arch/mips/pci/pci.c

   1 /*
   2  * This program is free software; you can redistribute  it and/or modify it
   3  * under  the terms of  the GNU General  Public License as published by the
   4  * Free Software Foundation;  either version 2 of the  License, or (at your
   5  * option) any later version.
   6  *
   7  * Copyright (C) 2003, 04 Ralf Baechle (ralf@linux-mips.org)
   8  */
   9 #include <linux/kernel.h>
  10 #include <linux/mm.h>
  11 #include <linux/bootmem.h>
  12 #include <linux/init.h>
  13 #include <linux/types.h>
  14 #include <linux/pci.h>
  15
  16 /*
  17  * Indicate whether we respect the PCI setup left by the firmware.
  18  *
  19  * Make this long-lived  so that we know when shutting down
  20  * whether we probed only or not.
  21  */
  22 int pci_probe_only;
  23
  24 #define PCI_ASSIGN_ALL_BUSSES   1
  25
  26 unsigned int pci_probe = PCI_ASSIGN_ALL_BUSSES;
  27
  28 /*
  29  * The PCI controller list.
  30  */
  31
  32 static struct pci_controller *hose_head, **hose_tail = &hose_head;
  33
  34 unsigned long PCIBIOS_MIN_IO;
  35 unsigned long PCIBIOS_MIN_MEM;
  36
  37 static int pci_initialized;
  38
  39 /*
  40  * We need to avoid collisions with `mirrored' VGA ports
  41  * and other strange ISA hardware, so we always want the
  42  * addresses to be allocated in the 0x000-0x0ff region
  43  * modulo 0x400.
  44  *
  45  * Why? Because some silly external IO cards only decode
  46  * the low 10 bits of the IO address. The 0x00-0xff region
  47  * is reserved for motherboard devices that decode all 16
  48  * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
  49  * but we want to try to avoid allocating at 0x2900-0x2bff
  50  * which might have be mirrored at 0x0100-0x03ff..
  51  */
  52 resource_size_t
  53 pcibios_align_resource(void *data, const struct resource *res,
  54                        resource_size_t size, resource_size_t align)
  55 {
  56         struct pci_dev *dev = data;
  57         struct pci_controller *hose = dev->sysdata;
  58         resource_size_t start = res->start;
  59
  60         if (res->flags & IORESOURCE_IO) {
  61                 /* Make sure we start at our min on all hoses */
  62                 if (start < PCIBIOS_MIN_IO + hose->io_resource->start)
  63                         start = PCIBIOS_MIN_IO + hose->io_resource->start;
  64
  65                 /*
  66                  * Put everything into 0x00-0xff region modulo 0x400
  67                  */
  68                 if (start & 0x300)
  69                         start = (start + 0x3ff) & ~0x3ff;
  70         } else if (res->flags & IORESOURCE_MEM) {
  71                 /* Make sure we start at our min on all hoses */
  72                 if (start < PCIBIOS_MIN_MEM + hose->mem_resource->start)
  73                         start = PCIBIOS_MIN_MEM + hose->mem_resource->start;
  74         }
  75
  76         return start;
  77 }
  78
  79 static void __devinit pcibios_scanbus(struct pci_controller *hose)
  80 {
  81         static int next_busno;
  82         static int need_domain_info;
  83         struct pci_bus *bus;
  84
  85         if (!hose->iommu)
  86                 PCI_DMA_BUS_IS_PHYS = 1;
  87
  88         if (hose->get_busno && pci_probe_only)
  89                 next_busno = (*hose->get_busno)();
  90
  91         bus = pci_scan_bus(next_busno, hose->pci_ops, hose);
  92         hose->bus = bus;
  93
  94         need_domain_info = need_domain_info || hose->index;
  95         hose->need_domain_info = need_domain_info;
  96         if (bus) {
  97                 next_busno = bus->subordinate + 1;
  98                 /* Don't allow 8-bit bus number overflow inside the hose -
  99                    reserve some space for bridges. */
 100                 if (next_busno > 224) {
 101                         next_busno = 0;
 102                         need_domain_info = 1;
 103                 }
 104
 105                 if (!pci_probe_only) {
 106                         pci_bus_size_bridges(bus);
 107                         pci_bus_assign_resources(bus);
 108                         pci_enable_bridges(bus);
 109                 }
 110         }
 111 }
 112
 113 static DEFINE_MUTEX(pci_scan_mutex);
 114
 115 void __devinit register_pci_controller(struct pci_controller *hose)
 116 {
 117         if (request_resource(&iomem_resource, hose->mem_resource) < 0)
 118                 goto out;
 119         if (request_resource(&ioport_resource, hose->io_resource) < 0) {
 120                 release_resource(hose->mem_resource);
 121                 goto out;
 122         }
 123
 124         *hose_tail = hose;
 125         hose_tail = &hose->next;
 126
 127         /*
 128          * Do not panic here but later - this might happen before console init.
