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 #include <linux/gfp.h> 27 28 #include <asm/io.h> 29 #include <asm/prom.h> 30 #include <asm/pci-bridge.h> 31 #include <asm/ppc-pci.h> 32 #include <asm/firmware.h> 33 34 /* 35 * Traverse_func that inits the PCI fields of the device node. 36 * NOTE: this *must* be done before read/write config to the device. 37 */ 38 void * __devinit update_dn_pci_info(struct device_node *dn, void *data) 39 { 40 struct pci_controller *phb = data; 41 const int *type = 42 of_get_property(dn, "ibm,pci-config-space-type", NULL); 43 const u32 *regs; 44 struct pci_dn *pdn; 45 46 pdn = alloc_maybe_bootmem(sizeof(*pdn), GFP_KERNEL); 47 if (pdn == NULL) 48 return NULL; 49 memset(pdn, 0, sizeof(*pdn)); 50 dn->data = pdn; 51 pdn->node = dn; 52 pdn->phb = phb; 53 regs = of_get_property(dn, "reg", NULL); 54 if (regs) { 55 /* First register entry is addr (00BBSS00) */ 56 pdn->busno = (regs[0] >> 16) & 0xff; 57 pdn->devfn = (regs[0] >> 8) & 0xff; 58 } 59 60 pdn->pci_ext_config_space = (type && *type == 1); 61 return NULL; 62 } 63 64 /* 65 * Traverse a device tree stopping each PCI device in the tree. 66 * This is done depth first. As each node is processed, a "pre" 67 * function is called and the children are processed recursively. 68 * 69 * The "pre" func returns a value. If non-zero is returned from 70 * the "pre" func, the traversal stops and this value is returned. 71 * This return value is useful when using traverse as a method of 72 * finding a device. 73 * 74 * NOTE: we do not run the func for devices that do not appear to 75 * be PCI except for the start node which we assume (this is good 76 * because the start node is often a phb which may be missing PCI 77 * properties). 78 * We use the class-code as an indicator. If we run into 79 * one of these nodes we also assume its siblings are non-pci for 80 * performance. 81 */ 82 void *traverse_pci_devices(struct device_node *start, traverse_func pre, 83 void *data) 84 { 85 struct device_node *dn, *nextdn; 86 void *ret; 87 88 /* We started with a phb, iterate all childs */ 89 for (dn = start->child; dn; dn = nextdn) { 90 const u32 *classp; 91 u32 class; 92 93 nextdn = NULL; 94 classp = of_get_property(dn, "class-code", NULL); 95 class = classp ? *classp : 0; 96 97 if (pre && ((ret = pre(dn, data)) != NULL)) 98 return ret; 99 100 /* If we are a PCI bridge, go down */ 101 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI || 102 (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS)) 103 /* Depth first...do children */ 104 nextdn = dn->child; 105 else if (dn->sibling) 106 /* ok, try next sibling instead. */ 107 nextdn = dn->sibling; 108 if (!nextdn) { 109 /* Walk up to next valid sibling. */ 110 do { 111 dn = dn->parent; 112 if (dn == start) 113 return NULL; 114 } while (dn->sibling == NULL); 115 nextdn = dn->sibling; 116 } 117 } 118 return NULL; 119 } 120 121 /** 122 * pci_devs_phb_init_dynamic - setup pci devices under this PHB 123 * phb: pci-to-host bridge (top-level bridge connecting to cpu) 124 * 125 * This routine is called both during boot, (before the memory 126 * subsystem is set up, before kmalloc is valid) and during the 127 * dynamic lpar operation of adding a PHB to a running system. 128 */ 129 void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb) 130 { 131 struct device_node *dn = phb->dn; 132 struct pci_dn *pdn; 133 134 /* PHB nodes themselves must not match */ 135 update_dn_pci_info(dn, phb); 136 pdn = dn->data; 137 if (pdn) { 138 pdn->devfn = pdn->busno = -1; 139 pdn->phb = phb; 140 } 141 142 /* Update dn->phb ptrs for new phb and children devices */ 143 traverse_pci_devices(dn, update_dn_pci_info, phb); 144 } 145 146 /* 147 * Traversal func that looks for a <busno,devfcn> value. 148 * If found, the pci_dn is returned (thus terminating the traversal). 149 */ 150 static void *is_devfn_node(struct device_node *dn, void *data) 151 { 152 int busno = ((unsigned long)data >> 8) & 0xff; 153 int devfn = ((unsigned long)data) & 0xff; 154 struct pci_dn *pci = dn->data; 155 156 if (pci && (devfn == pci->devfn) && (busno == pci->busno)) 157 return dn; 158 return NULL; 159 } 160 161 /* 162 * This is the "slow" path for looking up a device_node from a 163 * pci_dev. It will hunt for the device under its parent's 164 * phb and then update sysdata for a future fastpath. 165 * 166 * It may also do fixups on the actual device since this happens 167 * on the first read/write. 168 * 169 * Note that it also must deal with devices that don't exist. 170 * In this case it may probe for real hardware ("just in case") 171 * and add a device_node to the device tree if necessary. 172 * 173 */ 174 struct device_node *fetch_dev_dn(struct pci_dev *dev) 175 { 176 struct device_node *orig_dn = dev->sysdata; 177 struct device_node *dn; 178 unsigned long searchval = (dev->bus->number << 8) | dev->devfn; 179 180 dn = traverse_pci_devices(orig_dn, is_devfn_node, (void *)searchval); 181 if (dn) 182 dev->sysdata = dn; 183 return dn; 184 } 185 EXPORT_SYMBOL(fetch_dev_dn); 186 187 /** 188 * pci_devs_phb_init - Initialize phbs and pci devs under them. 189 * 190 * This routine walks over all phb's (pci-host bridges) on the 191 * system, and sets up assorted pci-related structures 192 * (including pci info in the device node structs) for each 193 * pci device found underneath. This routine runs once, 194 * early in the boot sequence. 195 */ 196 void __init pci_devs_phb_init(void) 197 { 198 struct pci_controller *phb, *tmp; 199 200 /* This must be done first so the device nodes have valid pci info! */ 201 list_for_each_entry_safe(phb, tmp, &hose_list, list_node) 202 pci_devs_phb_init_dynamic(phb); 203 } 204