source: rtems/bsps/powerpc/motorola_powerpc/bootloader/pci.c

/*
 *  pci.c -- Crude pci handling for early boot.
 *
 *  Copyright (C) 1998, 1999 Gabriel Paubert, paubert@iram.es
 *
 *  Modified to compile in RTEMS development environment
 *  by Eric Valette
 *
 *  Copyright (C) 1999 Eric Valette. valette@crf.canon.fr
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.rtems.org/license/LICENSE.
 */

#include <sys/param.h>
#include <sys/types.h>
#include <rtems/bspIo.h>
#include <libcpu/spr.h>
#include "bootldr.h"
#include "pci.h"
#include <libcpu/io.h>
#include <bsp/consoleIo.h>
#include <string.h>
#include <bsp.h>

#include <string.h>


/*
#define DEBUG
#define PCI_DEBUG
*/

/* Used to reorganize PCI space on stupid machines which spread resources
 * across a wide address space. This is bad when P2P bridges are present
 * or when it limits the mappings that a resource hog like a PCI<->VME
 * bridge can use.
 */

typedef struct _pci_resource {
      struct _pci_resource *next;
      struct pci_dev *dev;
      u_long base;    /* will be 64 bits on 64 bits machines */
      u_long size;
      u_char type;      /* 1 is I/O else low order 4 bits of the memory type */
      u_char reg;       /* Register # in conf space header */
      u_short cmd;    /* Original cmd byte */
} pci_resource;

typedef struct _pci_area {
      struct _pci_area *next;
      u_long start;
      u_long end;
      struct pci_bus *bus;
      u_int flags;
} pci_area;

typedef struct _pci_area_head {
      pci_area *head;
      u_long mask;
      int high; /* To allocate from top */
} pci_area_head;

#define PCI_AREA_PREFETCHABLE 0
#define PCI_AREA_MEMORY 1
#define PCI_AREA_IO 2

struct _pci_private {
      volatile void * config_addr;
      volatile u_char * config_data;
      struct pci_dev **last_dev_p;
      struct pci_bus pci_root;
      pci_resource *resources;
      pci_area_head io, mem;

} pci_private = {
   config_addr: NULL,
   config_data: (volatile u_char *) 0x80800000,
   last_dev_p: NULL,
   resources: NULL,
   io: {NULL, 0xfff, 0},
   mem: {NULL, 0xfffff, 0}
};

#define pci ((struct _pci_private *)(bd->pci_private))
#define pci_root pci->pci_root

#if !defined(DEBUG)
#undef PCI_DEBUG
/*
  #else
  #define PCI_DEBUG
*/
#endif

#if defined(PCI_DEBUG)
static void
print_pci_resources(const char *s) {
   pci_resource *p;
   printk("%s", s);
   for (p=pci->resources; p; p=p->next) {
/*
      printk("  %p:%p %06x %08lx %08lx %d\n",
             p, p->next,
             (p->dev->devfn<<8)+(p->dev->bus->number<<16)
             +0x10+p->reg*4,
             p->base,
             p->size,
             p->type);
*/

      printk("  %p:%p %d:%02x (%04x:%04x) %08lx %08lx %d\n",
             p, p->next,
             p->dev->bus->number, PCI_SLOT(p->dev->devfn),
             p->dev->vendor, p->dev->device,
             p->base,
             p->size,
             p->type);

   }
}

static void
print_pci_area(pci_area *p) {
   for (; p; p=p->next) {
      printk("    %p:%p %p %08lx %08lx\n",
             p, p->next, p->bus, p->start, p->end);
   }
}

static void
print_pci_areas(const char *s) {
   printk("%s  PCI I/O areas:\n",s);
   print_pci_area(pci->io.head);
   printk("  PCI memory areas:\n");
   print_pci_area(pci->mem.head);
}
#else
#define print_pci_areas(x)
#define print_pci_resources(x)
#endif

/* Maybe there are some devices who use a size different
 * from the alignment. For now we assume both are the same.
 * The blacklist might be used for other weird things in the future too,
 * since weird non PCI complying devices seem to proliferate these days.
 */

struct blacklist_entry {
      u_short vendor, device;
      u_char reg;
      u_long actual_size;
};

#define BLACKLIST(vid, did, breg, actual_size) \
        {PCI_VENDOR_ID_##vid, PCI_DEVICE_ID_##vid##_##did, breg, actual_size}

static struct blacklist_entry blacklist[] = {
   BLACKLIST(S3, TRIO, 0, 0x04000000),
   {0xffff, 0, 0, 0}
};

/* This function filters resources and then inserts them into a list of
 * configurable pci resources.
 */

#define AREA(r) \
(((r->type&PCI_BASE_ADDRESS_SPACE)==PCI_BASE_ADDRESS_SPACE_IO) ? PCI_AREA_IO :\
          ((r->type&PCI_BASE_ADDRESS_MEM_PREFETCH) ? PCI_AREA_PREFETCHABLE :\
           PCI_AREA_MEMORY))

static int insert_before(pci_resource *e, pci_resource *t) {
   if (e->dev->bus->number != t->dev->bus->number)
      return e->dev->bus->number > t->dev->bus->number;
   if (AREA(e) != AREA(t)) return AREA(e)<AREA(t);
   return (e->size > t->size);
}

static void insert_resource(pci_resource *r) {
   struct blacklist_entry *b;
   pci_resource *p;
   if (!r) return;

   /* First fixup in case we have a blacklist entry. Note that this
    * may temporarily leave a resource in an inconsistent state: with
    * (base & (size-1)) !=0. This is harmless.
    */
   for (b=blacklist; b->vendor!=0xffff; b++) {
      if ((r->dev->vendor==b->vendor) &&
          (r->dev->device==b->device) &&
          (r->reg==b->reg)) {
         r->size=b->actual_size;
         break;
      }
   }

