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/config.h>
  10 #include <linux/kernel.h>
  11 #include <linux/mm.h>
  12 #include <linux/bootmem.h>
  13 #include <linux/init.h>
  14 #include <linux/types.h>
  15 #include <linux/pci.h>
  16
  17 /*
  18  * Indicate whether we respect the PCI setup left by the firmware.
  19  *
  20  * Make this long-lived  so that we know when shutting down
  21  * whether we probed only or not.
  22  */
  23 int pci_probe_only;
  24
  25 #define PCI_ASSIGN_ALL_BUSSES   1
  26
  27 unsigned int pci_probe = PCI_ASSIGN_ALL_BUSSES;
  28
  29 /*
  30  * The PCI controller list.
  31  */
  32
  33 struct pci_controller *hose_head, **hose_tail = &hose_head;
  34 struct pci_controller *pci_isa_hose;
  35
  36 unsigned long PCIBIOS_MIN_IO    = 0x0000;
  37 unsigned long PCIBIOS_MIN_MEM   = 0;
  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 void
  53 pcibios_align_resource(void *data, struct resource *res,
  54                        unsigned long size, unsigned long align)
  55 {
  56         struct pci_dev *dev = data;
  57         struct pci_controller *hose = dev->sysdata;
  58         unsigned long 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         res->start = start;
  77 }
  78
  79 struct pci_controller * __init alloc_pci_controller(void)
  80 {
  81         return alloc_bootmem(sizeof(struct pci_controller));
  82 }
  83
  84 void __init register_pci_controller(struct pci_controller *hose)
  85 {
  86         *hose_tail = hose;
  87         hose_tail = &hose->next;
  88 }
  89
  90 /* Most MIPS systems have straight-forward swizzling needs.  */
  91
  92 static inline u8 bridge_swizzle(u8 pin, u8 slot)
  93 {
  94         return (((pin - 1) + slot) % 4) + 1;
  95 }
  96
  97 static u8 __init common_swizzle(struct pci_dev *dev, u8 *pinp)
  98 {
  99         u8 pin = *pinp;
 100
 101         while (dev->bus->parent) {
 102                 pin = bridge_swizzle(pin, PCI_SLOT(dev->devfn));
 103                 /* Move up the chain of bridges. */
 104                 dev = dev->bus->self;
 105         }
 106         *pinp = pin;
 107
 108         /* The slot is the slot of the last bridge. */
 109         return PCI_SLOT(dev->devfn);
 110 }
 111
 112 static int __init pcibios_init(void)
 113 {
 114         struct pci_controller *hose;
 115         struct pci_bus *bus;
 116         int next_busno;
 117         int need_domain_info = 0;
 118
 119         /* Scan all of the recorded PCI controllers.  */
 120         for (next_busno = 0, hose = hose_head; hose; hose = hose->next) {
 121
 122                 if (request_resource(&iomem_resource, hose->mem_resource) < 0)
 123                         goto out;
 124                 if (request_resource(&ioport_resource, hose->io_resource) < 0)
 125                         goto out_free_mem_resource;
 126
 127                 if (!hose->iommu)
 128                         PCI_DMA_BUS_IS_PHYS = 1;
 129
 130                 bus = pci_scan_bus(next_busno, hose->pci_ops, hose);
 131                 hose->bus = bus;
 132                 hose->need_domain_info = need_domain_info;
 133                 next_busno = bus->subordinate + 1;
 134                 /* Don't allow 8-bit bus number overflow inside the hose -
 135                    reserve some space for bridges. */
 136                 if (next_busno > 224) {
 137                         next_busno = 0;
 138                         need_domain_info = 1;
 139                 }
 140                 continue;
 141
 142 out_free_mem_resource:
 143                 release_resource(hose->mem_resource);
 144
 145 out:
 146                 printk(KERN_WARNING
 147                        "Skipping PCI bus scan due to resource conflict\n");
 148         }
 149
 150         if (!pci_probe_only)
 151                 pci_assign_unassigned_resources();
 152         pci_fixup_irqs(common_swizzle, pcibios_map_irq);
 153
 154         return 0;
 155 }
 156
 157 subsys_initcall(pcibios_init);
 158
 159 static int pcibios_enable_resources(struct pci_dev *dev, int mask)
 160 {
 161         u16 cmd, old_cmd;
 162         int idx;
 163         struct resource *r;
 164
 165         pci_read_config_word(dev, PCI_COMMAND, &cmd);
 166         old_cmd = cmd;
 167         for(idx=0; idx<6; idx++) {
 168                 /* Only set up the requested stuff */
 169                 if (!(mask & (1<<idx)))
 170                         continue;
 171
 172                 r = &dev->resource[idx];
 173                 if (!r->start && r->end) {
 174                         printk(KERN_ERR "PCI: Device %s not available because of resource collisions\n", pci_name(dev));
 175                         return -EINVAL;
 176                 }
 177                 if (r->flags & IORESOURCE_IO)
 178                         cmd |= PCI_COMMAND_IO;
 179                 if (r->flags & IORESOURCE_MEM)
 180                         cmd |= PCI_COMMAND_MEMORY;
 181         }
 182         if (dev->resource[PCI_ROM_RESOURCE].start)
 183                 cmd |= PCI_COMMAND_MEMORY;
 184         if (cmd != old_cmd) {
 185                 printk("PCI: Enabling device %s (%04x -> %04x)\n", pci_name(dev), old_cmd, cmd);
 186                 pci_write_config_word(dev, PCI_COMMAND, cmd);
 187         }
 188         return 0;
 189 }
 190
 191 /*
 192  *  If we set up a device for bus mastering, we need to check the latency
 193  *  timer as certain crappy BIOSes forget to set it properly.
