1 /****************************************************************************** 2 * platform-pci-unplug.c 3 * 4 * Xen platform PCI device driver 5 * Copyright (c) 2010, Citrix 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms and conditions of the GNU General Public License, 9 * version 2, as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 * more details. 15 * 16 * You should have received a copy of the GNU General Public License along with 17 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple 18 * Place - Suite 330, Boston, MA 02111-1307 USA. 19 * 20 */ 21 22 #include <linux/init.h> 23 #include <linux/io.h> 24 #include <linux/module.h> 25 26 #include <xen/platform_pci.h> 27 #include "xen-ops.h" 28 29 #define XEN_PLATFORM_ERR_MAGIC -1 30 #define XEN_PLATFORM_ERR_PROTOCOL -2 31 #define XEN_PLATFORM_ERR_BLACKLIST -3 32 33 /* store the value of xen_emul_unplug after the unplug is done */ 34 int xen_platform_pci_unplug; 35 EXPORT_SYMBOL_GPL(xen_platform_pci_unplug); 36 #ifdef CONFIG_XEN_PVHVM 37 static int xen_emul_unplug; 38 39 static int check_platform_magic(void) 40 { 41 short magic; 42 char protocol; 43 44 magic = inw(XEN_IOPORT_MAGIC); 45 if (magic != XEN_IOPORT_MAGIC_VAL) { 46 printk(KERN_ERR "Xen Platform PCI: unrecognised magic value\n"); 47 return XEN_PLATFORM_ERR_MAGIC; 48 } 49 50 protocol = inb(XEN_IOPORT_PROTOVER); 51 52 printk(KERN_DEBUG "Xen Platform PCI: I/O protocol version %d\n", 53 protocol); 54 55 switch (protocol) { 56 case 1: 57 outw(XEN_IOPORT_LINUX_PRODNUM, XEN_IOPORT_PRODNUM); 58 outl(XEN_IOPORT_LINUX_DRVVER, XEN_IOPORT_DRVVER); 59 if (inw(XEN_IOPORT_MAGIC) != XEN_IOPORT_MAGIC_VAL) { 60 printk(KERN_ERR "Xen Platform: blacklisted by host\n"); 61 return XEN_PLATFORM_ERR_BLACKLIST; 62 } 63 break; 64 default: 65 printk(KERN_WARNING "Xen Platform PCI: unknown I/O protocol version"); 66 return XEN_PLATFORM_ERR_PROTOCOL; 67 } 68 69 return 0; 70 } 71 72 void xen_unplug_emulated_devices(void) 73 { 74 int r; 75 76 /* user explicitly requested no unplug */ 77 if (xen_emul_unplug & XEN_UNPLUG_NEVER) 78 return; 79 /* check the version of the xen platform PCI device */ 80 r = check_platform_magic(); 81 /* If the version matches enable the Xen platform PCI driver. 82 * Also enable the Xen platform PCI driver if the host does 83 * not support the unplug protocol (XEN_PLATFORM_ERR_MAGIC) 84 * but the user told us that unplugging is unnecessary. */ 85 if (r && !(r == XEN_PLATFORM_ERR_MAGIC && 86 (xen_emul_unplug & XEN_UNPLUG_UNNECESSARY))) 87 return; 88 /* Set the default value of xen_emul_unplug depending on whether or 89 * not the Xen PV frontends and the Xen platform PCI driver have 90 * been compiled for this kernel (modules or built-in are both OK). */ 91 if (!xen_emul_unplug) { 92 if (xen_must_unplug_nics()) { 93 printk(KERN_INFO "Netfront and the Xen platform PCI driver have " 94 "been compiled for this kernel: unplug emulated NICs.\n"); 95 xen_emul_unplug |= XEN_UNPLUG_ALL_NICS; 96 } 97 if (xen_must_unplug_disks()) { 98 printk(KERN_INFO "Blkfront and the Xen platform PCI driver have " 99 "been compiled for this kernel: unplug emulated disks.\n" 100 "You might have to change the root device\n" 101 "from /dev/hd[a-d] to /dev/xvd[a-d]\n" 102 "in your root= kernel command line option\n"); 103 xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS; 104 } 105 } 106 /* Now unplug the emulated devices */ 107 if (!(xen_emul_unplug & XEN_UNPLUG_UNNECESSARY)) 108 outw(xen_emul_unplug, XEN_IOPORT_UNPLUG); 109 xen_platform_pci_unplug = xen_emul_unplug; 110 } 111 112 static int __init parse_xen_emul_unplug(char *arg) 113 { 114 char *p, *q; 115 int l; 116 117 for (p = arg; p; p = q) { 118 q = strchr(p, ','); 119 if (q) { 120 l = q - p; 121 q++; 122 } else { 123 l = strlen(p); 124 } 125 if (!strncmp(p, "all", l)) 126 xen_emul_unplug |= XEN_UNPLUG_ALL; 127 else if (!strncmp(p, "ide-disks", l)) 128 xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS; 129 else if (!strncmp(p, "aux-ide-disks", l)) 130 xen_emul_unplug |= XEN_UNPLUG_AUX_IDE_DISKS; 131 else if (!strncmp(p, "nics", l)) 132 xen_emul_unplug |= XEN_UNPLUG_ALL_NICS; 133 else if (!strncmp(p, "unnecessary", l)) 134 xen_emul_unplug |= XEN_UNPLUG_UNNECESSARY; 135 else if (!strncmp(p, "never", l)) 136 xen_emul_unplug |= XEN_UNPLUG_NEVER; 137 else 138 printk(KERN_WARNING "unrecognised option '%s' " 139 "in parameter 'xen_emul_unplug'\n", p); 140 } 141 return 0; 142 } 143 early_param("xen_emul_unplug", parse_xen_emul_unplug); 144 #endif 145