   /* Motorola NT firmware does not configure pci devices which are not
    * required for booting, others do. For now:
    * - allocated devices in the ISA range (64kB I/O, 16Mb memory)
    *   but non zero base registers are left as is.
    * - all other registers, whether already allocated or not, are
    *   reallocated unless they require an inordinate amount of
    *   resources (>256 Mb for memory >64kB for I/O). These
    *   devices with too large mapping requirements are simply ignored
    *   and their bases are set to 0. This should disable the
    *   corresponding decoders according to the PCI specification.
    *   Many devices are buggy in this respect, however, but the
    *   limits have hopefully been set high enough to avoid problems.
    */

   /*
   ** This is little ugly below.  It seems that at least on the MCP750,
   ** the PBC has some default IO space mappings that the bsp #defines
   ** that read/write to PCI I/O space assume, particuarly the i8259
   ** manipulation code.  So, if we allow the small IO spaces on PCI bus
   ** 0 and 1 to be remapped, the registers can shift out from under the
   ** #defines.  This is particuarly awful, but short of redefining the
   ** PCI I/O primitives to be functions with base addresses read from
   ** the hardware, we are stuck with the kludge below.  Note that
   ** everything is remapped on the CPCI backplane and any downstream
   ** hardware, its just the builtin stuff we're tiptoeing around.
   **
   ** Gregm, 7/16/2003
   **
   ** Gregm, changed 11/2003 so IO devices only on bus 0 zero are not
   ** remapped.  This covers the builtin pc-like io devices- but
   ** properly maps IO devices on higher busses.
   */
   if( r->dev->bus->number == 0 )
   {
   if ((r->type==PCI_BASE_ADDRESS_SPACE_IO)
       ? (r->base && r->base <0x10000)
       : (r->base && r->base <0x1000000)) {

#ifdef PCI_DEBUG
         printk("freeing region;  %p:%p %d:%02x (%04x:%04x) %08lx %08lx %d\n",
                r, r->next,
                r->dev->bus->number, PCI_SLOT(r->dev->devfn),
                r->dev->vendor, r->dev->device,
                r->base,
                r->size,
                r->type);
#endif
      sfree(r);
      return;
   }
   }


   /* 2004/11/30, PR 729 fix is removing the r->size=0 and r->base=0
    * assignement which makes too-large regions conflict with onboard
    * hardware, replacing it with sfree which deletes the memory region
    * from the setup code, leaving it disabled. */
   if ((r->type==PCI_BASE_ADDRESS_SPACE_IO)
       ? (r->size > 0x10000)
       : (r->size > 0x18000000)) {
      sfree(r);
      return;
   }

   /* Now insert into the list sorting by
    * 1) decreasing bus number
    * 2) space: prefetchable memory, non-prefetchable and finally I/O
    * 3) decreasing size
    */
   if (!pci->resources || insert_before(r, pci->resources)) {
      r->next = pci->resources;
      pci->resources=r;
   } else {
      for (p=pci->resources; p->next; p=p->next) {
         if (insert_before(r, p->next)) break;
      }
      r->next=p->next;
      p->next=r;
   }
}

/* This version only works for bus 0. I don't have any P2P bridges to test
 * a more sophisticated version which has therefore not been implemented.
 * Prefetchable memory is not yet handled correctly either.
 * And several levels of PCI bridges much less even since there must be
 * allocated together to be able to setup correctly the top bridge.
 */

static u_long find_range(u_char bus, u_char type,
                         pci_resource **first,
                         pci_resource **past, u_int *flags) {
   pci_resource *p;
   u_long total=0;
   u_int fl=0;

   for (p=pci->resources; p; p=p->next)
   {
      if ((p->dev->bus->number == bus) &&
          AREA(p)==type) break;
   }

   *first = p;

   for (; p; p=p->next)
   {
      if ((p->dev->bus->number != bus) ||
          AREA(p)!=type || p->size == 0) break;
      total = total+p->size;
      fl |= 1<<p->type;
   }

   *past = p;
   /* This will be used later to tell whether there are any 32 bit
    * devices in an area which could be mapped higher than 4Gb
    * on 64 bits architectures
    */
   *flags = fl;
   return total;
}

static inline void init_free_area(pci_area_head *h, u_long start,
                                  u_long end, u_int mask, int high) {
   pci_area *p;
   p = salloc(sizeof(pci_area));
   if (!p) return;
   h->head = p;
   p->next = NULL;
   p->start = (start+mask)&~mask;
   p->end = (end-mask)|mask;
   p->bus = NULL;
   h->mask = mask;
   h->high = high;
}

static void insert_area(pci_area_head *h, pci_area *p) {
   pci_area *q = h->head;
   if (!p) return;
   if (q && (q->start< p->start)) {
      for(;q->next && q->next->start<p->start; q = q->next);
      if ((q->end >= p->start) ||
          (q->next && p->end>=q->next->start)) {
         sfree(p);
         printk("Overlapping pci areas!\n");
         return;
      }
      p->next = q->next;
      q->next = p;
   } else { /* Insert at head */
      if (q && (p->end >= q->start)) {
         sfree(p);
         printk("Overlapping pci areas!\n");
         return;
      }
      p->next = q;
      h->head = p;
   }
}

static
void remove_area(pci_area_head *h, pci_area *p)
{
   pci_area *q = h->head;

   if (!p || !q) return;
   if (q==p)
   {
      h->head = q->next;
      return;
   }
   for(;q && q->next!=p; q=q->next);
   if (q) q->next=p->next;
}

static pci_area * alloc_area(pci_area_head *h, struct pci_bus *bus,
                             u_long required, u_long mask, u_int flags) {
   pci_area *p;
   pci_area *from, *split, *new;

   required = (required+h->mask) & ~h->mask;
   for (p=h->head, from=NULL; p; p=p->next)
   {
      u_long l1 = ((p->start+required+mask)&~mask)-1;
      u_long l2 = ((p->start+mask)&~mask)+required-1;
      /* Allocated areas point to the bus to which they pertain */
      if (p->bus) continue;
      if ((p->end)>=l1 || (p->end)>=l2) from=p;
      if (from && !h->high) break;
   }
   if (!from) return NULL;

