forked from Minki/linux
c4ec84c7db
Multiple race conditions are possible between PCI hotplug and the generic PCI bus rescan and device removal that can be triggered via sysfs. To avoid those race conditions make PCI hotplug use global PCI rescan-remove locking. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
124 lines
3.3 KiB
C
124 lines
3.3 KiB
C
/*
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* Standard Hot Plug Controller Driver
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*
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* Copyright (C) 1995,2001 Compaq Computer Corporation
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* Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
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* Copyright (C) 2001 IBM Corp.
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* Copyright (C) 2003-2004 Intel Corporation
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*
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for more
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* details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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* Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
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*
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/pci.h>
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#include "../pci.h"
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#include "shpchp.h"
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int __ref shpchp_configure_device(struct slot *p_slot)
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{
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struct pci_dev *dev;
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struct controller *ctrl = p_slot->ctrl;
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struct pci_dev *bridge = ctrl->pci_dev;
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struct pci_bus *parent = bridge->subordinate;
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int num, ret = 0;
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pci_lock_rescan_remove();
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dev = pci_get_slot(parent, PCI_DEVFN(p_slot->device, 0));
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if (dev) {
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ctrl_err(ctrl, "Device %s already exists "
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"at %04x:%02x:%02x, cannot hot-add\n", pci_name(dev),
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pci_domain_nr(parent), p_slot->bus, p_slot->device);
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pci_dev_put(dev);
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ret = -EINVAL;
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goto out;
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}
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num = pci_scan_slot(parent, PCI_DEVFN(p_slot->device, 0));
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if (num == 0) {
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ctrl_err(ctrl, "No new device found\n");
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ret = -ENODEV;
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goto out;
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}
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list_for_each_entry(dev, &parent->devices, bus_list) {
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if (PCI_SLOT(dev->devfn) != p_slot->device)
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continue;
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if ((dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) ||
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(dev->hdr_type == PCI_HEADER_TYPE_CARDBUS))
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pci_hp_add_bridge(dev);
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}
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pci_assign_unassigned_bridge_resources(bridge);
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list_for_each_entry(dev, &parent->devices, bus_list) {
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if (PCI_SLOT(dev->devfn) != p_slot->device)
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continue;
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pci_configure_slot(dev);
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}
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pci_bus_add_devices(parent);
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out:
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pci_unlock_rescan_remove();
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return ret;
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}
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int shpchp_unconfigure_device(struct slot *p_slot)
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{
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int rc = 0;
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u8 bctl = 0;
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struct pci_bus *parent = p_slot->ctrl->pci_dev->subordinate;
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struct pci_dev *dev, *temp;
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struct controller *ctrl = p_slot->ctrl;
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ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:%02x\n",
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__func__, pci_domain_nr(parent), p_slot->bus, p_slot->device);
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pci_lock_rescan_remove();
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list_for_each_entry_safe(dev, temp, &parent->devices, bus_list) {
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if (PCI_SLOT(dev->devfn) != p_slot->device)
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continue;
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pci_dev_get(dev);
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if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
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pci_read_config_byte(dev, PCI_BRIDGE_CONTROL, &bctl);
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if (bctl & PCI_BRIDGE_CTL_VGA) {
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ctrl_err(ctrl,
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"Cannot remove display device %s\n",
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pci_name(dev));
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pci_dev_put(dev);
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rc = -EINVAL;
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break;
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}
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}
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pci_stop_and_remove_bus_device(dev);
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pci_dev_put(dev);
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}
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pci_unlock_rescan_remove();
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return rc;
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}
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