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 #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
  34 #include "pci.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         int *type = (int *)get_property(dn, "ibm,pci-config-space-type", NULL);
  44         u32 *regs;
  45         struct pci_dn *pdn;
  46
  47         if (phb->is_dynamic)
  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 = (u32 *)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
  64         pdn->pci_ext_config_space = (type && *type == 1);
  65         return NULL;
  66 }
  67
  68 /*
  69  * Traverse a device tree stopping each PCI device in the tree.
  70  * This is done depth first.  As each node is processed, a "pre"
  71  * function is called and the children are processed recursively.
  72  *
  73  * The "pre" func returns a value.  If non-zero is returned from
  74  * the "pre" func, the traversal stops and this value is returned.
  75  * This return value is useful when using traverse as a method of
  76  * finding a device.
  77  *
  78  * NOTE: we do not run the func for devices that do not appear to
  79  * be PCI except for the start node which we assume (this is good
  80  * because the start node is often a phb which may be missing PCI
  81  * properties).
  82  * We use the class-code as an indicator. If we run into
  83  * one of these nodes we also assume its siblings are non-pci for
  84  * performance.
  85  */
  86 void *traverse_pci_devices(struct device_node *start, traverse_func pre,
  87                 void *data)
  88 {
  89         struct device_node *dn, *nextdn;
  90         void *ret;
  91
  92         /* We started with a phb, iterate all childs */
  93         for (dn = start->child; dn; dn = nextdn) {
  94                 u32 *classp, class;
  95
  96                 nextdn = NULL;
  97                 classp = (u32 *)get_property(dn, "class-code", NULL);
  98                 class = classp ? *classp : 0;
  99
 100                 if (pre && ((ret = pre(dn, data)) != NULL))
 101                         return ret;
 102
 103                 /* If we are a PCI bridge, go down */
 104                 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
 105                                   (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
 106                         /* Depth first...do children */
 107                         nextdn = dn->child;
 108                 else if (dn->sibling)
 109                         /* ok, try next sibling instead. */
 110                         nextdn = dn->sibling;
 111                 if (!nextdn) {
 112                         /* Walk up to next valid sibling. */
 113                         do {
 114                                 dn = dn->parent;
 115                                 if (dn == start)
 116                                         return NULL;
 117                         } while (dn->sibling == NULL);
 118                         nextdn = dn->sibling;
 119                 }
 120         }
 121         return NULL;
 122 }
 123
 124 void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
 125 {
 126         struct device_node * dn = (struct device_node *) phb->arch_data;
 127         struct pci_dn *pdn;
 128
 129         /* PHB nodes themselves must not match */
 130         update_dn_pci_info(dn, phb);
 131         pdn = dn->data;
 132         if (pdn) {
 133                 pdn->devfn = pdn->busno = -1;
 134                 pdn->phb = phb;
 135         }
 136
 137         /* Update dn->phb ptrs for new phb and children devices */
 138         traverse_pci_devices(dn, update_dn_pci_info, phb);
 139 }
 140
 141 /*
 142  * Traversal func that looks for a <busno,devfcn> value.
 143  * If found, the pci_dn is returned (thus terminating the traversal).
 144  */
 145 static void *is_devfn_node(struct device_node *dn, void *data)
 146 {
 147         int busno = ((unsigned long)data >> 8) & 0xff;
 148         int devfn = ((unsigned long)data) & 0xff;
 149         struct pci_dn *pci = dn->data;
 150
 151         if (pci && (devfn == pci->devfn) && (busno == pci->busno))
 152                 return dn;
 153         return NULL;
 154 }
 155
 156 /*
 157  * This is the "slow" path for looking up a device_node from a
 158  * pci_dev.  It will hunt for the device under its parent's
 159  * phb and then update sysdata for a future fastpath.
 160  *
 161  * It may also do fixups on the actual device since this happens
 162  * on the first read/write.
 163  *
 164  * Note that it also must deal with devices that don't exist.
 165  * In this case it may probe for real hardware ("just in case")
 166  * and add a device_node to the device tree if necessary.
 167  *
 168  */
 169 struct device_node *fetch_dev_dn(struct pci_dev *dev)
 170 {
 171         struct device_node *orig_dn = dev->sysdata;
 172         struct device_node *dn;
 173         unsigned long searchval = (dev->bus->number << 8) | dev->devfn;
 174
 175         dn = traverse_pci_devices(orig_dn, is_devfn_node, (void *)searchval);
 176         if (dn)
 177                 dev->sysdata = dn;
 178         return dn;
 179 }
 180 EXPORT_SYMBOL(fetch_dev_dn);
 181
 182 static int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *node)
 183 {
 184         struct device_node *np = node;
 185         struct pci_dn *pci;
 186         int err = NOTIFY_OK;
 187
 188         switch (action) {
 189         case PSERIES_RECONFIG_ADD:
 190                 pci = np->parent->data;
 191                 update_dn_pci_info(np, pci->phb);
 192                 break;
 193         default:
 194                 err = NOTIFY_DONE;
 195                 break;
 196         }
 197         return err;
 198 }
 199
 200 static struct notifier_block pci_dn_reconfig_nb = {
 201         .notifier_call = pci_dn_reconfig_notifier,
 202 };
 203
 204 /*
 205  * Actually initialize the phbs.
 206  * The buswalk on this phb has not happened yet.
 207  */
 208 void __init pci_devs_phb_init(void)
 209 {
 210         struct pci_controller *phb, *tmp;
 211
 212         /* This must be done first so the device nodes have valid pci info! */
 213         list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
 214                 pci_devs_phb_init_dynamic(phb);
 215
 216         pSeries_reconfig_notifier_register(&pci_dn_reconfig_nb);
 217 }