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