   split = salloc(sizeof(pci_area));
   new = salloc(sizeof(pci_area));
   /* If allocation of new succeeds then allocation of split has
    * also been successful (given the current mm algorithms) !
    */
   if (!new) {
      sfree(split);
      return NULL;
   }
   new->bus = bus;
   new->flags = flags;
   /* Now allocate pci_space taking alignment into account ! */
   if (h->high)
   {
      u_long l1 = ((from->end+1)&~mask)-required;
      u_long l2 = (from->end+1-required)&~mask;
      new->start = (l1>l2) ? l1 : l2;
      split->end = from->end;
      from->end = new->start-1;
      split->start = new->start+required;
      new->end = new->start+required-1;
   }
   else
   {
      u_long l1 = ((from->start+mask)&~mask)+required-1;
      u_long l2 = ((from->start+required+mask)&~mask)-1;
      new->end = (l1<l2) ? l1 : l2;
      split->start = from->start;
      from->start = new->end+1;
      new->start = new->end+1-required;
      split->end = new->start-1;
   }

   if (from->end+1 == from->start) remove_area(h, from);
   if (split->end+1 != split->start)
   {
      split->bus = NULL;
      insert_area(h, split);
   }
   else
   {
      sfree(split);
   }
   insert_area(h, new);
   print_pci_areas("alloc_area called:\n");
   return new;
}

static inline
void alloc_space(pci_area *p, pci_resource *r)
{
   if (p->start & (r->size-1)) {
      r->base = p->end+1-r->size;
      p->end -= r->size;
   } else {
      r->base = p->start;
      p->start += r->size;
   }
}

static void reconfigure_bus_space(u_char bus, u_char type, pci_area_head *h)
{
   pci_resource *first, *past, *r;
   pci_area *area, tmp;
   u_int flags;
   u_int required = find_range(bus, type, &first, &past, &flags);

   if (required==0) return;

   area = alloc_area(h, first->dev->bus, required, first->size-1, flags);

   if (!area) return;

   tmp = *area;
   for (r=first; r!=past; r=r->next)
   {
      alloc_space(&tmp, r);
   }
}

#define BUS0_IO_START           0x10000
#define BUS0_IO_END             0x1ffff
#define BUS0_MEM_START          0x1000000
#define BUS0_MEM_END            0x3f00000

#define BUSREST_IO_START        0x20000
#define BUSREST_IO_END          0x7ffff
#define BUSREST_MEM_START       0x4000000
#define BUSREST_MEM_END        0x10000000

static void reconfigure_pci(void) {
   pci_resource *r;
   struct pci_dev *dev;

   u_long bus0_mem_start = BUS0_MEM_START;
   u_long bus0_mem_end   = BUS0_MEM_END;

   if ( residual_fw_is_qemu( bd->residual ) ) {
     bus0_mem_start += PREP_ISA_MEM_BASE;
     bus0_mem_end   += PREP_ISA_MEM_BASE;
   }

   /* FIXME: for now memory is relocated from low, it's better
    * to start from higher addresses.
    */
   /*
   init_free_area(&pci->io, 0x10000, 0x7fffff, 0xfff, 0);
   init_free_area(&pci->mem, 0x1000000, 0x3cffffff, 0xfffff, 0);
   */

   init_free_area(&pci->io, BUS0_IO_START, BUS0_IO_END, 0xfff, 0);
   init_free_area(&pci->mem, bus0_mem_start, bus0_mem_end, 0xfffff, 0);

   /* First reconfigure the I/O space, this will be more
    * complex when there is more than 1 bus. And 64 bits
    * devices are another kind of problems.
    */
   reconfigure_bus_space(0, PCI_AREA_IO, &pci->io);
   reconfigure_bus_space(0, PCI_AREA_MEMORY, &pci->mem);
   reconfigure_bus_space(0, PCI_AREA_PREFETCHABLE, &pci->mem);

   /* Now we have to touch the configuration space of all
    * the devices to remap them better than they are right now.
    * This is done in 3 steps:
    * 1) first disable I/O and memory response of all devices
    * 2) modify the base registers
    * 3) restore the original PCI_COMMAND register.
    */
   for (r=pci->resources; r; r= r->next) {
      if (!r->dev->sysdata) {
         r->dev->sysdata=r;
         pci_bootloader_read_config_word(r->dev, PCI_COMMAND, &r->cmd);
         pci_bootloader_write_config_word(r->dev, PCI_COMMAND,
                               r->cmd & ~(PCI_COMMAND_IO|
                                          PCI_COMMAND_MEMORY));
      }
   }

   for (r=pci->resources; r; r= r->next) {
      pci_bootloader_write_config_dword(r->dev,
                             PCI_BASE_ADDRESS_0+(r->reg<<2),
                             r->base);

      if ( residual_fw_is_qemu( bd->residual ) && r->dev->sysdata ) {
        if ( PCI_BASE_ADDRESS_SPACE_IO == (r->type &  PCI_BASE_ADDRESS_SPACE) )
                        ((pci_resource*)r->dev->sysdata)->cmd |= PCI_COMMAND_IO;
                else
                        ((pci_resource*)r->dev->sysdata)->cmd |= PCI_COMMAND_MEMORY;
      }

      if ((r->type&
           (PCI_BASE_ADDRESS_SPACE|
            PCI_BASE_ADDRESS_MEM_TYPE_MASK)) ==
          (PCI_BASE_ADDRESS_SPACE_MEMORY|
           PCI_BASE_ADDRESS_MEM_TYPE_64)) {
         pci_bootloader_write_config_dword(r->dev,
                                PCI_BASE_ADDRESS_1+(r->reg<<2),
                                0);
      }
   }
   for (dev=bd->pci_devices; dev; dev= dev->next) {
      if (dev->sysdata) {
         pci_bootloader_write_config_word(dev, PCI_COMMAND,
                               ((pci_resource *)dev->sysdata)
                               ->cmd);
         dev->sysdata=NULL;
      }
   }
}

