drivers/xen/platform-pci.c

   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);