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 28 #define XEN_PLATFORM_ERR_MAGIC -1 29 #define XEN_PLATFORM_ERR_PROTOCOL -2 30 #define XEN_PLATFORM_ERR_BLACKLIST -3 31 32 /* store the value of xen_emul_unplug after the unplug is done */ 33 int xen_platform_pci_unplug; 34 EXPORT_SYMBOL_GPL(xen_platform_pci_unplug); 35 #ifdef CONFIG_XEN_PVHVM 36 static int xen_emul_unplug; 37 38 static int __init check_platform_magic(void) 39 { 40 short magic; 41 char protocol; 42 43 magic = inw(XEN_IOPORT_MAGIC); 44 if (magic != XEN_IOPORT_MAGIC_VAL) { 45 printk(KERN_ERR "Xen Platform PCI: unrecognised magic value\n"); 46 return XEN_PLATFORM_ERR_MAGIC; 47 } 48 49 protocol = inb(XEN_IOPORT_PROTOVER); 50 51 printk(KERN_DEBUG "Xen Platform PCI: I/O protocol version %d\n", 52 protocol); 53 54 switch (protocol) { 55 case 1: 56 outw(XEN_IOPORT_LINUX_PRODNUM, XEN_IOPORT_PRODNUM); 57 outl(XEN_IOPORT_LINUX_DRVVER, XEN_IOPORT_DRVVER); 58 if (inw(XEN_IOPORT_MAGIC) != XEN_IOPORT_MAGIC_VAL) { 59 printk(KERN_ERR "Xen Platform: blacklisted by host\n"); 60 return XEN_PLATFORM_ERR_BLACKLIST; 61 } 62 break; 63 default: 64 printk(KERN_WARNING "Xen Platform PCI: unknown I/O protocol version"); 65 return XEN_PLATFORM_ERR_PROTOCOL; 66 } 67 68 return 0; 69 } 70 71 void __init xen_unplug_emulated_devices(void) 72 { 73 int r; 74 75 /* user explicitly requested no unplug */ 76 if (xen_emul_unplug & XEN_UNPLUG_NEVER) 77 return; 78 /* check the version of the xen platform PCI device */ 79 r = check_platform_magic(); 80 /* If the version matches enable the Xen platform PCI driver. 81 * Also enable the Xen platform PCI driver if the host does 82 * not support the unplug protocol (XEN_PLATFORM_ERR_MAGIC) 83 * but the user told us that unplugging is unnecessary. */ 84 if (r && !(r == XEN_PLATFORM_ERR_MAGIC && 85 (xen_emul_unplug & XEN_UNPLUG_UNNECESSARY))) 86 return; 87 /* Set the default value of xen_emul_unplug depending on whether or 88 * not the Xen PV frontends and the Xen platform PCI driver have 89 * been compiled for this kernel (modules or built-in are both OK). */ 90 if (!xen_emul_unplug) { 91 if (xen_must_unplug_nics()) { 92 printk(KERN_INFO "Netfront and the Xen platform PCI driver have " 93 "been compiled for this kernel: unplug emulated NICs.\n"); 94 xen_emul_unplug |= XEN_UNPLUG_ALL_NICS; 95 } 96 if (xen_must_unplug_disks()) { 97 printk(KERN_INFO "Blkfront and the Xen platform PCI driver have " 98 "been compiled for this kernel: unplug emulated disks.\n" 99 "You might have to change the root device\n" 100 "from /dev/hd[a-d] to /dev/xvd[a-d]\n" 101 "in your root= kernel command line option\n"); 102 xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS; 103 } 104 } 105 /* Now unplug the emulated devices */ 106 if (!(xen_emul_unplug & XEN_UNPLUG_UNNECESSARY)) 107 outw(xen_emul_unplug, XEN_IOPORT_UNPLUG); 108 xen_platform_pci_unplug = xen_emul_unplug; 109 } 110 111 static int __init parse_xen_emul_unplug(char *arg) 112 { 113 char *p, *q; 114 int l; 115 116 for (p = arg; p; p = q) { 117 q = strchr(p, ','); 118 if (q) { 119 l = q - p; 120 q++; 121 } else { 122 l = strlen(p); 123 } 124 if (!strncmp(p, "all", l)) 125 xen_emul_unplug |= XEN_UNPLUG_ALL; 126 else if (!strncmp(p, "ide-disks", l)) 127 xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS; 128 else if (!strncmp(p, "aux-ide-disks", l)) 129 xen_emul_unplug |= XEN_UNPLUG_AUX_IDE_DISKS; 130 else if (!strncmp(p, "nics", l)) 131 xen_emul_unplug |= XEN_UNPLUG_ALL_NICS; 132 else if (!strncmp(p, "unnecessary", l)) 133 xen_emul_unplug |= XEN_UNPLUG_UNNECESSARY; 134 else if (!strncmp(p, "never", l)) 135 xen_emul_unplug |= XEN_UNPLUG_NEVER; 136 else 137 printk(KERN_WARNING "unrecognised option '%s' " 138 "in parameter 'xen_emul_unplug'\n", p); 139 } 140 return 0; 141 } 142 early_param("xen_emul_unplug", parse_xen_emul_unplug); 143 #endif 144