Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  * probe.c - PCI detection and setup code
  3  */
  4 
  5 #include <linux/kernel.h>
  6 #include <linux/delay.h>
  7 #include <linux/init.h>
  8 #include <linux/pci.h>
  9 #include <linux/slab.h>
 10 #include <linux/module.h>
 11 #include <linux/cpumask.h>
 12 #include "pci.h"
 13 
 14 #define CARDBUS_LATENCY_TIMER   176     /* secondary latency timer */
 15 #define CARDBUS_RESERVE_BUSNR   3
 16 #define PCI_CFG_SPACE_SIZE      256
 17 #define PCI_CFG_SPACE_EXP_SIZE  4096
 18 
 19 /* Ugh.  Need to stop exporting this to modules. */
 20 LIST_HEAD(pci_root_buses);
 21 EXPORT_SYMBOL(pci_root_buses);
 22 
 23 LIST_HEAD(pci_devices);
 24 
 25 /*
 26  * Some device drivers need know if pci is initiated.
 27  * Basically, we think pci is not initiated when there
 28  * is no device in list of pci_devices.
 29  */
 30 int no_pci_devices(void)
 31 {
 32         return list_empty(&pci_devices);
 33 }
 34 
 35 EXPORT_SYMBOL(no_pci_devices);
 36 
 37 #ifdef HAVE_PCI_LEGACY
 38 /**
 39  * pci_create_legacy_files - create legacy I/O port and memory files
 40  * @b: bus to create files under
 41  *
 42  * Some platforms allow access to legacy I/O port and ISA memory space on
 43  * a per-bus basis.  This routine creates the files and ties them into
 44  * their associated read, write and mmap files from pci-sysfs.c
 45  */
 46 static void pci_create_legacy_files(struct pci_bus *b)
 47 {
 48         b->legacy_io = kzalloc(sizeof(struct bin_attribute) * 2,
 49                                GFP_ATOMIC);
 50         if (b->legacy_io) {
 51                 b->legacy_io->attr.name = "legacy_io";
 52                 b->legacy_io->size = 0xffff;
 53                 b->legacy_io->attr.mode = S_IRUSR | S_IWUSR;
 54                 b->legacy_io->read = pci_read_legacy_io;
 55                 b->legacy_io->write = pci_write_legacy_io;
 56                 device_create_bin_file(&b->dev, b->legacy_io);
 57 
 58                 /* Allocated above after the legacy_io struct */
 59                 b->legacy_mem = b->legacy_io + 1;
 60                 b->legacy_mem->attr.name = "legacy_mem";
 61                 b->legacy_mem->size = 1024*1024;
 62                 b->legacy_mem->attr.mode = S_IRUSR | S_IWUSR;
 63                 b->legacy_mem->mmap = pci_mmap_legacy_mem;
 64                 device_create_bin_file(&b->dev, b->legacy_mem);
 65         }
 66 }
 67 
 68 void pci_remove_legacy_files(struct pci_bus *b)
 69 {
 70         if (b->legacy_io) {
 71                 device_remove_bin_file(&b->dev, b->legacy_io);
 72                 device_remove_bin_file(&b->dev, b->legacy_mem);
 73                 kfree(b->legacy_io); /* both are allocated here */
 74         }
 75 }
 76 #else /* !HAVE_PCI_LEGACY */
 77 static inline void pci_create_legacy_files(struct pci_bus *bus) { return; }
 78 void pci_remove_legacy_files(struct pci_bus *bus) { return; }
 79 #endif /* HAVE_PCI_LEGACY */
 80 
 81 /*
 82  * PCI Bus Class Devices
 83  */
 84 static ssize_t pci_bus_show_cpuaffinity(struct device *dev,
 85                                         struct device_attribute *attr,
 86                                         char *buf)
 87 {
 88         int ret;
 89         cpumask_t cpumask;
 90 
 91         cpumask = pcibus_to_cpumask(to_pci_bus(dev));
 92         ret = cpumask_scnprintf(buf, PAGE_SIZE, cpumask);
 93         if (ret < PAGE_SIZE)
 94                 buf[ret++] = '\n';
 95         return ret;
 96 }
 97 DEVICE_ATTR(cpuaffinity, S_IRUGO, pci_bus_show_cpuaffinity, NULL);
 98 
 99 /*
100  * PCI Bus Class
101  */
102 static void release_pcibus_dev(struct device *dev)
103 {
104         struct pci_bus *pci_bus = to_pci_bus(dev);
105 
106         if (pci_bus->bridge)
107                 put_device(pci_bus->bridge);
108         kfree(pci_bus);
109 }
110 
111 static struct class pcibus_class = {
112         .name           = "pci_bus",
113         .dev_release    = &release_pcibus_dev,
114 };
115 
116 static int __init pcibus_class_init(void)
117 {
118         return class_register(&pcibus_class);
119 }
120 postcore_initcall(pcibus_class_init);
121 
122 /*
123  * Translate the low bits of the PCI base
124  * to the resource type
125  */
126 static inline unsigned int pci_calc_resource_flags(unsigned int flags)
127 {
128         if (flags & PCI_BASE_ADDRESS_SPACE_IO)
129                 return IORESOURCE_IO;
130 
131         if (flags & PCI_BASE_ADDRESS_MEM_PREFETCH)
132                 return IORESOURCE_MEM | IORESOURCE_PREFETCH;
133 
134         return IORESOURCE_MEM;
135 }
136 
137 /*
138  * Find the extent of a PCI decode..