 194  */
 195 unsigned int pcibios_max_latency = 255;
 196
 197 void pcibios_set_master(struct pci_dev *dev)
 198 {
 199         u8 lat;
 200         pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
 201         if (lat < 16)
 202                 lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
 203         else if (lat > pcibios_max_latency)
 204                 lat = pcibios_max_latency;
 205         else
 206                 return;
 207         printk(KERN_DEBUG "PCI: Setting latency timer of device %s to %d\n",
 208                pci_name(dev), lat);
 209         pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
 210 }
 211
 212 unsigned int pcibios_assign_all_busses(void)
 213 {
 214         return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
 215 }
 216
 217 int pcibios_enable_device(struct pci_dev *dev, int mask)
 218 {
 219         int err;
 220
 221         if ((err = pcibios_enable_resources(dev, mask)) < 0)
 222                 return err;
 223
 224         return pcibios_plat_dev_init(dev);
 225 }
 226
 227 static void __init pcibios_fixup_device_resources(struct pci_dev *dev,
 228         struct pci_bus *bus)
 229 {
 230         /* Update device resources.  */
 231         struct pci_controller *hose = (struct pci_controller *)bus->sysdata;
 232         unsigned long offset = 0;
 233         int i;
 234
 235         for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 236                 if (!dev->resource[i].start)
 237                         continue;
 238                 if (dev->resource[i].flags & IORESOURCE_IO)
 239                         offset = hose->io_offset;
 240                 else if (dev->resource[i].flags & IORESOURCE_MEM)
 241                         offset = hose->mem_offset;
 242
 243                 dev->resource[i].start += offset;
 244                 dev->resource[i].end += offset;
 245         }
 246 }
 247
 248 void __devinit pcibios_fixup_bus(struct pci_bus *bus)
 249 {
 250         /* Propagate hose info into the subordinate devices.  */
 251
 252         struct pci_controller *hose = bus->sysdata;
 253         struct list_head *ln;
 254         struct pci_dev *dev = bus->self;
 255
 256         if (!dev) {
 257                 bus->resource[0] = hose->io_resource;
 258                 bus->resource[1] = hose->mem_resource;
 259         } else if (pci_probe_only &&
 260                    (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
 261                 pci_read_bridge_bases(bus);
 262                 pcibios_fixup_device_resources(dev, bus);
 263         }
 264
 265         for (ln = bus->devices.next; ln != &bus->devices; ln = ln->next) {
 266                 struct pci_dev *dev = pci_dev_b(ln);
 267
 268                 if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
 269                         pcibios_fixup_device_resources(dev, bus);
 270         }
 271 }
 272
 273 void __init
 274 pcibios_update_irq(struct pci_dev *dev, int irq)
 275 {
 276         pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
 277 }
 278
 279 void __devinit
 280 pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
 281                          struct resource *res)
 282 {
 283         struct pci_controller *hose = (struct pci_controller *)dev->sysdata;
 284         unsigned long offset = 0;
 285
 286         if (res->flags & IORESOURCE_IO)
 287                 offset = hose->io_offset;
 288         else if (res->flags & IORESOURCE_MEM)
 289                 offset = hose->mem_offset;
 290
 291         region->start = res->start - offset;
 292         region->end = res->end - offset;
 293 }
 294
 295 #ifdef CONFIG_HOTPLUG
 296 EXPORT_SYMBOL(pcibios_resource_to_bus);
 297 EXPORT_SYMBOL(PCIBIOS_MIN_IO);
 298 EXPORT_SYMBOL(PCIBIOS_MIN_MEM);
 299 #endif
 300
 301 char *pcibios_setup(char *str)
 302 {
 303         return str;
 304 }