From: Stephen Rothwell Date: Tue, 4 Apr 2006 04:49:48 +0000 (+1000) Subject: powerpc: iSeries has only 256 IRQs X-Git-Tag: v2.6.17-rc2~16^2~9 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7d01c880856bae31502095bc68784c1518a680cb;p=linux-2.6 powerpc: iSeries has only 256 IRQs The iSeries Hypervisor only allows us to specify IRQ numbers up to 255 (it has a u8 field to pass it in). This patch allows platforms to specify a maximum to the virtual IRQ numbers we will use and has iSeries set that to 255. If not set, the maximum is NR_IRQS - 1 (as before). Signed-off-by: Stephen Rothwell --- diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index bb5c950123..57d560c688 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -272,18 +272,26 @@ unsigned int virt_irq_to_real_map[NR_IRQS]; * Don't use virtual irqs 0, 1, 2 for devices. * The pcnet32 driver considers interrupt numbers < 2 to be invalid, * and 2 is the XICS IPI interrupt. - * We limit virtual irqs to 17 less than NR_IRQS so that when we - * offset them by 16 (to reserve the first 16 for ISA interrupts) - * we don't end up with an interrupt number >= NR_IRQS. + * We limit virtual irqs to __irq_offet_value less than virt_irq_max so + * that when we offset them we don't end up with an interrupt + * number >= virt_irq_max. */ #define MIN_VIRT_IRQ 3 -#define MAX_VIRT_IRQ (NR_IRQS - NUM_ISA_INTERRUPTS - 1) -#define NR_VIRT_IRQS (MAX_VIRT_IRQ - MIN_VIRT_IRQ + 1) + +unsigned int virt_irq_max; +static unsigned int max_virt_irq; +static unsigned int nr_virt_irqs; void virt_irq_init(void) { int i; + + if ((virt_irq_max == 0) || (virt_irq_max > (NR_IRQS - 1))) + virt_irq_max = NR_IRQS - 1; + max_virt_irq = virt_irq_max - __irq_offset_value; + nr_virt_irqs = max_virt_irq - MIN_VIRT_IRQ + 1; + for (i = 0; i < NR_IRQS; i++) virt_irq_to_real_map[i] = UNDEFINED_IRQ; } @@ -308,17 +316,17 @@ int virt_irq_create_mapping(unsigned int real_irq) return real_irq; } - /* map to a number between MIN_VIRT_IRQ and MAX_VIRT_IRQ */ + /* map to a number between MIN_VIRT_IRQ and max_virt_irq */ virq = real_irq; - if (virq > MAX_VIRT_IRQ) - virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ; + if (virq > max_virt_irq) + virq = (virq % nr_virt_irqs) + MIN_VIRT_IRQ; /* search for this number or a free slot */ first_virq = virq; while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) { if (virt_irq_to_real_map[virq] == real_irq) return virq; - if (++virq > MAX_VIRT_IRQ) + if (++virq > max_virt_irq) virq = MIN_VIRT_IRQ; if (virq == first_virq) goto nospace; /* oops, no free slots */ @@ -330,8 +338,8 @@ int virt_irq_create_mapping(unsigned int real_irq) nospace: if (!warned) { printk(KERN_CRIT "Interrupt table is full\n"); - printk(KERN_CRIT "Increase NR_IRQS (currently %d) " - "in your kernel sources and rebuild.\n", NR_IRQS); + printk(KERN_CRIT "Increase virt_irq_max (currently %d) " + "in your kernel sources and rebuild.\n", virt_irq_max); warned = 1; } return NO_IRQ; @@ -349,8 +357,8 @@ unsigned int real_irq_to_virt_slowpath(unsigned int real_irq) virq = real_irq; - if (virq > MAX_VIRT_IRQ) - virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ; + if (virq > max_virt_irq) + virq = (virq % nr_virt_irqs) + MIN_VIRT_IRQ; first_virq = virq; @@ -360,7 +368,7 @@ unsigned int real_irq_to_virt_slowpath(unsigned int real_irq) virq++; - if (virq >= MAX_VIRT_IRQ) + if (virq >= max_virt_irq) virq = 0; } while (first_virq != virq); diff --git a/arch/powerpc/platforms/iseries/setup.c b/arch/powerpc/platforms/iseries/setup.c index 6ce8a404ba..a6fd9bedb0 100644 --- a/arch/powerpc/platforms/iseries/setup.c +++ b/arch/powerpc/platforms/iseries/setup.c @@ -54,6 +54,7 @@ #include #include #include +#include #include "naca.h" #include "setup.h" @@ -684,6 +685,12 @@ static int __init iseries_probe(void) powerpc_firmware_features |= FW_FEATURE_ISERIES; powerpc_firmware_features |= FW_FEATURE_LPAR; + /* + * The Hypervisor only allows us up to 256 interrupt + * sources (the irq number is passed in a u8). + */ + virt_irq_max = 255; + return 1; } diff --git a/include/asm-powerpc/irq.h b/include/asm-powerpc/irq.h index 51f87d9993..7bc6d73b28 100644 --- a/include/asm-powerpc/irq.h +++ b/include/asm-powerpc/irq.h @@ -54,6 +54,13 @@ */ extern unsigned int virt_irq_to_real_map[NR_IRQS]; +/* The maximum virtual IRQ number that we support. This + * can be set by the platform and will be reduced by the + * value of __irq_offset_value. It defaults to and is + * capped by (NR_IRQS - 1). + */ +extern unsigned int virt_irq_max; + /* Create a mapping for a real_irq if it doesn't already exist. * Return the virtual irq as a convenience. */