diff options
author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2013-12-09 09:17:02 +0100 |
---|---|---|
committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2013-12-09 09:19:14 +0100 |
commit | f7698ba75fa283435f5077b9dfb4319d28b9de9a (patch) | |
tree | 4bc16a615a35baaf2b482de81cd256a69067ff72 /arch/parisc/lib/delay.c | |
parent | 798183c54799fbe1e5a5bfabb3a8c0505ffd2149 (diff) | |
parent | 374b105797c3d4f29c685f3be535c35f5689b30e (diff) |
Merge tag 'v3.13-rc3' into drm-intel-next-queued
Linux 3.13-rc3
I need a backmerge for two reasons:
- For merging the ppgtt patches from Ben I need to pull in the bdw
support.
- We now have duplicated calls to intel_uncore_forcewake_reset in the
setup code to due 2 different patches merged into -next and 3.13.
The conflict is silen so I need the merge to be able to apply
Deepak's fixup patch.
Conflicts:
drivers/gpu/drm/i915/intel_display.c
Trivial conflict, it doesn't even show up in the merge diff.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'arch/parisc/lib/delay.c')
-rw-r--r-- | arch/parisc/lib/delay.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/arch/parisc/lib/delay.c b/arch/parisc/lib/delay.c new file mode 100644 index 00000000000..ec9255f27a8 --- /dev/null +++ b/arch/parisc/lib/delay.c @@ -0,0 +1,73 @@ +/* + * Precise Delay Loops for parisc + * + * based on code by: + * Copyright (C) 1993 Linus Torvalds + * Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz> + * Copyright (C) 2008 Jiri Hladky <hladky _dot_ jiri _at_ gmail _dot_ com> + * + * parisc implementation: + * Copyright (C) 2013 Helge Deller <deller@gmx.de> + */ + + +#include <linux/module.h> +#include <linux/preempt.h> +#include <linux/init.h> + +#include <asm/processor.h> +#include <asm/delay.h> + +#include <asm/special_insns.h> /* for mfctl() */ +#include <asm/processor.h> /* for boot_cpu_data */ + +/* CR16 based delay: */ +static void __cr16_delay(unsigned long __loops) +{ + /* + * Note: Due to unsigned math, cr16 rollovers shouldn't be + * a problem here. However, on 32 bit, we need to make sure + * we don't pass in too big a value. The current default + * value of MAX_UDELAY_MS should help prevent this. + */ + u32 bclock, now, loops = __loops; + int cpu; + + preempt_disable(); + cpu = smp_processor_id(); + bclock = mfctl(16); + for (;;) { + now = mfctl(16); + if ((now - bclock) >= loops) + break; + + /* Allow RT tasks to run */ + preempt_enable(); + asm volatile(" nop\n"); + barrier(); + preempt_disable(); + + /* + * It is possible that we moved to another CPU, and + * since CR16's are per-cpu we need to calculate + * that. The delay must guarantee that we wait "at + * least" the amount of time. Being moved to another + * CPU could make the wait longer but we just need to + * make sure we waited long enough. Rebalance the + * counter for this CPU. + */ + if (unlikely(cpu != smp_processor_id())) { + loops -= (now - bclock); + cpu = smp_processor_id(); + bclock = mfctl(16); + } + } + preempt_enable(); +} + + +void __udelay(unsigned long usecs) +{ + __cr16_delay(usecs * ((unsigned long)boot_cpu_data.cpu_hz / 1000000UL)); +} +EXPORT_SYMBOL(__udelay); |