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lguest: Override pcibios_enable_irq/pcibios_disable_irq to our stupid PIC

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This lets us deliver interrupts for our emulated PCI devices using our
dumb PIC, and not emulate an 8259 and PCI irq mapping tables or whatever.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell 2015-02-11 15:15:10 +10:30
parent ee72576c14
commit e1b83e2788
1 changed files with 24 additions and 0 deletions
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24
arch/x86/lguest/boot.c
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@ -56,6 +56,7 @@
#include <linux/virtio_console.h>
#include <linux/pm.h>
#include <linux/export.h>
#include <linux/pci.h>
#include <asm/acpi.h>
#include <asm/apic.h>
#include <asm/lguest.h>
@ -72,6 +73,7 @@
#include <asm/stackprotector.h>
#include <asm/reboot.h> /* for struct machine_ops */
#include <asm/kvm_para.h>
#include <asm/pci_x86.h>
/*G:010
* Welcome to the Guest!
@ -832,6 +834,24 @@ static struct irq_chip lguest_irq_controller = {
.irq_unmask = enable_lguest_irq,
};
static int lguest_enable_irq(struct pci_dev *dev)
{
u8 line = 0;
/* We literally use the PCI interrupt line as the irq number. */
pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &line);
irq_set_chip_and_handler_name(line, &lguest_irq_controller,
handle_level_irq, "level");
dev->irq = line;
return 0;
}
/* We don't do hotplug PCI, so this shouldn't be called. */
static void lguest_disable_irq(struct pci_dev *dev)
{
WARN_ON(1);
}
/*
* This sets up the Interrupt Descriptor Table (IDT) entry for each hardware
* interrupt (except 128, which is used for system calls), and then tells the
@ -1432,6 +1452,10 @@ __init void lguest_init(void)
/* Don't let ACPI try to control our PCI interrupts. */
disable_acpi();
/* We control them ourselves, by overriding these two hooks. */
pcibios_enable_irq = lguest_enable_irq;
pcibios_disable_irq = lguest_disable_irq;
/*
* Last of all, we set the power management poweroff hook to point to
* the Guest routine to power off, and the reboot hook to our restart