powerpc: iSeries has only 256 IRQs (7d01c880) · Commits · 戴 / test

arch/powerpc/kernel/irq.c

+22 −14

Original line number	Diff line number	Diff line
		@@ -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);

arch/powerpc/platforms/iseries/setup.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -54,6 +54,7 @@
		#include <asm/iseries/hv_lp_event.h>
		#include <asm/iseries/lpar_map.h>
		#include <asm/udbg.h>
		#include <asm/irq.h>

		#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;
		}

include/asm-powerpc/irq.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -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.
		*/

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