139  */
140 static u32 pci_size(u32 base, u32 maxbase, u32 mask)
141 {
142         u32 size = mask & maxbase;      /* Find the significant bits */
143         if (!size)
144                 return 0;
145 
146         /* Get the lowest of them to find the decode size, and
147            from that the extent.  */
148         size = (size & ~(size-1)) - 1;
149 
150         /* base == maxbase can be valid only if the BAR has
151            already been programmed with all 1s.  */
152         if (base == maxbase && ((base | size) & mask) != mask)
153                 return 0;
154 
155         return size;
156 }
157 
158 static u64 pci_size64(u64 base, u64 maxbase, u64 mask)
159 {
160         u64 size = mask & maxbase;      /* Find the significant bits */
161         if (!size)
162                 return 0;
163 
164         /* Get the lowest of them to find the decode size, and
165            from that the extent.  */
166         size = (size & ~(size-1)) - 1;
167 
168         /* base == maxbase can be valid only if the BAR has
169            already been programmed with all 1s.  */
170         if (base == maxbase && ((base | size) & mask) != mask)
171                 return 0;
172 
173         return size;
174 }
175 
176 static inline int is_64bit_memory(u32 mask)
177 {
178         if ((mask & (PCI_BASE_ADDRESS_SPACE|PCI_BASE_ADDRESS_MEM_TYPE_MASK)) ==
179             (PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64))
180                 return 1;
181         return 0;
182 }
183 
184 static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
185 {
186         unsigned int pos, reg, next;
187         u32 l, sz;
188         struct resource *res;
189 
190         for(pos=0; pos<howmany; pos = next) {
191                 u64 l64;
192                 u64 sz64;
193                 u32 raw_sz;
194 
195                 next = pos+1;
196                 res = &dev->resource[pos];
197                 res->name = pci_name(dev);
198                 reg = PCI_BASE_ADDRESS_0 + (pos << 2);
199                 pci_read_config_dword(dev, reg, &l);
200                 pci_write_config_dword(dev, reg, ~0);
201                 pci_read_config_dword(dev, reg, &sz);
202                 pci_write_config_dword(dev, reg, l);
203                 if (!sz || sz == 0xffffffff)
204                         continue;
205                 if (l == 0xffffffff)
206                         l = 0;
207                 raw_sz = sz;
208                 if ((l & PCI_BASE_ADDRESS_SPACE) ==
209                                 PCI_BASE_ADDRESS_SPACE_MEMORY) {
210                         sz = pci_size(l, sz, (u32)PCI_BASE_ADDRESS_MEM_MASK);
211                         /*
212                          * For 64bit prefetchable memory sz could be 0, if the
213                          * real size is bigger than 4G, so we need to check
214                          * szhi for that.
215                          */
216                         if (!is_64bit_memory(l) && !sz)
217                                 continue;
218                         res->start = l & PCI_BASE_ADDRESS_MEM_MASK;
219                         res->flags |= l & ~PCI_BASE_ADDRESS_MEM_MASK;
220                 } else {
221                         sz = pci_size(l, sz, PCI_BASE_ADDRESS_IO_MASK & 0xffff);
222                         if (!sz)
223                                 continue;
224                         res->start = l & PCI_BASE_ADDRESS_IO_MASK;
225                         res->flags |= l & ~PCI_BASE_ADDRESS_IO_MASK;
226                 }
227                 res->end = res->start + (unsigned long) sz;
228                 res->flags |= pci_calc_resource_flags(l);
229                 if (is_64bit_memory(l)) {
230                         u32 szhi, lhi;
231 
232                         pci_read_config_dword(dev, reg+4, &lhi);
233                         pci_write_config_dword(dev, reg+4, ~0);
234                         pci_read_config_dword(dev, reg+4, &szhi);
235                         pci_write_config_dword(dev, reg+4, lhi);
236                         sz64 = ((u64)szhi << 32) | raw_sz;
237                         l64 = ((u64)lhi << 32) | l;
238                         sz64 = pci_size64(l64, sz64, PCI_BASE_ADDRESS_MEM_MASK);
239                         next++;
240 #if BITS_PER_LONG == 64
241                         if (!sz64) {
242                                 res->start = 0;
243                                 res->end = 0;
244                                 res->flags = 0;
245                                 continue;
246                         }
247                         res->start = l64 & PCI_BASE_ADDRESS_MEM_MASK;
248                         res->end = res->start + sz64;
249 #else
250                         if (sz64 > 0x100000000ULL) {
251                                 printk(KERN_ERR "PCI: Unable to handle 64-bit "
252                                         "BAR for device %s\n", pci_name(dev));
253                                 res->start = 0;
254                                 res->flags = 0;
255                         } else if (lhi) {
256                                 /* 64-bit wide address, treat as disabled */
257                                 pci_write_config_dword(dev, reg,
258                                         l & ~(u32)PCI_BASE_ADDRESS_MEM_MASK);
259                                 pci_write_config_dword(dev, reg+4, 0);
260                                 res->start = 0;
261                                 res->end = sz;
262                         }
263 #endif
264                 }
265         }
266         if (rom) {
267                 dev->rom_base_reg = rom;
268                 res = &dev->resource[PCI_ROM_RESOURCE];
269                 res->name = pci_name(dev);
270                 pci_read_config_dword(dev, rom, &l);
271                 pci_write_config_dword(dev, rom, ~PCI_ROM_ADDRESS_ENABLE);
272                 pci_read_config_dword(dev, rom, &sz);
273                 pci_write_config_dword(dev, rom, l);
274                 if (l == 0xffffffff)
275                         l = 0;
276                 if (sz && sz != 0xffffffff) {
