Commit 9059d8fa authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar
Browse files

irq: add irq_desc_without_new 



add an irq_desc accessor that will not allocate any sparse entry
but returns failure if there's no entry present.

Signed-off-by: default avatarYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 7f95ec9e

include/linux/irq.h

+13 −0
Original line number Diff line number Diff line
@@ -191,10 +191,23 @@ struct irq_desc { 
} ____cacheline_internodealigned_in_smp;



extern struct irq_desc *irq_to_desc(unsigned int irq);

extern struct irq_desc *__irq_to_desc(unsigned int irq);



#ifndef CONFIG_HAVE_SPARSE_IRQ



#ifndef CONFIG_HAVE_DYN_ARRAY

/* could be removed if we get rid of all irq_desc reference */

extern struct irq_desc irq_desc[NR_IRQS];

#else

extern struct irq_desc *irq_desc;

#endif



#else



extern struct irq_desc *sparse_irqs;



#endif



#define kstat_irqs_this_cpu(DESC) \

	((DESC)->kstat_irqs[smp_processor_id()])

kernel/irq/handle.c

+24 −4
Original line number Diff line number Diff line
@@ -112,7 +112,6 @@ static void init_kstat_irqs(struct irq_desc *desc, int nr_desc, int nr) 
	}

}





static void __init init_work(void *data)

{

	struct dyn_array *da = data;
@@ -149,9 +148,27 @@ static int __init parse_nr_irq_desc(char *arg) 


early_param("nr_irq_desc", parse_nr_irq_desc);



static struct irq_desc *sparse_irqs;

struct irq_desc *sparse_irqs;

DEFINE_DYN_ARRAY(sparse_irqs, sizeof(struct irq_desc), nr_irq_desc, PAGE_SIZE, init_work);



struct irq_desc *__irq_to_desc(unsigned int irq)

{

	struct irq_desc *desc;



	BUG_ON(irq == -1U);



	desc = &sparse_irqs[0];

	while (desc) {

		if (desc->irq == irq)

			return desc;



		if (desc->irq == -1U)

			return NULL;



		desc = desc->next;

	}

	return NULL;

}

struct irq_desc *irq_to_desc(unsigned int irq)

{

	struct irq_desc *desc, *desc_pri;
@@ -208,8 +225,7 @@ struct irq_desc *irq_to_desc(unsigned int irq) 
	return desc;

}

#else



static struct irq_desc *irq_desc;

struct irq_desc *irq_desc;

DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work);



#endif
@@ -239,6 +255,10 @@ struct irq_desc *irq_to_desc(unsigned int irq) 


	return NULL;

}

struct irq_desc *__irq_to_desc(unsigned int irq)

{

	return irq_to_desc(irq);

}

#endif



/*