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 /*
  26  * Called after each bus is probed, but before its children are examined
  27  */
  28 void pcibios_fixup_bus(struct pci_bus *bus)
  29 {
  30         /* nothing to do, expected to be removed in the future */
  31 }
  32
  33 /*
  34  * We don't have to worry about legacy ISA devices, so nothing to do here
  35  */
  36 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
  37                                 resource_size_t size, resource_size_t align)
  38 {
  39         return res->start;
  40 }
  41
  42 #ifdef CONFIG_ACPI
  43 /*
  44  * Try to assign the IRQ number when probing a new device
  45  */
  46 int pcibios_alloc_irq(struct pci_dev *dev)
  47 {
  48         if (!acpi_disabled)
  49                 acpi_pci_irq_enable(dev);
  50
  51         return 0;
  52 }
  53 #endif
  54
  55 /*
  56  * raw_pci_read/write - Platform-specific PCI config space access.
  57  */
  58 int raw_pci_read(unsigned int domain, unsigned int bus,
  59                   unsigned int devfn, int reg, int len, u32 *val)
  60 {
  61         struct pci_bus *b = pci_find_bus(domain, bus);
  62
  63         if (!b)
  64                 return PCIBIOS_DEVICE_NOT_FOUND;
  65         return b->ops->read(b, devfn, reg, len, val);
  66 }
  67
  68 int raw_pci_write(unsigned int domain, unsigned int bus,
  69                 unsigned int devfn, int reg, int len, u32 val)
  70 {
  71         struct pci_bus *b = pci_find_bus(domain, bus);
  72
  73         if (!b)
  74                 return PCIBIOS_DEVICE_NOT_FOUND;
  75         return b->ops->write(b, devfn, reg, len, val);
  76 }
  77
  78 #ifdef CONFIG_NUMA
  79
  80 int pcibus_to_node(struct pci_bus *bus)
  81 {
  82         return dev_to_node(&bus->dev);
  83 }
  84 EXPORT_SYMBOL(pcibus_to_node);
  85
  86 #endif
  87
  88 #ifdef CONFIG_ACPI
  89
  90 struct acpi_pci_generic_root_info {
  91         struct acpi_pci_root_info       common;
  92         struct pci_config_window        *cfg;   /* config space mapping */
  93 };
  94
  95 int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
  96 {
  97         struct pci_config_window *cfg = bus->sysdata;
  98         struct acpi_device *adev = to_acpi_device(cfg->parent);
  99         struct acpi_pci_root *root = acpi_driver_data(adev);
 100
 101         return root->segment;
 102 }
 103
 104 int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
 105 {
 106         if (!acpi_disabled) {
 107                 struct pci_config_window *cfg = bridge->bus->sysdata;
 108                 struct acpi_device *adev = to_acpi_device(cfg->parent);
 109                 struct device *bus_dev = &bridge->bus->dev;
 110
 111                 ACPI_COMPANION_SET(&bridge->dev, adev);
 112                 set_dev_node(bus_dev, acpi_get_node(acpi_device_handle(adev)));
 113         }
 114
 115         return 0;
 116 }
 117
 118 static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci)
 119 {
 120         struct resource_entry *entry, *tmp;
 121         int status;
 122
 123         status = acpi_pci_probe_root_resources(ci);
 124         resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
 125                 if (!(entry->res->flags & IORESOURCE_WINDOW))
 126                         resource_list_destroy_entry(entry);
 127         }
 128         return status;
 129 }
 130
 131 /*
 132  * Lookup the bus range for the domain in MCFG, and set up config space
 133  * mapping.
 134  */
 135 static struct pci_config_window *
 136 pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
 137 {
 138         struct device *dev = &root->device->dev;
 139         struct resource *bus_res = &root->secondary;
 140         u16 seg = root->segment;
 141         struct pci_ecam_ops *ecam_ops;
 142         struct resource cfgres;
 143         struct acpi_device *adev;
 144         struct pci_config_window *cfg;
 145         int ret;
 146
 147         ret = pci_mcfg_lookup(root, &cfgres, &ecam_ops);
 148         if (ret) {
 149                 dev_err(dev, "%04x:%pR ECAM region not found\n", seg, bus_res);
 150                 return NULL;
 151         }
 152
 153         adev = acpi_resource_consumer(&cfgres);
 154         if (adev)
 155                 dev_info(dev, "ECAM area %pR reserved by %s\n", &cfgres,
 156                          dev_name(&adev->dev));
 157         else
 158                 dev_warn(dev, FW_BUG "ECAM area %pR not reserved in ACPI namespace\n",
 159                          &cfgres);
 160
 161         cfg = pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
 162         if (IS_ERR(cfg)) {
 163                 dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res,
 164                         PTR_ERR(cfg));
 165                 return NULL;
 166         }
 167
 168         return cfg;
 169 }
 170
 171 /* release_info: free resources allocated by init_info */
 172 static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
 173 {
 174         struct acpi_pci_generic_root_info *ri;
 175
 176         ri = container_of(ci, struct acpi_pci_generic_root_info, common);
 177         pci_ecam_free(ri->cfg);
 178         kfree(ci->ops);
 179         kfree(ri);
 180 }
 181
 182 /* Interface called from ACPI code to setup PCI host controller */
 183 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 184 {
 185         int node = acpi_get_node(root->device->handle);
 186         struct acpi_pci_generic_root_info *ri;
 187         struct pci_bus *bus, *child;
 188         struct acpi_pci_root_ops *root_ops;
 189
 190         ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
 191         if (!ri)
 192                 return NULL;
 193
 194         root_ops = kzalloc_node(sizeof(*root_ops), GFP_KERNEL, node);
 195         if (!root_ops) {
 196                 kfree(ri);
 197                 return NULL;
 198         }
 199
 200         ri->cfg = pci_acpi_setup_ecam_mapping(root);
 201         if (!ri->cfg) {
 202                 kfree(ri);
 203                 kfree(root_ops);
 204                 return NULL;
 205         }
 206
 207         root_ops->release_info = pci_acpi_generic_release_info;
 208         root_ops->prepare_resources = pci_acpi_root_prepare_resources;
 209         root_ops->pci_ops = &ri->cfg->ops->pci_ops;
 210         bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
 211         if (!bus)
 212                 return NULL;
 213
 214         pci_bus_size_bridges(bus);
 215         pci_bus_assign_resources(bus);
 216
 217         list_for_each_entry(child, &bus->children, node)
 218                 pcie_bus_configure_settings(child);
 219
 220         return bus;
 221 }
 222
 223 void pcibios_add_bus(struct pci_bus *bus)
 224 {
 225         acpi_pci_add_bus(bus);
 226 }
 227
 228 void pcibios_remove_bus(struct pci_bus *bus)
 229 {
 230         acpi_pci_remove_bus(bus);
 231 }
 232
 233 #endif