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Commit cd015707 authored by Michael Ellerman's avatar Michael Ellerman Committed by Benjamin Herrenschmidt
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powerpc: Enable sparse irq_descs on powerpc 



Defining CONFIG_SPARSE_IRQ enables generic code that gets rid of the
static irq_desc array, and replaces it with an array of pointers to
irq_descs.

It also allows node local allocation of irq_descs, however we
currently don't have the information available to do that, so we just
allocate them on all on node 0.

Signed-off-by: default avatarMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 750ab112

arch/powerpc/Kconfig

+13 −0
Original line number Diff line number Diff line
@@ -377,6 +377,19 @@ config IRQ_ALL_CPUS 
	  CPU.  Generally saying Y is safe, although some problems have been

	  reported with SMP Power Macintoshes with this option enabled.



config SPARSE_IRQ

	bool "Support sparse irq numbering"

	default y

	help

	  This enables support for sparse irqs. This is useful for distro

	  kernels that want to define a high CONFIG_NR_CPUS value but still

	  want to have low kernel memory footprint on smaller machines.



	  ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread

	    out the irq_desc[] array in a more NUMA-friendly way. )



	  If you don't know what to do here, say Y.



config NUMA

	bool "NUMA support"

	depends on PPC64

arch/powerpc/include/asm/irq.h

+3 −0
Original line number Diff line number Diff line
@@ -38,6 +38,9 @@ extern atomic_t ppc_n_lost_interrupts; 
/* Number of irqs reserved for the legacy controller */

#define NUM_ISA_INTERRUPTS	16



/* Same thing, used by the generic IRQ code */

#define NR_IRQS_LEGACY		NUM_ISA_INTERRUPTS



/* This type is the placeholder for a hardware interrupt number. It has to

 * be big enough to enclose whatever representation is used by a given

 * platform.

arch/powerpc/kernel/irq.c

+33 −7
Original line number Diff line number Diff line
@@ -85,7 +85,10 @@ extern int tau_interrupts(int); 
#endif /* CONFIG_PPC32 */



#ifdef CONFIG_PPC64



#ifndef CONFIG_SPARSE_IRQ

EXPORT_SYMBOL(irq_desc);

#endif



int distribute_irqs = 1;
@@ -613,8 +616,16 @@ void irq_set_virq_count(unsigned int count) 
static int irq_setup_virq(struct irq_host *host, unsigned int virq,

			    irq_hw_number_t hwirq)

{

	struct irq_desc *desc;



	desc = irq_to_desc_alloc_node(virq, 0);

	if (!desc) {

		pr_debug("irq: -> allocating desc failed\n");

		goto error;

	}



	/* Clear IRQ_NOREQUEST flag */

	irq_to_desc(virq)->status &= ~IRQ_NOREQUEST;

	desc->status &= ~IRQ_NOREQUEST;



	/* map it */

	smp_wmb();
@@ -623,11 +634,14 @@ static int irq_setup_virq(struct irq_host *host, unsigned int virq, 


	if (host->ops->map(host, virq, hwirq)) {

		pr_debug("irq: -> mapping failed, freeing\n");

		irq_free_virt(virq, 1);

		return -1;

		goto error;

	}



	return 0;



error:

	irq_free_virt(virq, 1);

	return -1;

}



unsigned int irq_create_direct_mapping(struct irq_host *host)
@@ -1008,12 +1022,24 @@ void irq_free_virt(unsigned int virq, unsigned int count) 
	spin_unlock_irqrestore(&irq_big_lock, flags);

}



void irq_early_init(void)

int arch_early_irq_init(void)

{

	unsigned int i;

	struct irq_desc *desc;

	int i;



	for (i = 0; i < NR_IRQS; i++) {

		desc = irq_to_desc(i);

		if (desc)

			desc->status |= IRQ_NOREQUEST;

	}



	for (i = 0; i < NR_IRQS; i++)

		irq_to_desc(i)->status |= IRQ_NOREQUEST;

	return 0;

}



int arch_init_chip_data(struct irq_desc *desc, int node)

{

	desc->status |= IRQ_NOREQUEST;

	return 0;

}



/* We need to create the radix trees late */

arch/powerpc/kernel/ppc_ksyms.c

+0 −1
Original line number Diff line number Diff line
@@ -162,7 +162,6 @@ EXPORT_SYMBOL(screen_info); 


#ifdef CONFIG_PPC32

EXPORT_SYMBOL(timer_interrupt);

EXPORT_SYMBOL(irq_desc);

EXPORT_SYMBOL(tb_ticks_per_jiffy);

EXPORT_SYMBOL(cacheable_memcpy);

EXPORT_SYMBOL(cacheable_memzero);

arch/powerpc/kernel/setup_64.c

+0 −5
Original line number Diff line number Diff line
@@ -356,11 +356,6 @@ void __init setup_system(void) 
	 */

	initialize_cache_info();



	/*

	 * Initialize irq remapping subsystem

	 */

	irq_early_init();



#ifdef CONFIG_PPC_RTAS

	/*

	 * Initialize RTAS if available