Fail to access pcie user space (e.g. bar 2)

[yhuyhu]

I am unable to access a standard memory pcie card bar registers through my driver on the pcie interface for Zotec H55 ITX motherboard (it includes a built in NVideo engine). This is the following setup:
1. Fedora 14 32 bit pcie scan does see the board (lspci -n show card on pcie bus #2)
2. Configuration register read is good. (pci_read_config_byte())
3. The following driver commands did correctly return bar information: pci_rsource_start(), pci_resource_end(),pci_resource_len()
4. The commands iowrite32() or memcopy_toio() results in no pcie transfers (determined through pcie core probing)
5. The same driver code fully functioned on the Intel DH57JG mini-ITX. (using lspci -n, pcie located on pcie bus #1)
6. Note, it seems that the pcie connector for Zotec is on bus#2, where as Intel MB pcie connector is on bus#1. Note also that the Zotec has a built in NVidia graphics engine.

The following driver code was used. Again, it worked on DH57JG:
pcid.pciaddr_phy_str_bar0 = pci_resource_start(pcid.pcidev,0);
if(pcid.pciaddr_phy_str_bar0 == 0) {
printk(KERN_INFO "fail to get pci start address for Bar0.\n");
return -ENODEV; }
pcid.pciaddr_phy_len_bar0 = pci_resource_len(pcid.pcidev,0);
if(pcid.pciaddr_phy_len_bar0 == 0) {
printk(KERN_INFO "fail to get pci end address for Bar0.\n");
return -ENODEV; }
pcid.pciaddr_phy_str_bar2 = pci_resource_start(pcid.pcidev,2);
if(pcid.pciaddr_phy_str_bar2 == 0) {
printk(KERN_INFO "fail to get pci start address for Bar2.\n");
return -ENODEV; }
pcid.pciaddr_phy_len_bar2 = pci_resource_len(pcid.pcidev,2);
if(pcid.pciaddr_phy_len_bar2 == 0) {
printk(KERN_INFO "fail to get pci end address for Bar2.\n");
return -ENODEV; }


printk(KERN_INFO "pci captured: pcidev=%#lx pciaddr_phy_str_bar(0,1)=(%#lx,%#lx)\n",
pci_resource_start(pcid.pcidev,0), pci_resource_start(pcid.pcidev,1));
if(PRINTK_DB)
{
printk(KERN_INFO "pci captured: pcidev=%#lx pciaddr_phy_str_bar(0,2)=(%#lx,%#lx)\n",
pcid.pcidev, (long unsigned int)pcid.pciaddr_phy_str_bar0,(long unsigned int)pcid.pciaddr_phy_str_bar2);
printk(KERN_INFO " pciaddr_phy_len_bar(0,2)=(%#lx,%#lx)\n",
pcid.pciaddr_phy_len_bar0,pcid.pciaddr_phy_len_bar 2);
}
if(!request_mem_region(pcid.pciaddr_phy_str_bar0, pcid.pciaddr_phy_len_bar0, "pci_bar0"))
printk(KERN_INFO "request_mem_region fail: bar0\n");
if(!request_mem_region(pcid.pciaddr_phy_str_bar2, pcid.pciaddr_phy_len_bar2,"pci_bar2"))
printk(KERN_INFO "request_mem_region fail: bar2\n");


pcid.pciaddr_base_bar0 = (unsigned long) ioremap(pcid.pciaddr_phy_str_bar0, pcid.pciaddr_phy_len_bar0);
pcid.pciaddr_base_bar2 = (unsigned long) ioremap(pcid.pciaddr_phy_str_bar2, pcid.pciaddr_phy_len_bar2);
if(PRINTK_DB)
{
printk(KERN_INFO "pci bar0 io remap addr = %#lx\n",
(long unsigned int)(pcid.pciaddr_base_bar0));
printk(KERN_INFO "pci bar2 io remap addr = %#lx\n",
(long unsigned int)(pcid.pciaddr_base_bar2));
}

// testing

for(i=0;i<100;i++)
for(j=0;j<4;j++){
iowrite32(0x13572348,(void *)(pcid.pciaddr_base_bar2+(long unsigned int)(4*j)));
iowrite32(0x12344321,(void *)(pcid.pciaddr_base_bar0));}
i = ioread32((void *)(pcid.pciaddr_base_bar2));
printk(KERN_INFO "pci bar2 reg0=%x\n",i); <<<<< FAIL

for(i=0;i<100;i++) {
pci_read_config_byte(pcid.pcidev,i,&j);
pci_write_config_byte(pcid.pcidev,i+70,&j);
printk(KERN_INFO "pci cfg %d=%x\n",i,j); } <<<<GOD

[yhuyhu]

(Solved) This turns out to be a Xilinx evaluation PCIe core on the ML505 board that works on Intel motherboards, but not on the Zotek boards. The Xilinx PCIe core on the SP605 works on both motherboards. The root cause is still unknown.