277                         sz = pci_size(l, sz, (u32)PCI_ROM_ADDRESS_MASK);
278                         if (sz) {
279                                 res->flags = (l & IORESOURCE_ROM_ENABLE) |
280                                   IORESOURCE_MEM | IORESOURCE_PREFETCH |
281                                   IORESOURCE_READONLY | IORESOURCE_CACHEABLE;
282                                 res->start = l & PCI_ROM_ADDRESS_MASK;
283                                 res->end = res->start + (unsigned long) sz;
284                         }
285                 }
286         }
287 }
288 
289 void __devinit pci_read_bridge_bases(struct pci_bus *child)
290 {
291         struct pci_dev *dev = child->self;
292         u8 io_base_lo, io_limit_lo;
293         u16 mem_base_lo, mem_limit_lo;
294         unsigned long base, limit;
295         struct resource *res;
296         int i;
297 
298         if (!dev)               /* It's a host bus, nothing to read */
299                 return;
300 
301         if (dev->transparent) {
302                 printk(KERN_INFO "PCI: Transparent bridge - %s\n", pci_name(dev));
303                 for(i = 3; i < PCI_BUS_NUM_RESOURCES; i++)
304                         child->resource[i] = child->parent->resource[i - 3];
305         }
306 
307         for(i=0; i<3; i++)
308                 child->resource[i] = &dev->resource[PCI_BRIDGE_RESOURCES+i];
309 
310         res = child->resource[0];
311         pci_read_config_byte(dev, PCI_IO_BASE, &io_base_lo);
312         pci_read_config_byte(dev, PCI_IO_LIMIT, &io_limit_lo);
313         base = (io_base_lo & PCI_IO_RANGE_MASK) << 8;
314         limit = (io_limit_lo & PCI_IO_RANGE_MASK) << 8;
315 
316         if ((io_base_lo & PCI_IO_RANGE_TYPE_MASK) == PCI_IO_RANGE_TYPE_32) {
317                 u16 io_base_hi, io_limit_hi;
318                 pci_read_config_word(dev, PCI_IO_BASE_UPPER16, &io_base_hi);
319                 pci_read_config_word(dev, PCI_IO_LIMIT_UPPER16, &io_limit_hi);
320                 base |= (io_base_hi << 16);
321                 limit |= (io_limit_hi << 16);
322         }
323 
324         if (base <= limit) {
325                 res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO;
326                 if (!res->start)
327                         res->start = base;
328                 if (!res->end)
329                         res->end = limit + 0xfff;
330         }
331 
332         res = child->resource[1];
333         pci_read_config_word(dev, PCI_MEMORY_BASE, &mem_base_lo);
334         pci_read_config_word(dev, PCI_MEMORY_LIMIT, &mem_limit_lo);
335         base = (mem_base_lo & PCI_MEMORY_RANGE_MASK) << 16;
336         limit = (mem_limit_lo & PCI_MEMORY_RANGE_MASK) << 16;
337         if (base <= limit) {
338                 res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM;
339                 res->start = base;
340                 res->end = limit + 0xfffff;
341         }
342 
343         res = child->resource[2];
344         pci_read_config_word(dev, PCI_PREF_MEMORY_BASE, &mem_base_lo);
345         pci_read_config_word(dev, PCI_PREF_MEMORY_LIMIT, &mem_limit_lo);
346         base = (mem_base_lo & PCI_PREF_RANGE_MASK) << 16;
347         limit = (mem_limit_lo & PCI_PREF_RANGE_MASK) << 16;
348 
349         if ((mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) {
350                 u32 mem_base_hi, mem_limit_hi;
351                 pci_read_config_dword(dev, PCI_PREF_BASE_UPPER32, &mem_base_hi);
352                 pci_read_config_dword(dev, PCI_PREF_LIMIT_UPPER32, &mem_limit_hi);
353 
354                 /*
355                  * Some bridges set the base > limit by default, and some
356                  * (broken) BIOSes do not initialize them.  If we find
357                  * this, just assume they are not being used.
358                  */
359                 if (mem_base_hi <= mem_limit_hi) {
360 #if BITS_PER_LONG == 64
361                         base |= ((long) mem_base_hi) << 32;
362                         limit |= ((long) mem_limit_hi) << 32;
363 #else
364                         if (mem_base_hi || mem_limit_hi) {
365                                 printk(KERN_ERR "PCI: Unable to handle 64-bit address space for bridge %s\n", pci_name(dev));
366                                 return;
367                         }
368 #endif
369                 }
370         }
371         if (base <= limit) {
372                 res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM | IORESOURCE_PREFETCH;
373                 res->start = base;
374                 res->end = limit + 0xfffff;
375         }
376 }
377 
378 static struct pci_bus * pci_alloc_bus(void)
379 {
380         struct pci_bus *b;
381 
382         b = kzalloc(sizeof(*b), GFP_KERNEL);
383         if (b) {
384                 INIT_LIST_HEAD(&b->node);
385                 INIT_LIST_HEAD(&b->children);
386                 INIT_LIST_HEAD(&b->devices);
387         }
388         return b;
389 }
390 
391 static struct pci_bus * __devinit
392 pci_alloc_child_bus(struct pci_bus *parent, struct pci_dev *bridge, int busnr)
393 {
394         struct pci_bus *child;
395         int i;
396 
397         /*
398          * Allocate a new bus, and inherit stuff from the parent..
399          */
400         child = pci_alloc_bus();
401         if (!child)
402                 return NULL;
403 
404         child->self = bridge;
405         child->parent = parent;
406         child->ops = parent->ops;
407         child->sysdata = parent->sysdata;
408         child->bus_flags = parent->bus_flags;
409         child->bridge = get_device(&bridge->dev);
410 
411         /* initialize some portions of the bus device, but don't register it
412          * now as the parent is not properly set up yet.  This device will get
413          * registered later in pci_bus_add_devices()
414          */
415         child->dev.class = &pcibus_class;
416         sprintf(child->dev.bus_id, "%04x:%02x", pci_domain_nr(child), busnr);
417 
418         /*
419          * Set up the primary, secondary and subordinate
420          * bus numbers.
