1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * PCI Express Hot Plug Controller Driver
4 *
5 * Copyright (C) 1995,2001 Compaq Computer Corporation
6 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
7 * Copyright (C) 2001 IBM Corp.
8 * Copyright (C) 2003-2004 Intel Corporation
9 *
10 * All rights reserved.
11 *
12 * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
13 *
14 */
15
16 #define dev_fmt(fmt) "pciehp: " fmt
17
18 #include <linux/kernel.h>
19 #include <linux/types.h>
20 #include <linux/pci.h>
21 #include "../pci.h"
22 #include "pciehp.h"
23
24 /**
25 * pciehp_configure_device() - enumerate PCI devices below a hotplug bridge
26 * @ctrl: PCIe hotplug controller
27 *
28 * Enumerate PCI devices below a hotplug bridge and add them to the system.
29 * Return 0 on success, %-EEXIST if the devices are already enumerated or
30 * %-ENODEV if enumeration failed.
31 */
32 int pciehp_configure_device(struct controller *ctrl)
33 {
34 struct pci_dev *dev;
35 struct pci_dev *bridge = ctrl->pcie->port;
36 struct pci_bus *parent = bridge->subordinate;
37 int num, ret = 0;
38
39 pci_lock_rescan_remove();
40
41 dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
42 if (dev) {
43 /*
44 * The device is already there. Either configured by the
45 * boot firmware or a previous hotplug event.
46 */
47 ctrl_dbg(ctrl, "Device %s already exists at %04x:%02x:00, skipping hot-add\n",
48 pci_name(dev), pci_domain_nr(parent), parent->number);
49 pci_dev_put(dev);
50 ret = -EEXIST;
51 goto out;
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 ret = -ENODEV;
58 goto out;
59 }
60
61 for_each_pci_bridge(dev, parent)
62 pci_hp_add_bridge(dev);
63
64 pci_assign_unassigned_bridge_resources(bridge);
65 pcie_bus_configure_settings(parent);
66 pci_bus_add_devices(parent);
67
68 out:
69 pci_unlock_rescan_remove();
70 return ret;
71 }
72
73 /**
74 * pciehp_unconfigure_device() - remove PCI devices below a hotplug bridge
75 * @ctrl: PCIe hotplug controller
76 * @presence: whether the card is still present in the slot;
77 * true for safe removal via sysfs or an Attention Button press,
78 * false for surprise removal
79 *
80 * Unbind PCI devices below a hotplug bridge from their drivers and remove
81 * them from the system. Safely removed devices are quiesced. Surprise
82 * removed devices are marked as such to prevent further accesses.
83 */
84 void pciehp_unconfigure_device(struct controller *ctrl, bool presence)
85 {
86 struct pci_dev *dev, *temp;
87 struct pci_bus *parent = ctrl->pcie->port->subordinate;
88 u16 command;
89
90 ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
91 __func__, pci_domain_nr(parent), parent->number);
92
93 if (!presence)
94 pci_walk_bus(parent, pci_dev_set_disconnected, NULL);
95
96 pci_lock_rescan_remove();
97
98 /*
99 * Stopping an SR-IOV PF device removes all the associated VFs,
100 * which will update the bus->devices list and confuse the
101 * iterator. Therefore, iterate in reverse so we remove the VFs
102 * first, then the PF. We do the same in pci_stop_bus_device().
103 */
104 list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
105 bus_list) {
106 pci_dev_get(dev);
107 pci_stop_and_remove_bus_device(dev);
108 /*
109 * Ensure that no new Requests will be generated from
110 * the device.
111 */
112 if (presence) {
113 pci_read_config_word(dev, PCI_COMMAND, &command);
114 command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR);
115 command |= PCI_COMMAND_INTX_DISABLE;
116 pci_write_config_word(dev, PCI_COMMAND, command);
117 }
118 pci_dev_put(dev);
119 }
120
121 pci_unlock_rescan_remove();
122 }