 129          */
 130         if (!hose->io_map_base) {
 131                 printk(KERN_WARNING
 132                        "registering PCI controller with io_map_base unset\n");
 133         }
 134
 135         /*
 136          * Scan the bus if it is register after the PCI subsystem
 137          * initialization.
 138          */
 139         if (pci_initialized) {
 140                 mutex_lock(&pci_scan_mutex);
 141                 pcibios_scanbus(hose);
 142                 mutex_unlock(&pci_scan_mutex);
 143         }
 144
 145         return;
 146
 147 out:
 148         printk(KERN_WARNING
 149                "Skipping PCI bus scan due to resource conflict\n");
 150 }
 151
 152 static int __init pcibios_init(void)
 153 {
 154         struct pci_controller *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_fixup_irqs(pci_common_swizzle, pcibios_map_irq);
 161
 162         pci_initialized = 1;
 163
 164         return 0;
 165 }
 166
 167 subsys_initcall(pcibios_init);
 168
 169 static int pcibios_enable_resources(struct pci_dev *dev, int mask)
 170 {
 171         u16 cmd, old_cmd;
 172         int idx;
 173         struct resource *r;
 174
 175         pci_read_config_word(dev, PCI_COMMAND, &cmd);
 176         old_cmd = cmd;
 177         for (idx=0; idx < PCI_NUM_RESOURCES; idx++) {
 178                 /* Only set up the requested stuff */
 179                 if (!(mask & (1<<idx)))
 180                         continue;
 181
 182                 r = &dev->resource[idx];
 183                 if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
 184                         continue;
 185                 if ((idx == PCI_ROM_RESOURCE) &&
 186                                 (!(r->flags & IORESOURCE_ROM_ENABLE)))
 187                         continue;
 188                 if (!r->start && r->end) {
 189                         printk(KERN_ERR "PCI: Device %s not available "
 190                                "because of resource collisions\n",
 191                                pci_name(dev));
 192                         return -EINVAL;
 193                 }
 194                 if (r->flags & IORESOURCE_IO)
 195                         cmd |= PCI_COMMAND_IO;
 196                 if (r->flags & IORESOURCE_MEM)
 197                         cmd |= PCI_COMMAND_MEMORY;
 198         }
 199         if (cmd != old_cmd) {
 200                 printk("PCI: Enabling device %s (%04x -> %04x)\n",
 201                        pci_name(dev), old_cmd, cmd);
 202                 pci_write_config_word(dev, PCI_COMMAND, cmd);
 203         }
 204         return 0;
 205 }
 206
 207 /*
 208  *  If we set up a device for bus mastering, we need to check the latency
 209  *  timer as certain crappy BIOSes forget to set it properly.
