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 struct pci_controller *hose_head, **hose_tail = &hose_head;
  33 struct pci_controller *pci_isa_hose;
  34
  35 unsigned long PCIBIOS_MIN_IO    = 0x0000;
  36 unsigned long PCIBIOS_MIN_MEM   = 0;
  37
  38 /*
  39  * We need to avoid collisions with `mirrored' VGA ports
  40  * and other strange ISA hardware, so we always want the
  41  * addresses to be allocated in the 0x000-0x0ff region
  42  * modulo 0x400.
  43  *
  44  * Why? Because some silly external IO cards only decode
  45  * the low 10 bits of the IO address. The 0x00-0xff region
  46  * is reserved for motherboard devices that decode all 16
  47  * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
  48  * but we want to try to avoid allocating at 0x2900-0x2bff
  49  * which might have be mirrored at 0x0100-0x03ff..
  50  */
  51 void
  52 pcibios_align_resource(void *data, struct resource *res,
  53                        resource_size_t size, resource_size_t align)
  54 {
  55         struct pci_dev *dev = data;
  56         struct pci_controller *hose = dev->sysdata;
  57         resource_size_t start = res->start;
  58
  59         if (res->flags & IORESOURCE_IO) {
  60                 /* Make sure we start at our min on all hoses */
  61                 if (start < PCIBIOS_MIN_IO + hose->io_resource->start)
  62                         start = PCIBIOS_MIN_IO + hose->io_resource->start;
  63
  64                 /*
  65                  * Put everything into 0x00-0xff region modulo 0x400
  66                  */
  67                 if (start & 0x300)
  68                         start = (start + 0x3ff) & ~0x3ff;
  69         } else if (res->flags & IORESOURCE_MEM) {
  70                 /* Make sure we start at our min on all hoses */
  71                 if (start < PCIBIOS_MIN_MEM + hose->mem_resource->start)
  72                         start = PCIBIOS_MIN_MEM + hose->mem_resource->start;
  73         }
  74
  75         res->start = start;
  76 }
  77
  78 void __devinit register_pci_controller(struct pci_controller *hose)
  79 {
  80         if (request_resource(&iomem_resource, hose->mem_resource) < 0)
  81                 goto out;
  82         if (request_resource(&ioport_resource, hose->io_resource) < 0) {
  83                 release_resource(hose->mem_resource);
  84                 goto out;
  85         }
  86
  87         *hose_tail = hose;
  88         hose_tail = &hose->next;
  89
  90         /*
  91          * Do not panic here but later - this might hapen before console init.
  92          */
  93         if (!hose->io_map_base) {
  94                 printk(KERN_WARNING
  95                        "registering PCI controller with io_map_base unset\n");
  96         }
  97         return;
  98
  99 out:
 100         printk(KERN_WARNING
 101                "Skipping PCI bus scan due to resource conflict\n");
 102 }
 103
 104 /* Most MIPS systems have straight-forward swizzling needs.  */
 105
 106 static inline u8 bridge_swizzle(u8 pin, u8 slot)
 107 {
 108         return (((pin - 1) + slot) % 4) + 1;
 109 }
 110
 111 static u8 __init common_swizzle(struct pci_dev *dev, u8 *pinp)
 112 {
 113         u8 pin = *pinp;
 114
 115         while (dev->bus->parent) {
 116                 pin = bridge_swizzle(pin, PCI_SLOT(dev->devfn));
 117                 /* Move up the chain of bridges. */
 118                 dev = dev->bus->self;
 119         }
 120         *pinp = pin;
 121
 122         /* The slot is the slot of the last bridge. */
 123         return PCI_SLOT(dev->devfn);
 124 }
 125
 126 static int __init pcibios_init(void)
 127 {
 128         struct pci_controller *hose;
 129         struct pci_bus *bus;
 130         int next_busno;
 131         int need_domain_info = 0;
 132
 133         /* Scan all of the recorded PCI controllers.  */
 134         for (next_busno = 0, hose = hose_head; hose; hose = hose->next) {
 135
 136                 if (!hose->iommu)
 137                         PCI_DMA_BUS_IS_PHYS = 1;
 138
 139                 if (hose->get_busno && pci_probe_only)
 140                         next_busno = (*hose->get_busno)();
 141
 142                 bus = pci_scan_bus(next_busno, hose->pci_ops, hose);
 143                 hose->bus = bus;
 144                 need_domain_info = need_domain_info || hose->index;
 145                 hose->need_domain_info = need_domain_info;
 146                 if (bus) {
 147                         next_busno = bus->subordinate + 1;
 148                         /* Don't allow 8-bit bus number overflow inside the hose -
 149                            reserve some space for bridges. */
 150                         if (next_busno > 224) {
 151                                 next_busno = 0;
 152                                 need_domain_info = 1;
 153                         }
 154                 }
 155         }
 156
 157         if (!pci_probe_only)
 158                 pci_assign_unassigned_resources();
 159         pci_fixup_irqs(common_swizzle, pcibios_map_irq);
 160
 161         return 0;
 162 }
 163
 164 subsys_initcall(pcibios_init);
 165
 166 static int pcibios_enable_resources(struct pci_dev *dev, int mask)
 167 {
 168         u16 cmd, old_cmd;
 169         int idx;
 170         struct resource *r;
 171
 172         pci_read_config_word(dev, PCI_COMMAND, &cmd);
 173         old_cmd = cmd;
 174         for (idx=0; idx < PCI_NUM_RESOURCES; idx++) {
 175                 /* Only set up the requested stuff */
 176                 if (!(mask & (1<<idx)))
 177                         continue;
 178
 179                 r = &dev->resource[idx];
 180                 if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
 181                         continue;
 182                 if ((idx == PCI_ROM_RESOURCE) &&
 183                                 (!(r->flags & IORESOURCE_ROM_ENABLE)))
 184                         continue;
 185                 if (!r->start && r->end) {
 186                         printk(KERN_ERR "PCI: Device %s not available "
 187                                "because of resource collisions\n",
 188                                pci_name(dev));
 189                         return -EINVAL;
 190                 }
 191                 if (r->flags & IORESOURCE_IO)
 192                         cmd |= PCI_COMMAND_IO;
 193                 if (r->flags & IORESOURCE_MEM)
 194                         cmd |= PCI_COMMAND_MEMORY;
 195         }
 196         if (cmd != old_cmd) {
 197                 printk("PCI: Enabling device %s (%04x -> %04x)\n",
 198                        pci_name(dev), old_cmd, cmd);
 199                 pci_write_config_word(dev, PCI_COMMAND, cmd);
 200         }
 201         return 0;
 202 }
 203
 204 /*
 205  *  If we set up a device for bus mastering, we need to check the latency
 206  *  timer as certain crappy BIOSes forget to set it properly.
