arch/mips/pci/pci-legacy.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *
   4  * Copyright (C) 2003, 04, 11 Ralf Baechle (ralf@linux-mips.org)
   5  * Copyright (C) 2011 Wind River Systems,
   6  *   written by Ralf Baechle (ralf@linux-mips.org)
   7  */
   8 #include <linux/bug.h>
   9 #include <linux/kernel.h>
  10 #include <linux/mm.h>
  11 #include <linux/memblock.h>
  12 #include <linux/export.h>
  13 #include <linux/init.h>
  14 #include <linux/types.h>
  15 #include <linux/pci.h>
  16 #include <linux/of_address.h>
  17
  18 #include <asm/cpu-info.h>
  19
  20 /*
  21  * If PCI_PROBE_ONLY in pci_flags is set, we don't change any PCI resource
  22  * assignments.
  23  */
  24
  25 /*
  26  * The PCI controller list.
  27  */
  28 static LIST_HEAD(controllers);
  29
  30 static int pci_initialized;
  31
  32 /*
  33  * We need to avoid collisions with `mirrored' VGA ports
  34  * and other strange ISA hardware, so we always want the
  35  * addresses to be allocated in the 0x000-0x0ff region
  36  * modulo 0x400.
  37  *
  38  * Why? Because some silly external IO cards only decode
  39  * the low 10 bits of the IO address. The 0x00-0xff region
  40  * is reserved for motherboard devices that decode all 16
  41  * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
  42  * but we want to try to avoid allocating at 0x2900-0x2bff
  43  * which might have be mirrored at 0x0100-0x03ff..
  44  */
  45 resource_size_t
  46 pcibios_align_resource(void *data, const struct resource *res,
  47                        resource_size_t size, resource_size_t align)
  48 {
  49         struct pci_dev *dev = data;
  50         struct pci_controller *hose = dev->sysdata;
  51         resource_size_t start = res->start;
  52
  53         if (res->flags & IORESOURCE_IO) {
  54                 /* Make sure we start at our min on all hoses */
  55                 if (start < PCIBIOS_MIN_IO + hose->io_resource->start)
  56                         start = PCIBIOS_MIN_IO + hose->io_resource->start;
  57
  58                 /*
  59                  * Put everything into 0x00-0xff region modulo 0x400
  60                  */
  61                 if (start & 0x300)
  62                         start = (start + 0x3ff) & ~0x3ff;
  63         } else if (res->flags & IORESOURCE_MEM) {
  64                 /* Make sure we start at our min on all hoses */
  65                 if (start < PCIBIOS_MIN_MEM + hose->mem_resource->start)
  66                         start = PCIBIOS_MIN_MEM + hose->mem_resource->start;
  67         }
  68
  69         return start;
  70 }
  71
  72 static void pcibios_scanbus(struct pci_controller *hose)
  73 {
  74         static int next_busno;
  75         static int need_domain_info;
  76         LIST_HEAD(resources);
  77         struct pci_bus *bus;
  78         struct pci_host_bridge *bridge;
  79         int ret;
  80
  81         bridge = pci_alloc_host_bridge(0);
  82         if (!bridge)
  83                 return;
  84
  85         if (hose->get_busno && pci_has_flag(PCI_PROBE_ONLY))
  86                 next_busno = (*hose->get_busno)();
  87
  88         pci_add_resource_offset(&resources,
  89                                 hose->mem_resource, hose->mem_offset);
  90         pci_add_resource_offset(&resources,
  91                                 hose->io_resource, hose->io_offset);
  92         pci_add_resource(&resources, hose->busn_resource);
  93         list_splice_init(&resources, &bridge->windows);
  94         bridge->dev.parent = NULL;
  95         bridge->sysdata = hose;
  96         bridge->busnr = next_busno;
  97         bridge->ops = hose->pci_ops;
  98         bridge->swizzle_irq = pci_common_swizzle;
  99         bridge->map_irq = pcibios_map_irq;
 100         ret = pci_scan_root_bus_bridge(bridge);
 101         if (ret) {
 102                 pci_free_host_bridge(bridge);
 103                 return;
 104         }
 105
 106         hose->bus = bus = bridge->bus;
 107
 108         need_domain_info = need_domain_info || pci_domain_nr(bus);
 109         set_pci_need_domain_info(hose, need_domain_info);
 110
 111         next_busno = bus->busn_res.end + 1;
 112         /* Don't allow 8-bit bus number overflow inside the hose -
 113            reserve some space for bridges. */
 114         if (next_busno > 224) {
 115                 next_busno = 0;
 116                 need_domain_info = 1;
 117         }
 118
 119         /*
 120          * We insert PCI resources into the iomem_resource and
 121          * ioport_resource trees in either pci_bus_claim_resources()
 122          * or pci_bus_assign_resources().
