1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2014 Hudson River Trading LLC
5 * Written by: John H. Baldwin <jhb@FreeBSD.org>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD$");
32
33#include <sys/types.h>
34#include <stdio.h>
35
36#include <machine/vmm.h>
37#include <vmmapi.h>
38
39#include "ioapic.h"
40#include "pci_emul.h"
41#include "pci_lpc.h"
42
43/*
44 * Assign PCI INTx interrupts to I/O APIC pins in a round-robin
45 * fashion.  Note that we have no idea what the HPET is using, but the
46 * HPET is also programmable whereas this is intended for hardwired
47 * PCI interrupts.
48 *
49 * This assumes a single I/O APIC where pins >= 16 are permitted for
50 * PCI devices.
51 */
52static int pci_pins;
53
54void
55ioapic_init(struct vmctx *ctx)
56{
57
58	if (vm_ioapic_pincount(ctx, &pci_pins) < 0) {
59		pci_pins = 0;
60		return;
61	}
62
63	/* Ignore the first 16 pins. */
64	if (pci_pins <= 16) {
65		pci_pins = 0;
66		return;
67	}
68	pci_pins -= 16;
69}
70
71int
72ioapic_pci_alloc_irq(struct pci_devinst *pi)
73{
74	static int last_pin;
75
76	if (pci_pins == 0)
77		return (-1);
78	if (lpc_bootrom()) {
79		/* For external bootrom use fixed mapping. */
80		return (16 + (4 + pi->pi_slot + pi->pi_lintr.pin) % 8);
81	}
82	return (16 + (last_pin++ % pci_pins));
83}
84