 210  */
 211 static unsigned int pcibios_max_latency = 255;
 212
 213 void pcibios_set_master(struct pci_dev *dev)
 214 {
 215         u8 lat;
 216         pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
 217         if (lat < 16)
 218                 lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
 219         else if (lat > pcibios_max_latency)
 220                 lat = pcibios_max_latency;
 221         else
 222                 return;
 223         printk(KERN_DEBUG "PCI: Setting latency timer of device %s to %d\n",
 224                pci_name(dev), lat);
 225         pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
 226 }
 227
 228 unsigned int pcibios_assign_all_busses(void)
 229 {
 230         return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
 231 }
 232
 233 int pcibios_enable_device(struct pci_dev *dev, int mask)
 234 {
 235         int err;
 236
 237         if ((err = pcibios_enable_resources(dev, mask)) < 0)
 238                 return err;
 239
 240         return pcibios_plat_dev_init(dev);
 241 }
 242
 243 static void pcibios_fixup_device_resources(struct pci_dev *dev,
 244         struct pci_bus *bus)
 245 {
 246         /* Update device resources.  */
 247         struct pci_controller *hose = (struct pci_controller *)bus->sysdata;
 248         unsigned long offset = 0;
 249         int i;
 250
 251         for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 252                 if (!dev->resource[i].start)
 253                         continue;
 254                 if (dev->resource[i].flags & IORESOURCE_IO)
 255                         offset = hose->io_offset;
 256                 else if (dev->resource[i].flags & IORESOURCE_MEM)
 257                         offset = hose->mem_offset;
 258
 259                 dev->resource[i].start += offset;
 260                 dev->resource[i].end += offset;
 261         }
 262 }
 263
 264 void __devinit pcibios_fixup_bus(struct pci_bus *bus)
 265 {
 266         /* Propagate hose info into the subordinate devices.  */
 267
 268         struct pci_controller *hose = bus->sysdata;
 269         struct list_head *ln;
 270         struct pci_dev *dev = bus->self;
 271
 272         if (!dev) {
 273                 bus->resource[0] = hose->io_resource;
 274                 bus->resource[1] = hose->mem_resource;
 275         } else if (pci_probe_only &&
 276                    (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
 277                 pci_read_bridge_bases(bus);
 278                 pcibios_fixup_device_resources(dev, bus);
 279         }
 280
 281         for (ln = bus->devices.next; ln != &bus->devices; ln = ln->next) {
 282                 dev = pci_dev_b(ln);
 283
 284                 if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
 285                         pcibios_fixup_device_resources(dev, bus);
 286         }
 287 }
 288
 289 void __init
 290 pcibios_update_irq(struct pci_dev *dev, int irq)
 291 {
 292         pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
 293 }
 294
 295 void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
 296                          struct resource *res)
 297 {
 298         struct pci_controller *hose = (struct pci_controller *)dev->sysdata;
 299         unsigned long offset = 0;
 300
 301         if (res->flags & IORESOURCE_IO)
 302                 offset = hose->io_offset;
 303         else if (res->flags & IORESOURCE_MEM)
 304                 offset = hose->mem_offset;
 305
 306         region->start = res->start - offset;
 307         region->end = res->end - offset;
 308 }
 309
 310 void __devinit
 311 pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
 312                         struct pci_bus_region *region)
 313 {
 314         struct pci_controller *hose = (struct pci_controller *)dev->sysdata;
 315         unsigned long offset = 0;
 316
 317         if (res->flags & IORESOURCE_IO)
 318                 offset = hose->io_offset;
 319         else if (res->flags & IORESOURCE_MEM)
 320                 offset = hose->mem_offset;
 321
 322         res->start = region->start + offset;
 323         res->end = region->end + offset;
 324 }
 325
 326 #ifdef CONFIG_HOTPLUG
 327 EXPORT_SYMBOL(pcibios_resource_to_bus);
 328 EXPORT_SYMBOL(pcibios_bus_to_resource);
 329 EXPORT_SYMBOL(PCIBIOS_MIN_IO);
 330 EXPORT_SYMBOL(PCIBIOS_MIN_MEM);
 331 #endif
 332
 333 int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
 334                         enum pci_mmap_state mmap_state, int write_combine)
 335 {
 336         unsigned long prot;
 337
 338         /*
 339          * I/O space can be accessed via normal processor loads and stores on
 340          * this platform but for now we elect not to do this and portable
 341          * drivers should not do this anyway.
 342          */
 343         if (mmap_state == pci_mmap_io)
 344                 return -EINVAL;
 345
 346         /*
 347          * Ignore write-combine; for now only return uncached mappings.
 348          */
 349         prot = pgprot_val(vma->vm_page_prot);
 350         prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED;
 351         vma->vm_page_prot = __pgprot(prot);
 352
 353         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 354                 vma->vm_end - vma->vm_start, vma->vm_page_prot);
 355 }
 356
 357 char * (*pcibios_plat_setup)(char *str) __devinitdata;
 358
 359 char *__devinit pcibios_setup(char *str)
 360 {
 361         if (pcibios_plat_setup)
 362                 return pcibios_plat_setup(str);
 363         return str;
 364 }