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/export.h>
  26 #include <linux/init.h>
  27 #include <linux/gfp.h>
  28
  29 #include <asm/io.h>
  30 #include <asm/prom.h>
  31 #include <asm/pci-bridge.h>
  32 #include <asm/ppc-pci.h>
  33 #include <asm/firmware.h>
  34
  35 /*
  36  * Traverse_func that inits the PCI fields of the device node.
  37  * NOTE: this *must* be done before read/write config to the device.
  38  */
  39 void *update_dn_pci_info(struct device_node *dn, void *data)
  40 {
  41         struct pci_controller *phb = data;
  42         const int *type =
  43                 of_get_property(dn, "ibm,pci-config-space-type", NULL);
  44         const u32 *regs;
  45         struct pci_dn *pdn;
  46
  47         pdn = zalloc_maybe_bootmem(sizeof(*pdn), GFP_KERNEL);
  48         if (pdn == NULL)
  49                 return NULL;
  50         dn->data = pdn;
  51         pdn->node = dn;
  52         pdn->phb = phb;
  53 #ifdef CONFIG_PPC_POWERNV
  54         pdn->pe_number = IODA_INVALID_PE;
  55 #endif
  56         regs = of_get_property(dn, "reg", NULL);
  57         if (regs) {
  58                 /* First register entry is addr (00BBSS00)  */
  59                 pdn->busno = (regs[0] >> 16) & 0xff;
  60                 pdn->devfn = (regs[0] >> 8) & 0xff;
  61         }
  62
  63         pdn->pci_ext_config_space = (type && *type == 1);
  64         return NULL;
  65 }
  66
  67 /*
  68  * Traverse a device tree stopping each PCI device in the tree.
  69  * This is done depth first.  As each node is processed, a "pre"
  70  * function is called and the children are processed recursively.
  71  *
  72  * The "pre" func returns a value.  If non-zero is returned from
  73  * the "pre" func, the traversal stops and this value is returned.
  74  * This return value is useful when using traverse as a method of
  75  * finding a device.
  76  *
  77  * NOTE: we do not run the func for devices that do not appear to
  78  * be PCI except for the start node which we assume (this is good
  79  * because the start node is often a phb which may be missing PCI
  80  * properties).
  81  * We use the class-code as an indicator. If we run into
  82  * one of these nodes we also assume its siblings are non-pci for
  83  * performance.
  84  */
  85 void *traverse_pci_devices(struct device_node *start, traverse_func pre,
  86                 void *data)
  87 {
  88         struct device_node *dn, *nextdn;
  89         void *ret;
  90
  91         /* We started with a phb, iterate all childs */
  92         for (dn = start->child; dn; dn = nextdn) {
  93                 const u32 *classp;
  94                 u32 class;
  95
  96                 nextdn = NULL;
  97                 classp = of_get_property(dn, "class-code", NULL);
  98                 class = classp ? *classp : 0;
  99
 100                 if (pre && ((ret = pre(dn, data)) != NULL))
 101                         return ret;
 102
 103                 /* If we are a PCI bridge, go down */
 104                 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
 105                                   (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
 106                         /* Depth first...do children */
 107                         nextdn = dn->child;
 108                 else if (dn->sibling)
 109                         /* ok, try next sibling instead. */
 110                         nextdn = dn->sibling;
 111                 if (!nextdn) {
 112                         /* Walk up to next valid sibling. */
 113                         do {
 114                                 dn = dn->parent;
 115                                 if (dn == start)
 116                                         return NULL;
 117                         } while (dn->sibling == NULL);
 118                         nextdn = dn->sibling;
 119                 }
 120         }
 121         return NULL;
 122 }
 123
 124 /**
 125  * pci_devs_phb_init_dynamic - setup pci devices under this PHB
 126  * phb: pci-to-host bridge (top-level bridge connecting to cpu)
 127  *
 128  * This routine is called both during boot, (before the memory
 129  * subsystem is set up, before kmalloc is valid) and during the
 130  * dynamic lpar operation of adding a PHB to a running system.
 131  */
 132 void pci_devs_phb_init_dynamic(struct pci_controller *phb)
 133 {
 134         struct device_node *dn = phb->dn;
 135         struct pci_dn *pdn;
 136
 137         /* PHB nodes themselves must not match */
 138         update_dn_pci_info(dn, phb);
 139         pdn = dn->data;
 140         if (pdn) {
 141                 pdn->devfn = pdn->busno = -1;
 142                 pdn->phb = phb;
 143         }
 144
 145         /* Update dn->phb ptrs for new phb and children devices */
 146         traverse_pci_devices(dn, update_dn_pci_info, phb);
 147 }
 148
 149 /**
 150  * pci_devs_phb_init - Initialize phbs and pci devs under them.
 151  *
 152  * This routine walks over all phb's (pci-host bridges) on the
 153  * system, and sets up assorted pci-related structures
 154  * (including pci info in the device node structs) for each
 155  * pci device found underneath.  This routine runs once,
 156  * early in the boot sequence.
 157  */
 158 void __init pci_devs_phb_init(void)
 159 {
 160         struct pci_controller *phb, *tmp;
 161
 162         /* This must be done first so the device nodes have valid pci info! */
 163         list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
 164                 pci_devs_phb_init_dynamic(phb);
 165 }