kernel-ark/drivers/pci/hotplug/pciehp_pci.c
Praveen Kalamegham ac81860ea0 PCI: hotplug: pciehp: Removed check for hotplug of display devices
Removed check to prevent hotplug of display devices within pciehp.
Originally this was thought to have been required within the PCI
Hotplug specification for some legacy devices.  However there is
no such requirement in the most recent revision. The check prevents
hotplug of not only display devices but also computational GPUs
which require serviceability.

Signed-off-by: Praveen Kalamegham <praveen@nextio.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-05-21 14:43:46 -07:00

160 lines
4.1 KiB
C

/*
* PCI Express Hot Plug Controller Driver
*
* Copyright (C) 1995,2001 Compaq Computer Corporation
* Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
* Copyright (C) 2001 IBM Corp.
* Copyright (C) 2003-2004 Intel Corporation
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/pci.h>
#include "../pci.h"
#include "pciehp.h"
static int __ref pciehp_add_bridge(struct pci_dev *dev)
{
struct pci_bus *parent = dev->bus;
int pass, busnr, start = parent->secondary;
int end = parent->subordinate;
for (busnr = start; busnr <= end; busnr++) {
if (!pci_find_bus(pci_domain_nr(parent), busnr))
break;
}
if (busnr-- > end) {
err("No bus number available for hot-added bridge %s\n",
pci_name(dev));
return -1;
}
for (pass = 0; pass < 2; pass++)
busnr = pci_scan_bridge(parent, dev, busnr, pass);
if (!dev->subordinate)
return -1;
return 0;
}
int pciehp_configure_device(struct slot *p_slot)
{
struct pci_dev *dev;
struct pci_dev *bridge = p_slot->ctrl->pcie->port;
struct pci_bus *parent = bridge->subordinate;
int num, fn;
struct controller *ctrl = p_slot->ctrl;
dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
if (dev) {
ctrl_err(ctrl, "Device %s already exists "
"at %04x:%02x:00, cannot hot-add\n", pci_name(dev),
pci_domain_nr(parent), parent->number);
pci_dev_put(dev);
return -EINVAL;
}
num = pci_scan_slot(parent, PCI_DEVFN(0, 0));
if (num == 0) {
ctrl_err(ctrl, "No new device found\n");
return -ENODEV;
}
for (fn = 0; fn < 8; fn++) {
dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
if (!dev)
continue;
if ((dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) ||
(dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)) {
pciehp_add_bridge(dev);
}
pci_dev_put(dev);
}
pci_assign_unassigned_bridge_resources(bridge);
for (fn = 0; fn < 8; fn++) {
dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
if (!dev)
continue;
if ((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY) {
pci_dev_put(dev);
continue;
}
pci_configure_slot(dev);
pci_dev_put(dev);
}
pci_bus_add_devices(parent);
return 0;
}
int pciehp_unconfigure_device(struct slot *p_slot)
{
int ret, rc = 0;
int j;
u8 bctl = 0;
u8 presence = 0;
struct pci_bus *parent = p_slot->ctrl->pcie->port->subordinate;
u16 command;
struct controller *ctrl = p_slot->ctrl;
ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
__func__, pci_domain_nr(parent), parent->number);
ret = pciehp_get_adapter_status(p_slot, &presence);
if (ret)
presence = 0;
for (j = 0; j < 8; j++) {
struct pci_dev *temp = pci_get_slot(parent, PCI_DEVFN(0, j));
if (!temp)
continue;
if (temp->hdr_type == PCI_HEADER_TYPE_BRIDGE && presence) {
pci_read_config_byte(temp, PCI_BRIDGE_CONTROL, &bctl);
if (bctl & PCI_BRIDGE_CTL_VGA) {
ctrl_err(ctrl,
"Cannot remove display device %s\n",
pci_name(temp));
pci_dev_put(temp);
rc = EINVAL;
break;
}
}
pci_remove_bus_device(temp);
/*
* Ensure that no new Requests will be generated from
* the device.
*/
if (presence) {
pci_read_config_word(temp, PCI_COMMAND, &command);
command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR);
command |= PCI_COMMAND_INTX_DISABLE;
pci_write_config_word(temp, PCI_COMMAND, command);
}
pci_dev_put(temp);
}
return rc;
}