 123          */
 124         if (pci_has_flag(PCI_PROBE_ONLY)) {
 125                 pci_bus_claim_resources(bus);
 126         } else {
 127                 struct pci_bus *child;
 128
 129                 pci_bus_size_bridges(bus);
 130                 pci_bus_assign_resources(bus);
 131                 list_for_each_entry(child, &bus->children, node)
 132                         pcie_bus_configure_settings(child);
 133         }
 134         pci_bus_add_devices(bus);
 135 }
 136
 137 #ifdef CONFIG_OF
 138 void pci_load_of_ranges(struct pci_controller *hose, struct device_node *node)
 139 {
 140         struct of_pci_range range;
 141         struct of_pci_range_parser parser;
 142
 143         pr_info("PCI host bridge %pOF ranges:\n", node);
 144         hose->of_node = node;
 145
 146         if (of_pci_range_parser_init(&parser, node))
 147                 return;
 148
 149         for_each_of_pci_range(&parser, &range) {
 150                 struct resource *res = NULL;
 151
 152                 switch (range.flags & IORESOURCE_TYPE_BITS) {
 153                 case IORESOURCE_IO:
 154                         pr_info("  IO 0x%016llx..0x%016llx\n",
 155                                 range.cpu_addr,
 156                                 range.cpu_addr + range.size - 1);
 157                         hose->io_map_base =
 158                                 (unsigned long)ioremap(range.cpu_addr,
 159                                                        range.size);
 160                         res = hose->io_resource;
 161                         break;
 162                 case IORESOURCE_MEM:
 163                         pr_info(" MEM 0x%016llx..0x%016llx\n",
 164                                 range.cpu_addr,
 165                                 range.cpu_addr + range.size - 1);
 166                         res = hose->mem_resource;
 167                         break;
 168                 }
 169                 if (res != NULL)
 170                         of_pci_range_to_resource(&range, node, res);
 171         }
 172 }
 173
 174 struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus)
 175 {
 176         struct pci_controller *hose = bus->sysdata;
 177
 178         return of_node_get(hose->of_node);
 179 }
 180 #endif
 181
 182 static DEFINE_MUTEX(pci_scan_mutex);
 183
 184 void register_pci_controller(struct pci_controller *hose)
 185 {
 186         struct resource *parent;
 187
 188         parent = hose->mem_resource->parent;
 189         if (!parent)
 190                 parent = &iomem_resource;
 191
 192         if (request_resource(parent, hose->mem_resource) < 0)
 193                 goto out;
 194
 195         parent = hose->io_resource->parent;
 196         if (!parent)
 197                 parent = &ioport_resource;
 198
 199         if (request_resource(parent, hose->io_resource) < 0) {
 200                 release_resource(hose->mem_resource);
 201                 goto out;
 202         }
 203
 204         INIT_LIST_HEAD(&hose->list);
 205         list_add_tail(&hose->list, &controllers);
 206
 207         /*
 208          * Do not panic here but later - this might happen before console init.
 209          */
 210         if (!hose->io_map_base) {
 211                 printk(KERN_WARNING
 212                        "registering PCI controller with io_map_base unset\n");
 213         }
 214
 215         /*
 216          * Scan the bus if it is register after the PCI subsystem
 217          * initialization.
 218          */
 219         if (pci_initialized) {
 220                 mutex_lock(&pci_scan_mutex);
 221                 pcibios_scanbus(hose);
 222                 mutex_unlock(&pci_scan_mutex);
 223         }
 224
 225         return;
 226
 227 out:
 228         printk(KERN_WARNING
 229                "Skipping PCI bus scan due to resource conflict\n");
 230 }
 231
 232 static int __init pcibios_init(void)
 233 {
 234         struct pci_controller *hose;
 235
 236         /* Scan all of the recorded PCI controllers.  */
 237         list_for_each_entry(hose, &controllers, list)
 238                 pcibios_scanbus(hose);
 239
 240         pci_initialized = 1;
 241
 242         return 0;
 243 }
 244
 245 subsys_initcall(pcibios_init);
 246
 247 static int pcibios_enable_resources(struct pci_dev *dev, int mask)
 248 {
 249         u16 cmd, old_cmd;
 250         int idx;
 251         struct resource *r;
 252
 253         pci_read_config_word(dev, PCI_COMMAND, &cmd);
 254         old_cmd = cmd;
 255         for (idx=0; idx < PCI_NUM_RESOURCES; idx++) {
 256                 /* Only set up the requested stuff */
 257                 if (!(mask & (1<<idx)))
 258                         continue;
 259
 260                 r = &dev->resource[idx];
 261                 if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
 262                         continue;
 263                 if ((idx == PCI_ROM_RESOURCE) &&
 264                                 (!(r->flags & IORESOURCE_ROM_ENABLE)))
 265                         continue;
 266                 if (!r->start && r->end) {
 267                         pci_err(dev,
 268                                 "can't enable device: resource collisions\n");
 269                         return -EINVAL;
 270                 }
 271                 if (r->flags & IORESOURCE_IO)
 272                         cmd |= PCI_COMMAND_IO;
 273                 if (r->flags & IORESOURCE_MEM)
 274                         cmd |= PCI_COMMAND_MEMORY;
 275         }
 276         if (cmd != old_cmd) {
 277                 pci_info(dev, "enabling device (%04x -> %04x)\n", old_cmd, cmd);
 278                 pci_write_config_word(dev, PCI_COMMAND, cmd);
 279         }
 280         return 0;
 281 }
 282
 283 int pcibios_enable_device(struct pci_dev *dev, int mask)
 284 {
 285         int err;
 286
 287         if ((err = pcibios_enable_resources(dev, mask)) < 0)
 288                 return err;
 289
 290         return pcibios_plat_dev_init(dev);
 291 }
 292
 293 void pcibios_fixup_bus(struct pci_bus *bus)
 294 {
 295         struct pci_dev *dev = bus->self;
 296
 297         if (pci_has_flag(PCI_PROBE_ONLY) && dev &&
 298             (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
 299                 pci_read_bridge_bases(bus);
 300         }
 301 }
 302
 303 char * (*pcibios_plat_setup)(char *str) __initdata;
 304
 305 char *__init pcibios_setup(char *str)
 306 {
 307         if (pcibios_plat_setup)
 308                 return pcibios_plat_setup(str);
 309         return str;
 310 }