arch/sh/drivers/pci/pci.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * New-style PCI core.
   4  *
   5  * Copyright (c) 2004 - 2009  Paul Mundt
   6  * Copyright (c) 2002  M. R. Brown
   7  *
   8  * Modelled after arch/mips/pci/pci.c:
   9  *  Copyright (C) 2003, 04 Ralf Baechle (ralf@linux-mips.org)
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/mm.h>
  13 #include <linux/pci.h>
  14 #include <linux/init.h>
  15 #include <linux/types.h>
  16 #include <linux/dma-debug.h>
  17 #include <linux/io.h>
  18 #include <linux/mutex.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/export.h>
  21
  22 unsigned long PCIBIOS_MIN_IO = 0x0000;
  23 unsigned long PCIBIOS_MIN_MEM = 0;
  24
  25 /*
  26  * The PCI controller list.
  27  */
  28 static struct pci_channel *hose_head, **hose_tail = &hose_head;
  29
  30 static int pci_initialized;
  31
  32 static void pcibios_scanbus(struct pci_channel *hose)
  33 {
  34         static int next_busno;
  35         static int need_domain_info;
  36         LIST_HEAD(resources);
  37         struct resource *res;
  38         resource_size_t offset;
  39         int i, ret;
  40         struct pci_host_bridge *bridge;
  41
  42         bridge = pci_alloc_host_bridge(0);
  43         if (!bridge)
  44                 return;
  45
  46         for (i = 0; i < hose->nr_resources; i++) {
  47                 res = hose->resources + i;
  48                 offset = 0;
  49                 if (res->flags & IORESOURCE_DISABLED)
  50                         continue;
  51                 if (res->flags & IORESOURCE_IO)
  52                         offset = hose->io_offset;
  53                 else if (res->flags & IORESOURCE_MEM)
  54                         offset = hose->mem_offset;
  55                 pci_add_resource_offset(&resources, res, offset);
  56         }
  57
  58         list_splice_init(&resources, &bridge->windows);
  59         bridge->dev.parent = NULL;
  60         bridge->sysdata = hose;
  61         bridge->busnr = next_busno;
  62         bridge->ops = hose->pci_ops;
  63         bridge->swizzle_irq = pci_common_swizzle;
  64         bridge->map_irq = pcibios_map_platform_irq;
  65
  66         ret = pci_scan_root_bus_bridge(bridge);
  67         if (ret) {
  68                 pci_free_host_bridge(bridge);
  69                 return;
  70         }
  71
  72         hose->bus = bridge->bus;
  73
  74         need_domain_info = need_domain_info || hose->index;
  75         hose->need_domain_info = need_domain_info;
  76
  77         next_busno = hose->bus->busn_res.end + 1;
  78         /* Don't allow 8-bit bus number overflow inside the hose -
  79            reserve some space for bridges. */
  80         if (next_busno > 224) {
  81                 next_busno = 0;
  82                 need_domain_info = 1;
  83         }
  84
  85         pci_bus_size_bridges(hose->bus);
  86         pci_bus_assign_resources(hose->bus);
  87         pci_bus_add_devices(hose->bus);
  88 }
  89
  90 /*
  91  * This interrupt-safe spinlock protects all accesses to PCI
  92  * configuration space.
  93  */
  94 DEFINE_RAW_SPINLOCK(pci_config_lock);
  95 static DEFINE_MUTEX(pci_scan_mutex);
  96
  97 int register_pci_controller(struct pci_channel *hose)
  98 {
  99         int i;
 100
 101         for (i = 0; i < hose->nr_resources; i++) {
 102                 struct resource *res = hose->resources + i;
 103
 104                 if (res->flags & IORESOURCE_DISABLED)
 105                         continue;
 106
 107                 if (res->flags & IORESOURCE_IO) {
 108                         if (request_resource(&ioport_resource, res) < 0)
 109                                 goto out;
 110                 } else {
 111                         if (request_resource(&iomem_resource, res) < 0)
 112                                 goto out;
 113                 }
 114         }
 115
 116         *hose_tail = hose;
 117         hose_tail = &hose->next;
 118
 119         /*
 120          * Do not panic here but later - this might happen before console init.
 121          */
 122         if (!hose->io_map_base) {
 123                 printk(KERN_WARNING
 124                        "registering PCI controller with io_map_base unset\n");
 125         }
 126
 127         /*
 128          * Setup the ERR/PERR and SERR timers, if available.
 129          */
 130         pcibios_enable_timers(hose);
 131
 132         /*
 133          * Scan the bus if it is register after the PCI subsystem
 134          * initialization.
