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/delay.h>
  25 #include <linux/string.h>
  26 #include <linux/init.h>
  27 #include <linux/bootmem.h>
  28
  29 #include <asm/io.h>
  30 #include <asm/pgtable.h>
  31 #include <asm/irq.h>
  32 #include <asm/prom.h>
  33 #include <asm/machdep.h>
  34 #include <asm/pci-bridge.h>
  35 #include <asm/ppcdebug.h>
  36 #include <asm/naca.h>
  37 #include <asm/iommu.h>
  38
  39 #include "pci.h"
  40
  41 /*
  42  * Traverse_func that inits the PCI fields of the device node.
  43  * NOTE: this *must* be done before read/write config to the device.
  44  */
  45 static void * __init update_dn_pci_info(struct device_node *dn, void *data)
  46 {
  47         struct pci_controller *phb = data;
  48         u32 *regs;
  49         char *device_type = get_property(dn, "device_type", NULL);
  50         char *model;
  51
  52         dn->phb = phb;
  53         if (device_type && (strcmp(device_type, "pci") == 0) &&
  54                         (get_property(dn, "class-code", NULL) == 0)) {
  55                 /* special case for PHB's.  Sigh. */
  56                 regs = (u32 *)get_property(dn, "bus-range", NULL);
  57                 dn->busno = regs[0];
  58
  59                 model = (char *)get_property(dn, "model", NULL);
  60
  61                 if (strstr(model, "U3"))
  62                         dn->devfn = -1;
  63                 else
  64                         dn->devfn = 0;  /* assumption */
  65         } else {
  66                 regs = (u32 *)get_property(dn, "reg", NULL);
  67                 if (regs) {
  68                         /* First register entry is addr (00BBSS00)  */
  69                         dn->busno = (regs[0] >> 16) & 0xff;
  70                         dn->devfn = (regs[0] >> 8) & 0xff;
  71                 }
  72         }
  73         return NULL;
  74 }
  75
  76 /*
  77  * Traverse a device tree stopping each PCI device in the tree.
  78  * This is done depth first.  As each node is processed, a "pre"
  79  * function is called and the children are processed recursively.
  80  *
  81  * The "pre" func returns a value.  If non-zero is returned from
  82  * the "pre" func, the traversal stops and this value is returned.
  83  * This return value is useful when using traverse as a method of
  84  * finding a device.
  85  *
  86  * NOTE: we do not run the func for devices that do not appear to
  87  * be PCI except for the start node which we assume (this is good
  88  * because the start node is often a phb which may be missing PCI
  89  * properties).
  90  * We use the class-code as an indicator. If we run into
  91  * one of these nodes we also assume its siblings are non-pci for
  92  * performance.
  93  */
  94 void *traverse_pci_devices(struct device_node *start, traverse_func pre,
  95                 void *data)
  96 {
  97         struct device_node *dn, *nextdn;
  98         void *ret;
  99
 100         if (pre && ((ret = pre(start, data)) != NULL))
 101                 return ret;
 102         for (dn = start->child; dn; dn = nextdn) {
 103                 nextdn = NULL;
 104                 if (get_property(dn, "class-code", NULL)) {
 105                         if (pre && ((ret = pre(dn, data)) != NULL))
 106                                 return ret;
 107                         if (dn->child)
 108                                 /* Depth first...do children */
 109                                 nextdn = dn->child;
 110                         else if (dn->sibling)
 111                                 /* ok, try next sibling instead. */
 112                                 nextdn = dn->sibling;
 113                 }
 114                 if (!nextdn) {
 115                         /* Walk up to next valid sibling. */
 116                         do {
 117                                 dn = dn->parent;
 118                                 if (dn == start)
 119                                         return NULL;
 120                         } while (dn->sibling == NULL);
 121                         nextdn = dn->sibling;
 122                 }
 123         }
 124         return NULL;
 125 }
 126
 127 /*
 128  * Same as traverse_pci_devices except this does it for all phbs.
 129  */
 130 static void *traverse_all_pci_devices(traverse_func pre)
 131 {
 132         struct pci_controller *phb, *tmp;
 133         void *ret;
 134
 135         list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
 136                 if ((ret = traverse_pci_devices(phb->arch_data, pre, phb))
 137                                 != NULL)
 138                         return ret;
 139         return NULL;
 140 }
 141
 142
 143 /*
 144  * Traversal func that looks for a <busno,devfcn> value.
 145  * If found, the device_node is returned (thus terminating the traversal).
 146  */
 147 static void *is_devfn_node(struct device_node *dn, void *data)
 148 {
 149         int busno = ((unsigned long)data >> 8) & 0xff;
 150         int devfn = ((unsigned long)data) & 0xff;
 151         return ((devfn == dn->devfn) && (busno == dn->busno)) ? dn : NULL;
 152 }
 153
 154 /*
 155  * This is the "slow" path for looking up a device_node from a
 156  * pci_dev.  It will hunt for the device under its parent's
 157  * phb and then update sysdata for a future fastpath.
 158  *
 159  * It may also do fixups on the actual device since this happens
 160  * on the first read/write.
 161  *
 162  * Note that it also must deal with devices that don't exist.
 163  * In this case it may probe for real hardware ("just in case")
 164  * and add a device_node to the device tree if necessary.
 165  *
 166  */
 167 struct device_node *fetch_dev_dn(struct pci_dev *dev)
 168 {
 169         struct device_node *orig_dn = dev->sysdata;
 170         struct pci_controller *phb = orig_dn->phb; /* assume same phb as orig_dn */
 171         struct device_node *phb_dn;
 172         struct device_node *dn;
 173         unsigned long searchval = (dev->bus->number << 8) | dev->devfn;
 174
 175         phb_dn = phb->arch_data;
 176         dn = traverse_pci_devices(phb_dn, is_devfn_node, (void *)searchval);
 177         if (dn) {
 178                 dev->sysdata = dn;
 179                 /* ToDo: call some device init hook here */
 180         }
 181         return dn;
 182 }
 183 EXPORT_SYMBOL(fetch_dev_dn);
 184
 185
 186 /*
 187  * Actually initialize the phbs.
 188  * The buswalk on this phb has not happened yet.
 189  */
 190 void __init pci_devs_phb_init(void)
 191 {
 192         /* This must be done first so the device nodes have valid pci info! */
 193         traverse_all_pci_devices(update_dn_pci_info);
 194 }
 195
 196
 197 static void __init pci_fixup_bus_sysdata_list(struct list_head *bus_list)
 198 {
 199         struct list_head *ln;
 200         struct pci_bus *bus;
 201
 202         for (ln = bus_list->next; ln != bus_list; ln = ln->next) {
 203                 bus = pci_bus_b(ln);
 204                 if (bus->self)
 205                         bus->sysdata = bus->self->sysdata;
 206                 pci_fixup_bus_sysdata_list(&bus->children);
 207         }
 208 }
 209
 210 /*
 211  * Fixup the bus->sysdata ptrs to point to the bus' device_node.
 212  * This is done late in pcibios_init().  We do this mostly for
 213  * sanity, but pci_dma.c uses these at DMA time so they must be
 214  * correct.
 215  * To do this we recurse down the bus hierarchy.  Note that PHB's
 216  * have bus->self == NULL, but fortunately bus->sysdata is already
 217  * correct in this case.
 218  */
 219 void __init pci_fix_bus_sysdata(void)
 220 {
 221         pci_fixup_bus_sysdata_list(&pci_root_buses);
 222 }