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 /*
  43  * Try to assign the IRQ number when probing a new device
  44  */
  45 int pcibios_alloc_irq(struct pci_dev *dev)
  46 {
  47         if (acpi_disabled)
  48                 dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
  49 #ifdef CONFIG_ACPI
  50         else
  51                 return acpi_pci_irq_enable(dev);
  52 #endif
  53
  54         return 0;
  55 }
  56
  57 /*
  58  * raw_pci_read/write - Platform-specific PCI config space access.
  59  */
  60 int raw_pci_read(unsigned int domain, unsigned int bus,
  61                   unsigned int devfn, int reg, int len, u32 *val)
  62 {
  63         struct pci_bus *b = pci_find_bus(domain, bus);
  64
  65         if (!b)
  66                 return PCIBIOS_DEVICE_NOT_FOUND;
  67         return b->ops->read(b, devfn, reg, len, val);
  68 }
  69
  70 int raw_pci_write(unsigned int domain, unsigned int bus,
  71                 unsigned int devfn, int reg, int len, u32 val)
  72 {
  73         struct pci_bus *b = pci_find_bus(domain, bus);
  74
  75         if (!b)
  76                 return PCIBIOS_DEVICE_NOT_FOUND;
  77         return b->ops->write(b, devfn, reg, len, val);
  78 }
  79
  80 #ifdef CONFIG_NUMA
  81
  82 int pcibus_to_node(struct pci_bus *bus)
  83 {
  84         return dev_to_node(&bus->dev);
  85 }
  86 EXPORT_SYMBOL(pcibus_to_node);
  87
  88 #endif
  89
  90 #ifdef CONFIG_ACPI
  91
  92 struct acpi_pci_generic_root_info {
  93         struct acpi_pci_root_info       common;
  94         struct pci_config_window        *cfg;   /* config space mapping */
  95 };
  96
  97 int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
  98 {
  99         struct pci_config_window *cfg = bus->sysdata;
 100         struct acpi_device *adev = to_acpi_device(cfg->parent);
 101         struct acpi_pci_root *root = acpi_driver_data(adev);
 102
 103         return root->segment;
 104 }
 105
 106 int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
 107 {
 108         if (!acpi_disabled) {
 109                 struct pci_config_window *cfg = bridge->bus->sysdata;
 110                 struct acpi_device *adev = to_acpi_device(cfg->parent);
 111                 ACPI_COMPANION_SET(&bridge->dev, adev);
 112         }
 113
 114         return 0;
 115 }
 116
 117 /*
 118  * Lookup the bus range for the domain in MCFG, and set up config space
 119  * mapping.
 120  */
 121 static struct pci_config_window *
 122 pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
 123 {
 124         struct resource *bus_res = &root->secondary;
 125         u16 seg = root->segment;
 126         struct pci_config_window *cfg;
 127         struct resource cfgres;
 128         unsigned int bsz;
 129
 130         /* Use address from _CBA if present, otherwise lookup MCFG */
 131         if (!root->mcfg_addr)
 132                 root->mcfg_addr = pci_mcfg_lookup(seg, bus_res);
 133
 134         if (!root->mcfg_addr) {
 135                 dev_err(&root->device->dev, "%04x:%pR ECAM region not found\n",
 136                         seg, bus_res);
 137                 return NULL;
 138         }
 139
 140         bsz = 1 << pci_generic_ecam_ops.bus_shift;
 141         cfgres.start = root->mcfg_addr + bus_res->start * bsz;
 142         cfgres.end = cfgres.start + resource_size(bus_res) * bsz - 1;
 143         cfgres.flags = IORESOURCE_MEM;
 144         cfg = pci_ecam_create(&root->device->dev, &cfgres, bus_res,
 145                               &pci_generic_ecam_ops);
 146         if (IS_ERR(cfg)) {
 147                 dev_err(&root->device->dev, "%04x:%pR error %ld mapping ECAM\n",
 148                         seg, bus_res, PTR_ERR(cfg));
 149                 return NULL;
 150         }
 151
 152         return cfg;
 153 }
 154
 155 /* release_info: free resources allocated by init_info */
 156 static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
 157 {
 158         struct acpi_pci_generic_root_info *ri;
 159
 160         ri = container_of(ci, struct acpi_pci_generic_root_info, common);
 161         pci_ecam_free(ri->cfg);
 162         kfree(ri);
 163 }
 164
 165 static struct acpi_pci_root_ops acpi_pci_root_ops = {
 166         .release_info = pci_acpi_generic_release_info,
 167 };
 168
 169 /* Interface called from ACPI code to setup PCI host controller */
 170 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 171 {
 172         int node = acpi_get_node(root->device->handle);
 173         struct acpi_pci_generic_root_info *ri;
 174         struct pci_bus *bus, *child;
 175
 176         ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
 177         if (!ri)
 178                 return NULL;
 179
 180         ri->cfg = pci_acpi_setup_ecam_mapping(root);
 181         if (!ri->cfg) {
 182                 kfree(ri);
 183                 return NULL;
 184         }
 185
 186         acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
 187         bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
 188                                    ri->cfg);
 189         if (!bus)
 190                 return NULL;
 191
 192         pci_bus_size_bridges(bus);
 193         pci_bus_assign_resources(bus);
 194
 195         list_for_each_entry(child, &bus->children, node)
 196                 pcie_bus_configure_settings(child);
 197
 198         return bus;
 199 }
 200
 201 void pcibios_add_bus(struct pci_bus *bus)
 202 {
 203         acpi_pci_add_bus(bus);
 204 }
 205
 206 void pcibios_remove_bus(struct pci_bus *bus)
 207 {
 208         acpi_pci_remove_bus(bus);
 209 }
 210
 211 #endif