static int
indirect_pci_read_config_byte(unsigned char bus, unsigned char dev_fn,
                              unsigned char offset, uint8_t *val) {
   out_be32(pci->config_addr,
            0x80|(bus<<8)|(dev_fn<<16)|((offset&~3)<<24));
   *val=in_8(pci->config_data + (offset&3));
   return PCIBIOS_SUCCESSFUL;
}

static int
indirect_pci_read_config_word(unsigned char bus, unsigned char dev_fn,
                              unsigned char offset, uint16_t *val) {
   *val = 0xffff;
   if (offset&1) return PCIBIOS_BAD_REGISTER_NUMBER;
   out_be32(pci->config_addr,
            0x80|(bus<<8)|(dev_fn<<16)|((offset&~3)<<24));
   *val=in_le16((volatile uint16_t *)(pci->config_data + (offset&3)));
   return PCIBIOS_SUCCESSFUL;
}

static int
indirect_pci_read_config_dword(unsigned char bus, unsigned char dev_fn,
                               unsigned char offset, uint32_t *val) {
   *val = 0xffffffff;
   if (offset&3) return PCIBIOS_BAD_REGISTER_NUMBER;
   out_be32(pci->config_addr,
            0x80|(bus<<8)|(dev_fn<<16)|(offset<<24));
   *val=in_le32((volatile uint32_t *)pci->config_data);
   return PCIBIOS_SUCCESSFUL;
}

static int
indirect_pci_write_config_byte(unsigned char bus, unsigned char dev_fn,
                               unsigned char offset, uint8_t val) {
   out_be32(pci->config_addr,
            0x80|(bus<<8)|(dev_fn<<16)|((offset&~3)<<24));
   out_8(pci->config_data + (offset&3), val);
   return PCIBIOS_SUCCESSFUL;
}

static int
indirect_pci_write_config_word(unsigned char bus, unsigned char dev_fn,
                               unsigned char offset, uint16_t val) {
   if (offset&1) return PCIBIOS_BAD_REGISTER_NUMBER;
   out_be32(pci->config_addr,
            0x80|(bus<<8)|(dev_fn<<16)|((offset&~3)<<24));
   out_le16((volatile uint16_t *)(pci->config_data + (offset&3)), val);
   return PCIBIOS_SUCCESSFUL;
}

static int
indirect_pci_write_config_dword(unsigned char bus, unsigned char dev_fn,
                                unsigned char offset, uint32_t val) {
   if (offset&3) return PCIBIOS_BAD_REGISTER_NUMBER;
   out_be32(pci->config_addr,
            0x80|(bus<<8)|(dev_fn<<16)|(offset<<24));
   out_le32((volatile uint32_t *)pci->config_data, val);
   return PCIBIOS_SUCCESSFUL;
}

static const struct pci_bootloader_config_access_functions indirect_functions = {
   indirect_pci_read_config_byte,
   indirect_pci_read_config_word,
   indirect_pci_read_config_dword,
   indirect_pci_write_config_byte,
   indirect_pci_write_config_word,
   indirect_pci_write_config_dword
};

static int
direct_pci_read_config_byte(unsigned char bus, unsigned char dev_fn,
                            unsigned char offset, uint8_t *val) {
   if (bus != 0 || (1<<PCI_SLOT(dev_fn) & 0xff8007fe)) {
      *val=0xff;
      return PCIBIOS_DEVICE_NOT_FOUND;
   }
   *val=in_8(pci->config_data + ((1<<PCI_SLOT(dev_fn))&~1)
             + (PCI_FUNC(dev_fn)<<8) + offset);
   return PCIBIOS_SUCCESSFUL;
}

static int
direct_pci_read_config_word(unsigned char bus, unsigned char dev_fn,
                            unsigned char offset, uint16_t *val) {
   *val = 0xffff;
   if (offset&1) return PCIBIOS_BAD_REGISTER_NUMBER;
   if (bus != 0 || (1<<PCI_SLOT(dev_fn) & 0xff8007fe)) {
      return PCIBIOS_DEVICE_NOT_FOUND;
   }
   *val=in_le16((volatile uint16_t *)
                (pci->config_data + ((1<<PCI_SLOT(dev_fn))&~1)
                 + (PCI_FUNC(dev_fn)<<8) + offset));
   return PCIBIOS_SUCCESSFUL;
}

static int
direct_pci_read_config_dword(unsigned char bus, unsigned char dev_fn,
                             unsigned char offset, uint32_t *val) {
   *val = 0xffffffff;
   if (offset&3) return PCIBIOS_BAD_REGISTER_NUMBER;
   if (bus != 0 || (1<<PCI_SLOT(dev_fn) & 0xff8007fe)) {
      return PCIBIOS_DEVICE_NOT_FOUND;
   }
   *val=in_le32((volatile uint32_t *)
                (pci->config_data + ((1<<PCI_SLOT(dev_fn))&~1)
                 + (PCI_FUNC(dev_fn)<<8) + offset));
   return PCIBIOS_SUCCESSFUL;
}

static int
direct_pci_write_config_byte(unsigned char bus, unsigned char dev_fn,
                             unsigned char offset, uint8_t val) {
   if (bus != 0 || (1<<PCI_SLOT(dev_fn) & 0xff8007fe)) {
      return PCIBIOS_DEVICE_NOT_FOUND;
   }
   out_8(pci->config_data + ((1<<PCI_SLOT(dev_fn))&~1)
         + (PCI_FUNC(dev_fn)<<8) + offset,
         val);
   return PCIBIOS_SUCCESSFUL;
}

