/*
   * Copyright (c) 2009, Intel Corporation.
   *
   * 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.
   *
   * Author: Weidong Han <weidong.han@intel.com>
   */
  
  #include <linux/pci.h>

  #include <linux/acpi.h>

  #include <xen/xen.h>
  #include <xen/interface/physdev.h>
  #include <xen/interface/xen.h>
  
  #include <asm/xen/hypervisor.h>
  #include <asm/xen/hypercall.h>
  #include "../pci/pci.h"

  static bool __read_mostly pci_seg_supported = true;

  static int xen_add_device(struct device *dev)
  {
  	int r;
  	struct pci_dev *pci_dev = to_pci_dev(dev);

  #ifdef CONFIG_PCI_IOV
  	struct pci_dev *physfn = pci_dev->physfn;
  #endif
  
  	if (pci_seg_supported) {
  		struct physdev_pci_device_add add = {
  			.seg = pci_domain_nr(pci_dev->bus),
  			.bus = pci_dev->bus->number,
  			.devfn = pci_dev->devfn
  		};
  #ifdef CONFIG_ACPI
  		acpi_handle handle;
  #endif

  
  #ifdef CONFIG_PCI_IOV

  		if (pci_dev->is_virtfn) {
  			add.flags = XEN_PCI_DEV_VIRTFN;
  			add.physfn.bus = physfn->bus->number;
  			add.physfn.devfn = physfn->devfn;
  		} else
  #endif
  		if (pci_ari_enabled(pci_dev->bus) && PCI_SLOT(pci_dev->devfn))
  			add.flags = XEN_PCI_DEV_EXTFN;
  
  #ifdef CONFIG_ACPI
  		handle = DEVICE_ACPI_HANDLE(&pci_dev->dev);
  		if (!handle)
  			handle = DEVICE_ACPI_HANDLE(pci_dev->bus->bridge);
  #ifdef CONFIG_PCI_IOV
  		if (!handle && pci_dev->is_virtfn)
  			handle = DEVICE_ACPI_HANDLE(physfn->bus->bridge);
  #endif
  		if (handle) {
  			acpi_status status;
  
  			do {
  				unsigned long long pxm;
  
  				status = acpi_evaluate_integer(handle, "_PXM",
  							       NULL, &pxm);
  				if (ACPI_SUCCESS(status)) {
  					add.optarr[0] = pxm;
  					add.flags |= XEN_PCI_DEV_PXM;
  					break;
  				}
  				status = acpi_get_parent(handle, &handle);
  			} while (ACPI_SUCCESS(status));
  		}
  #endif /* CONFIG_ACPI */
  
  		r = HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_add, &add);
  		if (r != -ENOSYS)
  			return r;
  		pci_seg_supported = false;
  	}
  
  	if (pci_domain_nr(pci_dev->bus))
  		r = -ENOSYS;
  #ifdef CONFIG_PCI_IOV
  	else if (pci_dev->is_virtfn) {

  		struct physdev_manage_pci_ext manage_pci_ext = {
  			.bus		= pci_dev->bus->number,
  			.devfn		= pci_dev->devfn,
  			.is_virtfn 	= 1,

  			.physfn.bus	= physfn->bus->number,
  			.physfn.devfn	= physfn->devfn,

  		};
  
  		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
  			&manage_pci_ext);

  	}

  #endif

  	else if (pci_ari_enabled(pci_dev->bus) && PCI_SLOT(pci_dev->devfn)) {

  		struct physdev_manage_pci_ext manage_pci_ext = {
  			.bus		= pci_dev->bus->number,
  			.devfn		= pci_dev->devfn,
  			.is_extfn	= 1,
  		};
  
  		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
  			&manage_pci_ext);
  	} else {
  		struct physdev_manage_pci manage_pci = {

  			.bus	= pci_dev->bus->number,

  			.devfn	= pci_dev->devfn,
  		};
  
  		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add,
  			&manage_pci);
  	}
  
  	return r;
  }
  
  static int xen_remove_device(struct device *dev)
  {
  	int r;
  	struct pci_dev *pci_dev = to_pci_dev(dev);

  	if (pci_seg_supported) {
  		struct physdev_pci_device device = {
  			.seg = pci_domain_nr(pci_dev->bus),
  			.bus = pci_dev->bus->number,
  			.devfn = pci_dev->devfn
  		};

  		r = HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_remove,
  					  &device);
  	} else if (pci_domain_nr(pci_dev->bus))
  		r = -ENOSYS;
  	else {
  		struct physdev_manage_pci manage_pci = {
  			.bus = pci_dev->bus->number,
  			.devfn = pci_dev->devfn
  		};
  
  		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove,
  					  &manage_pci);
  	}

  
  	return r;
  }
  
  static int xen_pci_notifier(struct notifier_block *nb,
  			    unsigned long action, void *data)
  {
  	struct device *dev = data;
  	int r = 0;
  
  	switch (action) {
  	case BUS_NOTIFY_ADD_DEVICE:
  		r = xen_add_device(dev);
  		break;
  	case BUS_NOTIFY_DEL_DEVICE:
  		r = xen_remove_device(dev);
  		break;
  	default:

  		return NOTIFY_DONE;

  	}

  	if (r)
  		dev_err(dev, "Failed to %s - passthrough or MSI/MSI-X might fail!
  ",
  			action == BUS_NOTIFY_ADD_DEVICE ? "add" :
  			(action == BUS_NOTIFY_DEL_DEVICE ? "delete" : "?"));
  	return NOTIFY_OK;

  }

  static struct notifier_block device_nb = {

  	.notifier_call = xen_pci_notifier,
  };
  
  static int __init register_xen_pci_notifier(void)
  {
  	if (!xen_initial_domain())
  		return 0;
  
  	return bus_register_notifier(&pci_bus_type, &device_nb);
  }
  
  arch_initcall(register_xen_pci_notifier);