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
  27 #include <asm/io.h>
  28 #include <asm/prom.h>
  29 #include <asm/pci-bridge.h>
  30 #include <asm/pSeries_reconfig.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 static 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         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
  60                 const u32 *busp = of_get_property(dn, "linux,subbus", NULL);
  61                 if (busp)
  62                         pdn->bussubno = *busp;
  63         }
  64
  65         pdn->pci_ext_config_space = (type && *type == 1);
  66         return NULL;
  67 }
  68
  69 /*
  70  * Traverse a device tree stopping each PCI device in the tree.
  71  * This is done depth first.  As each node is processed, a "pre"
  72  * function is called and the children are processed recursively.
  73  *
  74  * The "pre" func returns a value.  If non-zero is returned from
  75  * the "pre" func, the traversal stops and this value is returned.
  76  * This return value is useful when using traverse as a method of
  77  * finding a device.
  78  *
  79  * NOTE: we do not run the func for devices that do not appear to
  80  * be PCI except for the start node which we assume (this is good
  81  * because the start node is often a phb which may be missing PCI
  82  * properties).
  83  * We use the class-code as an indicator. If we run into
  84  * one of these nodes we also assume its siblings are non-pci for
  85  * performance.
  86  */
  87 void *traverse_pci_devices(struct device_node *start, traverse_func pre,
  88                 void *data)
  89 {
  90         struct device_node *dn, *nextdn;
  91         void *ret;
  92
  93         /* We started with a phb, iterate all childs */
  94         for (dn = start->child; dn; dn = nextdn) {
  95                 const u32 *classp;
  96                 u32 class;
  97
  98                 nextdn = NULL;
  99                 classp = of_get_property(dn, "class-code", NULL);
 100                 class = classp ? *classp : 0;
 101
 102                 if (pre && ((ret = pre(dn, data)) != NULL))
 103                         return ret;
 104
 105                 /* If we are a PCI bridge, go down */
 106                 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
 107                                   (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
 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                 if (!nextdn) {
 114                         /* Walk up to next valid sibling. */
 115                         do {
 116                                 dn = dn->parent;
 117                                 if (dn == start)
 118                                         return NULL;
 119                         } while (dn->sibling == NULL);
 120                         nextdn = dn->sibling;
 121                 }
 122         }
 123         return NULL;
 124 }
 125
 126 /**
 127  * pci_devs_phb_init_dynamic - setup pci devices under this PHB
 128  * phb: pci-to-host bridge (top-level bridge connecting to cpu)
 129  *
 130  * This routine is called both during boot, (before the memory
 131  * subsystem is set up, before kmalloc is valid) and during the
 132  * dynamic lpar operation of adding a PHB to a running system.
 133  */
 134 void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
 135 {
 136         struct device_node *dn = phb->dn;
 137         struct pci_dn *pdn;
 138
 139         /* PHB nodes themselves must not match */
 140         update_dn_pci_info(dn, phb);
 141         pdn = dn->data;
 142         if (pdn) {
 143                 pdn->devfn = pdn->busno = -1;
 144                 pdn->phb = phb;
 145         }
 146
 147         /* Update dn->phb ptrs for new phb and children devices */
 148         traverse_pci_devices(dn, update_dn_pci_info, phb);
 149 }
 150
 151 /*
 152  * Traversal func that looks for a <busno,devfcn> value.
 153  * If found, the pci_dn is returned (thus terminating the traversal).
 154  */
 155 static void *is_devfn_node(struct device_node *dn, void *data)
 156 {
 157         int busno = ((unsigned long)data >> 8) & 0xff;
 158         int devfn = ((unsigned long)data) & 0xff;
 159         struct pci_dn *pci = dn->data;
 160
 161         if (pci && (devfn == pci->devfn) && (busno == pci->busno))
 162                 return dn;
 163         return NULL;
 164 }
 165
 166 /*
 167  * This is the "slow" path for looking up a device_node from a
 168  * pci_dev.  It will hunt for the device under its parent's
 169  * phb and then update sysdata for a future fastpath.
 170  *
 171  * It may also do fixups on the actual device since this happens
 172  * on the first read/write.
 173  *
 174  * Note that it also must deal with devices that don't exist.
 175  * In this case it may probe for real hardware ("just in case")
 176  * and add a device_node to the device tree if necessary.
 177  *
 178  */
 179 struct device_node *fetch_dev_dn(struct pci_dev *dev)
 180 {
 181         struct device_node *orig_dn = dev->sysdata;
 182         struct device_node *dn;
 183         unsigned long searchval = (dev->bus->number << 8) | dev->devfn;
 184
 185         dn = traverse_pci_devices(orig_dn, is_devfn_node, (void *)searchval);
 186         if (dn)
 187                 dev->sysdata = dn;
 188         return dn;
 189 }
 190 EXPORT_SYMBOL(fetch_dev_dn);
 191
 192 static int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *node)
 193 {
 194         struct device_node *np = node;
 195         struct pci_dn *pci = NULL;
 196         int err = NOTIFY_OK;
 197
 198         switch (action) {
 199         case PSERIES_RECONFIG_ADD:
 200                 pci = np->parent->data;
 201                 if (pci)
 202                         update_dn_pci_info(np, pci->phb);
 203                 break;
 204         default:
 205                 err = NOTIFY_DONE;
 206                 break;
 207         }
 208         return err;
 209 }
 210
 211 static struct notifier_block pci_dn_reconfig_nb = {
 212         .notifier_call = pci_dn_reconfig_notifier,
 213 };
 214
 215 /**
 216  * pci_devs_phb_init - Initialize phbs and pci devs under them.
 217  *
 218  * This routine walks over all phb's (pci-host bridges) on the
 219  * system, and sets up assorted pci-related structures
 220  * (including pci info in the device node structs) for each
 221  * pci device found underneath.  This routine runs once,
 222  * early in the boot sequence.
 223  */
 224 void __init pci_devs_phb_init(void)
 225 {
 226         struct pci_controller *phb, *tmp;
 227
 228         /* This must be done first so the device nodes have valid pci info! */
 229         list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
 230                 pci_devs_phb_init_dynamic(phb);
 231
 232         pSeries_reconfig_notifier_register(&pci_dn_reconfig_nb);
 233 }