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