static int
direct_pci_write_config_word(unsigned char bus, unsigned char dev_fn,
                             unsigned char offset, uint16_t val) {
   if (offset&1) return PCIBIOS_BAD_REGISTER_NUMBER;
   if (bus != 0 || (1<<PCI_SLOT(dev_fn) & 0xff8007fe)) {
      return PCIBIOS_DEVICE_NOT_FOUND;
   }
   out_le16((volatile uint16_t *)
            (pci->config_data + ((1<<PCI_SLOT(dev_fn))&~1)
             + (PCI_FUNC(dev_fn)<<8) + offset),
            val);
   return PCIBIOS_SUCCESSFUL;
}

static int
direct_pci_write_config_dword(unsigned char bus, unsigned char dev_fn,
                              unsigned char offset, uint32_t val) {
   if (offset&3) return PCIBIOS_BAD_REGISTER_NUMBER;
   if (bus != 0 || (1<<PCI_SLOT(dev_fn) & 0xff8007fe)) {
      return PCIBIOS_DEVICE_NOT_FOUND;
   }
   out_le32((volatile uint32_t *)
            (pci->config_data + ((1<<PCI_SLOT(dev_fn))&~1)
             + (PCI_FUNC(dev_fn)<<8) + offset),
            val);
   return PCIBIOS_SUCCESSFUL;
}

static const struct pci_bootloader_config_access_functions direct_functions = {
   direct_pci_read_config_byte,
   direct_pci_read_config_word,
   direct_pci_read_config_dword,
   direct_pci_write_config_byte,
   direct_pci_write_config_word,
   direct_pci_write_config_dword
};

static void pci_read_bases(struct pci_dev *dev, unsigned int howmany)
{
   unsigned int reg, nextreg;

#define REG (PCI_BASE_ADDRESS_0 + (reg<<2))

   u_short cmd;
   uint32_t l, ml;
   pci_bootloader_read_config_word(dev, PCI_COMMAND, &cmd);

   for(reg=0; reg<howmany; reg=nextreg)
   {
      pci_resource *r;

      nextreg=reg+1;
      pci_bootloader_read_config_dword(dev, REG, &l);
#if 0
      if (l == 0xffffffff /*AJF || !l*/) continue;
#endif
      /* Note that disabling the memory response of a host bridge
       * would lose data if a DMA transfer were in progress. In a
       * bootloader we don't care however. Also we can't print any
       * message for a while since we might just disable the console.
       */
      pci_bootloader_write_config_word(dev, PCI_COMMAND, cmd &
                            ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY));
      pci_bootloader_write_config_dword(dev, REG, ~0);
      pci_bootloader_read_config_dword(dev, REG, &ml);
      pci_bootloader_write_config_dword(dev, REG, l);

      /* Reenable the device now that we've played with
       * base registers.
       */
      pci_bootloader_write_config_word(dev, PCI_COMMAND, cmd);

      /* seems to be an unused entry skip it */
      if ( ml == 0 || ml == 0xffffffff ) continue;

      if ((l &
           (PCI_BASE_ADDRESS_SPACE|PCI_BASE_ADDRESS_MEM_TYPE_MASK))
          == (PCI_BASE_ADDRESS_MEM_TYPE_64
              |PCI_BASE_ADDRESS_SPACE_MEMORY)) {
         nextreg=reg+2;
      }
      dev->base_address[reg] = l;
      r = salloc(sizeof(pci_resource));
      if (!r) {
         printk("Error allocating pci_resource struct.\n");
         continue;
      }
      r->dev = dev;
      r->reg = reg;
      if ((l&PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
         r->type = l&~PCI_BASE_ADDRESS_IO_MASK;
         r->base = l&PCI_BASE_ADDRESS_IO_MASK;
         /* r->size = ~(ml&PCI_BASE_ADDRESS_IO_MASK)+1; */
      } else {
         r->type = l&~PCI_BASE_ADDRESS_MEM_MASK;
         r->base = l&PCI_BASE_ADDRESS_MEM_MASK;
         /* r->size = ~(ml&PCI_BASE_ADDRESS_MEM_MASK)+1; */
      }

      /* find the first bit set to one after the base
         address type bits to find length of region */
      {
         unsigned int c= 16 , val= 0;
         while( !(val= ml & c) ) c <<= 1;
         r->size = val;
      }

#ifdef PCI_DEBUG
      printk("   readbase bus %d, (%04x:%04x), base %08x, size %08x, type %d\n",
             r->dev->bus->number,
             r->dev->vendor,
             r->dev->device,
             r->base,
             r->size,
             r->type );
#endif

      /* Check for the blacklisted entries */
      insert_resource(r);
   }
}

static u_int pci_scan_bus(struct pci_bus *bus)
{
   unsigned int devfn, max;
   uint32_t class;
   uint32_t l;
   unsigned char irq, hdr_type, is_multi = 0;
   struct pci_dev *dev, **bus_last;
   struct pci_bus *child;

#if 0
   printk("scanning pci bus %d\n", bus->number );
#endif

   bus_last = &bus->devices;
   max = bus->secondary;
   for (devfn = 0; devfn < 0xff; ++devfn) {
      if (PCI_FUNC(devfn) && !is_multi) {
         /* not a multi-function device */
         continue;
      }
      if (pcibios_read_config_byte(bus->number, devfn, PCI_HEADER_TYPE, &hdr_type))
         continue;
      if (!PCI_FUNC(devfn))
         is_multi = hdr_type & 0x80;

      if (pcibios_read_config_dword(bus->number, devfn, PCI_VENDOR_ID, &l) ||
          /* some broken boards return 0 if a slot is empty: */
          l == 0xffffffff || l == 0x00000000 || l == 0x0000ffff || l == 0xffff0000) {
         is_multi = 0;
         continue;
      }

      dev = salloc(sizeof(*dev));
      dev->bus = bus;
      dev->devfn  = devfn;
      dev->vendor = l & 0xffff;
      dev->device = (l >> 16) & 0xffff;

      pcibios_read_config_dword(bus->number, devfn,
                                PCI_CLASS_REVISION, &class);
      class >>= 8;                                  /* upper 3 bytes */
      dev->class = class;
      class >>= 8;
      dev->hdr_type = hdr_type;

