1 /****************************************************************************** 2 * platform-pci.c 3 * 4 * Xen platform PCI device driver 5 * 6 * Authors: ssmith@xensource.com and stefano.stabellini@eu.citrix.com 7 * 8 * Copyright (c) 2005, Intel Corporation. 9 * Copyright (c) 2007, XenSource Inc. 10 * Copyright (c) 2010, Citrix 11 * 12 * This program is free software; you can redistribute it and/or modify it 13 * under the terms and conditions of the GNU General Public License, 14 * version 2, as published by the Free Software Foundation. 15 * 16 * This program is distributed in the hope it will be useful, but WITHOUT 17 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 18 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 19 * more details. 20 * 21 * You should have received a copy of the GNU General Public License along with 22 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple 23 * Place - Suite 330, Boston, MA 02111-1307 USA. 24 * 25 */ 26 27 28 #include <linux/interrupt.h> 29 #include <linux/io.h> 30 #include <linux/init.h> 31 #include <linux/pci.h> 32 33 #include <xen/platform_pci.h> 34 #include <xen/grant_table.h> 35 #include <xen/xenbus.h> 36 #include <xen/events.h> 37 #include <xen/hvm.h> 38 #include <xen/xen-ops.h> 39 40 #define DRV_NAME "xen-platform-pci" 41 42 static unsigned long platform_mmio; 43 static unsigned long platform_mmio_alloc; 44 static unsigned long platform_mmiolen; 45 static uint64_t callback_via; 46 47 static unsigned long alloc_xen_mmio(unsigned long len) 48 { 49 unsigned long addr; 50 51 addr = platform_mmio + platform_mmio_alloc; 52 platform_mmio_alloc += len; 53 BUG_ON(platform_mmio_alloc > platform_mmiolen); 54 55 return addr; 56 } 57 58 static uint64_t get_callback_via(struct pci_dev *pdev) 59 { 60 u8 pin; 61 int irq; 62 63 irq = pdev->irq; 64 if (irq < 16) 65 return irq; /* ISA IRQ */ 66 67 pin = pdev->pin; 68 69 /* We don't know the GSI. Specify the PCI INTx line instead. */ 70 return ((uint64_t)0x01 << HVM_CALLBACK_VIA_TYPE_SHIFT) | /* PCI INTx identifier */ 71 ((uint64_t)pci_domain_nr(pdev->bus) << 32) | 72 ((uint64_t)pdev->bus->number << 16) | 73 ((uint64_t)(pdev->devfn & 0xff) << 8) | 74 ((uint64_t)(pin - 1) & 3); 75 } 76 77 static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id) 78 { 79 xen_hvm_evtchn_do_upcall(); 80 return IRQ_HANDLED; 81 } 82 83 static int xen_allocate_irq(struct pci_dev *pdev) 84 { 85 return request_irq(pdev->irq, do_hvm_evtchn_intr, 86 IRQF_NOBALANCING | IRQF_TRIGGER_RISING, 87 "xen-platform-pci", pdev); 88 } 89 90 static int platform_pci_resume(struct pci_dev *pdev) 91 { 92 int err; 93 if (!xen_pv_domain()) 94 return 0; 95 err = xen_set_callback_via(callback_via); 96 if (err) { 97 dev_err(&pdev->dev, "platform_pci_resume failure!\n"); 98 return err; 99 } 100 return 0; 101 } 102 103 static int platform_pci_probe(struct pci_dev *pdev, 104 const struct pci_device_id *ent) 105 { 106 int i, ret; 107 long ioaddr; 108 long mmio_addr, mmio_len; 109 unsigned int max_nr_gframes; 110 unsigned long grant_frames; 111 112 if (!xen_domain()) 113 return -ENODEV; 114 115 i = pci_enable_device(pdev); 116 if (i) 117 return i; 118 119 ioaddr = pci_resource_start(pdev, 0); 120 121 mmio_addr = pci_resource_start(pdev, 1); 122 mmio_len = pci_resource_len(pdev, 1); 123 124 if (mmio_addr == 0 || ioaddr == 0) { 125 dev_err(&pdev->dev, "no resources found\n"); 126 ret = -ENOENT; 127 goto pci_out; 128 } 129 130 ret = pci_request_region(pdev, 1, DRV_NAME); 131 if (ret < 0) 132 goto pci_out; 133 134 ret = pci_request_region(pdev, 0, DRV_NAME); 135 if (ret < 0) 136 goto mem_out; 137 138 platform_mmio = mmio_addr; 139 platform_mmiolen = mmio_len; 140 141 /* 142 * Xen HVM guests always use the vector callback mechanism. 143 * L1 Dom0 in a nested Xen environment is a PV guest inside in an 144 * HVM environment. It needs the platform-pci driver to get 145 * notifications from L0 Xen, but it cannot use the vector callback 146 * as it is not exported by L1 Xen. 147 */ 148 if (xen_pv_domain()) { 149 ret = xen_allocate_irq(pdev); 150 if (ret) { 151 dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret); 152 goto out; 153 } 154 callback_via = get_callback_via(pdev); 155 ret = xen_set_callback_via(callback_via); 156 if (ret) { 157 dev_warn(&pdev->dev, "Unable to set the evtchn callback " 158 "err=%d\n", ret); 159 goto out; 160 } 161 } 162 163 max_nr_gframes = gnttab_max_grant_frames(); 164 grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes); 165 ret = gnttab_setup_auto_xlat_frames(grant_frames); 166 if (ret) 167 goto out; 168 ret = gnttab_init(); 169 if (ret) 170 goto grant_out; 171 xenbus_probe(NULL); 172 return 0; 173 grant_out: 174 gnttab_free_auto_xlat_frames(); 175 out: 176 pci_release_region(pdev, 0); 177 mem_out: 178 pci_release_region(pdev, 1); 179 pci_out: 180 pci_disable_device(pdev); 181 return ret; 182 } 183 184 static struct pci_device_id platform_pci_tbl[] = { 185 {PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM, 186 PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, 187 {0,} 188 }; 189 190 static struct pci_driver platform_driver = { 191 .name = DRV_NAME, 192 .probe = platform_pci_probe, 193 .id_table = platform_pci_tbl, 194 #ifdef CONFIG_PM 195 .resume_early = platform_pci_resume, 196 #endif 197 }; 198 199 builtin_pci_driver(platform_driver); 200