1 /*- 2 * Copyright (c) 2014 Advanced Computing Technologies 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: head/usr.sbin/bhyve/ioapic.c 261268 2014-01-29 14:56:48Z jhb $"); 30 31 #include <sys/types.h> 32 33 #include <machine/vmm.h> 34 #include <vmmapi.h> 35 36 #include "ioapic.h" 37 38 /* 39 * Assign PCI INTx interrupts to I/O APIC pins in a round-robin 40 * fashion. Note that we have no idea what the HPET is using, but the 41 * HPET is also programmable whereas this is intended for hardwired 42 * PCI interrupts. 43 * 44 * This assumes a single I/O APIC where pins >= 16 are permitted for 45 * PCI devices. 46 */ 47 static int pci_pins; 48 49 void 50 ioapic_init(struct vmctx *ctx) 51 { 52 53 if (vm_ioapic_pincount(ctx, &pci_pins) < 0) { 54 pci_pins = 0; 55 return; 56 } 57 58 /* Ignore the first 16 pins. */ 59 if (pci_pins <= 16) { 60 pci_pins = 0; 61 return; 62 } 63 pci_pins -= 16; 64 } 65 66 int 67 ioapic_pci_alloc_irq(void) 68 { 69 static int last_pin; 70 71 if (pci_pins == 0) 72 return (-1); 73 return (16 + (last_pin++ % pci_pins)); 74 } 75