arch/arm64/kernel/pci.c

   1 /*
   2  * Code borrowed from powerpc/kernel/pci-common.c
   3  *
   4  * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
   5  * Copyright (C) 2014 ARM Ltd.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  *
  11  */
  12
  13 #include <linux/acpi.h>
  14 #include <linux/init.h>
  15 #include <linux/io.h>
  16 #include <linux/kernel.h>
  17 #include <linux/mm.h>
  18 #include <linux/of_pci.h>
  19 #include <linux/of_platform.h>
  20 #include <linux/pci.h>
  21 #include <linux/pci-acpi.h>
  22 #include <linux/pci-ecam.h>
  23 #include <linux/slab.h>
  24
  25 #ifdef CONFIG_ACPI
  26 /*
  27  * Try to assign the IRQ number when probing a new device
  28  */
  29 int pcibios_alloc_irq(struct pci_dev *dev)
  30 {
  31         if (!acpi_disabled)
  32                 acpi_pci_irq_enable(dev);
  33
  34         return 0;
  35 }
  36 #endif
  37
  38 /*
  39  * raw_pci_read/write - Platform-specific PCI config space access.
  40  */
  41 int raw_pci_read(unsigned int domain, unsigned int bus,
  42                   unsigned int devfn, int reg, int len, u32 *val)
  43 {
  44         struct pci_bus *b = pci_find_bus(domain, bus);
  45
  46         if (!b)
  47                 return PCIBIOS_DEVICE_NOT_FOUND;
  48         return b->ops->read(b, devfn, reg, len, val);
  49 }
  50
  51 int raw_pci_write(unsigned int domain, unsigned int bus,
  52                 unsigned int devfn, int reg, int len, u32 val)
  53 {
  54         struct pci_bus *b = pci_find_bus(domain, bus);
  55
  56         if (!b)
  57                 return PCIBIOS_DEVICE_NOT_FOUND;
  58         return b->ops->write(b, devfn, reg, len, val);
  59 }
  60
  61 #ifdef CONFIG_NUMA
  62
  63 int pcibus_to_node(struct pci_bus *bus)
  64 {
  65         return dev_to_node(&bus->dev);
  66 }
  67 EXPORT_SYMBOL(pcibus_to_node);
  68
  69 #endif
  70
  71 #ifdef CONFIG_ACPI
  72
  73 struct acpi_pci_generic_root_info {
  74         struct acpi_pci_root_info       common;
  75         struct pci_config_window        *cfg;   /* config space mapping */
  76 };
  77
  78 int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
  79 {
  80         struct pci_config_window *cfg = bus->sysdata;
  81         struct acpi_device *adev = to_acpi_device(cfg->parent);
  82         struct acpi_pci_root *root = acpi_driver_data(adev);
  83
  84         return root->segment;
  85 }
  86
  87 int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
  88 {
  89         if (!acpi_disabled) {
  90                 struct pci_config_window *cfg = bridge->bus->sysdata;
  91                 struct acpi_device *adev = to_acpi_device(cfg->parent);
  92                 struct device *bus_dev = &bridge->bus->dev;
  93
  94                 ACPI_COMPANION_SET(&bridge->dev, adev);
  95                 set_dev_node(bus_dev, acpi_get_node(acpi_device_handle(adev)));
  96         }
  97
  98         return 0;
  99 }
 100
 101 static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci)
 102 {
 103         struct resource_entry *entry, *tmp;
 104         int status;
 105
 106         status = acpi_pci_probe_root_resources(ci);
 107         resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
 108                 if (!(entry->res->flags & IORESOURCE_WINDOW))
 109                         resource_list_destroy_entry(entry);
 110         }
 111         return status;
 112 }
 113
 114 /*
 115  * Lookup the bus range for the domain in MCFG, and set up config space
 116  * mapping.
 117  */
 118 static struct pci_config_window *
 119 pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
 120 {
 121         struct device *dev = &root->device->dev;
 122         struct resource *bus_res = &root->secondary;
 123         u16 seg = root->segment;
 124         struct pci_ecam_ops *ecam_ops;
 125         struct resource cfgres;
 126         struct acpi_device *adev;
 127         struct pci_config_window *cfg;
 128         int ret;
 129
 130         ret = pci_mcfg_lookup(root, &cfgres, &ecam_ops);
 131         if (ret) {
 132                 dev_err(dev, "%04x:%pR ECAM region not found\n", seg, bus_res);
 133                 return NULL;
 134         }
 135
 136         adev = acpi_resource_consumer(&cfgres);
 137         if (adev)
 138                 dev_info(dev, "ECAM area %pR reserved by %s\n", &cfgres,
 139                          dev_name(&adev->dev));
 140         else
 141                 dev_warn(dev, FW_BUG "ECAM area %pR not reserved in ACPI namespace\n",
 142                          &cfgres);
 143
 144         cfg = pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
 145         if (IS_ERR(cfg)) {
 146                 dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res,
 147                         PTR_ERR(cfg));
 148                 return NULL;
 149         }
 150
 151         return cfg;
 152 }
 153
 154 /* release_info: free resources allocated by init_info */
 155 static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
 156 {
 157         struct acpi_pci_generic_root_info *ri;
 158
 159         ri = container_of(ci, struct acpi_pci_generic_root_info, common);
 160         pci_ecam_free(ri->cfg);
 161         kfree(ci->ops);
 162         kfree(ri);
 163 }
 164
 165 /* Interface called from ACPI code to setup PCI host controller */
 166 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 167 {
 168         int node = acpi_get_node(root->device->handle);
 169         struct acpi_pci_generic_root_info *ri;
 170         struct pci_bus *bus, *child;
 171         struct acpi_pci_root_ops *root_ops;
 172
 173         ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
 174         if (!ri)
 175                 return NULL;
 176
 177         root_ops = kzalloc_node(sizeof(*root_ops), GFP_KERNEL, node);
 178         if (!root_ops) {
 179                 kfree(ri);
 180                 return NULL;
 181         }
 182
 183         ri->cfg = pci_acpi_setup_ecam_mapping(root);
 184         if (!ri->cfg) {
 185                 kfree(ri);
 186                 kfree(root_ops);
 187                 return NULL;
 188         }
 189
 190         root_ops->release_info = pci_acpi_generic_release_info;
 191         root_ops->prepare_resources = pci_acpi_root_prepare_resources;
 192         root_ops->pci_ops = &ri->cfg->ops->pci_ops;
 193         bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
 194         if (!bus)
 195                 return NULL;
 196
 197         pci_bus_size_bridges(bus);
 198         pci_bus_assign_resources(bus);
 199
 200         list_for_each_entry(child, &bus->children, node)
 201                 pcie_bus_configure_settings(child);
 202
 203         return bus;
 204 }
 205
 206 void pcibios_add_bus(struct pci_bus *bus)
 207 {
 208         acpi_pci_add_bus(bus);
 209 }
 210
 211 void pcibios_remove_bus(struct pci_bus *bus)
 212 {
 213         acpi_pci_remove_bus(bus);
 214 }
 215
 216 #endif