1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Derived from "arch/powerpc/platforms/pseries/pci_dlpar.c" 4 * 5 * Copyright (C) 2003 Linda Xie <lxie@us.ibm.com> 6 * Copyright (C) 2005 International Business Machines 7 * 8 * Updates, 2005, John Rose <johnrose@austin.ibm.com> 9 * Updates, 2005, Linas Vepstas <linas@austin.ibm.com> 10 * Updates, 2013, Gavin Shan <shangw@linux.vnet.ibm.com> 11 */ 12 13 #include <linux/pci.h> 14 #include <linux/export.h> 15 #include <linux/of.h> 16 #include <asm/pci-bridge.h> 17 #include <asm/ppc-pci.h> 18 #include <asm/firmware.h> 19 #include <asm/eeh.h> 20 21 static struct pci_bus *find_bus_among_children(struct pci_bus *bus, 22 struct device_node *dn) 23 { 24 struct pci_bus *child = NULL; 25 struct pci_bus *tmp; 26 27 if (pci_bus_to_OF_node(bus) == dn) 28 return bus; 29 30 list_for_each_entry(tmp, &bus->children, node) { 31 child = find_bus_among_children(tmp, dn); 32 if (child) 33 break; 34 } 35 36 return child; 37 } 38 39 struct pci_bus *pci_find_bus_by_node(struct device_node *dn) 40 { 41 struct pci_dn *pdn = PCI_DN(dn); 42 43 if (!pdn || !pdn->phb || !pdn->phb->bus) 44 return NULL; 45 46 return find_bus_among_children(pdn->phb->bus, dn); 47 } 48 EXPORT_SYMBOL_GPL(pci_find_bus_by_node); 49 50 /** 51 * pcibios_release_device - release PCI device 52 * @dev: PCI device 53 * 54 * The function is called before releasing the indicated PCI device. 55 */ 56 void pcibios_release_device(struct pci_dev *dev) 57 { 58 struct pci_controller *phb = pci_bus_to_host(dev->bus); 59 struct pci_dn *pdn = pci_get_pdn(dev); 60 61 if (phb->controller_ops.release_device) 62 phb->controller_ops.release_device(dev); 63 64 /* free()ing the pci_dn has been deferred to us, do it now */ 65 if (pdn && (pdn->flags & PCI_DN_FLAG_DEAD)) { 66 pci_dbg(dev, "freeing dead pdn\n"); 67 kfree(pdn); 68 } 69 } 70 71 /** 72 * pci_hp_remove_devices - remove all devices under this bus 73 * @bus: the indicated PCI bus 74 * 75 * Remove all of the PCI devices under this bus both from the 76 * linux pci device tree, and from the powerpc EEH address cache. 77 */ 78 void pci_hp_remove_devices(struct pci_bus *bus) 79 { 80 struct pci_dev *dev, *tmp; 81 struct pci_bus *child_bus; 82 83 /* First go down child busses */ 84 list_for_each_entry(child_bus, &bus->children, node) 85 pci_hp_remove_devices(child_bus); 86 87 pr_debug("PCI: Removing devices on bus %04x:%02x\n", 88 pci_domain_nr(bus), bus->number); 89 list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) { 90 pr_debug(" Removing %s...\n", pci_name(dev)); 91 pci_stop_and_remove_bus_device(dev); 92 } 93 } 94 EXPORT_SYMBOL_GPL(pci_hp_remove_devices); 95 96 static void traverse_siblings_and_scan_slot(struct device_node *start, struct pci_bus *bus) 97 { 98 struct device_node *dn; 99 int slotno; 100 101 u32 class = 0; 102 103 if (!of_property_read_u32(start->child, "class-code", &class)) { 104 /* Call of pci_scan_slot for non-bridge/EP case */ 105 if (!((class >> 8) == PCI_CLASS_BRIDGE_PCI)) { 106 slotno = PCI_SLOT(PCI_DN(start->child)->devfn); 107 pci_scan_slot(bus, PCI_DEVFN(slotno, 0)); 108 return; 109 } 110 } 111 112 /* Iterate all siblings */ 113 for_each_child_of_node(start, dn) { 114 class = 0; 115 116 if (!of_property_read_u32(start->child, "class-code", &class)) { 117 /* Call of pci_scan_slot on each sibling-nodes/bridge-ports */ 118 if ((class >> 8) == PCI_CLASS_BRIDGE_PCI) { 119 slotno = PCI_SLOT(PCI_DN(dn)->devfn); 120 pci_scan_slot(bus, PCI_DEVFN(slotno, 0)); 121 } 122 } 123 } 124 } 125 126 /** 127 * pci_hp_add_devices - adds new pci devices to bus 128 * @bus: the indicated PCI bus 129 * 130 * This routine will find and fixup new pci devices under 131 * the indicated bus. This routine presumes that there 132 * might already be some devices under this bridge, so 133 * it carefully tries to add only new devices. (And that 134 * is how this routine differs from other, similar pcibios 135 * routines.) 136 */ 137 void pci_hp_add_devices(struct pci_bus *bus) 138 { 139 int mode, max; 140 struct pci_dev *dev; 141 struct pci_controller *phb; 142 struct device_node *dn = pci_bus_to_OF_node(bus); 143 144 phb = pci_bus_to_host(bus); 145 146 mode = PCI_PROBE_NORMAL; 147 if (phb->controller_ops.probe_mode) 148 mode = phb->controller_ops.probe_mode(bus); 149 150 if (mode == PCI_PROBE_DEVTREE) { 151 /* use ofdt-based probe */ 152 of_rescan_bus(dn, bus); 153 } else if (mode == PCI_PROBE_NORMAL && 154 dn->child && PCI_DN(dn->child)) { 155 /* 156 * Use legacy probe. In the partial hotplug case, we 157 * probably have grandchildren devices unplugged. So 158 * we don't check the return value from pci_scan_slot() in 159 * order for fully rescan all the way down to pick them up. 160 * They can have been removed during partial hotplug. 161 */ 162 traverse_siblings_and_scan_slot(dn, bus); 163 max = bus->busn_res.start; 164 /* 165 * Scan bridges that are already configured. We don't touch 166 * them unless they are misconfigured (which will be done in 167 * the second scan below). 168 */ 169 for_each_pci_bridge(dev, bus) 170 max = pci_scan_bridge(bus, dev, max, 0); 171 172 /* Scan bridges that need to be reconfigured */ 173 for_each_pci_bridge(dev, bus) 174 max = pci_scan_bridge(bus, dev, max, 1); 175 } 176 pcibios_finish_adding_to_bus(bus); 177 } 178 EXPORT_SYMBOL_GPL(pci_hp_add_devices); 179