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/slab.h> 27#include <linux/bootmem.h> 28 29#include <asm/io.h> 30#include <asm/prom.h> 31#include <asm/pci-bridge.h> 32#include <asm/pSeries_reconfig.h> 33#include <asm/ppc-pci.h> 34#include <asm/firmware.h> 35 36/* 37 * Traverse_func that inits the PCI fields of the device node. 38 * NOTE: this *must* be done before read/write config to the device. 39 */ 40static void * __devinit update_dn_pci_info(struct device_node *dn, void *data) 41{ 42 struct pci_controller *phb = data; 43 const int *type = 44 of_get_property(dn, "ibm,pci-config-space-type", NULL); 45 const u32 *regs; 46 struct pci_dn *pdn; 47 48 if (mem_init_done) 49 pdn = kmalloc(sizeof(*pdn), GFP_KERNEL); 50 else 51 pdn = alloc_bootmem(sizeof(*pdn)); 52 if (pdn == NULL) 53 return NULL; 54 memset(pdn, 0, sizeof(*pdn)); 55 dn->data = pdn; 56 pdn->node = dn; 57 pdn->phb = phb; 58 regs = of_get_property(dn, "reg", NULL); 59 if (regs) { 60 /* First register entry is addr (00BBSS00) */ 61 pdn->busno = (regs[0] >> 16) & 0xff; 62 pdn->devfn = (regs[0] >> 8) & 0xff; 63 } 64 if (firmware_has_feature(FW_FEATURE_ISERIES)) { 65 const u32 *busp = of_get_property(dn, "linux,subbus", NULL); 66 if (busp) 67 pdn->bussubno = *busp; 68 } 69 70 pdn->pci_ext_config_space = (type && *type == 1); 71 return NULL; 72} 73 74/* 75 * Traverse a device tree stopping each PCI device in the tree. 76 * This is done depth first. As each node is processed, a "pre" 77 * function is called and the children are processed recursively. 78 * 79 * The "pre" func returns a value. If non-zero is returned from 80 * the "pre" func, the traversal stops and this value is returned. 81 * This return value is useful when using traverse as a method of 82 * finding a device. 83 * 84 * NOTE: we do not run the func for devices that do not appear to 85 * be PCI except for the start node which we assume (this is good 86 * because the start node is often a phb which may be missing PCI 87 * properties). 88 * We use the class-code as an indicator. If we run into 89 * one of these nodes we also assume its siblings are non-pci for 90 * performance. 91 */ 92void *traverse_pci_devices(struct device_node *start, traverse_func pre, 93 void *data) 94{ 95 struct device_node *dn, *nextdn; 96 void *ret; 97 98 /* We started with a phb, iterate all childs */ 99 for (dn = start->child; dn; dn = nextdn) { 100 const u32 *classp; 101 u32 class; 102 103 nextdn = NULL; 104 classp = of_get_property(dn, "class-code", NULL); 105 class = classp ? *classp : 0; 106 107 if (pre && ((ret = pre(dn, data)) != NULL)) 108 return ret; 109 110 /* If we are a PCI bridge, go down */ 111 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI || 112 (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS)) 113 /* Depth first...do children */ 114 nextdn = dn->child; 115 else if (dn->sibling) 116 /* ok, try next sibling instead. */ 117 nextdn = dn->sibling; 118 if (!nextdn) { 119 /* Walk up to next valid sibling. */ 120 do { 121 dn = dn->parent; 122 if (dn == start) 123 return NULL; 124 } while (dn->sibling == NULL); 125 nextdn = dn->sibling; 126 } 127 } 128 return NULL; 129} 130 131/** 132 * pci_devs_phb_init_dynamic - setup pci devices under this PHB 133 * phb: pci-to-host bridge (top-level bridge connecting to cpu) 134 * 135 * This routine is called both during boot, (before the memory 136 * subsystem is set up, before kmalloc is valid) and during the 137 * dynamic lpar operation of adding a PHB to a running system. 138 */ 139void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb) 140{ 141 struct device_node * dn = (struct device_node *) phb->arch_data; 142 struct pci_dn *pdn; 143 144 /* PHB nodes themselves must not match */ 145 update_dn_pci_info(dn, phb); 146 pdn = dn->data; 147 if (pdn) { 148 pdn->devfn = pdn->busno = -1; 149 pdn->phb = phb; 150 } 151 152 /* Update dn->phb ptrs for new phb and children devices */ 153 traverse_pci_devices(dn, update_dn_pci_info, phb); 154} 155 156/* 157 * Traversal func that looks for a <busno,devfcn> value. 158 * If found, the pci_dn is returned (thus terminating the traversal). 159 */ 160static void *is_devfn_node(struct device_node *dn, void *data) 161{ 162 int busno = ((unsigned long)data >> 8) & 0xff; 163 int devfn = ((unsigned long)data) & 0xff; 164 struct pci_dn *pci = dn->data; 165 166 if (pci && (devfn == pci->devfn) && (busno == pci->busno)) 167 return dn; 168 return NULL; 169} 170 171/* 172 * This is the "slow" path for looking up a device_node from a 173 * pci_dev. It will hunt for the device under its parent's 174 * phb and then update sysdata for a future fastpath. 175 * 176 * It may also do fixups on the actual device since this happens 177 * on the first read/write. 178 * 179 * Note that it also must deal with devices that don't exist. 180 * In this case it may probe for real hardware ("just in case") 181 * and add a device_node to the device tree if necessary. 182 * 183 */ 184struct device_node *fetch_dev_dn(struct pci_dev *dev) 185{ 186 struct device_node *orig_dn = dev->sysdata; 187 struct device_node *dn; 188 unsigned long searchval = (dev->bus->number << 8) | dev->devfn; 189 190 dn = traverse_pci_devices(orig_dn, is_devfn_node, (void *)searchval); 191 if (dn) 192 dev->sysdata = dn; 193 return dn; 194} 195EXPORT_SYMBOL(fetch_dev_dn); 196 197static int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *node) 198{ 199 struct device_node *np = node; 200 struct pci_dn *pci = NULL; 201 int err = NOTIFY_OK; 202 203 switch (action) { 204 case PSERIES_RECONFIG_ADD: 205 pci = np->parent->data; 206 if (pci) 207 update_dn_pci_info(np, pci->phb); 208 break; 209 default: 210 err = NOTIFY_DONE; 211 break; 212 } 213 return err; 214} 215 216static struct notifier_block pci_dn_reconfig_nb = { 217 .notifier_call = pci_dn_reconfig_notifier, 218}; 219 220/** 221 * pci_devs_phb_init - Initialize phbs and pci devs under them. 222 * 223 * This routine walks over all phb's (pci-host bridges) on the 224 * system, and sets up assorted pci-related structures 225 * (including pci info in the device node structs) for each 226 * pci device found underneath. This routine runs once, 227 * early in the boot sequence. 228 */ 229void __init pci_devs_phb_init(void) 230{ 231 struct pci_controller *phb, *tmp; 232 233 /* This must be done first so the device nodes have valid pci info! */ 234 list_for_each_entry_safe(phb, tmp, &hose_list, list_node) 235 pci_devs_phb_init_dynamic(phb); 236 237 pSeries_reconfig_notifier_register(&pci_dn_reconfig_nb); 238} 239