sparc64: Fix PCI resource mapping on sparc64

There is a problem discovered in recent versions of ATI Mach64 driver
in X.org on sparc64 architecture. In short, the driver fails to mmap
MMIO aperture (PCI resource #2).

I've found that kernel's __pci_mmap_make_offset() returns EINVAL. It
checks whether user attempts to mmap more than the resource length,
which is 0x1000 bytes in our case. But PAGE_SIZE on SPARC64 is 0x2000
and this is what actually is being mmaped. So __pci_mmap_make_offset()
failed for this PCI resource.

Signed-off-by: Max Dmitrichenko <dmitrmax@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/arch/sparc64/kernel/pci.c b/arch/sparc64/kernel/pci.c
index 242ac1c..bdb7c0a 100644 (file)
--- a/arch/sparc64/kernel/pci.c
+++ b/arch/sparc64/kernel/pci.c
@@ -889,6 +889,7 @@ static int __pci_mmap_make_offset(struct pci_dev *pdev,
 
        for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
                struct resource *rp = &pdev->resource[i];
+               resource_size_t aligned_end;
 
                /* Active? */
                if (!rp->flags)
@@ -906,8 +907,15 @@ static int __pci_mmap_make_offset(struct pci_dev *pdev,
                                continue;
                }
 
+               /* Align the resource end to the next page address.
+                * PAGE_SIZE intentionally added instead of (PAGE_SIZE - 1),
+                * because actually we need the address of the next byte
+                * after rp->end.
+                */
+               aligned_end = (rp->end + PAGE_SIZE) & PAGE_MASK;
+
                if ((rp->start <= user_paddr) &&
-                   (user_paddr + user_size) <= (rp->end + 1UL))
+                   (user_paddr + user_size) <= aligned_end)
                        break;
        }