static int
pciscan(int bno, Pcidev** list)
{
Pcidev *p, *head, *tail;
int dno, fno, i, hdt, l, maxfno, maxubn, rno, sbn, tbdf, ubn;
maxubn = bno;
head = nil;
tail = nil;
for(dno = 0; dno <= pcimaxdno; dno++){
maxfno = 0;
for(fno = 0; fno <= maxfno; fno++){
/*
* For this possible device, form the bus+device+function
* triplet needed to address it and try to read the vendor
* and device ID. If successful, allocate a device struct
* and start to fill it in with some useful information from
* the device's configuration space.
*/
tbdf = MKBUS(BusPCI, bno, dno, fno);
l = pcicfgrw32(tbdf, PciVID, 0, 1);
if(l == 0xFFFFFFFF || l == 0)
continue;
p = ialloc(sizeof(*p), 0);
p->tbdf = tbdf;
p->vid = l;
p->did = l>>16;
/*
* If the device is a multi-function device adjust the
* loop count so all possible functions are checked.
*/
hdt = pcicfgr8(p, PciHDT);
if(hdt & 0x80)
maxfno = MaxFNO;
/*
* If appropriate, read the base address registers
* and work out the sizes.
*/
switch(p->ccru>>8){
case 0x01: /* mass storage controller */
case 0x02: /* network controller */
case 0x03: /* display controller */
case 0x04: /* multimedia device */
case 0x07: /* simple communication controllers */
case 0x08: /* base system peripherals */
case 0x09: /* input devices */
case 0x0A: /* docking stations */
case 0x0B: /* processors */
case 0x0C: /* serial bus controllers */
if((hdt & 0x7F) != 0)
break;
rno = PciBAR0 - 4;
for(i = 0; i < nelem(p->mem); i++){
rno += 4;
p->mem[i].bar = pcicfgr32(p, rno);
p->mem[i].size = pcibarsize(p, rno);
}
break;
case 0x00:
case 0x05: /* memory controller */
case 0x06: /* bridge device */
default:
break;
}
*list = head;
for(p = head; p != nil; p = p->link){
/*
* Find PCI-PCI bridges and recursively descend the tree.
*/
if(p->ccru != ((0x06<<8)|0x04))
continue;
/*
* If the secondary or subordinate bus number is not initialized
* try to do what the PCI BIOS should have done and fill in the
* numbers as the tree is descended. On the way down the subordinate
* bus number is set to the maximum as it's not known how many
* buses are behind this one; the final value is set on the way
* back up.
*/
sbn = pcicfgr8(p, PciSBN);
ubn = pcicfgr8(p, PciUBN);
if(sbn == 0 || ubn == 0){
sbn = maxubn+1;
/*
* Make sure memory, I/O and master enables are off,
* set the primary, secondary and subordinate bus numbers
* and clear the secondary status before attempting to
* scan the secondary bus.
*
* Initialisation of the bridge should be done here.
*/
pcicfgw32(p, PciPCR, 0xFFFF0000);
l = (MaxUBN<<16)|(sbn<<8)|bno;
pcicfgw32(p, PciPBN, l);
pcicfgw16(p, PciSPSR, 0xFFFF);
maxubn = pciscan(sbn, &p->bridge);
l = (maxubn<<16)|(sbn<<8)|bno;
pcicfgw32(p, PciPBN, l);
}
else{
maxubn = ubn;
pciscan(sbn, &p->bridge);
}
}
return maxubn;
}
static void
pcicfginit(void)
{
char *p;
int bno;
Pcidev **list;
lock(&pcicfginitlock);
if(pcicfgmode == -1){
/*
* Try to determine which PCI configuration mode is implemented.
* Mode2 uses a byte at 0xCF8 and another at 0xCFA; Mode1 uses
* a DWORD at 0xCF8 and another at 0xCFC and will pass through
* any non-DWORD accesses as normal I/O cycles. There shouldn't be
* a device behind these addresses so if Mode2 accesses fail try
* for Mode1 (which is preferred, Mode2 is deprecated).
*/
outb(PciCSE, 0);
if(inb(PciCSE) == 0){
pcicfgmode = 2;
pcimaxdno = 15;
}
else{
outl(PciADDR, 0);
if(inl(PciADDR) == 0){
pcicfgmode = 1;
pcimaxdno = 31;
}
}