421          */
422         child->number = child->secondary = busnr;
423         child->primary = parent->secondary;
424         child->subordinate = 0xff;
425 
426         /* Set up default resource pointers and names.. */
427         for (i = 0; i < 4; i++) {
428                 child->resource[i] = &bridge->resource[PCI_BRIDGE_RESOURCES+i];
429                 child->resource[i]->name = child->name;
430         }
431         bridge->subordinate = child;
432 
433         return child;
434 }
435 
436 struct pci_bus *__ref pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev, int busnr)
437 {
438         struct pci_bus *child;
439 
440         child = pci_alloc_child_bus(parent, dev, busnr);
441         if (child) {
442                 down_write(&pci_bus_sem);
443                 list_add_tail(&child->node, &parent->children);
444                 up_write(&pci_bus_sem);
445         }
446         return child;
447 }
448 
449 static void pci_fixup_parent_subordinate_busnr(struct pci_bus *child, int max)
450 {
451         struct pci_bus *parent = child->parent;
452 
453         /* Attempts to fix that up are really dangerous unless
454            we're going to re-assign all bus numbers. */
455         if (!pcibios_assign_all_busses())
456                 return;
457 
458         while (parent->parent && parent->subordinate < max) {
459                 parent->subordinate = max;
460                 pci_write_config_byte(parent->self, PCI_SUBORDINATE_BUS, max);
461                 parent = parent->parent;
462         }
463 }
464 
465 /*
466  * If it's a bridge, configure it and scan the bus behind it.
467  * For CardBus bridges, we don't scan behind as the devices will
468  * be handled by the bridge driver itself.
469  *
470  * We need to process bridges in two passes -- first we scan those
471  * already configured by the BIOS and after we are done with all of
472  * them, we proceed to assigning numbers to the remaining buses in
473  * order to avoid overlaps between old and new bus numbers.
474  */
475 int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
476 {
477         struct pci_bus *child;
478         int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS);
479         u32 buses, i, j = 0;
480         u16 bctl;
481 
482         pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);
483 
484         pr_debug("PCI: Scanning behind PCI bridge %s, config %06x, pass %d\n",
485                  pci_name(dev), buses & 0xffffff, pass);
486 
487         /* Disable MasterAbortMode during probing to avoid reporting
488            of bus errors (in some architectures) */ 
489         pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl);
490         pci_write_config_word(dev, PCI_BRIDGE_CONTROL,
491                               bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT);
492 
493         if ((buses & 0xffff00) && !pcibios_assign_all_busses() && !is_cardbus) {
494                 unsigned int cmax, busnr;
495                 /*
496                  * Bus already configured by firmware, process it in the first
497                  * pass and just note the configuration.
498                  */
499                 if (pass)
500                         goto out;
501                 busnr = (buses >> 8) & 0xFF;
502 
503                 /*
504                  * If we already got to this bus through a different bridge,
505                  * ignore it.  This can happen with the i450NX chipset.
506                  */
507                 if (pci_find_bus(pci_domain_nr(bus), busnr)) {
508                         printk(KERN_INFO "PCI: Bus %04x:%02x already known\n",
509                                         pci_domain_nr(bus), busnr);
510                         goto out;
511                 }
512 
513                 child = pci_add_new_bus(bus, dev, busnr);
514                 if (!child)
515                         goto out;
516                 child->primary = buses & 0xFF;
517                 child->subordinate = (buses >> 16) & 0xFF;
518                 child->bridge_ctl = bctl;
519 
520                 cmax = pci_scan_child_bus(child);
521                 if (cmax > max)
522                         max = cmax;
523                 if (child->subordinate > max)
524                         max = child->subordinate;
525         } else {
526                 /*
527                  * We need to assign a number to this bus which we always
528                  * do in the second pass.
529                  */
530                 if (!pass) {
531                         if (pcibios_assign_all_busses())
532                                 /* Temporarily disable forwarding of the
533                                    configuration cycles on all bridges in
534                                    this bus segment to avoid possible
535                                    conflicts in the second pass between two
536                                    bridges programmed with overlapping
537                                    bus ranges. */
538                                 pci_write_config_dword(dev, PCI_PRIMARY_BUS,
539                                                        buses & ~0xffffff);
540                         goto out;
541                 }
542 
543                 /* Clear errors */
544                 pci_write_config_word(dev, PCI_STATUS, 0xffff);
545 
546                 /* Prevent assigning a bus number that already exists.
547                  * This can happen when a bridge is hot-plugged */
548                 if (pci_find_bus(pci_domain_nr(bus), max+1))
549                         goto out;
550                 child = pci_add_new_bus(bus, dev, ++max);
551                 buses = (buses & 0xff000000)
552                       | ((unsigned int)(child->primary)     <<  0)
553                       | ((unsigned int)(child->secondary)   <<  8)
554                       | ((unsigned int)(child->subordinate) << 16);
555 
556                 /*
557                  * yenta.c forces a secondary latency timer of 176.
558                  * Copy that behaviour here.
559                  */
560                 if (is_cardbus) {
561                         buses &= ~0xff000000;
562                         buses |= CARDBUS_LATENCY_TIMER << 24;
563                 }
564                         
565                 /*
566                  * We need to blast all three values with a single write.
567                  */
568                 pci_write_config_dword(dev, PCI_PRIMARY_BUS, buses);
569 
570                 if (!is_cardbus) {
571                         child->bridge_ctl = bctl;
572                         /*
573                          * Adjust subordinate busnr in parent buses.
574                          * We do this before scanning for children because
575                          * some devices may not be detected if the bios
576                          * was lazy.
577                          */
578                         pci_fixup_parent_subordinate_busnr(child, max);
579                         /* Now we can scan all subordinate buses... */
580                         max = pci_scan_child_bus(child);
581                         /*
582                          * now fix it up again since we have found
583                          * the real value of max.
584                          */
585                         pci_fixup_parent_subordinate_busnr(child, max);
586                 } else {
587                         /*
588                          * For CardBus bridges, we leave 4 bus numbers
589                          * as cards with a PCI-to-PCI bridge can be
590                          * inserted later.
