diff options
author | Olof Johansson <olof@lixom.net> | 2013-11-15 15:17:59 -0800 |
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committer | Olof Johansson <olof@lixom.net> | 2013-11-15 15:17:59 -0800 |
commit | 6886059f2ef5d62c73e87a905e84fa4f87d56074 (patch) | |
tree | dfe6e1611d7c50057df52db7b55eafbfb8e33a93 /include/asm-generic/preempt.h | |
parent | ca439c9b983ffa14e9eae6030e3ee80ad039388f (diff) | |
parent | 26273e02a0cf18eb72416559310d3294390a9024 (diff) |
Merge tag 'omap-for-v3.13/fixes-for-merge-window-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes
Few clock fixes, a runtime PM fix, and pinctrl-single fix along
with few other fixes that popped up during the merge window.
* tag 'omap-for-v3.13/fixes-for-merge-window-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
ARM: OMAP2+: Fix build for dra7xx without omap4 and 5
ARM: OMAP2+: omap_device: maintain sane runtime pm status around suspend/resume
doc: devicetree: Add bindings documentation for omap-des driver
ARM: dts: doc: Document missing compatible property for omap-sham driver
ARM: OMAP3: Beagle: fix return value check in beagle_opp_init()
ARM: OMAP: devicetree: fix SPI node compatible property syntax items
pinctrl: single: call pcs_soc->rearm() whenever IRQ mask is changed
ARM: OMAP2+: smsc911x: fix return value check in gpmc_smsc911x_init()
+ sync with newer trunk
Diffstat (limited to 'include/asm-generic/preempt.h')
-rw-r--r-- | include/asm-generic/preempt.h | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h new file mode 100644 index 00000000000..ddf2b420ac8 --- /dev/null +++ b/include/asm-generic/preempt.h @@ -0,0 +1,105 @@ +#ifndef __ASM_PREEMPT_H +#define __ASM_PREEMPT_H + +#include <linux/thread_info.h> + +/* + * We mask the PREEMPT_NEED_RESCHED bit so as not to confuse all current users + * that think a non-zero value indicates we cannot preempt. + */ +static __always_inline int preempt_count(void) +{ + return current_thread_info()->preempt_count & ~PREEMPT_NEED_RESCHED; +} + +static __always_inline int *preempt_count_ptr(void) +{ + return ¤t_thread_info()->preempt_count; +} + +/* + * We now loose PREEMPT_NEED_RESCHED and cause an extra reschedule; however the + * alternative is loosing a reschedule. Better schedule too often -- also this + * should be a very rare operation. + */ +static __always_inline void preempt_count_set(int pc) +{ + *preempt_count_ptr() = pc; +} + +/* + * must be macros to avoid header recursion hell + */ +#define task_preempt_count(p) \ + (task_thread_info(p)->preempt_count & ~PREEMPT_NEED_RESCHED) + +#define init_task_preempt_count(p) do { \ + task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \ +} while (0) + +#define init_idle_preempt_count(p, cpu) do { \ + task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \ +} while (0) + +/* + * We fold the NEED_RESCHED bit into the preempt count such that + * preempt_enable() can decrement and test for needing to reschedule with a + * single instruction. + * + * We invert the actual bit, so that when the decrement hits 0 we know we both + * need to resched (the bit is cleared) and can resched (no preempt count). + */ + +static __always_inline void set_preempt_need_resched(void) +{ + *preempt_count_ptr() &= ~PREEMPT_NEED_RESCHED; +} + +static __always_inline void clear_preempt_need_resched(void) +{ + *preempt_count_ptr() |= PREEMPT_NEED_RESCHED; +} + +static __always_inline bool test_preempt_need_resched(void) +{ + return !(*preempt_count_ptr() & PREEMPT_NEED_RESCHED); +} + +/* + * The various preempt_count add/sub methods + */ + +static __always_inline void __preempt_count_add(int val) +{ + *preempt_count_ptr() += val; +} + +static __always_inline void __preempt_count_sub(int val) +{ + *preempt_count_ptr() -= val; +} + +static __always_inline bool __preempt_count_dec_and_test(void) +{ + return !--*preempt_count_ptr(); +} + +/* + * Returns true when we need to resched and can (barring IRQ state). + */ +static __always_inline bool should_resched(void) +{ + return unlikely(!*preempt_count_ptr()); +} + +#ifdef CONFIG_PREEMPT +extern asmlinkage void preempt_schedule(void); +#define __preempt_schedule() preempt_schedule() + +#ifdef CONFIG_CONTEXT_TRACKING +extern asmlinkage void preempt_schedule_context(void); +#define __preempt_schedule_context() preempt_schedule_context() +#endif +#endif /* CONFIG_PREEMPT */ + +#endif /* __ASM_PREEMPT_H */ |