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/*

 * We put the hardirq and softirq counter into the preemption

 * counter. The bitmask has the following meaning:

 *

 * - bits 0-7 are the preemption count (max preemption depth: 256)

 * - bits 8-15 are the softirq count (max # of softirqs: 256)

 *

 * interrupts in the system, but we run all interrupt handlers with

 * interrupts disabled, so we cannot have nesting interrupts. Though

 * there are a few palaeontologic drivers which reenable interrupts in

 * the handler, so we need more than one bit here.

 *

 *         PREEMPT_MASK:	0x000000ff

 *         SOFTIRQ_MASK:	0x0000ff00

 *         HARDIRQ_MASK:	0x000f0000

 * PREEMPT_NEED_RESCHED:	0x80000000

 */

#define PREEMPT_BITS	8

#define SOFTIRQ_BITS	8

#define HARDIRQ_BITS	4

#define NMI_BITS	1

#define PREEMPT_SHIFT	0

#define SOFTIRQ_SHIFT	(PREEMPT_SHIFT + PREEMPT_BITS)

#define HARDIRQ_SHIFT	(SOFTIRQ_SHIFT + SOFTIRQ_BITS)

#define NMI_SHIFT	(HARDIRQ_SHIFT + HARDIRQ_BITS)

#define __IRQ_MASK(x)	((1UL << (x))-1)

#define PREEMPT_MASK	(__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)

#define SOFTIRQ_MASK	(__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)

#define HARDIRQ_MASK	(__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)

#define NMI_MASK	(__IRQ_MASK(NMI_BITS)     << NMI_SHIFT)

#define PREEMPT_OFFSET	(1UL << PREEMPT_SHIFT)

#define SOFTIRQ_OFFSET	(1UL << SOFTIRQ_SHIFT)

#define HARDIRQ_OFFSET	(1UL << HARDIRQ_SHIFT)

#define NMI_OFFSET	(1UL << NMI_SHIFT)

#define SOFTIRQ_DISABLE_OFFSET	(2 * SOFTIRQ_OFFSET)

/* We use the MSB mostly because its available */

/* preempt_count() and related functions, depends on PREEMPT_NEED_RESCHED */

#include 

#define hardirq_count()	(preempt_count() & HARDIRQ_MASK)

#define softirq_count()	(preempt_count() & SOFTIRQ_MASK)

#define irq_count()	(preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \

				 | NMI_MASK))

/*

 * Are we doing bottom half or hardware interrupt processing?

 * Are we in a softirq context? Interrupt context?

 * in_softirq - Are we currently processing softirq or have bh disabled?

 * in_serving_softirq - Are we currently processing softirq?

 */

#define in_irq()		(hardirq_count())

#define in_softirq()		(softirq_count())

#define in_interrupt()		(irq_count())

#define in_serving_softirq()	(softirq_count() & SOFTIRQ_OFFSET)

/*

 * Are we in NMI context?

 */

#define in_nmi()	(preempt_count() & NMI_MASK)

/*

 * The preempt_count offset after preempt_disable();

 */

#if defined(CONFIG_PREEMPT_COUNT)

# define PREEMPT_DISABLE_OFFSET	PREEMPT_OFFSET

#else

# define PREEMPT_DISABLE_OFFSET	0

#endif

/*

 * The preempt_count offset after spin_lock()

 */

#define PREEMPT_LOCK_OFFSET	PREEMPT_DISABLE_OFFSET

/*

 * The preempt_count offset needed for things like:

 *

 *  spin_lock_bh()

 *

 * Which need to disable both preemption (CONFIG_PREEMPT_COUNT) and

 * softirqs, such that unlock sequences of:

 *

 *  spin_unlock();

 *  local_bh_enable();

 *

 * Work as expected.

 */

#define SOFTIRQ_LOCK_OFFSET (SOFTIRQ_DISABLE_OFFSET + PREEMPT_LOCK_OFFSET)

/*

 * Are we running in atomic context?  WARNING: this macro cannot

 * always detect atomic context; in particular, it cannot know about

 * held spinlocks in non-preemptible kernels.  Thus it should not be

 * used in the general case to determine whether sleeping is possible.

 * Do not use in_atomic() in driver code.

 */

#define in_atomic()	(preempt_count() != 0)

/*

 * Check whether we were atomic before we did preempt_disable():

#define preempt_enable_no_resched() sched_preempt_enable_no_resched()

		__preempt_schedule(); \

} while (0)

#define preempt_enable_notrace() \

do { \

	barrier(); \

	if (unlikely(__preempt_count_dec_and_test())) \

} while (0)

#define preempt_enable_notrace()		barrier()

void preempt_notifier_inc(void);