arch/ppc64/kernel/pci_dn.c

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