From cd015707176820b86d07b5dffdecfefdd539a497 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 13 Oct 2009 19:45:03 +0000 Subject: [PATCH] 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 Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/Kconfig | 13 +++++++++++++ arch/powerpc/include/asm/irq.h | 3 +++ arch/powerpc/kernel/irq.c | 40 +++++++++++++++++++++++++++++++++------- arch/powerpc/kernel/ppc_ksyms.c | 1 - arch/powerpc/kernel/setup_64.c | 5 ----- 5 files changed, 49 insertions(+), 13 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 3aa79f8e39e..61abde11a45 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -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 diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h index 03dc28cdb4d..c85a32f1a17 100644 --- a/arch/powerpc/include/asm/irq.h +++ b/arch/powerpc/include/asm/irq.h @@ -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. diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 63e27d5c52d..eba53923630 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -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 */ diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c index c8b27bb4dbd..07115d6cd4b 100644 --- a/arch/powerpc/kernel/ppc_ksyms.c +++ b/arch/powerpc/kernel/ppc_ksyms.c @@ -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); diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 04f638d82fb..fd785f7a279 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -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 -- 2.11.4.GIT