arch/powerpc/platforms/pseries/pci_dlpar.c

   1 /*
   2  * PCI Dynamic LPAR, PCI Hot Plug and PCI EEH recovery code
   3  * for RPA-compliant PPC64 platform.
   4  * Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>
   5  * Copyright (C) 2005 International Business Machines
   6  *
   7  * Updates, 2005, John Rose <johnrose@austin.ibm.com>
   8  * Updates, 2005, Linas Vepstas <linas@austin.ibm.com>
   9  *
  10  * All rights reserved.
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or (at
  15  * your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  20  * NON INFRINGEMENT.  See the GNU General Public License for more
  21  * details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  26  */
  27
  28 #include <linux/pci.h>
  29 #include <linux/export.h>
  30 #include <asm/pci-bridge.h>
  31 #include <asm/ppc-pci.h>
  32 #include <asm/firmware.h>
  33 #include <asm/eeh.h>
  34
  35 static struct pci_bus *
  36 find_bus_among_children(struct pci_bus *bus,
  37                         struct device_node *dn)
  38 {
  39         struct pci_bus *child = NULL;
  40         struct list_head *tmp;
  41         struct device_node *busdn;
  42
  43         busdn = pci_bus_to_OF_node(bus);
  44         if (busdn == dn)
  45                 return bus;
  46
  47         list_for_each(tmp, &bus->children) {
  48                 child = find_bus_among_children(pci_bus_b(tmp), dn);
  49                 if (child)
  50                         break;
  51         };
  52         return child;
  53 }
  54
  55 struct pci_bus *
  56 pcibios_find_pci_bus(struct device_node *dn)
  57 {
  58         struct pci_dn *pdn = dn->data;
  59
  60         if (!pdn  || !pdn->phb || !pdn->phb->bus)
  61                 return NULL;
  62
  63         return find_bus_among_children(pdn->phb->bus, dn);
  64 }
  65 EXPORT_SYMBOL_GPL(pcibios_find_pci_bus);
  66
  67 struct pci_controller *init_phb_dynamic(struct device_node *dn)
  68 {
  69         struct pci_controller *phb;
  70
  71         pr_debug("PCI: Initializing new hotplug PHB %s\n", dn->full_name);
  72
  73         phb = pcibios_alloc_controller(dn);
  74         if (!phb)
  75                 return NULL;
  76         rtas_setup_phb(phb);
  77         pci_process_bridge_OF_ranges(phb, dn, 0);
  78
  79         pci_devs_phb_init_dynamic(phb);
  80
  81         /* Create EEH devices for the PHB */
  82         eeh_dev_phb_init_dynamic(phb);
  83
  84         if (dn->child)
  85                 eeh_add_device_tree_early(dn);
  86
  87         pcibios_scan_phb(phb);
  88         pcibios_finish_adding_to_bus(phb->bus);
  89
  90         return phb;
  91 }
  92 EXPORT_SYMBOL_GPL(init_phb_dynamic);
  93
  94 /* RPA-specific bits for removing PHBs */
  95 int remove_phb_dynamic(struct pci_controller *phb)
  96 {
  97         struct pci_bus *b = phb->bus;
  98         struct resource *res;
  99         int rc, i;
 100
 101         pr_debug("PCI: Removing PHB %04x:%02x...\n",
 102                  pci_domain_nr(b), b->number);
 103
 104         /* We cannot to remove a root bus that has children */
 105         if (!(list_empty(&b->children) && list_empty(&b->devices)))
 106                 return -EBUSY;
 107
 108         /* We -know- there aren't any child devices anymore at this stage
 109          * and thus, we can safely unmap the IO space as it's not in use
 110          */
 111         res = &phb->io_resource;
 112         if (res->flags & IORESOURCE_IO) {
 113                 rc = pcibios_unmap_io_space(b);
 114                 if (rc) {
 115                         printk(KERN_ERR "%s: failed to unmap IO on bus %s\n",
 116                                __func__, b->name);
 117                         return 1;
 118                 }
 119         }
 120
 121         /* Unregister the bridge device from sysfs and remove the PCI bus */
 122         device_unregister(b->bridge);
 123         phb->bus = NULL;
 124         pci_remove_bus(b);
 125
 126         /* Now release the IO resource */
 127         if (res->flags & IORESOURCE_IO)
 128                 release_resource(res);
 129
 130         /* Release memory resources */
 131         for (i = 0; i < 3; ++i) {
 132                 res = &phb->mem_resources[i];
 133                 if (!(res->flags & IORESOURCE_MEM))
 134                         continue;
 135                 release_resource(res);
 136         }
 137
 138         /* Free pci_controller data structure */
 139         pcibios_free_controller(phb);
 140
 141         return 0;
 142 }
 143 EXPORT_SYMBOL_GPL(remove_phb_dynamic);