xref: /openbmc/linux/drivers/pci/remove.c (revision 93f5715e)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/pci.h>
3 #include <linux/module.h>
4 #include "pci.h"
5 
6 static void pci_free_resources(struct pci_dev *dev)
7 {
8 	int i;
9 
10 	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
11 		struct resource *res = dev->resource + i;
12 		if (res->parent)
13 			release_resource(res);
14 	}
15 }
16 
17 static void pci_stop_dev(struct pci_dev *dev)
18 {
19 	pci_pme_active(dev, false);
20 
21 	if (pci_dev_is_added(dev)) {
22 		device_release_driver(&dev->dev);
23 		pci_proc_detach_device(dev);
24 		pci_remove_sysfs_dev_files(dev);
25 
26 		pci_dev_assign_added(dev, false);
27 	}
28 
29 	if (dev->bus->self)
30 		pcie_aspm_exit_link_state(dev);
31 }
32 
33 static void pci_destroy_dev(struct pci_dev *dev)
34 {
35 	if (!dev->dev.kobj.parent)
36 		return;
37 
38 	device_del(&dev->dev);
39 
40 	down_write(&pci_bus_sem);
41 	list_del(&dev->bus_list);
42 	up_write(&pci_bus_sem);
43 
44 	pci_bridge_d3_update(dev);
45 	pci_free_resources(dev);
46 	put_device(&dev->dev);
47 }
48 
49 void pci_remove_bus(struct pci_bus *bus)
50 {
51 	pci_proc_detach_bus(bus);
52 
53 	down_write(&pci_bus_sem);
54 	list_del(&bus->node);
55 	pci_bus_release_busn_res(bus);
56 	up_write(&pci_bus_sem);
57 	pci_remove_legacy_files(bus);
58 
59 	if (bus->ops->remove_bus)
60 		bus->ops->remove_bus(bus);
61 
62 	pcibios_remove_bus(bus);
63 	device_unregister(&bus->dev);
64 }
65 EXPORT_SYMBOL(pci_remove_bus);
66 
67 static void pci_stop_bus_device(struct pci_dev *dev)
68 {
69 	struct pci_bus *bus = dev->subordinate;
70 	struct pci_dev *child, *tmp;
71 
72 	/*
73 	 * Stopping an SR-IOV PF device removes all the associated VFs,
74 	 * which will update the bus->devices list and confuse the
75 	 * iterator.  Therefore, iterate in reverse so we remove the VFs
76 	 * first, then the PF.
77 	 */
78 	if (bus) {
79 		list_for_each_entry_safe_reverse(child, tmp,
80 						 &bus->devices, bus_list)
81 			pci_stop_bus_device(child);
82 	}
83 
84 	pci_stop_dev(dev);
85 }
86 
87 static void pci_remove_bus_device(struct pci_dev *dev)
88 {
89 	struct pci_bus *bus = dev->subordinate;
90 	struct pci_dev *child, *tmp;
91 
92 	if (bus) {
93 		list_for_each_entry_safe(child, tmp,
94 					 &bus->devices, bus_list)
95 			pci_remove_bus_device(child);
96 
97 		pci_remove_bus(bus);
98 		dev->subordinate = NULL;
99 	}
100 
101 	pci_destroy_dev(dev);
102 }
103 
104 /**
105  * pci_stop_and_remove_bus_device - remove a PCI device and any children
106  * @dev: the device to remove
107  *
108  * Remove a PCI device from the device lists, informing the drivers
109  * that the device has been removed.  We also remove any subordinate
110  * buses and children in a depth-first manner.
111  *
112  * For each device we remove, delete the device structure from the
113  * device lists, remove the /proc entry, and notify userspace
114  * (/sbin/hotplug).
115  */
116 void pci_stop_and_remove_bus_device(struct pci_dev *dev)
117 {
118 	pci_stop_bus_device(dev);
119 	pci_remove_bus_device(dev);
120 }
121 EXPORT_SYMBOL(pci_stop_and_remove_bus_device);
122 
123 void pci_stop_and_remove_bus_device_locked(struct pci_dev *dev)
124 {
125 	pci_lock_rescan_remove();
126 	pci_stop_and_remove_bus_device(dev);
127 	pci_unlock_rescan_remove();
128 }
129 EXPORT_SYMBOL_GPL(pci_stop_and_remove_bus_device_locked);
130 
131 void pci_stop_root_bus(struct pci_bus *bus)
132 {
133 	struct pci_dev *child, *tmp;
134 	struct pci_host_bridge *host_bridge;
135 
136 	if (!pci_is_root_bus(bus))
137 		return;
138 
139 	host_bridge = to_pci_host_bridge(bus->bridge);
140 	list_for_each_entry_safe_reverse(child, tmp,
141 					 &bus->devices, bus_list)
142 		pci_stop_bus_device(child);
143 
144 	/* stop the host bridge */
145 	device_release_driver(&host_bridge->dev);
146 }
147 EXPORT_SYMBOL_GPL(pci_stop_root_bus);
148 
149 void pci_remove_root_bus(struct pci_bus *bus)
150 {
151 	struct pci_dev *child, *tmp;
152 	struct pci_host_bridge *host_bridge;
153 
154 	if (!pci_is_root_bus(bus))
155 		return;
156 
157 	host_bridge = to_pci_host_bridge(bus->bridge);
158 	list_for_each_entry_safe(child, tmp,
159 				 &bus->devices, bus_list)
160 		pci_remove_bus_device(child);
161 	pci_remove_bus(bus);
162 	host_bridge->bus = NULL;
163 
164 	/* remove the host bridge */
165 	device_unregister(&host_bridge->dev);
166 }
167 EXPORT_SYMBOL_GPL(pci_remove_root_bus);
168