Re: [git pull] AGP patches for 2.6.28-rc4

["Dave Airlie" <airlied@gmail.com>]

On Thu, Nov 6, 2008 at 4:46 PM, Dave Airlie <airlied@linux.ie> wrote:
> Hi Linus,
>
> Please pull the 'agp-fixes' branch from
> git://master.kernel.org/pub/scm/linux/kernel/git/airlied/agp-2.6.git agp-fixes

Actually Linus please skip this, we really want this PAE patch in but
I suspect I will need
 to do more widespread changes than this patch does :(

Dave.

>
> This contains two fixes,
>
> oops fix: intel g33 fix for 1MB aperture setting
>
> PAE kernel + AGP + GEM fix. The patch contains more explaination, but
> since GEM uses shmem to allocate pages it can pass highmem pages into AGP,
> AGP just needs to pass those addressess around cleanly in dma_addr_t. The
> correct answer is to use struct page *, but that is way too invasive for
> this stage of a kernel release.
>
> Dave.
>
>  drivers/char/agp/agp.h          |    8 ++++----
>  drivers/char/agp/efficeon-agp.c |    2 +-
>  drivers/char/agp/generic.c      |   15 ++++++---------
>  drivers/char/agp/hp-agp.c       |    2 +-
>  drivers/char/agp/i460-agp.c     |    2 +-
>  drivers/char/agp/intel-agp.c    |   11 +++++++++--
>  drivers/char/agp/parisc-agp.c   |    2 +-
>  drivers/char/agp/sgi-agp.c      |    2 +-
>  drivers/gpu/drm/drm_memory.c    |    3 ++-
>  drivers/gpu/drm/drm_vm.c        |    4 ++--
>  include/linux/agp_backend.h     |    4 ++--
>  11 files changed, 30 insertions(+), 25 deletions(-)
>
> commit d5e4cc00c911a72709a8d012179980a6157ba552
> Author: Brandon Philips <bphilips@suse.de>
> Date:   Tue Oct 28 22:22:18 2008 -0700
>
>    intel-agp: Avoid oops for G33 on 1MB stolen case
>
>    This is similar to f443675affe3f16dd428e46f0f7fd3f4d703eeab which was
>    reverted because it broke older X.org driver. This patch only fixes
>    the 1MB stolen case since it causes an oops.
>
>    Xorg will not work without the accompanying patch[1] but avoiding an
>    oops and making it possible to work with patched xorg driver is
>    reasonable.
>
>    [1] http://ifup.org/~philips/review/xf86-video-intel-G33-1mb.patch
>
>    Explanation of the oops:
>
>    > static void intel_i830_init_gtt_entries(void)
>    ...
>    >         } else if (IS_G33) {
>    >         /* G33's GTT size defined in gmch_ctrl */
>    >                 switch (gmch_ctrl & G33_PGETBL_SIZE_MASK) {
>    >                 case G33_PGETBL_SIZE_1M:
>    >                         size = 1024;
>    >                         break;
>    ...
>    >                 size += 4;
>
>    size = 1028
>
>    Then since we have the BIOS setting 1MB for the device in the GMCH
>    control we get to here:
>
>    >         } else {
>    >                 switch (gmch_ctrl & I855_GMCH_GMS_MASK) {
>    >                 case I855_GMCH_GMS_STOLEN_1M:
>    >                         gtt_entries = MB(1) - KB(size);
>    >                         break;
>
>    MB(1) = 1 * 1024 * 1024
>    KB(1028) = 1028 * 1024
>
>    MB(1) - KB(1028) = -4096
>
>    >         gtt_entries /= KB(4);
>    >         intel_private.gtt_entries = gtt_entries;
>
>    We end up with -1 in gtt_entries.
>
>    This leads to intel_i915_configure reading/writing to areas outside of
>    mapped memory and the oops.
>
>    Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=391261
>
>    Signed-off-by: Brandon Philips <bphilips@suse.de>
>    Signed-off-by: Dave Airlie <airlied@linux.ie>
>
> commit b4f5dfa4b12efeea816a6f16ddb4c8851adbd39a
> Author: Pierre Willenbrock <pierre@pirsoft.de>
> Date:   Mon Nov 3 21:14:56 2008 -0800
>
>    agp: change physical address type from unsigned long to dma_addr_t
>
>    This fixes enough of the interface for i915 DRM with CONFIG_HIGHMEM64. It
>    doesn't fix the physical addresses when passed to intelfb, mtrr or userspace.
>
>    airlied: This patch is sufficent to fix GEM use cases, we should overhaul AGP
>    later to make it use struct page *, instead of this. AGP allocated pages are
>    safe because we never use highmem pages, GEM allocated pages never use
>    virt_to_*.
>
>    Signed-off-by: Pierre Willenbrock <pierre@pirsoft.de>
>    Signed-off-by: Eric Anholt <eric@anholt.net>
>    Signed-off-by: Dave Airlie <airlied@linux.ie>
> --
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