PCI: Fix proc mmap on sparc

PCI: Fix proc mmap on sparc

In 8c05cd08a7 ("PCI: fix offset check for sysfs mmapped files"), try
to check exposed value with resource start/end in proc mmap path.

|        start = vma->vm_pgoff;
|        size = ((pci_resource_len(pdev, resno) - 1) >> PAGE_SHIFT) + 1;
|        pci_start = (mmap_api == PCI_MMAP_PROCFS) ?
|                        pci_resource_start(pdev, resno) >> PAGE_SHIFT : 0;
|        if (start >= pci_start && start < pci_start + size &&
|                        start + nr <= pci_start + size)

vma->vm_pgoff is above code segment is user/BAR value >> PAGE_SHIFT.
pci_start is resource->start >> PAGE_SHIFT.

For sparc, resource start is different from BAR start aka pci bus address.
pci bus address need to add offset to be the resource start.

So that commit breaks all arch that exposed value is BAR/user value,
and need to be offseted to resource address.

test code using: ./test_mmap_proc /proc/bus/pci/0000:00/04.0 0x2000000
test code segment:
  fd = open(argv[1], O_RDONLY);
  ...
  sscanf(argv[2], "0x%lx", &offset);
  left = offset & (PAGE_SIZE - 1);
  offset &= PAGE_MASK;
  ioctl(fd, PCIIOC_MMAP_IS_MEM);
  addr = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_SHARED, fd, offset);
  for (i = 0; i < 8; i++)
    printf("%x ", addr[i + left]);
  munmap(addr, PAGE_SIZE);
  close(fd);

Fixes: 8c05cd08a7 ("PCI: fix offset check for sysfs mmapped files")
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Orabug: 22855133

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
(cherry picked from commit 7bd8ad7855e6ecdac36c6dc7946f5b6beff13ae2)
Signed-off-by: Allen Pais <allen.pais@oracle.com>