ioapic.c revision 321411 
1/*-
2 * Copyright (c) 2014 Hudson River Trading LLC
3 * Written by: John H. Baldwin <jhb@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: stable/11/usr.sbin/bhyve/ioapic.c 321411 2017-07-24 05:52:10Z mav $");
30
31#include <sys/types.h>
32#include <stdio.h>
33
34#include <machine/vmm.h>
35#include <vmmapi.h>
36
37#include "ioapic.h"
38#include "pci_emul.h"
39#include "pci_lpc.h"
40
41/*
42 * Assign PCI INTx interrupts to I/O APIC pins in a round-robin
43 * fashion.  Note that we have no idea what the HPET is using, but the
44 * HPET is also programmable whereas this is intended for hardwired
45 * PCI interrupts.
46 *
47 * This assumes a single I/O APIC where pins >= 16 are permitted for
48 * PCI devices.
49 */
50static int pci_pins;
51
52void
53ioapic_init(struct vmctx *ctx)
54{
55
56	if (vm_ioapic_pincount(ctx, &pci_pins) < 0) {
57		pci_pins = 0;
58		return;
59	}
60
61	/* Ignore the first 16 pins. */
62	if (pci_pins <= 16) {
63		pci_pins = 0;
64		return;
65	}
66	pci_pins -= 16;
67}
68
69int
70ioapic_pci_alloc_irq(struct pci_devinst *pi)
71{
72	static int last_pin;
73
74	if (pci_pins == 0)
75		return (-1);
76	if (lpc_bootrom()) {
77		/* For external bootrom use fixed mapping. */
78		return (16 + (4 + pi->pi_slot + pi->pi_lintr.pin) % 8);
79	}
80	return (16 + (last_pin++ % pci_pins));
81}
82