pci.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

/*
 *  pci.c -- Crude pci handling for early boot.
 *
 *  Copyright (C) 1998, 1999 Gabriel Paubert, [e-mail]
 *
 *  Modified to compile in RTEMS development environment
 *  by Eric Valette
 *
 *  Copyright (C) 1999 Eric Valette. [e-mail]
 *
 *  The license and distribution terms for this file may be
 *  found in found in the file LICENSE in this distribution or at
 *  http://www.rtems.com/license/LICENSE.
 *
 * pci.c,v 1.3 2003/06/13 17:39:44 joel Exp
 */


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

typedef unsigned int u32;

/*
#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 u_int * 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;
   }
   }

   if ((r->type==PCI_BASE_ADDRESS_SPACE_IO) 
       ? (r->size >= 0x10000)
       : (r->size >= 0x10000000)) {
      r->size  = 0;
      r->base  = 0;
   }

   /* 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;