arch/powerpc/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 #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 }