Re: [PATCH] Fix PCI resource mmaping on sparc64

[David Miller <davem@davemloft.net>]

From: "Max Dmitrichenko" <dmitrmax@gmail.com>
Date: Fri, 31 Oct 2008 16:09:48 +0300

Please post sparc patches to the sparclinux mailing list,
CC:'d

> 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>
> 
> Code seems to be rather old. At least it was the same in 2.6.24. I
> have no explanation why this bug exposed only now. May be before X.org
> used to use some other method to mmap PCI resource into userspace (now
> it uses libpciaccess).
> 
> The patch is against 2.6.26. Greg, please consider to include it into
> the stable trees.

No, the sparc maintainer (that's me) will submit this patch to -stable
if it is correct and appropriate.