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 
29 #include <stdio.h>
30 #include "pci_core.h"
31 #include "acrn_common.h"
32 
33 /* 16 IRQs reserved for kdb/mouse, COM1/2, RTC... */
34 #define LEGACY_IRQ_NUM	16
35 
36 /*
37  * Assign PCI INTx interrupts to I/O APIC pins in a round-robin
38  * fashion.  Note that we have no idea what the HPET is using, but the
39  * HPET is also programmable whereas this is intended for hardwired
40  * PCI interrupts.
41  *
42  * This assumes a single I/O APIC where pins >= 16 are permitted for
43  * PCI devices.
44  */
45 static int pci_pins;
46 static int last_pin;
47 
48 void
ioapic_init(struct vmctx * ctx)49 ioapic_init(struct vmctx *ctx)
50 {
51 	last_pin = 0;
52 
53 	/* Ignore the first 16 pins for legacy IRQ. */
54 	pci_pins = VIOAPIC_RTE_NUM - LEGACY_IRQ_NUM;
55 }
56 
ioapic_deinit(void)57 void ioapic_deinit(void)
58 {
59 	last_pin = 0;
60 }
61 
62 int
ioapic_pci_alloc_irq(struct pci_vdev * dev)63 ioapic_pci_alloc_irq(struct pci_vdev *dev)
64 {
65 	/* No support of vGSI sharing */
66 	assert(last_pin < pci_pins);
67 
68 	return (LEGACY_IRQ_NUM + (last_pin++ % pci_pins));
69 }
70