 135          */
 136         if (pci_initialized) {
 137                 mutex_lock(&pci_scan_mutex);
 138                 pcibios_scanbus(hose);
 139                 mutex_unlock(&pci_scan_mutex);
 140         }
 141
 142         return 0;
 143
 144 out:
 145         for (--i; i >= 0; i--)
 146                 release_resource(&hose->resources[i]);
 147
 148         printk(KERN_WARNING "Skipping PCI bus scan due to resource conflict\n");
 149         return -1;
 150 }
 151
 152 static int __init pcibios_init(void)
 153 {
 154         struct pci_channel *hose;
 155
 156         /* Scan all of the recorded PCI controllers.  */
 157         for (hose = hose_head; hose; hose = hose->next)
 158                 pcibios_scanbus(hose);
 159
 160         pci_initialized = 1;
 161
 162         return 0;
 163 }
 164 subsys_initcall(pcibios_init);
 165
 166 /*
 167  * We need to avoid collisions with `mirrored' VGA ports
 168  * and other strange ISA hardware, so we always want the
 169  * addresses to be allocated in the 0x000-0x0ff region
 170  * modulo 0x400.
 171  */
 172 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 173                                 resource_size_t size, resource_size_t align)
 174 {
 175         struct pci_dev *dev = data;
 176         struct pci_channel *hose = dev->sysdata;
 177         resource_size_t start = res->start;
 178
 179         if (res->flags & IORESOURCE_IO) {
 180                 if (start < PCIBIOS_MIN_IO + hose->resources[0].start)
 181                         start = PCIBIOS_MIN_IO + hose->resources[0].start;
 182
 183                 /*
 184                  * Put everything into 0x00-0xff region modulo 0x400.
 185                  */
 186                 if (start & 0x300)
 187                         start = (start + 0x3ff) & ~0x3ff;
 188         }
 189
 190         return start;
 191 }
 192
 193 static void __init
 194 pcibios_bus_report_status_early(struct pci_channel *hose,
 195                                 int top_bus, int current_bus,
 196                                 unsigned int status_mask, int warn)
 197 {
 198         unsigned int pci_devfn;
 199         u16 status;
 200         int ret;
 201
 202         for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
 203                 if (PCI_FUNC(pci_devfn))
 204                         continue;
 205                 ret = early_read_config_word(hose, top_bus, current_bus,
 206                                              pci_devfn, PCI_STATUS, &status);
 207                 if (ret != PCIBIOS_SUCCESSFUL)
 208                         continue;
 209                 if (status == 0xffff)
 210                         continue;
 211
 212                 early_write_config_word(hose, top_bus, current_bus,
 213                                         pci_devfn, PCI_STATUS,
 214                                         status & status_mask);
 215                 if (warn)
 216                         printk("(%02x:%02x: %04X) ", current_bus,
 217                                pci_devfn, status);
 218         }
 219 }
 220
 221 /*
 222  * We can't use pci_find_device() here since we are
 223  * called from interrupt context.
 224  */
 225 static void __ref
 226 pcibios_bus_report_status(struct pci_bus *bus, unsigned int status_mask,
 227                           int warn)
 228 {
 229         struct pci_dev *dev;
 230
 231         list_for_each_entry(dev, &bus->devices, bus_list) {
 232                 u16 status;
 233
 234                 /*
 235                  * ignore host bridge - we handle
 236                  * that separately
 237                  */
 238                 if (dev->bus->number == 0 && dev->devfn == 0)
 239                         continue;
 240
 241                 pci_read_config_word(dev, PCI_STATUS, &status);
 242                 if (status == 0xffff)
 243                         continue;
 244
 245                 if ((status & status_mask) == 0)
 246                         continue;
 247
 248                 /* clear the status errors */
 249                 pci_write_config_word(dev, PCI_STATUS, status & status_mask);
 250
 251                 if (warn)
 252                         printk("(%s: %04X) ", pci_name(dev), status);
 253         }
 254
 255         list_for_each_entry(dev, &bus->devices, bus_list)
 256                 if (dev->subordinate)
 257                         pcibios_bus_report_status(dev->subordinate, status_mask, warn);
 258 }
 259
 260 void __ref pcibios_report_status(unsigned int status_mask, int warn)
 261 {
 262         struct pci_channel *hose;
 263
 264         for (hose = hose_head; hose; hose = hose->next) {
 265                 if (unlikely(!hose->bus))
 266                         pcibios_bus_report_status_early(hose, hose_head->index,
 267                                         hose->index, status_mask, warn);
 268                 else
 269                         pcibios_bus_report_status(hose->bus, status_mask, warn);
 270         }
 271 }
 272
 273 #ifndef CONFIG_GENERIC_IOMAP
 274
 275 void __iomem *__pci_ioport_map(struct pci_dev *dev,
 276                                unsigned long port, unsigned int nr)
 277 {
 278         struct pci_channel *chan = dev->sysdata;
 279
 280         if (unlikely(!chan->io_map_base)) {
 281                 chan->io_map_base = sh_io_port_base;
 282
 283                 if (pci_domains_supported)
 284                         panic("To avoid data corruption io_map_base MUST be "
 285                               "set with multiple PCI domains.");
 286         }
 287
 288         return (void __iomem *)(chan->io_map_base + port);
 289 }
 290
 291 void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
 292 {
 293         iounmap(addr);
 294 }
 295 EXPORT_SYMBOL(pci_iounmap);
 296
 297 #endif /* CONFIG_GENERIC_IOMAP */
 298
 299 EXPORT_SYMBOL(PCIBIOS_MIN_IO);
 300 EXPORT_SYMBOL(PCIBIOS_MIN_MEM);