1 /* 2 * pci_dn.c 3 * 4 * Copyright (C) 2001 Todd Inglett, IBM Corporation 5 * 6 * PCI manipulation via device_nodes. 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 */ 22 #include <linux/kernel.h> 23 #include <linux/pci.h> 24 #include <linux/string.h> 25 #include <linux/init.h> 26 27 #include <asm/io.h> 28 #include <asm/prom.h> 29 #include <asm/pci-bridge.h> 30 #include <asm/ppc-pci.h> 31 #include <asm/firmware.h> 32 33 /* 34 * Traverse_func that inits the PCI fields of the device node. 35 * NOTE: this *must* be done before read/write config to the device. 36 */ 37 void * __devinit update_dn_pci_info(struct device_node *dn, void *data) 38 { 39 struct pci_controller *phb = data; 40 const int *type = 41 of_get_property(dn, "ibm,pci-config-space-type", NULL); 42 const u32 *regs; 43 struct pci_dn *pdn; 44 45 pdn = alloc_maybe_bootmem(sizeof(*pdn), GFP_KERNEL); 46 if (pdn == NULL) 47 return NULL; 48 memset(pdn, 0, sizeof(*pdn)); 49 dn->data = pdn; 50 pdn->node = dn; 51 pdn->phb = phb; 52 regs = of_get_property(dn, "reg", NULL); 53 if (regs) { 54 /* First register entry is addr (00BBSS00) */ 55 pdn->busno = (regs[0] >> 16) & 0xff; 56 pdn->devfn = (regs[0] >> 8) & 0xff; 57 } 58 59 pdn->pci_ext_config_space = (type && *type == 1); 60 return NULL; 61 } 62 63 /* 64 * Traverse a device tree stopping each PCI device in the tree. 65 * This is done depth first. As each node is processed, a "pre" 66 * function is called and the children are processed recursively. 67 * 68 * The "pre" func returns a value. If non-zero is returned from 69 * the "pre" func, the traversal stops and this value is returned. 70 * This return value is useful when using traverse as a method of 71 * finding a device. 72 * 73 * NOTE: we do not run the func for devices that do not appear to 74 * be PCI except for the start node which we assume (this is good 75 * because the start node is often a phb which may be missing PCI 76 * properties). 77 * We use the class-code as an indicator. If we run into 78 * one of these nodes we also assume its siblings are non-pci for 79 * performance. 80 */ 81 void *traverse_pci_devices(struct device_node *start, traverse_func pre, 82 void *data) 83 { 84 struct device_node *dn, *nextdn; 85 void *ret; 86 87 /* We started with a phb, iterate all childs */ 88 for (dn = start->child; dn; dn = nextdn) { 89 const u32 *classp; 90 u32 class; 91 92 nextdn = NULL; 93 classp = of_get_property(dn, "class-code", NULL); 94 class = classp ? *classp : 0; 95 96 if (pre && ((ret = pre(dn, data)) != NULL)) 97 return ret; 98 99 /* If we are a PCI bridge, go down */ 100 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI || 101 (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS)) 102 /* Depth first...do children */ 103 nextdn = dn->child; 104 else if (dn->sibling) 105 /* ok, try next sibling instead. */ 106 nextdn = dn->sibling; 107 if (!nextdn) { 108 /* Walk up to next valid sibling. */ 109 do { 110 dn = dn->parent; 111 if (dn == start) 112 return NULL; 113 } while (dn->sibling == NULL); 114 nextdn = dn->sibling; 115 } 116 } 117 return NULL; 118 } 119 120 /** 121 * pci_devs_phb_init_dynamic - setup pci devices under this PHB 122 * phb: pci-to-host bridge (top-level bridge connecting to cpu) 123 * 124 * This routine is called both during boot, (before the memory 125 * subsystem is set up, before kmalloc is valid) and during the 126 * dynamic lpar operation of adding a PHB to a running system. 127 */ 128 void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb) 129 { 130 struct device_node *dn = phb->dn; 131 struct pci_dn *pdn; 132 133 /* PHB nodes themselves must not match */ 134 update_dn_pci_info(dn, phb); 135 pdn = dn->data; 136 if (pdn) { 137 pdn->devfn = pdn->busno = -1; 138 pdn->phb = phb; 139 } 140 141 /* Update dn->phb ptrs for new phb and children devices */ 142 traverse_pci_devices(dn, update_dn_pci_info, phb); 143 } 144 145 /* 146 * Traversal func that looks for a <busno,devfcn> value. 147 * If found, the pci_dn is returned (thus terminating the traversal). 148 */ 149 static void *is_devfn_node(struct device_node *dn, void *data) 150 { 151 int busno = ((unsigned long)data >> 8) & 0xff; 152 int devfn = ((unsigned long)data) & 0xff; 153 struct pci_dn *pci = dn->data; 154 155 if (pci && (devfn == pci->devfn) && (busno == pci->busno)) 156 return dn; 157 return NULL; 158 } 159 160 /* 161 * This is the "slow" path for looking up a device_node from a 162 * pci_dev. It will hunt for the device under its parent's 163 * phb and then update sysdata for a future fastpath. 164 * 165 * It may also do fixups on the actual device since this happens 166 * on the first read/write. 167 * 168 * Note that it also must deal with devices that don't exist. 169 * In this case it may probe for real hardware ("just in case") 170 * and add a device_node to the device tree if necessary. 171 * 172 */ 173 struct device_node *fetch_dev_dn(struct pci_dev *dev) 174 { 175 struct device_node *orig_dn = dev->sysdata; 176 struct device_node *dn; 177 unsigned long searchval = (dev->bus->number << 8) | dev->devfn; 178 179 dn = traverse_pci_devices(orig_dn, is_devfn_node, (void *)searchval); 180 if (dn) 181 dev->sysdata = dn; 182 return dn; 183 } 184 EXPORT_SYMBOL(fetch_dev_dn); 185 186 /** 187 * pci_devs_phb_init - Initialize phbs and pci devs under them. 188 * 189 * This routine walks over all phb's (pci-host bridges) on the 190 * system, and sets up assorted pci-related structures 191 * (including pci info in the device node structs) for each 192 * pci device found underneath. This routine runs once, 193 * early in the boot sequence. 194 */ 195 void __init pci_devs_phb_init(void) 196 { 197 struct pci_controller *phb, *tmp; 198 199 /* This must be done first so the device nodes have valid pci info! */ 200 list_for_each_entry_safe(phb, tmp, &hose_list, list_node) 201 pci_devs_phb_init_dynamic(phb); 202 } 203