linux/drivers/xen/platform-pci.c
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   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
  39MODULE_AUTHOR("ssmith@xensource.com and stefano.stabellini@eu.citrix.com");
  40MODULE_DESCRIPTION("Xen platform PCI device");
  41MODULE_LICENSE("GPL");
  42
  43static unsigned long platform_mmio;
  44static unsigned long platform_mmio_alloc;
  45static unsigned long platform_mmiolen;
  46static uint64_t callback_via;
  47
  48unsigned 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
  59static 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
  78static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
  79{
  80        xen_hvm_evtchn_do_upcall();
  81        return IRQ_HANDLED;
  82}
  83
  84static int xen_allocate_irq(struct pci_dev *pdev)
  85{
  86        return request_irq(pdev->irq, do_hvm_evtchn_intr,
  87                        IRQF_DISABLED | IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
  88                        "xen-platform-pci", pdev);
  89}
  90
  91static 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
 104static int __devinit platform_pci_init(struct pci_dev *pdev,
 105                                       const struct pci_device_id *ent)
 106{
 107        int i, ret;
 108        long ioaddr, iolen;
 109        long mmio_addr, mmio_len;
 110        unsigned int max_nr_gframes;
 111
 112        i = pci_enable_device(pdev);
 113        if (i)
 114                return i;
 115
 116        ioaddr = pci_resource_start(pdev, 0);
 117        iolen = pci_resource_len(pdev, 0);
 118
 119        mmio_addr = pci_resource_start(pdev, 1);
 120        mmio_len = pci_resource_len(pdev, 1);
 121
 122        if (mmio_addr == 0 || ioaddr == 0) {
 123                dev_err(&pdev->dev, "no resources found\n");
 124                ret = -ENOENT;
 125                goto pci_out;
 126        }
 127
 128        if (request_mem_region(mmio_addr, mmio_len, DRV_NAME) == NULL) {
 129                dev_err(&pdev->dev, "MEM I/O resource 0x%lx @ 0x%lx busy\n",
 130                       mmio_addr, mmio_len);
 131                ret = -EBUSY;
 132                goto pci_out;
 133        }
 134
 135        if (request_region(ioaddr, iolen, DRV_NAME) == NULL) {
 136                dev_err(&pdev->dev, "I/O resource 0x%lx @ 0x%lx busy\n",
 137                       iolen, ioaddr);
 138                ret = -EBUSY;
 139                goto mem_out;
 140        }
 141
 142        platform_mmio = mmio_addr;
 143        platform_mmiolen = mmio_len;
 144
 145        if (!xen_have_vector_callback) {
 146                ret = xen_allocate_irq(pdev);
 147                if (ret) {
 148                        dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);
 149                        goto out;
 150                }
 151                callback_via = get_callback_via(pdev);
 152                ret = xen_set_callback_via(callback_via);
 153                if (ret) {
 154                        dev_warn(&pdev->dev, "Unable to set the evtchn callback "
 155                                         "err=%d\n", ret);
 156                        goto out;
 157                }
 158        }
 159
 160        max_nr_gframes = gnttab_max_grant_frames();
 161        xen_hvm_resume_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
 162        ret = gnttab_init();
 163        if (ret)
 164                goto out;
 165        xenbus_probe(NULL);
 166        ret = xen_setup_shutdown_event();
 167        if (ret)
 168                goto out;
 169        return 0;
 170
 171out:
 172        release_region(ioaddr, iolen);
 173mem_out:
 174        release_mem_region(mmio_addr, mmio_len);
 175pci_out:
 176        pci_disable_device(pdev);
 177        return ret;
 178}
 179
 180static struct pci_device_id platform_pci_tbl[] __devinitdata = {
 181        {PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
 182                PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
 183        {0,}
 184};
 185
 186MODULE_DEVICE_TABLE(pci, platform_pci_tbl);
 187
 188static struct pci_driver platform_driver = {
 189        .name =           DRV_NAME,
 190        .probe =          platform_pci_init,
 191        .id_table =       platform_pci_tbl,
 192#ifdef CONFIG_PM
 193        .resume_early =   platform_pci_resume,
 194#endif
 195};
 196
 197static int __init platform_pci_module_init(void)
 198{
 199        /* no unplug has been done, IGNORE hasn't been specified: just
 200         * return now */
 201        if (!xen_platform_pci_unplug)
 202                return -ENODEV;
 203
 204        return pci_register_driver(&platform_driver);
 205}
 206
 207module_init(platform_pci_module_init);
 208