      switch (hdr_type & 0x7f) {                    /* header type */
         case PCI_HEADER_TYPE_NORMAL:               /* standard header */
            if (class == PCI_CLASS_BRIDGE_PCI)
               goto bad;
            /*
             * If the card generates interrupts, read IRQ number
             * (some architectures change it during pcibios_fixup())
             */
            pcibios_read_config_byte(bus->number, dev->devfn, PCI_INTERRUPT_PIN, &irq);
            if (irq)
               pcibios_read_config_byte(bus->number, dev->devfn, PCI_INTERRUPT_LINE, &irq);
            dev->irq = irq;
            /*
             * read base address registers, again pcibios_fixup() can
             * tweak these
             */
            pci_read_bases(dev, 6);
            pcibios_read_config_dword(bus->number, devfn, PCI_ROM_ADDRESS, &l);
            dev->rom_address = (l == 0xffffffff) ? 0 : l;
            break;
         case PCI_HEADER_TYPE_BRIDGE:               /* bridge header */
            if (class != PCI_CLASS_BRIDGE_PCI)
               goto bad;
            pci_read_bases(dev, 2);
            pcibios_read_config_dword(bus->number, devfn, PCI_ROM_ADDRESS1, &l);
            dev->rom_address = (l == 0xffffffff) ? 0 : l;
            break;
         case PCI_HEADER_TYPE_CARDBUS:              /* CardBus bridge header */
            if (class != PCI_CLASS_BRIDGE_CARDBUS)
               goto bad;
            pci_read_bases(dev, 1);
            break;

         default:                                   /* unknown header */
        bad:
            printk("PCI device with unknown header type %d ignored.\n",
                   hdr_type&0x7f);
            continue;
      }

      /*
       * Put it into the global PCI device chain. It's used to
       * find devices once everything is set up.
       */
      *pci->last_dev_p = dev;
      pci->last_dev_p = &dev->next;

      /*
       * Now insert it into the list of devices held
       * by the parent bus.
       */
      *bus_last = dev;
      bus_last = &dev->sibling;

   }

   /*
    * After performing arch-dependent fixup of the bus, look behind
    * all PCI-to-PCI bridges on this bus.
    */
   for(dev=bus->devices; dev; dev=dev->sibling)
      /*
       * If it's a bridge, scan the bus behind it.
       */
      if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
         uint32_t buses;
         unsigned int devfn = dev->devfn;
         unsigned short cr;

         /*
          * Insert it into the tree of buses.
          */
         child = salloc(sizeof(*child));
         child->next = bus->children;
         bus->children = child;
         child->self = dev;
         child->parent = bus;

         /*
          * Set up the primary, secondary and subordinate
          * bus numbers.
          */
         child->number = child->secondary = ++max;
         child->primary = bus->secondary;
         child->subordinate = 0xff;
         /*
          * Clear all status bits and turn off memory,
          * I/O and master enables.
          */
         pcibios_read_config_word(bus->number, devfn, PCI_COMMAND, &cr);
         pcibios_write_config_word(bus->number, devfn, PCI_COMMAND, 0x0000);
         pcibios_write_config_word(bus->number, devfn, PCI_STATUS, 0xffff);
         /*
          * Read the existing primary/secondary/subordinate bus
          * number configuration to determine if the PCI bridge
          * has already been configured by the system.  If so,
          * do not modify the configuration, merely note it.
          */
         pcibios_read_config_dword(bus->number, devfn, PCI_PRIMARY_BUS, &buses);
         if ((buses & 0xFFFFFF) != 0)
         {
            unsigned int cmax;

            child->primary = buses & 0xFF;
            child->secondary = (buses >> 8) & 0xFF;
            child->subordinate = (buses >> 16) & 0xFF;
            child->number = child->secondary;
            cmax = pci_scan_bus(child);
            if (cmax > max) max = cmax;
         }
         else
         {
            /*
             * Configure the bus numbers for this bridge:
             */
            buses &= 0xff000000;
            buses |=
               (((unsigned int)(child->primary)     <<  0) |
                ((unsigned int)(child->secondary)   <<  8) |
                ((unsigned int)(child->subordinate) << 16));
            pcibios_write_config_dword(bus->number, devfn, PCI_PRIMARY_BUS, buses);
            /*
             * Now we can scan all subordinate buses:
             */
            max = pci_scan_bus(child);
            /*
             * Set the subordinate bus number to its real
             * value:
             */
            child->subordinate = max;
            buses = (buses & 0xff00ffff)
               | ((unsigned int)(child->subordinate) << 16);
            pcibios_write_config_dword(bus->number, devfn, PCI_PRIMARY_BUS, buses);
         }
         pcibios_write_config_word(bus->number, devfn, PCI_COMMAND, cr );
      }

   /*
    * We've scanned the bus and so we know all about what's on
    * the other side of any bridges that may be on this bus plus
    * any devices.
    *
    * Return how far we've got finding sub-buses.
    */
   return max;
}

#if 0

void
pci_fixup(void)
{
   struct pci_dev *p;
   struct pci_bus *bus;

   for (bus = &pci_root; bus; bus=bus->next)
   {
      for (p=bus->devices; p; p=p->sibling)
      {
      }
   }
}

static void print_pci_info()
{
   pci_resource *r;
   struct pci_bus *pb = &pci_root;

   printk("\n");
   printk("PCI busses:\n");

   for(pb= &pci_root; pb; pb=pb->children )
   {
      printk("   number %d, primary %d, secondary %d, subordinate %d\n",
             pb->number,
             pb->primary,
             pb->secondary,
             pb->subordinate );
      printk("   bridge; vendor %04x, device %04x\n",
             pb->self->vendor,
             pb->self->device );

      {
         struct pci_dev *pd;

         for(pd= pb->devices; pd; pd=pd->sibling )
         {
            printk("       vendor %04x, device %04x, irq %d\n",
                   pd->vendor,
                   pd->device,
                   pd->irq );

