 1999, 2008 + * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>, + * Heiko Carstens <heiko.carstens@de.ibm.com>, + */ + +#include <linux/sched.h> +#include <linux/delay.h> +#include <linux/timex.h> +#include <linux/module.h> +#include <linux/irqflags.h> +#include <linux/interrupt.h> +#include <asm/vtimer.h> +#include <asm/div64.h> + +void __delay(unsigned long loops) +{ + /* + * To end the bloody studid and useless discussion about the + * BogoMips number I took the liberty to define the __delay + * function in a way that that resulting BogoMips number will + * yield the megahertz number of the cpu. The important function + * is udelay and that is done using the tod clock. -- martin. + */ + asm volatile("0: brct %0,0b" : : "d" ((loops/2) + 1)); +} + +static void __udelay_disabled(unsigned long long usecs) +{ + unsigned long cr0, cr6, new; + u64 clock_saved, end; + + end = get_tod_clock() + (usecs << 12); + clock_saved = local_tick_disable(); + __ctl_store(cr0, 0, 0); + __ctl_store(cr6, 6, 6); + new = (cr0 & 0xffff00e0) | 0x00000800; + __ctl_load(new , 0, 0); + new = 0; + __ctl_load(new, 6, 6); + lockdep_off(); + do { + set_clock_comparator(end); + enabled_wait(); + } while (get_tod_clock_fast() < end); + lockdep_on(); + __ctl_load(cr0, 0, 0); + __ctl_load(cr6, 6, 6); + local_tick_enable(clock_saved); +} + +static void __udelay_enabled(unsigned long long usecs) +{ + u64 clock_saved, end; + + end = get_tod_clock_fast() + (usecs << 12); + do { + clock_saved = 0; + if (end < S390_lowcore.clock_comparator) { + clock_saved = local_tick_disable(); + set_clock_comparator(end); + } + enabled_wait(); + if (clock_saved) + local_tick_enable(clock_saved); + } while (get_tod_clock_fast() < end); +} + +/* + * Waits for 'usecs' microseconds using the TOD clock comparator. + */ +void __udelay(unsigned long long usecs) +{ + unsigned long flags; + + preempt_disable(); + local_irq_save(flags); + if (in_irq()) { + __udelay_disabled(usecs); + goto out; + } + if (in_softirq()) { + if (raw_irqs_disabled_flags(flags)) + __udelay_disabled(usecs); + else + __udelay_enabled(usecs); + goto out; + } + if (raw_irqs_disabled_flags(flags)) { + local_bh_disable(); + __udelay_disabled(usecs); + _local_bh_enable(); + goto out; + } + __udelay_enabled(usecs); +out: + local_irq_restore(flags); + preempt_enable(); +} +EXPORT_SYMBOL(__udelay); + +/* + * Simple udelay variant. To be used on startup and reboot + * when the interrupt handler isn't working. + */ +void udelay_simple(unsigned long long usecs) +{ + u64 end; + + end = get_tod_clock_fast() + (usecs << 12); + while (get_tod_clock_fast() < end) + cpu_relax(); +} + +void __ndelay(unsigned long long nsecs) +{ + u64 end; + + nsecs <<= 9; + do_div(nsecs, 125); + end = get_tod_clock_fast() + nsecs; + if (nsecs & ~0xfffUL) + __udelay(nsecs >> 12); + while (get_tod_clock_fast() < end) + barrier(); +} +EXPORT_SYMBOL(__ndelay); |