1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Code borrowed from powerpc/kernel/pci-common.c 4 * 5 * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM 6 * Copyright (C) 2014 ARM Ltd. 7 */ 8 9 #include <linux/acpi.h> 10 #include <linux/init.h> 11 #include <linux/io.h> 12 #include <linux/kernel.h> 13 #include <linux/mm.h> 14 #include <linux/of_pci.h> 15 #include <linux/of_platform.h> 16 #include <linux/pci.h> 17 #include <linux/pci-acpi.h> 18 #include <linux/pci-ecam.h> 19 #include <linux/slab.h> 20 21 #ifdef CONFIG_ACPI 22 /* 23 * Try to assign the IRQ number when probing a new device 24 */ 25 int pcibios_alloc_irq(struct pci_dev *dev) 26 { 27 if (!acpi_disabled) 28 acpi_pci_irq_enable(dev); 29 30 return 0; 31 } 32 #endif 33 34 /* 35 * raw_pci_read/write - Platform-specific PCI config space access. 36 */ 37 int raw_pci_read(unsigned int domain, unsigned int bus, 38 unsigned int devfn, int reg, int len, u32 *val) 39 { 40 struct pci_bus *b = pci_find_bus(domain, bus); 41 42 if (!b) 43 return PCIBIOS_DEVICE_NOT_FOUND; 44 return b->ops->read(b, devfn, reg, len, val); 45 } 46 47 int raw_pci_write(unsigned int domain, unsigned int bus, 48 unsigned int devfn, int reg, int len, u32 val) 49 { 50 struct pci_bus *b = pci_find_bus(domain, bus); 51 52 if (!b) 53 return PCIBIOS_DEVICE_NOT_FOUND; 54 return b->ops->write(b, devfn, reg, len, val); 55 } 56 57 #ifdef CONFIG_NUMA 58 59 int pcibus_to_node(struct pci_bus *bus) 60 { 61 return dev_to_node(&bus->dev); 62 } 63 EXPORT_SYMBOL(pcibus_to_node); 64 65 #endif 66 67 #ifdef CONFIG_ACPI 68 69 struct acpi_pci_generic_root_info { 70 struct acpi_pci_root_info common; 71 struct pci_config_window *cfg; /* config space mapping */ 72 }; 73 74 int acpi_pci_bus_find_domain_nr(struct pci_bus *bus) 75 { 76 struct pci_config_window *cfg = bus->sysdata; 77 struct acpi_device *adev = to_acpi_device(cfg->parent); 78 struct acpi_pci_root *root = acpi_driver_data(adev); 79 80 return root->segment; 81 } 82 83 int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) 84 { 85 if (!acpi_disabled) { 86 struct pci_config_window *cfg = bridge->bus->sysdata; 87 struct acpi_device *adev = to_acpi_device(cfg->parent); 88 struct device *bus_dev = &bridge->bus->dev; 89 90 ACPI_COMPANION_SET(&bridge->dev, adev); 91 set_dev_node(bus_dev, acpi_get_node(acpi_device_handle(adev))); 92 } 93 94 return 0; 95 } 96 97 static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci) 98 { 99 struct resource_entry *entry, *tmp; 100 int status; 101 102 status = acpi_pci_probe_root_resources(ci); 103 resource_list_for_each_entry_safe(entry, tmp, &ci->resources) { 104 if (!(entry->res->flags & IORESOURCE_WINDOW)) 105 resource_list_destroy_entry(entry); 106 } 107 return status; 108 } 109 110 /* 111 * Lookup the bus range for the domain in MCFG, and set up config space 112 * mapping. 113 */ 114 static struct pci_config_window * 115 pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root) 116 { 117 struct device *dev = &root->device->dev; 118 struct resource *bus_res = &root->secondary; 119 u16 seg = root->segment; 120 const struct pci_ecam_ops *ecam_ops; 121 struct resource cfgres; 122 struct acpi_device *adev; 123 struct pci_config_window *cfg; 124 int ret; 125 126 ret = pci_mcfg_lookup(root, &cfgres, &ecam_ops); 127 if (ret) { 128 dev_err(dev, "%04x:%pR ECAM region not found\n", seg, bus_res); 129 return NULL; 130 } 131 132 adev = acpi_resource_consumer(&cfgres); 133 if (adev) 134 dev_info(dev, "ECAM area %pR reserved by %s\n", &cfgres, 135 dev_name(&adev->dev)); 136 else 137 dev_warn(dev, FW_BUG "ECAM area %pR not reserved in ACPI namespace\n", 138 &cfgres); 139 140 cfg = pci_ecam_create(dev, &cfgres, bus_res, ecam_ops); 141 if (IS_ERR(cfg)) { 142 dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res, 143 PTR_ERR(cfg)); 144 return NULL; 145 } 146 147 return cfg; 148 } 149 150 /* release_info: free resources allocated by init_info */ 151 static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci) 152 { 153 struct acpi_pci_generic_root_info *ri; 154 155 ri = container_of(ci, struct acpi_pci_generic_root_info, common); 156 pci_ecam_free(ri->cfg); 157 kfree(ci->ops); 158 kfree(ri); 159 } 160 161 /* Interface called from ACPI code to setup PCI host controller */ 162 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) 163 { 164 struct acpi_pci_generic_root_info *ri; 165 struct pci_bus *bus, *child; 166 struct acpi_pci_root_ops *root_ops; 167 struct pci_host_bridge *host; 168 169 ri = kzalloc(sizeof(*ri), GFP_KERNEL); 170 if (!ri) 171 return NULL; 172 173 root_ops = kzalloc(sizeof(*root_ops), GFP_KERNEL); 174 if (!root_ops) { 175 kfree(ri); 176 return NULL; 177 } 178 179 ri->cfg = pci_acpi_setup_ecam_mapping(root); 180 if (!ri->cfg) { 181 kfree(ri); 182 kfree(root_ops); 183 return NULL; 184 } 185 186 root_ops->release_info = pci_acpi_generic_release_info; 187 root_ops->prepare_resources = pci_acpi_root_prepare_resources; 188 root_ops->pci_ops = (struct pci_ops *)&ri->cfg->ops->pci_ops; 189 bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg); 190 if (!bus) 191 return NULL; 192 193 /* If we must preserve the resource configuration, claim now */ 194 host = pci_find_host_bridge(bus); 195 if (host->preserve_config) 196 pci_bus_claim_resources(bus); 197 198 /* 199 * Assign whatever was left unassigned. If we didn't claim above, 200 * this will reassign everything. 201 */ 202 pci_assign_unassigned_root_bus_resources(bus); 203 204 list_for_each_entry(child, &bus->children, node) 205 pcie_bus_configure_settings(child); 206 207 return bus; 208 } 209 210 void pcibios_add_bus(struct pci_bus *bus) 211 { 212 acpi_pci_add_bus(bus); 213 } 214 215 void pcibios_remove_bus(struct pci_bus *bus) 216 { 217 acpi_pci_remove_bus(bus); 218 } 219 220 #endif 221