release/src-rt-6.x/linux/linux-2.6/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 =
  44                 of_get_property(dn, "ibm,pci-config-space-type", NULL);
  45         const u32 *regs;
  46         struct pci_dn *pdn;
  47
  48         if (mem_init_done)
  49                 pdn = kmalloc(sizeof(*pdn), GFP_KERNEL);
  50         else
  51                 pdn = alloc_bootmem(sizeof(*pdn));
  52         if (pdn == NULL)
  53                 return NULL;
  54         memset(pdn, 0, sizeof(*pdn));
  55         dn->data = pdn;
  56         pdn->node = dn;
  57         pdn->phb = phb;
  58         regs = of_get_property(dn, "reg", NULL);
  59         if (regs) {
  60                 /* First register entry is addr (00BBSS00)  */
  61                 pdn->busno = (regs[0] >> 16) & 0xff;
  62                 pdn->devfn = (regs[0] >> 8) & 0xff;
  63         }
  64         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
  65                 const u32 *busp = of_get_property(dn, "linux,subbus", NULL);
  66                 if (busp)
  67                         pdn->bussubno = *busp;
  68         }
  69
  70         pdn->pci_ext_config_space = (type && *type == 1);
  71         return NULL;
  72 }
  73
  74 /*
  75  * Traverse a device tree stopping each PCI device in the tree.
  76  * This is done depth first.  As each node is processed, a "pre"
  77  * function is called and the children are processed recursively.
  78  *
  79  * The "pre" func returns a value.  If non-zero is returned from
  80  * the "pre" func, the traversal stops and this value is returned.
  81  * This return value is useful when using traverse as a method of
  82  * finding a device.
  83  *
  84  * NOTE: we do not run the func for devices that do not appear to
  85  * be PCI except for the start node which we assume (this is good
  86  * because the start node is often a phb which may be missing PCI
  87  * properties).
  88  * We use the class-code as an indicator. If we run into
  89  * one of these nodes we also assume its siblings are non-pci for
  90  * performance.
  91  */
  92 void *traverse_pci_devices(struct device_node *start, traverse_func pre,
  93                 void *data)
  94 {
  95         struct device_node *dn, *nextdn;
  96         void *ret;
  97
  98         /* We started with a phb, iterate all childs */
  99         for (dn = start->child; dn; dn = nextdn) {
 100                 const u32 *classp;
 101                 u32 class;
 102
 103                 nextdn = NULL;
 104                 classp = of_get_property(dn, "class-code", NULL);
 105                 class = classp ? *classp : 0;
 106
 107                 if (pre && ((ret = pre(dn, data)) != NULL))
 108                         return ret;
 109
 110                 /* If we are a PCI bridge, go down */
 111                 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
 112                                   (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
 113                         /* Depth first...do children */
 114                         nextdn = dn->child;
 115                 else if (dn->sibling)
 116                         /* ok, try next sibling instead. */
 117                         nextdn = dn->sibling;
 118                 if (!nextdn) {
 119                         /* Walk up to next valid sibling. */
 120                         do {
 121                                 dn = dn->parent;
 122                                 if (dn == start)
 123                                         return NULL;
 124                         } while (dn->sibling == NULL);
 125                         nextdn = dn->sibling;
 126                 }
 127         }
 128         return NULL;
 129 }
 130
 131 /**
 132  * pci_devs_phb_init_dynamic - setup pci devices under this PHB
 133  * phb: pci-to-host bridge (top-level bridge connecting to cpu)
 134  *
 135  * This routine is called both during boot, (before the memory
 136  * subsystem is set up, before kmalloc is valid) and during the
 137  * dynamic lpar operation of adding a PHB to a running system.
 138  */
 139 void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
 140 {
 141         struct device_node * dn = (struct device_node *) phb->arch_data;
 142         struct pci_dn *pdn;
 143
 144         /* PHB nodes themselves must not match */
 145         update_dn_pci_info(dn, phb);
 146         pdn = dn->data;
 147         if (pdn) {
 148                 pdn->devfn = pdn->busno = -1;
 149                 pdn->phb = phb;
 150         }
 151
 152         /* Update dn->phb ptrs for new phb and children devices */
 153         traverse_pci_devices(dn, update_dn_pci_info, phb);
 154 }
 155
 156 /*
 157  * Traversal func that looks for a <busno,devfcn> value.
 158  * If found, the pci_dn is returned (thus terminating the traversal).
 159  */
 160 static void *is_devfn_node(struct device_node *dn, void *data)
 161 {
 162         int busno = ((unsigned long)data >> 8) & 0xff;
 163         int devfn = ((unsigned long)data) & 0xff;
 164         struct pci_dn *pci = dn->data;
 165
 166         if (pci && (devfn == pci->devfn) && (busno == pci->busno))
 167                 return dn;
 168         return NULL;
 169 }
 170
 171 /*
 172  * This is the "slow" path for looking up a device_node from a
 173  * pci_dev.  It will hunt for the device under its parent's
 174  * phb and then update sysdata for a future fastpath.
 175  *
 176  * It may also do fixups on the actual device since this happens
 177  * on the first read/write.
 178  *
 179  * Note that it also must deal with devices that don't exist.
 180  * In this case it may probe for real hardware ("just in case")
 181  * and add a device_node to the device tree if necessary.
 182  *
 183  */
 184 struct device_node *fetch_dev_dn(struct pci_dev *dev)
 185 {
 186         struct device_node *orig_dn = dev->sysdata;
 187         struct device_node *dn;
 188         unsigned long searchval = (dev->bus->number << 8) | dev->devfn;
 189
 190         dn = traverse_pci_devices(orig_dn, is_devfn_node, (void *)searchval);
 191         if (dn)
 192                 dev->sysdata = dn;
 193         return dn;
 194 }
 195 EXPORT_SYMBOL(fetch_dev_dn);
 196
 197 static int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *node)
 198 {
 199         struct device_node *np = node;
 200         struct pci_dn *pci = NULL;
 201         int err = NOTIFY_OK;
 202
 203         switch (action) {
 204         case PSERIES_RECONFIG_ADD:
 205                 pci = np->parent->data;
 206                 if (pci)
 207                         update_dn_pci_info(np, pci->phb);
 208                 break;
 209         default:
 210                 err = NOTIFY_DONE;
 211                 break;
 212         }
 213         return err;
 214 }
 215
 216 static struct notifier_block pci_dn_reconfig_nb = {
 217         .notifier_call = pci_dn_reconfig_notifier,
 218 };
 219
 220 /**
 221  * pci_devs_phb_init - Initialize phbs and pci devs under them.
 222  *
 223  * This routine walks over all phb's (pci-host bridges) on the
 224  * system, and sets up assorted pci-related structures
 225  * (including pci info in the device node structs) for each
 226  * pci device found underneath.  This routine runs once,
 227  * early in the boot sequence.
 228  */
 229 void __init pci_devs_phb_init(void)
 230 {
 231         struct pci_controller *phb, *tmp;
 232
 233         /* This must be done first so the device nodes have valid pci info! */
 234         list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
 235                 pci_devs_phb_init_dynamic(phb);
 236
 237         pSeries_reconfig_notifier_register(&pci_dn_reconfig_nb);
 238 }