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Subjectagp PAE issue (was Re: [git pull] AGP patches for 2.6.28-rc4)
>>
>> 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.
>>

So we have calls to set_memory_array_uc that used to take unsigned
long *, they now take
dma_addr_t *... this would be an issue.

Dave.

>> 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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>


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