591                          */
592                         for (i=0; i<CARDBUS_RESERVE_BUSNR; i++) {
593                                 struct pci_bus *parent = bus;
594                                 if (pci_find_bus(pci_domain_nr(bus),
595                                                         max+i+1))
596                                         break;
597                                 while (parent->parent) {
598                                         if ((!pcibios_assign_all_busses()) &&
599                                             (parent->subordinate > max) &&
600                                             (parent->subordinate <= max+i)) {
601                                                 j = 1;
602                                         }
603                                         parent = parent->parent;
604                                 }
605                                 if (j) {
606                                         /*
607                                          * Often, there are two cardbus bridges
608                                          * -- try to leave one valid bus number
609                                          * for each one.
610                                          */
611                                         i /= 2;
612                                         break;
613                                 }
614                         }
615                         max += i;
616                         pci_fixup_parent_subordinate_busnr(child, max);
617                 }
618                 /*
619                  * Set the subordinate bus number to its real value.
620                  */
621                 child->subordinate = max;
622                 pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max);
623         }
624 
625         sprintf(child->name, (is_cardbus ? "PCI CardBus #%02x" : "PCI Bus #%02x"), child->number);
626 
627         /* Has only triggered on CardBus, fixup is in yenta_socket */
628         while (bus->parent) {
629                 if ((child->subordinate > bus->subordinate) ||
630                     (child->number > bus->subordinate) ||
631                     (child->number < bus->number) ||
632                     (child->subordinate < bus->number)) {
633                         pr_debug("PCI: Bus #%02x (-#%02x) is %s "
634                                 "hidden behind%s bridge #%02x (-#%02x)\n",
635                                 child->number, child->subordinate,
636                                 (bus->number > child->subordinate &&
637                                  bus->subordinate < child->number) ?
638                                         "wholly" : "partially",
639                                 bus->self->transparent ? " transparent" : "",
640                                 bus->number, bus->subordinate);
641                 }
642                 bus = bus->parent;
643         }
644 
645 out:
646         pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl);
647 
648         return max;
649 }
650 
651 /*
652  * Read interrupt line and base address registers.
653  * The architecture-dependent code can tweak these, of course.
654  */
655 static void pci_read_irq(struct pci_dev *dev)
656 {
657         unsigned char irq;
658 
659         pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &irq);
660         dev->pin = irq;
661         if (irq)
662                 pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq);
663         dev->irq = irq;
664 }
665 
666 #define LEGACY_IO_RESOURCE      (IORESOURCE_IO | IORESOURCE_PCI_FIXED)
667 
668 /**
669  * pci_setup_device - fill in class and map information of a device
670  * @dev: the device structure to fill
671  *
672  * Initialize the device structure with information about the device's 
673  * vendor,class,memory and IO-space addresses,IRQ lines etc.
674  * Called at initialisation of the PCI subsystem and by CardBus services.
675  * Returns 0 on success and -1 if unknown type of device (not normal, bridge
676  * or CardBus).
677  */
678 static int pci_setup_device(struct pci_dev * dev)
679 {
680         u32 class;
681 
682         sprintf(pci_name(dev), "%04x:%02x:%02x.%d", pci_domain_nr(dev->bus),
683                 dev->bus->number, PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));
684 
685         pci_read_config_dword(dev, PCI_CLASS_REVISION, &class);
686         dev->revision = class & 0xff;
687         class >>= 8;                                /* upper 3 bytes */
688         dev->class = class;
689         class >>= 8;
690 
691         pr_debug("PCI: Found %s [%04x/%04x] %06x %02x\n", pci_name(dev),
692                  dev->vendor, dev->device, class, dev->hdr_type);
693 
694         /* "Unknown power state" */
695         dev->current_state = PCI_UNKNOWN;
696 
697         /* Early fixups, before probing the BARs */
698         pci_fixup_device(pci_fixup_early, dev);
699         class = dev->class >> 8;
700 
701         switch (dev->hdr_type) {                    /* header type */
702         case PCI_HEADER_TYPE_NORMAL:                /* standard header */
703                 if (class == PCI_CLASS_BRIDGE_PCI)
704                         goto bad;
705                 pci_read_irq(dev);
706                 pci_read_bases(dev, 6, PCI_ROM_ADDRESS);
707                 pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor);
708                 pci_read_config_word(dev, PCI_SUBSYSTEM_ID, &dev->subsystem_device);
709 
710                 /*
711                  *      Do the ugly legacy mode stuff here rather than broken chip
712                  *      quirk code. Legacy mode ATA controllers have fixed
713                  *      addresses. These are not always echoed in BAR0-3, and
714                  *      BAR0-3 in a few cases contain junk!
715                  */
716                 if (class == PCI_CLASS_STORAGE_IDE) {
717                         u8 progif;
718                         pci_read_config_byte(dev, PCI_CLASS_PROG, &progif);
719                         if ((progif & 1) == 0) {
720                                 dev->resource[0].start = 0x1F0;
721                                 dev->resource[0].end = 0x1F7;
722                                 dev->resource[0].flags = LEGACY_IO_RESOURCE;
723                                 dev->resource[1].start = 0x3F6;
724                                 dev->resource[1].end = 0x3F6;
725                                 dev->resource[1].flags = LEGACY_IO_RESOURCE;
726                         }
727                         if ((progif & 4) == 0) {
728                                 dev->resource[2].start = 0x170;
729                                 dev->resource[2].end = 0x177;
730                                 dev->resource[2].flags = LEGACY_IO_RESOURCE;
731                                 dev->resource[3].start = 0x376;
732                                 dev->resource[3].end = 0x376;
733                                 dev->resource[3].flags = LEGACY_IO_RESOURCE;
734                         }
735                 }
736                 break;
737 
738         case PCI_HEADER_TYPE_BRIDGE:                /* bridge header */
739                 if (class != PCI_CLASS_BRIDGE_PCI)
740                         goto bad;
741                 /* The PCI-to-PCI bridge spec requires that subtractive
742                    decoding (i.e. transparent) bridge must have programming
743                    interface code of 0x01. */ 
744                 pci_read_irq(dev);
745                 dev->transparent = ((dev->class & 0xff) == 1);
746                 pci_read_bases(dev, 2, PCI_ROM_ADDRESS1);
747                 break;
748 
749         case PCI_HEADER_TYPE_CARDBUS:               /* CardBus bridge header */
750                 if (class != PCI_CLASS_BRIDGE_CARDBUS)
751                         goto bad;
752                 pci_read_irq(dev);
753                 pci_read_bases(dev, 1, 0);
754                 pci_read_config_word(dev, PCI_CB_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor);
755                 pci_read_config_word(dev, PCI_CB_SUBSYSTEM_ID, &dev->subsystem_device);
756                 break;
757 
758         default:                                    /* unknown header */
759                 printk(KERN_ERR "PCI: device %s has unknown header type %02x, ignoring.\n",
760                         pci_name(dev), dev->hdr_type);
761                 return -1;
762 
763         bad:
764                 printk(KERN_ERR "PCI: %s: class %x doesn't match header type %02x. Ignoring class.\n",
765                        pci_name(dev), class, dev->hdr_type);
766                 dev->class = PCI_CLASS_NOT_DEFINED;
767         }
768 
769         /* We found a fine healthy device, go go go... */
770         return 0;
771 }
772 
773 /**
774  * pci_release_dev - free a pci device structure when all users of it are finished.
