platform-pci.c

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/******************************************************************************
 * platform-pci.c
 *
 * Xen platform PCI device driver
 * Copyright (c) 2005, Intel Corporation.
 * Copyright (c) 2007, XenSource Inc.
 * Copyright (c) 2010, Citrix
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307 USA.
 *
 */


#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/pci.h>

#include <xen/platform_pci.h>
#include <xen/grant_table.h>
#include <xen/xenbus.h>
#include <xen/events.h>
#include <xen/hvm.h>
#include <xen/xen-ops.h>

#define DRV_NAME    "xen-platform-pci"

MODULE_AUTHOR("[email protected] and [email protected]");
MODULE_DESCRIPTION("Xen platform PCI device");
MODULE_LICENSE("GPL");

static unsigned long platform_mmio;
static unsigned long platform_mmio_alloc;
static unsigned long platform_mmiolen;
static uint64_t callback_via;

unsigned long alloc_xen_mmio(unsigned long len)
{
    unsigned long addr;

    addr = platform_mmio + platform_mmio_alloc;
    platform_mmio_alloc += len;
    BUG_ON(platform_mmio_alloc > platform_mmiolen);

    return addr;
}

static uint64_t get_callback_via(struct pci_dev *pdev)
{
    u8 pin;
    int irq;

    irq = pdev->irq;
    if (irq < 16)
        return irq; /* ISA IRQ */

    pin = pdev->pin;

    /* We don't know the GSI. Specify the PCI INTx line instead. */
    return ((uint64_t)0x01 << 56) | /* PCI INTx identifier */
        ((uint64_t)pci_domain_nr(pdev->bus) << 32) |
        ((uint64_t)pdev->bus->number << 16) |
        ((uint64_t)(pdev->devfn & 0xff) << 8) |
        ((uint64_t)(pin - 1) & 3);
}

static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
{
    xen_hvm_evtchn_do_upcall();
    return IRQ_HANDLED;
}

static int xen_allocate_irq(struct pci_dev *pdev)
{
    return request_irq(pdev->irq, do_hvm_evtchn_intr,
            IRQF_DISABLED | IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
            "xen-platform-pci", pdev);
}

static int platform_pci_resume(struct pci_dev *pdev)
{
    int err;
    if (xen_have_vector_callback)
        return 0;
    err = xen_set_callback_via(callback_via);
    if (err) {
        dev_err(&pdev->dev, "platform_pci_resume failure!\n");
        return err;
    }
    return 0;
}

static int __devinit platform_pci_init(struct pci_dev *pdev,
                       const struct pci_device_id *ent)
{
    int i, ret;
    long ioaddr;
    long mmio_addr, mmio_len;
    unsigned int max_nr_gframes;

    if (!xen_domain())
        return -ENODEV;

    i = pci_enable_device(pdev);
    if (i)
        return i;

    ioaddr = pci_resource_start(pdev, 0);

    mmio_addr = pci_resource_start(pdev, 1);
    mmio_len = pci_resource_len(pdev, 1);

    if (mmio_addr == 0 || ioaddr == 0) {
        dev_err(&pdev->dev, "no resources found\n");
        ret = -ENOENT;
        goto pci_out;
    }

    ret = pci_request_region(pdev, 1, DRV_NAME);
    if (ret < 0)
        goto pci_out;

    ret = pci_request_region(pdev, 0, DRV_NAME);
    if (ret < 0)
        goto mem_out;

    platform_mmio = mmio_addr;
    platform_mmiolen = mmio_len;

    if (!xen_have_vector_callback) {
        ret = xen_allocate_irq(pdev);
        if (ret) {
            dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);
            goto out;
        }
        callback_via = get_callback_via(pdev);
        ret = xen_set_callback_via(callback_via);
        if (ret) {
            dev_warn(&pdev->dev, "Unable to set the evtchn callback "
                     "err=%d\n", ret);
            goto out;
        }
    }

    max_nr_gframes = gnttab_max_grant_frames();
    xen_hvm_resume_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
    ret = gnttab_init();
    if (ret)
        goto out;
    xenbus_probe(NULL);
    return 0;

out:
    pci_release_region(pdev, 0);
mem_out:
    pci_release_region(pdev, 1);
pci_out:
    pci_disable_device(pdev);
    return ret;
}

static struct pci_device_id platform_pci_tbl[] __devinitdata = {
    {PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
        PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
    {0,}
};

MODULE_DEVICE_TABLE(pci, platform_pci_tbl);

static struct pci_driver platform_driver = {
    .name =           DRV_NAME,
    .probe =          platform_pci_init,
    .id_table =       platform_pci_tbl,
#ifdef CONFIG_PM
    .resume_early =   platform_pci_resume,
#endif
};

static int __init platform_pci_module_init(void)
{
    return pci_register_driver(&platform_driver);
}

module_init(platform_pci_module_init);