xref: /openbmc/linux/drivers/pci/hotplug/pciehp_pci.c (revision 4f3db074)
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, ret = 0;
43 	struct controller *ctrl = p_slot->ctrl;
44 
45 	pci_lock_rescan_remove();
46 
47 	dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
48 	if (dev) {
49 		ctrl_err(ctrl, "Device %s already exists at %04x:%02x:00, cannot hot-add\n",
50 			 pci_name(dev), pci_domain_nr(parent), parent->number);
51 		pci_dev_put(dev);
52 		ret = -EEXIST;
53 		goto out;
54 	}
55 
56 	num = pci_scan_slot(parent, PCI_DEVFN(0, 0));
57 	if (num == 0) {
58 		ctrl_err(ctrl, "No new device found\n");
59 		ret = -ENODEV;
60 		goto out;
61 	}
62 
63 	list_for_each_entry(dev, &parent->devices, bus_list)
64 		if (pci_is_bridge(dev))
65 			pci_hp_add_bridge(dev);
66 
67 	pci_assign_unassigned_bridge_resources(bridge);
68 	pcie_bus_configure_settings(parent);
69 	pci_bus_add_devices(parent);
70 
71  out:
72 	pci_unlock_rescan_remove();
73 	return ret;
74 }
75 
76 int pciehp_unconfigure_device(struct slot *p_slot)
77 {
78 	int rc = 0;
79 	u8 bctl = 0;
80 	u8 presence = 0;
81 	struct pci_dev *dev, *temp;
82 	struct pci_bus *parent = p_slot->ctrl->pcie->port->subordinate;
83 	u16 command;
84 	struct controller *ctrl = p_slot->ctrl;
85 
86 	ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
87 		 __func__, pci_domain_nr(parent), parent->number);
88 	pciehp_get_adapter_status(p_slot, &presence);
89 
90 	pci_lock_rescan_remove();
91 
92 	/*
93 	 * Stopping an SR-IOV PF device removes all the associated VFs,
94 	 * which will update the bus->devices list and confuse the
95 	 * iterator.  Therefore, iterate in reverse so we remove the VFs
96 	 * first, then the PF.  We do the same in pci_stop_bus_device().
97 	 */
98 	list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
99 					 bus_list) {
100 		pci_dev_get(dev);
101 		if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE && presence) {
102 			pci_read_config_byte(dev, PCI_BRIDGE_CONTROL, &bctl);
103 			if (bctl & PCI_BRIDGE_CTL_VGA) {
104 				ctrl_err(ctrl,
105 					 "Cannot remove display device %s\n",
106 					 pci_name(dev));
107 				pci_dev_put(dev);
108 				rc = -EINVAL;
109 				break;
110 			}
111 		}
112 		pci_stop_and_remove_bus_device(dev);
113 		/*
114 		 * Ensure that no new Requests will be generated from
115 		 * the device.
116 		 */
117 		if (presence) {
118 			pci_read_config_word(dev, PCI_COMMAND, &command);
119 			command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR);
120 			command |= PCI_COMMAND_INTX_DISABLE;
121 			pci_write_config_word(dev, PCI_COMMAND, command);
122 		}
123 		pci_dev_put(dev);
124 	}
125 
126 	pci_unlock_rescan_remove();
127 	return rc;
128 }
129