775  * @dev: device that's been disconnected
776  *
777  * Will be called only by the device core when all users of this pci device are
778  * done.
779  */
780 static void pci_release_dev(struct device *dev)
781 {
782         struct pci_dev *pci_dev;
783 
784         pci_dev = to_pci_dev(dev);
785         kfree(pci_dev);
786 }
787 
788 static void set_pcie_port_type(struct pci_dev *pdev)
789 {
790         int pos;
791         u16 reg16;
792 
793         pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
794         if (!pos)
795                 return;
796         pdev->is_pcie = 1;
797         pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
798         pdev->pcie_type = (reg16 & PCI_EXP_FLAGS_TYPE) >> 4;
799 }
800 
801 /**
802  * pci_cfg_space_size - get the configuration space size of the PCI device.
803  * @dev: PCI device
804  *
805  * Regular PCI devices have 256 bytes, but PCI-X 2 and PCI Express devices
806  * have 4096 bytes.  Even if the device is capable, that doesn't mean we can
807  * access it.  Maybe we don't have a way to generate extended config space
808  * accesses, or the device is behind a reverse Express bridge.  So we try
809  * reading the dword at 0x100 which must either be 0 or a valid extended
810  * capability header.
811  */
812 int pci_cfg_space_size(struct pci_dev *dev)
813 {
814         int pos;
815         u32 status;
816 
817         pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
818         if (!pos) {
819                 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
820                 if (!pos)
821                         goto fail;
822 
823                 pci_read_config_dword(dev, pos + PCI_X_STATUS, &status);
824                 if (!(status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ)))
825                         goto fail;
826         }
827 
828         if (pci_read_config_dword(dev, 256, &status) != PCIBIOS_SUCCESSFUL)
829                 goto fail;
830         if (status == 0xffffffff)
831                 goto fail;
832 
833         return PCI_CFG_SPACE_EXP_SIZE;
834 
835  fail:
836         return PCI_CFG_SPACE_SIZE;
837 }
838 
839 static void pci_release_bus_bridge_dev(struct device *dev)
840 {
841         kfree(dev);
842 }
843 
844 struct pci_dev *alloc_pci_dev(void)
845 {
846         int i;
847         struct pci_dev *dev;
848 
849         dev = kzalloc(sizeof(struct pci_dev), GFP_KERNEL);
850         if (!dev)
851                 return NULL;
852 
853         INIT_LIST_HEAD(&dev->global_list);
854         INIT_LIST_HEAD(&dev->bus_list);
855 
856         for (i = 0; i < ARRAY_SIZE(dev->cached_capabilities); ++i)
857                 dev->cached_capabilities[i] = -1;
858 
859         pci_msi_init_pci_dev(dev);
860 
861         return dev;
862 }
863 EXPORT_SYMBOL(alloc_pci_dev);
864 
865 /*
866  * Read the config data for a PCI device, sanity-check it
867  * and fill in the dev structure...
868  */
869 static struct pci_dev * __devinit
870 pci_scan_device(struct pci_bus *bus, int devfn)
871 {
872         struct pci_dev *dev;
873         u32 l;
874         u8 hdr_type;
875         int delay = 1;
876 
877         if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, &l))
878                 return NULL;
879 
880         /* some broken boards return 0 or ~0 if a slot is empty: */
881         if (l == 0xffffffff || l == 0x00000000 ||
882             l == 0x0000ffff || l == 0xffff0000)
883                 return NULL;
884 
885         /* Configuration request Retry Status */
886         while (l == 0xffff0001) {
887                 msleep(delay);
888                 delay *= 2;
889                 if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, &l))
890                         return NULL;
891                 /* Card hasn't responded in 60 seconds?  Must be stuck. */
892                 if (delay > 60 * 1000) {
893                         printk(KERN_WARNING "Device %04x:%02x:%02x.%d not "
894                                         "responding\n", pci_domain_nr(bus),
895                                         bus->number, PCI_SLOT(devfn),
896                                         PCI_FUNC(devfn));
897                         return NULL;
898                 }
899         }
900 
901         if (pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type))
902                 return NULL;
903 
904         dev = alloc_pci_dev();
905         if (!dev)
906                 return NULL;
907 
908         dev->bus = bus;
909         dev->sysdata = bus->sysdata;
910         dev->dev.parent = bus->bridge;
911         dev->dev.bus = &pci_bus_type;
912         dev->devfn = devfn;
913         dev->hdr_type = hdr_type & 0x7f;
914         dev->multifunction = !!(hdr_type & 0x80);
915         dev->vendor = l & 0xffff;
916         dev->device = (l >> 16) & 0xffff;
917         dev->cfg_size = pci_cfg_space_size(dev);
918         dev->error_state = pci_channel_io_normal;
919         set_pcie_port_type(dev);
920 
921         /* Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)
922            set this higher, assuming the system even supports it.  */
923         dev->dma_mask = 0xffffffff;
924         if (pci_setup_device(dev) < 0) {
925                 kfree(dev);
926                 return NULL;
927         }
928 
929         return dev;
930 }
931 
932 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
933 {
934         device_initialize(&dev->dev);
935         dev->dev.release = pci_release_dev;
936         pci_dev_get(dev);
937 
938         set_dev_node(&dev->dev, pcibus_to_node(bus));
939         dev->dev.dma_mask = &dev->dma_mask;
940         dev->dev.dma_parms = &dev->dma_parms;
941         dev->dev.coherent_dma_mask = 0xffffffffull;
942 
943         pci_set_dma_max_seg_size(dev, 65536);
944         pci_set_dma_seg_boundary(dev, 0xffffffff);
945 
946         /* Fix up broken headers */
947         pci_fixup_device(pci_fixup_header, dev);
948 
949         /*
950          * Add the device to our list of discovered devices
951          * and the bus list for fixup functions, etc.