         }
         printk("\n");
      }

   }
   printk("\n");

   printk("PCI resources:\n");
   for (r=pci->resources; r; r= r->next)
   {
      printk("   bus %d, vendor %04x, device %04x, base %08x, size %08x, type %d\n",
             r->dev->bus->number,
             r->dev->vendor,
             r->dev->device,
             r->base,
             r->size,
             r->type );
   }
   printk("\n");

   return;
}

#endif

static struct _addr_start
{
      uint32_t   start_pcimem;
      uint32_t   start_pciio;
      uint32_t   start_prefetch;
} astart;

static pci_resource *enum_device_resources( struct pci_dev *pdev, int i )
{
   pci_resource *r;

   for(r= pci->resources; r; r= r->next )
   {
      if( r->dev == pdev )
      {
         if( i-- == 0 ) break;
      }
   }
   return r;
}

static void recursive_bus_reconfigure( struct pci_bus *pbus )
{
   struct pci_dev       *pdev;
   struct pci_bus       *childbus;
   int  isroot = 0;

   if( !pbus )
   {
      /* start with the root bus */
      astart.start_pcimem   = BUSREST_MEM_START;
      astart.start_pciio    = BUSREST_IO_START;
      astart.start_prefetch = ((BUSREST_MEM_END >> 16) << 16);

      pbus = &pci_root;
      isroot = -1;
   }

#define WRITE_BRIDGE_IO
#define WRITE_BRIDGE_MEM
#define WRITE_BRIDGE_PF
#define WRITE_BRIDGE_ENABLE

/*
** Run thru the p2p bridges on this bus and recurse into subordinate busses
*/
   for( childbus= pbus->children; childbus; childbus= childbus->next )
   {
      pdev= childbus->self;

      pcibios_write_config_byte(pdev->bus->number, pdev->devfn, PCI_LATENCY_TIMER,     0x80 );
      pcibios_write_config_byte(pdev->bus->number, pdev->devfn, PCI_SEC_LATENCY_TIMER, 0x80 );

      {
         struct _addr_start   addrhold;
         uint8_t              base8, limit8;
         uint16_t             base16, limit16, ubase16, ulimit16;

         /* save the base address values */
         memcpy( &addrhold, &astart, sizeof(struct _addr_start));

         recursive_bus_reconfigure( childbus );

#ifdef PCI_DEBUG
         printk("pci: configuring bus %d bridge (%04x:%04x), bus %d : (%d-%d)\n",
                pdev->bus->number,
                pdev->vendor,
                pdev->device,
                childbus->primary,
                childbus->secondary,
                childbus->subordinate );
#endif

         /*
          * use the current values & the saved ones to figure out
          * the address spaces for the bridge
          */

         if( addrhold.start_pciio == astart.start_pciio )
         {
            base8 = limit8 = 0xff;
            ubase16 = ulimit16 = 0xffff;
         }
         else
         {
            base8    = (uint8_t) ((addrhold.start_pciio >> 8) & 0xf0);
            ubase16  = (uint16_t)(addrhold.start_pciio >> 16);
            limit8   = (uint8_t) ((astart.start_pciio >> 8 ) & 0xf0);
            ulimit16 = (uint16_t)(astart.start_pciio >> 16);
            astart.start_pciio += 0x1000;
         }

#ifdef PCI_DEBUG
         printk("pci:     io base %08x limit %08x\n", (base8<<8)+(ubase16<<16), (limit8<<8)+(ulimit16<<16));
#endif
#ifdef WRITE_BRIDGE_IO
         pcibios_write_config_word(pdev->bus->number, pdev->devfn, PCI_IO_BASE_UPPER16, ubase16 );
         pcibios_write_config_byte(pdev->bus->number, pdev->devfn, PCI_IO_BASE, base8 );

         pcibios_write_config_word(pdev->bus->number, pdev->devfn, PCI_IO_LIMIT_UPPER16, ulimit16 );
         pcibios_write_config_byte(pdev->bus->number, pdev->devfn, PCI_IO_LIMIT, limit8 );
#endif

         if( addrhold.start_pcimem == astart.start_pcimem )
         {
            limit16 = 0;
            base16 = 0xffff;
         }
         else
         {
            limit16= (uint16_t)((astart.start_pcimem >> 16) & 0xfff0);
            base16 = (uint16_t)((addrhold.start_pcimem >> 16) & 0xfff0);
            astart.start_pcimem += 0x100000;
         }
#ifdef PCI_DEBUG
         printk("pci:      memory %04x, limit %04x\n", base16, limit16);
#endif
#ifdef WRITE_BRIDGE_MEM
         pcibios_write_config_word(pdev->bus->number, pdev->devfn, PCI_MEMORY_BASE, base16 );
         pcibios_write_config_word(pdev->bus->number, pdev->devfn, PCI_MEMORY_LIMIT, limit16 );
#endif


         if( astart.start_prefetch == addrhold.start_prefetch )
         {
            limit16 = 0;
            base16 = 0xffff;
         }
         else
         {
            limit16= (uint16_t)((addrhold.start_prefetch >> 16) & 0xfff0);
            base16 = (uint16_t)((astart.start_prefetch >> 16) & 0xfff0);
            astart.start_prefetch -= 0x100000;
         }
#ifdef PCI_DEBUG
         printk("pci:   pf memory %04x, limit %04x\n", base16, limit16);
#endif
#ifdef WRITE_BRIDGE_PF
         pcibios_write_config_dword(pdev->bus->number, pdev->devfn, PCI_PREF_BASE_UPPER32, 0);
         pcibios_write_config_word(pdev->bus->number, pdev->devfn, PCI_PREF_MEMORY_BASE, base16 );
         pcibios_write_config_dword(pdev->bus->number, pdev->devfn, PCI_PREF_LIMIT_UPPER32, 0);
         pcibios_write_config_word(pdev->bus->number, pdev->devfn, PCI_PREF_MEMORY_LIMIT, limit16 );
#endif

