tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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#include <linux/module.h>
17#include <linux/kernel.h>
18#include <linux/types.h>
19#include <linux/pci.h>
20#include "../pci.h"
21#include "pciehp.h"
22
23int pciehp_configure_device(struct slot *p_slot)
24{
25 struct pci_dev *dev;
26 struct pci_dev *bridge = p_slot->ctrl->pcie->port;
27 struct pci_bus *parent = bridge->subordinate;
28 int num, ret = 0;
29 struct controller *ctrl = p_slot->ctrl;
30
31 pci_lock_rescan_remove();
32
33 dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
34 if (dev) {
35 /*
36 * The device is already there. Either configured by the
37 * boot firmware or a previous hotplug event.
38 */
39 ctrl_dbg(ctrl, "Device %s already exists at %04x:%02x:00, skipping hot-add\n",
40 pci_name(dev), pci_domain_nr(parent), parent->number);
41 pci_dev_put(dev);
42 ret = -EEXIST;
43 goto out;
44 }
45
46 num = pci_scan_slot(parent, PCI_DEVFN(0, 0));
47 if (num == 0) {
48 ctrl_err(ctrl, "No new device found\n");
49 ret = -ENODEV;
50 goto out;
51 }
52
53 for_each_pci_bridge(dev, parent)
54 pci_hp_add_bridge(dev);
55
56 pci_assign_unassigned_bridge_resources(bridge);
57 pcie_bus_configure_settings(parent);
58 pci_bus_add_devices(parent);
59
60 out:
61 pci_unlock_rescan_remove();
62 return ret;
63}
64
65int pciehp_unconfigure_device(struct slot *p_slot)
66{
67 int rc = 0;
68 u8 presence = 0;
69 struct pci_dev *dev, *temp;
70 struct pci_bus *parent = p_slot->ctrl->pcie->port->subordinate;
71 u16 command;
72 struct controller *ctrl = p_slot->ctrl;
73
74 ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
75 __func__, pci_domain_nr(parent), parent->number);
76 pciehp_get_adapter_status(p_slot, &presence);
77
78 pci_lock_rescan_remove();
79
80 /*
81 * Stopping an SR-IOV PF device removes all the associated VFs,
82 * which will update the bus->devices list and confuse the
83 * iterator. Therefore, iterate in reverse so we remove the VFs
84 * first, then the PF. We do the same in pci_stop_bus_device().
85 */
86 list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
87 bus_list) {
88 pci_dev_get(dev);
89 if (!presence) {
90 pci_dev_set_disconnected(dev, NULL);
91 if (pci_has_subordinate(dev))
92 pci_walk_bus(dev->subordinate,
93 pci_dev_set_disconnected, NULL);
94 }
95 pci_stop_and_remove_bus_device(dev);
96 /*
97 * Ensure that no new Requests will be generated from
98 * the device.
99 */
100 if (presence) {
101 pci_read_config_word(dev, PCI_COMMAND, &command);
102 command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR);
103 command |= PCI_COMMAND_INTX_DISABLE;
104 pci_write_config_word(dev, PCI_COMMAND, command);
105 }
106 pci_dev_put(dev);
107 }
108
109 pci_unlock_rescan_remove();
110 return rc;
111}