952          */
953         INIT_LIST_HEAD(&dev->global_list);
954         down_write(&pci_bus_sem);
955         list_add_tail(&dev->bus_list, &bus->devices);
956         up_write(&pci_bus_sem);
957 }
958 
959 struct pci_dev *__ref pci_scan_single_device(struct pci_bus *bus, int devfn)
960 {
961         struct pci_dev *dev;
962 
963         dev = pci_scan_device(bus, devfn);
964         if (!dev)
965                 return NULL;
966 
967         pci_device_add(dev, bus);
968 
969         return dev;
970 }
971 EXPORT_SYMBOL(pci_scan_single_device);
972 
973 /**
974  * pci_scan_slot - scan a PCI slot on a bus for devices.
975  * @bus: PCI bus to scan
976  * @devfn: slot number to scan (must have zero function.)
977  *
978  * Scan a PCI slot on the specified PCI bus for devices, adding
979  * discovered devices to the @bus->devices list.  New devices
980  * will have an empty dev->global_list head.
981  */
982 int pci_scan_slot(struct pci_bus *bus, int devfn)
983 {
984         int func, nr = 0;
985         int scan_all_fns;
986 
987         scan_all_fns = pcibios_scan_all_fns(bus, devfn);
988 
989         for (func = 0; func < 8; func++, devfn++) {
990                 struct pci_dev *dev;
991 
992                 dev = pci_scan_single_device(bus, devfn);
993                 if (dev) {
994                         nr++;
995 
996                         /*
997                          * If this is a single function device,
998                          * don't scan past the first function.
999                          */
1000                         if (!dev->multifunction) {
1001                                 if (func > 0) {
1002                                         dev->multifunction = 1;
1003                                 } else {
1004                                         break;
1005                                 }
1006                         }
1007                 } else {
1008                         if (func == 0 && !scan_all_fns)
1009                                 break;
1010                 }
1011         }
1012         return nr;
1013 }
1014 
1015 unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus)
1016 {
1017         unsigned int devfn, pass, max = bus->secondary;
1018         struct pci_dev *dev;
1019 
1020         pr_debug("PCI: Scanning bus %04x:%02x\n", pci_domain_nr(bus), bus->number);
1021 
1022         /* Go find them, Rover! */
1023         for (devfn = 0; devfn < 0x100; devfn += 8)
1024                 pci_scan_slot(bus, devfn);
1025 
1026         /*
1027          * After performing arch-dependent fixup of the bus, look behind
1028          * all PCI-to-PCI bridges on this bus.
1029          */
1030         pr_debug("PCI: Fixups for bus %04x:%02x\n", pci_domain_nr(bus), bus->number);
1031         pcibios_fixup_bus(bus);
1032         for (pass=0; pass < 2; pass++)
1033                 list_for_each_entry(dev, &bus->devices, bus_list) {
1034                         if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
1035                             dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
1036                                 max = pci_scan_bridge(bus, dev, max, pass);
1037                 }
1038 
1039         /*
1040          * We've scanned the bus and so we know all about what's on
1041          * the other side of any bridges that may be on this bus plus
1042          * any devices.
1043          *
1044          * Return how far we've got finding sub-buses.
