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/gfp.h>
  27
  28 #include <asm/io.h>
  29 #include <asm/prom.h>
  30 #include <asm/pci-bridge.h>
  31 #include <asm/ppc-pci.h>
  32 #include <asm/firmware.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 void * __devinit update_dn_pci_info(struct device_node *dn, void *data)
  39 {
  40         struct pci_controller *phb = data;
  41         const int *type =
  42                 of_get_property(dn, "ibm,pci-config-space-type", NULL);
  43         const u32 *regs;
  44         struct pci_dn *pdn;
  45
  46         pdn = alloc_maybe_bootmem(sizeof(*pdn), GFP_KERNEL);
  47         if (pdn == NULL)
  48                 return NULL;
  49         memset(pdn, 0, sizeof(*pdn));
  50         dn->data = pdn;
  51         pdn->node = dn;
  52         pdn->phb = phb;
  53         regs = of_get_property(dn, "reg", NULL);
  54         if (regs) {
  55                 /* First register entry is addr (00BBSS00)  */
  56                 pdn->busno = (regs[0] >> 16) & 0xff;
  57                 pdn->devfn = (regs[0] >> 8) & 0xff;
  58         }
  59
  60         pdn->pci_ext_config_space = (type && *type == 1);
  61         return NULL;
  62 }
  63
  64 /*
  65  * Traverse a device tree stopping each PCI device in the tree.
  66  * This is done depth first.  As each node is processed, a "pre"
  67  * function is called and the children are processed recursively.
  68  *
  69  * The "pre" func returns a value.  If non-zero is returned from
  70  * the "pre" func, the traversal stops and this value is returned.
  71  * This return value is useful when using traverse as a method of
  72  * finding a device.
  73  *
  74  * NOTE: we do not run the func for devices that do not appear to
  75  * be PCI except for the start node which we assume (this is good
  76  * because the start node is often a phb which may be missing PCI
  77  * properties).
  78  * We use the class-code as an indicator. If we run into
  79  * one of these nodes we also assume its siblings are non-pci for
  80  * performance.
  81  */
  82 void *traverse_pci_devices(struct device_node *start, traverse_func pre,
  83                 void *data)
  84 {
  85         struct device_node *dn, *nextdn;
  86         void *ret;
  87
  88         /* We started with a phb, iterate all childs */
  89         for (dn = start->child; dn; dn = nextdn) {
  90                 const u32 *classp;
  91                 u32 class;
  92
  93                 nextdn = NULL;
  94                 classp = of_get_property(dn, "class-code", NULL);
  95                 class = classp ? *classp : 0;
  96
  97                 if (pre && ((ret = pre(dn, data)) != NULL))
  98                         return ret;
  99
 100                 /* If we are a PCI bridge, go down */
 101                 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
 102                                   (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
 103                         /* Depth first...do children */
 104                         nextdn = dn->child;
 105                 else if (dn->sibling)
 106                         /* ok, try next sibling instead. */
 107                         nextdn = dn->sibling;
 108                 if (!nextdn) {
 109                         /* Walk up to next valid sibling. */
 110                         do {
 111                                 dn = dn->parent;
 112                                 if (dn == start)
 113                                         return NULL;
 114                         } while (dn->sibling == NULL);
 115                         nextdn = dn->sibling;
 116                 }
 117         }
 118         return NULL;
 119 }
 120
 121 /**
 122  * pci_devs_phb_init_dynamic - setup pci devices under this PHB
 123  * phb: pci-to-host bridge (top-level bridge connecting to cpu)
 124  *
 125  * This routine is called both during boot, (before the memory
 126  * subsystem is set up, before kmalloc is valid) and during the
 127  * dynamic lpar operation of adding a PHB to a running system.
 128  */
 129 void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
 130 {
 131         struct device_node *dn = phb->dn;
 132         struct pci_dn *pdn;
 133
 134         /* PHB nodes themselves must not match */
 135         update_dn_pci_info(dn, phb);
 136         pdn = dn->data;
 137         if (pdn) {
 138                 pdn->devfn = pdn->busno = -1;
 139                 pdn->phb = phb;
 140         }
 141
 142         /* Update dn->phb ptrs for new phb and children devices */
 143         traverse_pci_devices(dn, update_dn_pci_info, phb);
 144 }
 145
 146 /*
 147  * Traversal func that looks for a <busno,devfcn> value.
 148  * If found, the pci_dn is returned (thus terminating the traversal).
 149  */
 150 static void *is_devfn_node(struct device_node *dn, void *data)
 151 {
 152         int busno = ((unsigned long)data >> 8) & 0xff;
 153         int devfn = ((unsigned long)data) & 0xff;
 154         struct pci_dn *pci = dn->data;
 155
 156         if (pci && (devfn == pci->devfn) && (busno == pci->busno))
 157                 return dn;
 158         return NULL;
 159 }
 160
 161 /*
 162  * This is the "slow" path for looking up a device_node from a
 163  * pci_dev.  It will hunt for the device under its parent's
 164  * phb and then update sysdata for a future fastpath.
 165  *
 166  * It may also do fixups on the actual device since this happens
 167  * on the first read/write.
 168  *
 169  * Note that it also must deal with devices that don't exist.
 170  * In this case it may probe for real hardware ("just in case")
 171  * and add a device_node to the device tree if necessary.
 172  *
 173  */
 174 struct device_node *fetch_dev_dn(struct pci_dev *dev)
 175 {
 176         struct device_node *orig_dn = dev->sysdata;
 177         struct device_node *dn;
 178         unsigned long searchval = (dev->bus->number << 8) | dev->devfn;
 179
 180         dn = traverse_pci_devices(orig_dn, is_devfn_node, (void *)searchval);
 181         if (dn)
 182                 dev->sysdata = dn;
 183         return dn;
 184 }
 185 EXPORT_SYMBOL(fetch_dev_dn);
 186
 187 /**
 188  * pci_devs_phb_init - Initialize phbs and pci devs under them.
 189  *
 190  * This routine walks over all phb's (pci-host bridges) on the
 191  * system, and sets up assorted pci-related structures
 192  * (including pci info in the device node structs) for each
 193  * pci device found underneath.  This routine runs once,
 194  * early in the boot sequence.
 195  */
 196 void __init pci_devs_phb_init(void)
 197 {
 198         struct pci_controller *phb, *tmp;
 199
 200         /* This must be done first so the device nodes have valid pci info! */
 201         list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
 202                 pci_devs_phb_init_dynamic(phb);
 203 }