drivers/xen/platform-pci.c

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