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