#ifdef WRITE_BRIDGE_ENABLE
         pcibios_write_config_word(pdev->bus->number,
                                   pdev->devfn,
                                   PCI_BRIDGE_CONTROL,
                                   (uint16_t)( 0 ));

         pcibios_write_config_word(pdev->bus->number,
                                   pdev->devfn,
                                   PCI_COMMAND,
                                   (uint16_t)( PCI_COMMAND_IO |
                                                 PCI_COMMAND_MEMORY |
                                                 PCI_COMMAND_MASTER ));
#endif
      }
   }

   if( !isroot )
   {
#ifdef PCI_DEBUG
      printk("pci: Configuring devices on bus %d\n", pbus->number);
#endif
      /*
      ** Run thru this bus and set up addresses for all the non-bridge devices
      */
      for( pdev = pbus->devices; pdev; pdev= pdev->sibling )
      {
         if( (pdev->class >> 8) != PCI_CLASS_BRIDGE_PCI )
         {
            pci_resource *r;
            int i = 0;
            unsigned alloc;

            /* enumerate all the resources defined by this device & reserve space
            ** for each of their defined regions.
            */

#ifdef PCI_DEBUG
            printk("pci: configuring; vendor %04x, device %04x\n", pdev->vendor, pdev->device );
#endif

            while( (r= enum_device_resources( pdev, i++ )) )
            {
               /*
               ** Force all memory spaces to be non-prefetchable because
               ** on the pci bus, byte-wise reads against prefetchable
               ** memory are applied as 32 bit reads, which is a pain
               ** when you're trying to talk to hardware.  This is a
               ** little sub-optimal because the algorithm doesn't sort
               ** the address regions to pack them in, OTOH, perhaps its
               ** not so bad because the inefficient packing will help
               ** avoid buffer overflow/underflow problems.
               */
#if 0
               if( (r->type & PCI_BASE_ADDRESS_MEM_PREFETCH) )
               {
                  /* prefetchable space */

                  /* shift base pointer down to an integer multiple of the size of the desired region */
                  astart.start_prefetch -= (alloc= ((r->size / PAGE_SIZE) + 1) * PAGE_SIZE);
                  /* shift base pointer down to an integer multiple of the size of the desired region */
                  astart.start_prefetch = (astart.start_prefetch / r->size) * r->size;

                  r->base = astart.start_prefetch;
#ifdef PCI_DEBUG
                  printk("pci:       pf %08X, size %08X, alloc %08X\n", r->base, r->size, alloc );
#endif
               }
#endif
               if( r->type & PCI_BASE_ADDRESS_SPACE_IO )
               {
                  /* io space */

                  /* shift base pointer up to an integer multiple of the size of the desired region */
                  if( astart.start_pciio % r->size )
                     astart.start_pciio = (((astart.start_pciio / r->size) + 1) * r->size);

                  r->base = astart.start_pciio;
                  astart.start_pciio += (alloc= ((r->size / PAGE_SIZE) + 1) * PAGE_SIZE);
#ifdef PCI_DEBUG
                  printk("pci:      io  %08X, size %08X, alloc %08X\n", r->base, r->size, alloc );
#endif
               }
               else
               {
                  /* memory space */

                  /* shift base pointer up to an integer multiple of the size of the desired region */
                  if( astart.start_pcimem % r->size )
                     astart.start_pcimem = (((astart.start_pcimem / r->size) + 1) * r->size);

                  r->base = astart.start_pcimem;
                  astart.start_pcimem += (alloc= ((r->size / PAGE_SIZE) + 1) * PAGE_SIZE);
#ifdef PCI_DEBUG
                  printk("pci:      mem %08X, size %08X, alloc %08X\n", r->base, r->size, alloc );
#endif
               }
            }

         }
      }
   }

}

void pci_init(void)
{
   PPC_DEVICE *hostbridge;

   if (pci->last_dev_p) {
      printk("Two or more calls to pci_init!\n");
      return;
   }
   pci->last_dev_p = &(bd->pci_devices);
   hostbridge=residual_find_device(PROCESSORDEVICE, NULL,
                                   BridgeController,
                                   PCIBridge, -1, 0);
   if (hostbridge) {
      if (hostbridge->DeviceId.Interface==PCIBridgeIndirect) {
         bd->pci_functions=&indirect_functions;
         /* Should be extracted from residual data,
          * indeed MPC106 in CHRP mode is different,
          * but we should not use residual data in
          * this case anyway.
          */
         pci->config_addr = ((volatile void *)
                             (ptr_mem_map->io_base+0xcf8));
         pci->config_data = ptr_mem_map->io_base+0xcfc;
      } else if(hostbridge->DeviceId.Interface==PCIBridgeDirect) {
         bd->pci_functions=&direct_functions;
         pci->config_data=(u_char *) 0x80800000;
      } else {
      }
   } else {
      /* Let us try by experimentation at our own risk! */
      uint32_t id0;
      bd->pci_functions = &direct_functions;
      /* On all direct bridges I know the host bridge itself
       * appears as device 0 function 0.
       */
      pcibios_read_config_dword(0, 0, PCI_VENDOR_ID, &id0);
      if (id0==~0U) {
         bd->pci_functions = &indirect_functions;
         pci->config_addr = ((volatile u_int *)
                             (ptr_mem_map->io_base+0xcf8));
         pci->config_data = ptr_mem_map->io_base+0xcfc;
      }
      /* Here we should check that the host bridge is actually
       * present, but if it not, we are in such a desperate
       * situation, that we probably can't even tell it.
       */
   }
   /* Now build a small database of all found PCI devices */
   printk("\nPCI: Probing PCI hardware\n");
   pci_root.subordinate=pci_scan_bus(&pci_root);

   print_pci_resources("Installed PCI resources:\n");

   recursive_bus_reconfigure(NULL);

   reconfigure_pci();

   print_pci_resources("Allocated PCI resources:\n");

#if 0
   print_pci_info();
#endif
}

/* eof */