1045          */
1046         pr_debug("PCI: Bus scan for %04x:%02x returning with max=%02x\n",
1047                 pci_domain_nr(bus), bus->number, max);
1048         return max;
1049 }
1050 
1051 struct pci_bus * pci_create_bus(struct device *parent,
1052                 int bus, struct pci_ops *ops, void *sysdata)
1053 {
1054         int error;
1055         struct pci_bus *b;
1056         struct device *dev;
1057 
1058         b = pci_alloc_bus();
1059         if (!b)
1060                 return NULL;
1061 
1062         dev = kmalloc(sizeof(*dev), GFP_KERNEL);
1063         if (!dev){
1064                 kfree(b);
1065                 return NULL;
1066         }
1067 
1068         b->sysdata = sysdata;
1069         b->ops = ops;
1070 
1071         if (pci_find_bus(pci_domain_nr(b), bus)) {
1072                 /* If we already got to this bus through a different bridge, ignore it */
1073                 pr_debug("PCI: Bus %04x:%02x already known\n", pci_domain_nr(b), bus);
1074                 goto err_out;
1075         }
1076 
1077         down_write(&pci_bus_sem);
1078         list_add_tail(&b->node, &pci_root_buses);
1079         up_write(&pci_bus_sem);
1080 
1081         memset(dev, 0, sizeof(*dev));
1082         dev->parent = parent;
1083         dev->release = pci_release_bus_bridge_dev;
1084         sprintf(dev->bus_id, "pci%04x:%02x", pci_domain_nr(b), bus);
1085         error = device_register(dev);
1086         if (error)
1087                 goto dev_reg_err;
1088         b->bridge = get_device(dev);
1089 
1090         b->dev.class = &pcibus_class;
1091         b->dev.parent = b->bridge;
1092         sprintf(b->dev.bus_id, "%04x:%02x", pci_domain_nr(b), bus);
1093         error = device_register(&b->dev);
1094         if (error)
1095                 goto class_dev_reg_err;
1096         error = device_create_file(&b->dev, &dev_attr_cpuaffinity);
1097         if (error)
1098                 goto dev_create_file_err;
1099 
1100         /* Create legacy_io and legacy_mem files for this bus */
1101         pci_create_legacy_files(b);
1102 
1103         b->number = b->secondary = bus;
1104         b->resource[0] = &ioport_resource;
1105         b->resource[1] = &iomem_resource;
1106 
1107         return b;
1108 
1109 dev_create_file_err:
1110         device_unregister(&b->dev);
1111 class_dev_reg_err:
1112         device_unregister(dev);
1113 dev_reg_err:
1114         down_write(&pci_bus_sem);
1115         list_del(&b->node);
1116         up_write(&pci_bus_sem);
1117 err_out:
1118         kfree(dev);
1119         kfree(b);
1120         return NULL;
1121 }
1122 
1123 struct pci_bus * __devinit pci_scan_bus_parented(struct device *parent,
1124                 int bus, struct pci_ops *ops, void *sysdata)
1125 {
1126         struct pci_bus *b;
1127 
1128         b = pci_create_bus(parent, bus, ops, sysdata);
1129         if (b)
1130                 b->subordinate = pci_scan_child_bus(b);
1131         return b;
1132 }
1133 EXPORT_SYMBOL(pci_scan_bus_parented);
1134 
1135 #ifdef CONFIG_HOTPLUG
1136 EXPORT_SYMBOL(pci_add_new_bus);
1137 EXPORT_SYMBOL(pci_scan_slot);
1138 EXPORT_SYMBOL(pci_scan_bridge);
1139 EXPORT_SYMBOL_GPL(pci_scan_child_bus);
1140 #endif
1141 
1142 static int __init pci_sort_bf_cmp(const struct pci_dev *a, const struct pci_dev *b)
1143 {
1144         if      (pci_domain_nr(a->bus) < pci_domain_nr(b->bus)) return -1;
1145         else if (pci_domain_nr(a->bus) > pci_domain_nr(b->bus)) return  1;
1146 
1147         if      (a->bus->number < b->bus->number) return -1;
1148         else if (a->bus->number > b->bus->number) return  1;
1149 
1150         if      (a->devfn < b->devfn) return -1;
1151         else if (a->devfn > b->devfn) return  1;
1152 
1153         return 0;
1154 }
1155 
1156 /*
1157  * Yes, this forcably breaks the klist abstraction temporarily.  It
1158  * just wants to sort the klist, not change reference counts and
1159  * take/drop locks rapidly in the process.  It does all this while
1160  * holding the lock for the list, so objects can't otherwise be
1161  * added/removed while we're swizzling.
1162  */
1163 static void __init pci_insertion_sort_klist(struct pci_dev *a, struct list_head *list)
1164 {
1165         struct list_head *pos;
1166         struct klist_node *n;
1167         struct device *dev;
1168         struct pci_dev *b;
1169 
1170         list_for_each(pos, list) {
1171                 n = container_of(pos, struct klist_node, n_node);
1172                 dev = container_of(n, struct device, knode_bus);
1173                 b = to_pci_dev(dev);
1174                 if (pci_sort_bf_cmp(a, b) <= 0) {
1175                         list_move_tail(&a->dev.knode_bus.n_node, &b->dev.knode_bus.n_node);
1176                         return;
1177                 }
1178         }
1179         list_move_tail(&a->dev.knode_bus.n_node, list);
1180 }
1181 
1182 static void __init pci_sort_breadthfirst_klist(void)
1183 {
1184         LIST_HEAD(sorted_devices);
1185         struct list_head *pos, *tmp;
1186         struct klist_node *n;
1187         struct device *dev;
1188         struct pci_dev *pdev;
1189         struct klist *device_klist;
1190 
1191         device_klist = bus_get_device_klist(&pci_bus_type);
1192 
1193         spin_lock(&device_klist->k_lock);
1194         list_for_each_safe(pos, tmp, &device_klist->k_list) {
1195                 n = container_of(pos, struct klist_node, n_node);
1196                 dev = container_of(n, struct device, knode_bus);
1197                 pdev = to_pci_dev(dev);
1198                 pci_insertion_sort_klist(pdev, &sorted_devices);
1199         }
1200         list_splice(&sorted_devices, &device_klist->k_list);
1201         spin_unlock(&device_klist->k_lock);
1202 }
1203 
1204 static void __init pci_insertion_sort_devices(struct pci_dev *a, struct list_head *list)
1205 {
1206         struct pci_dev *b;
1207 
1208         list_for_each_entry(b, list, global_list) {
1209                 if (pci_sort_bf_cmp(a, b) <= 0) {
1210                         list_move_tail(&a->global_list, &b->global_list);
1211                         return;
1212                 }
1213         }
1214         list_move_tail(&a->global_list, list);
1215 }
1216 
1217 static void __init pci_sort_breadthfirst_devices(void)
1218 {
1219         LIST_HEAD(sorted_devices);
1220         struct pci_dev *dev, *tmp;
1221 
1222         down_write(&pci_bus_sem);
1223         list_for_each_entry_safe(dev, tmp, &pci_devices, global_list) {
1224                 pci_insertion_sort_devices(dev, &sorted_devices);
1225         }
1226         list_splice(&sorted_devices, &pci_devices);
1227         up_write(&pci_bus_sem);
1228 }
1229 
1230 void __init pci_sort_breadthfirst(void)
1231 {
1232         pci_sort_breadthfirst_devices();
1233         pci_sort_breadthfirst_klist();
1234 }
1235 
1236 
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