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: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Michael Ellerman 2009-10-13 19:45:03 +00:00 committed by Benjamin Herrenschmidt
parent 750ab11291
commit cd01570717
5 changed files with 49 additions and 13 deletions

View file

@ -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

View file

@ -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.

View file

@ -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++)
irq_to_desc(i)->status |= IRQ_NOREQUEST;
for (i = 0; i < NR_IRQS; i++) {
desc = irq_to_desc(i);
if (desc)
desc->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 */

View file

@ -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);

View file

@ -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