acrn-hypervisor/devicemodel/hw/platform/ioapic.c

70 lines
2.2 KiB
C

/*-
* Copyright (c) 2014 Hudson River Trading LLC
* Written by: John H. Baldwin <jhb@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <stdio.h>
#include "vmm.h"
#include "pci_core.h"
/* 16 IRQs reserved for kdb/mouse, COM1/2, RTC... */
#define LEGACY_IRQ_NUM 16
/*
* Assign PCI INTx interrupts to I/O APIC pins in a round-robin
* fashion. Note that we have no idea what the HPET is using, but the
* HPET is also programmable whereas this is intended for hardwired
* PCI interrupts.
*
* This assumes a single I/O APIC where pins >= 16 are permitted for
* PCI devices.
*/
static int pci_pins;
static int last_pin;
void
ioapic_init(struct vmctx *ctx)
{
last_pin = 0;
/* Ignore the first 16 pins for legacy IRQ. */
pci_pins = VIOAPIC_RTE_NUM - LEGACY_IRQ_NUM;
}
void ioapic_deinit(void)
{
last_pin = 0;
}
int
ioapic_pci_alloc_irq(struct pci_vdev *dev)
{
/* No support of vGSI sharing */
assert(last_pin < pci_pins);
return (LEGACY_IRQ_NUM + (last_pin++ % pci_pins));
}