xref: /linux/drivers/pci/hotplug/pciehp_pci.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  * PCI Express Hot Plug Controller Driver
3  *
4  * Copyright (C) 1995,2001 Compaq Computer Corporation
5  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
6  * Copyright (C) 2001 IBM Corp.
7  * Copyright (C) 2003-2004 Intel Corporation
8  *
9  * All rights reserved.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or (at
14  * your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
19  * NON INFRINGEMENT.  See the GNU General Public License for more
20  * details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25  *
26  * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
27  *
28  */
29 
30 #include <linux/module.h>
31 #include <linux/kernel.h>
32 #include <linux/types.h>
33 #include <linux/pci.h>
34 #include "../pci.h"
35 #include "pciehp.h"
36 
37 int pciehp_configure_device(struct slot *p_slot)
38 {
39 	struct pci_dev *dev;
40 	struct pci_dev *bridge = p_slot->ctrl->pcie->port;
41 	struct pci_bus *parent = bridge->subordinate;
42 	int num;
43 	struct controller *ctrl = p_slot->ctrl;
44 
45 	dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
46 	if (dev) {
47 		ctrl_err(ctrl, "Device %s already exists "
48 			 "at %04x:%02x:00, cannot hot-add\n", pci_name(dev),
49 			 pci_domain_nr(parent), parent->number);
50 		pci_dev_put(dev);
51 		return -EINVAL;
52 	}
53 
54 	num = pci_scan_slot(parent, PCI_DEVFN(0, 0));
55 	if (num == 0) {
56 		ctrl_err(ctrl, "No new device found\n");
57 		return -ENODEV;
58 	}
59 
60 	list_for_each_entry(dev, &parent->devices, bus_list)
61 		if ((dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) ||
62 				(dev->hdr_type == PCI_HEADER_TYPE_CARDBUS))
63 			pci_hp_add_bridge(dev);
64 
65 	pci_assign_unassigned_bridge_resources(bridge);
66 
67 	list_for_each_entry(dev, &parent->devices, bus_list) {
68 		if ((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY)
69 			continue;
70 
71 		pci_configure_slot(dev);
72 	}
73 
74 	pci_bus_add_devices(parent);
75 
76 	return 0;
77 }
78 
79 int pciehp_unconfigure_device(struct slot *p_slot)
80 {
81 	int ret, rc = 0;
82 	u8 bctl = 0;
83 	u8 presence = 0;
84 	struct pci_dev *dev, *temp;
85 	struct pci_bus *parent = p_slot->ctrl->pcie->port->subordinate;
86 	u16 command;
87 	struct controller *ctrl = p_slot->ctrl;
88 
89 	ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
90 		 __func__, pci_domain_nr(parent), parent->number);
91 	ret = pciehp_get_adapter_status(p_slot, &presence);
92 	if (ret)
93 		presence = 0;
94 
95 	/*
96 	 * Stopping an SR-IOV PF device removes all the associated VFs,
97 	 * which will update the bus->devices list and confuse the
98 	 * iterator.  Therefore, iterate in reverse so we remove the VFs
99 	 * first, then the PF.  We do the same in pci_stop_bus_device().
100 	 */
101 	list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
102 					 bus_list) {
103 		pci_dev_get(dev);
104 		if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE && presence) {
105 			pci_read_config_byte(dev, PCI_BRIDGE_CONTROL, &bctl);
106 			if (bctl & PCI_BRIDGE_CTL_VGA) {
107 				ctrl_err(ctrl,
108 					 "Cannot remove display device %s\n",
109 					 pci_name(dev));
110 				pci_dev_put(dev);
111 				rc = -EINVAL;
112 				break;
113 			}
114 		}
115 		pci_stop_and_remove_bus_device(dev);
116 		/*
117 		 * Ensure that no new Requests will be generated from
118 		 * the device.
119 		 */
120 		if (presence) {
121 			pci_read_config_word(dev, PCI_COMMAND, &command);
122 			command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR);
123 			command |= PCI_COMMAND_INTX_DISABLE;
124 			pci_write_config_word(dev, PCI_COMMAND, command);
125 		}
126 		pci_dev_put(dev);
127 	}
128 
129 	return rc;
130 }
131