[patch 09/83] sparc64: Fix PCI resource mapping on sparc64

Greg KH
2008-12-11T19:21:26Z

[-- Attachment #1: 0003-sparc64-Fix-PCI-resource-mapping-on-sparc64.patch --]
[-- Type: text/plain, Size: 1734 bytes --]

2.6.27-stable review patch. If anyone has any objections, please let us know.

------------------

From: Max Dmitrichenko <dmitrmax@gmail.com>

[ Upstream commit 145e1c0023585e0e8f6df22316308ec61c5066b2 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/sparc64/kernel/pci.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

--- a/arch/sparc64/kernel/pci.c
+++ b/arch/sparc64/kernel/pci.c
@@ -1017,6 +1017,7 @@ static int __pci_mmap_make_offset(struct

for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
struct resource *rp = &pdev->resource[i];
+ resource_size_t aligned_end;

/* Active? */
if (!rp->flags)
@@ -1034,8 +1035,15 @@ static int __pci_mmap_make_offset(struct
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;
}