pciauto_setup_device(

Hello,

Does anyone familiar the this code? Would you please give some comment
on the code. Why PCI_BASE_ADDRESS_0 to 5 will contain the memory/io
range? Is there any document on this issue?

Thanks in advance,

Mike


void pciauto_setup_device(struct pci_controller *hose,
pci_dev_t dev, int bars_num,
struct pci_region *mem,
struct pci_region *io)
{
unsigned int bar_value, bar_response, bar_size;
unsigned int cmdstat = 0;
struct pci_region *bar_res;
int bar, bar_nr = 0;
int found_mem64 = 0;

pci_hose_read_config_dword(hose, dev, PCI_COMMAND, &cmdstat);
cmdstat = (cmdstat & ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) |
PCI_COMMAND_MASTER;

for (bar = PCI_BASE_ADDRESS_0; bar <= PCI_BASE_ADDRESS_0 +
(bars_num*4); bar += 4) {
/* Tickle the BAR and get the response */
pci_hose_write_config_dword(hose, dev, bar, 0xffffffff);
pci_hose_read_config_dword(hose, dev, bar, &bar_response);

/* If BAR is not implemented go to the next BAR */
if (!bar_response)
continue;

found_mem64 = 0;

/* Check the BAR type and set our address mask */
if (bar_response & PCI_BASE_ADDRESS_SPACE) {
bar_size = ~(bar_response & PCI_BASE_ADDRESS_IO_MASK) + 1;
bar_res = io;

DEBUGF("PCI Autoconfig: BAR %d, I/O, size=0x%x, ", bar_nr,
bar_size);
} else {
if ( (bar_response & PCI_BASE_ADDRESS_MEM_TYPE_MASK) ==
PCI_BASE_ADDRESS_MEM_TYPE_64)
found_mem64 = 1;

bar_size = ~(bar_response & PCI_BASE_ADDRESS_MEM_MASK) + 1;
bar_res = mem;

DEBUGF("PCI Autoconfig: BAR %d, Mem, size=0x%x, ", bar_nr,
bar_size);
}

if (pciauto_region_allocate(bar_res, bar_size, &bar_value) == 0) {
/* Write it out and update our limit */
pci_hose_write_config_dword(hose, dev, bar, bar_value);

/*
* If we are a 64-bit decoder then increment to the
* upper 32 bits of the bar and force it to locate
* in the lower 4GB of memory.
*/
if (found_mem64) {
bar += 4;
pci_hose_write_config_dword(hose, dev, bar, 0x00000000);
}

cmdstat |= (bar_response & PCI_BASE_ADDRESS_SPACE) ?
PCI_COMMAND_IO : PCI_COMMAND_MEMORY;
}

DEBUGF("\n");

bar_nr++;
}

pci_hose_write_config_dword(hose, dev, PCI_COMMAND, cmdstat);
pci_hose_write_config_byte(hose, dev, PCI_CACHE_LINE_SIZE, 0x08);
pci_hose_write_config_byte(hose, dev, PCI_LATENCY_TIMER, 0x80);
}