 207  */
 208 unsigned int pcibios_max_latency = 255;
 209
 210 void pcibios_set_master(struct pci_dev *dev)
 211 {
 212         u8 lat;
 213         pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
 214         if (lat < 16)
 215                 lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
 216         else if (lat > pcibios_max_latency)
 217                 lat = pcibios_max_latency;
 218         else
 219                 return;
 220         printk(KERN_DEBUG "PCI: Setting latency timer of device %s to %d\n",
 221                pci_name(dev), lat);
 222         pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
 223 }
 224
 225 unsigned int pcibios_assign_all_busses(void)
 226 {
 227         return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
 228 }
 229
 230 int pcibios_enable_device(struct pci_dev *dev, int mask)
 231 {
 232         int err;
 233
 234         if ((err = pcibios_enable_resources(dev, mask)) < 0)
 235                 return err;
 236
 237         return pcibios_plat_dev_init(dev);
 238 }
 239
 240 static void pcibios_fixup_device_resources(struct pci_dev *dev,
 241         struct pci_bus *bus)
 242 {
 243         /* Update device resources.  */
 244         struct pci_controller *hose = (struct pci_controller *)bus->sysdata;
 245         unsigned long offset = 0;
 246         int i;
 247
 248         for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 249                 if (!dev->resource[i].start)
 250                         continue;
 251                 if (dev->resource[i].flags & IORESOURCE_PCI_FIXED)
 252                         continue;
 253                 if (dev->resource[i].flags & IORESOURCE_IO)
 254                         offset = hose->io_offset;
 255                 else if (dev->resource[i].flags & IORESOURCE_MEM)
 256                         offset = hose->mem_offset;
 257
 258                 dev->resource[i].start += offset;
 259                 dev->resource[i].end += offset;
 260         }
 261 }
 262
 263 void pcibios_fixup_bus(struct pci_bus *bus)
 264 {
 265         /* Propagate hose info into the subordinate devices.  */
 266
 267         struct pci_controller *hose = bus->sysdata;
 268         struct list_head *ln;
 269         struct pci_dev *dev = bus->self;
 270
 271         if (!dev) {
 272                 bus->resource[0] = hose->io_resource;
 273                 bus->resource[1] = hose->mem_resource;
 274         } else if (pci_probe_only &&
 275                    (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
 276                 pci_read_bridge_bases(bus);
 277                 pcibios_fixup_device_resources(dev, bus);
 278         }
 279
 280         for (ln = bus->devices.next; ln != &bus->devices; ln = ln->next) {
 281                 dev = pci_dev_b(ln);
 282
 283                 if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
 284                         pcibios_fixup_device_resources(dev, bus);
 285         }
 286 }
 287
 288 void __init
 289 pcibios_update_irq(struct pci_dev *dev, int irq)
 290 {
 291         pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
 292 }
 293
 294 void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
 295                          struct resource *res)
 296 {
 297         struct pci_controller *hose = (struct pci_controller *)dev->sysdata;
 298         unsigned long offset = 0;
 299
 300         if (res->flags & IORESOURCE_IO)
 301                 offset = hose->io_offset;
 302         else if (res->flags & IORESOURCE_MEM)
 303                 offset = hose->mem_offset;
 304
 305         region->start = res->start - offset;
 306         region->end = res->end - offset;
 307 }
 308
 309 void __devinit
 310 pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
 311                         struct pci_bus_region *region)
 312 {
 313         struct pci_controller *hose = (struct pci_controller *)dev->sysdata;
 314         unsigned long offset = 0;
 315
 316         if (res->flags & IORESOURCE_IO)
 317                 offset = hose->io_offset;
 318         else if (res->flags & IORESOURCE_MEM)
 319                 offset = hose->mem_offset;
 320
 321         res->start = region->start + offset;
 322         res->end = region->end + offset;
 323 }
 324
 325 #ifdef CONFIG_HOTPLUG
 326 EXPORT_SYMBOL(pcibios_resource_to_bus);
 327 EXPORT_SYMBOL(pcibios_bus_to_resource);
 328 EXPORT_SYMBOL(PCIBIOS_MIN_IO);
 329 EXPORT_SYMBOL(PCIBIOS_MIN_MEM);
 330 #endif
 331
 332 char *pcibios_setup(char *str)
 333 {
 334         return str;
 335 }