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 #include <asm/firmware.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         const int *type = get_property(dn, "ibm,pci-config-space-type", NULL);
  44         const u32 *regs;
  45         struct pci_dn *pdn;
  46
  47         if (mem_init_done)
  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 = 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         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
  64                 const u32 *busp = get_property(dn, "linux,subbus", NULL);
  65                 if (busp)
  66                         pdn->bussubno = *busp;
  67         }
  68
  69         pdn->pci_ext_config_space = (type && *type == 1);
  70         return NULL;
  71 }
  72
  73 /*
  74  * Traverse a device tree stopping each PCI device in the tree.
  75  * This is done depth first.  As each node is processed, a "pre"
  76  * function is called and the children are processed recursively.
  77  *
  78  * The "pre" func returns a value.  If non-zero is returned from
  79  * the "pre" func, the traversal stops and this value is returned.
  80  * This return value is useful when using traverse as a method of
  81  * finding a device.
  82  *
  83  * NOTE: we do not run the func for devices that do not appear to
  84  * be PCI except for the start node which we assume (this is good
  85  * because the start node is often a phb which may be missing PCI
  86  * properties).
  87  * We use the class-code as an indicator. If we run into
  88  * one of these nodes we also assume its siblings are non-pci for
  89  * performance.
  90  */
  91 void *traverse_pci_devices(struct device_node *start, traverse_func pre,
  92                 void *data)
  93 {
  94         struct device_node *dn, *nextdn;
  95         void *ret;
  96
  97         /* We started with a phb, iterate all childs */
  98         for (dn = start->child; dn; dn = nextdn) {
  99                 const u32 *classp;
 100                 u32 class;
 101
 102                 nextdn = NULL;
 103                 classp = get_property(dn, "class-code", NULL);
 104                 class = classp ? *classp : 0;
 105
 106                 if (pre && ((ret = pre(dn, data)) != NULL))
 107                         return ret;
 108
 109                 /* If we are a PCI bridge, go down */
 110                 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
 111                                   (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
 112                         /* Depth first...do children */
 113                         nextdn = dn->child;
 114                 else if (dn->sibling)
 115                         /* ok, try next sibling instead. */
 116                         nextdn = dn->sibling;
 117                 if (!nextdn) {
 118                         /* Walk up to next valid sibling. */
 119                         do {
 120                                 dn = dn->parent;
 121                                 if (dn == start)
 122                                         return NULL;
 123                         } while (dn->sibling == NULL);
 124                         nextdn = dn->sibling;
 125                 }
 126         }
 127         return NULL;
 128 }
 129
 130 /**
 131  * pci_devs_phb_init_dynamic - setup pci devices under this PHB
 132  * phb: pci-to-host bridge (top-level bridge connecting to cpu)
 133  *
 134  * This routine is called both during boot, (before the memory
 135  * subsystem is set up, before kmalloc is valid) and during the
 136  * dynamic lpar operation of adding a PHB to a running system.
 137  */
 138 void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
 139 {
 140         struct device_node * dn = (struct device_node *) phb->arch_data;
 141         struct pci_dn *pdn;
 142
 143         /* PHB nodes themselves must not match */
 144         update_dn_pci_info(dn, phb);
 145         pdn = dn->data;
 146         if (pdn) {
 147                 pdn->devfn = pdn->busno = -1;
 148                 pdn->phb = phb;
 149         }
 150
 151         /* Update dn->phb ptrs for new phb and children devices */
 152         traverse_pci_devices(dn, update_dn_pci_info, phb);
 153 }
 154
 155 /*
 156  * Traversal func that looks for a <busno,devfcn> value.
 157  * If found, the pci_dn is returned (thus terminating the traversal).
 158  */
 159 static void *is_devfn_node(struct device_node *dn, void *data)
 160 {
 161         int busno = ((unsigned long)data >> 8) & 0xff;
 162         int devfn = ((unsigned long)data) & 0xff;
 163         struct pci_dn *pci = dn->data;
 164
 165         if (pci && (devfn == pci->devfn) && (busno == pci->busno))
 166                 return dn;
 167         return NULL;
 168 }
 169
 170 /*
 171  * This is the "slow" path for looking up a device_node from a
 172  * pci_dev.  It will hunt for the device under its parent's
 173  * phb and then update sysdata for a future fastpath.
 174  *
 175  * It may also do fixups on the actual device since this happens
 176  * on the first read/write.
 177  *
 178  * Note that it also must deal with devices that don't exist.
 179  * In this case it may probe for real hardware ("just in case")
 180  * and add a device_node to the device tree if necessary.
 181  *
 182  */
 183 struct device_node *fetch_dev_dn(struct pci_dev *dev)
 184 {
 185         struct device_node *orig_dn = dev->sysdata;
 186         struct device_node *dn;
 187         unsigned long searchval = (dev->bus->number << 8) | dev->devfn;
 188
 189         dn = traverse_pci_devices(orig_dn, is_devfn_node, (void *)searchval);
 190         if (dn)
 191                 dev->sysdata = dn;
 192         return dn;
 193 }
 194 EXPORT_SYMBOL(fetch_dev_dn);
 195
 196 static int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *node)
 197 {
 198         struct device_node *np = node;
 199         struct pci_dn *pci = NULL;
 200         int err = NOTIFY_OK;
 201
 202         switch (action) {
 203         case PSERIES_RECONFIG_ADD:
 204                 pci = np->parent->data;
 205                 if (pci)
 206                         update_dn_pci_info(np, pci->phb);
 207                 break;
 208         default:
 209                 err = NOTIFY_DONE;
 210                 break;
 211         }
 212         return err;
 213 }
 214
 215 static struct notifier_block pci_dn_reconfig_nb = {
 216         .notifier_call = pci_dn_reconfig_notifier,
 217 };
 218
 219 /**
 220  * pci_devs_phb_init - Initialize phbs and pci devs under them.
 221  *
 222  * This routine walks over all phb's (pci-host bridges) on the
 223  * system, and sets up assorted pci-related structures
 224  * (including pci info in the device node structs) for each
 225  * pci device found underneath.  This routine runs once,
 226  * early in the boot sequence.
 227  */
 228 void __init pci_devs_phb_init(void)
 229 {
 230         struct pci_controller *phb, *tmp;
 231
 232         /* This must be done first so the device nodes have valid pci info! */
 233         list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
 234                 pci_devs_phb_init_dynamic(phb);
 235
 236         pSeries_reconfig_notifier_register(&pci_dn_reconfig_nb);
 237 }