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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 /arch/x86/include/asm/preempt.h | |
parent | ca439c9b983ffa14e9eae6030e3ee80ad039388f (diff) | |
parent | 26273e02a0cf18eb72416559310d3294390a9024 (diff) | |
download | op-kernel-dev-6886059f2ef5d62c73e87a905e84fa4f87d56074.zip op-kernel-dev-6886059f2ef5d62c73e87a905e84fa4f87d56074.tar.gz |
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 'arch/x86/include/asm/preempt.h')
-rw-r--r-- | arch/x86/include/asm/preempt.h | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h new file mode 100644 index 0000000..8729723 --- /dev/null +++ b/arch/x86/include/asm/preempt.h @@ -0,0 +1,100 @@ +#ifndef __ASM_PREEMPT_H +#define __ASM_PREEMPT_H + +#include <asm/rmwcc.h> +#include <asm/percpu.h> +#include <linux/thread_info.h> + +DECLARE_PER_CPU(int, __preempt_count); + +/* + * 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 __this_cpu_read_4(__preempt_count) & ~PREEMPT_NEED_RESCHED; +} + +static __always_inline void preempt_count_set(int pc) +{ + __this_cpu_write_4(__preempt_count, pc); +} + +/* + * must be macros to avoid header recursion hell + */ +#define task_preempt_count(p) \ + (task_thread_info(p)->saved_preempt_count & ~PREEMPT_NEED_RESCHED) + +#define init_task_preempt_count(p) do { \ + task_thread_info(p)->saved_preempt_count = PREEMPT_DISABLED; \ +} while (0) + +#define init_idle_preempt_count(p, cpu) do { \ + task_thread_info(p)->saved_preempt_count = PREEMPT_ENABLED; \ + per_cpu(__preempt_count, (cpu)) = 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) +{ + __this_cpu_and_4(__preempt_count, ~PREEMPT_NEED_RESCHED); +} + +static __always_inline void clear_preempt_need_resched(void) +{ + __this_cpu_or_4(__preempt_count, PREEMPT_NEED_RESCHED); +} + +static __always_inline bool test_preempt_need_resched(void) +{ + return !(__this_cpu_read_4(__preempt_count) & PREEMPT_NEED_RESCHED); +} + +/* + * The various preempt_count add/sub methods + */ + +static __always_inline void __preempt_count_add(int val) +{ + __this_cpu_add_4(__preempt_count, val); +} + +static __always_inline void __preempt_count_sub(int val) +{ + __this_cpu_add_4(__preempt_count, -val); +} + +static __always_inline bool __preempt_count_dec_and_test(void) +{ + GEN_UNARY_RMWcc("decl", __preempt_count, __percpu_arg(0), "e"); +} + +/* + * Returns true when we need to resched and can (barring IRQ state). + */ +static __always_inline bool should_resched(void) +{ + return unlikely(!__this_cpu_read_4(__preempt_count)); +} + +#ifdef CONFIG_PREEMPT + extern asmlinkage void ___preempt_schedule(void); +# define __preempt_schedule() asm ("call ___preempt_schedule") + extern asmlinkage void preempt_schedule(void); +# ifdef CONFIG_CONTEXT_TRACKING + extern asmlinkage void ___preempt_schedule_context(void); +# define __preempt_schedule_context() asm ("call ___preempt_schedule_context") +# endif +#endif + +#endif /* __ASM_PREEMPT_H */ |