xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

agp: two-stage page destruction issue

Browse Source 
besides it apparently being useful only in 2.6.24 (the changes in 2.6.25
really mean that it could be converted back to a single-stage mechanism),
I'm seeing an issue in Xen Dom0 kernels, which is caused by the calling
of gart_to_virt() in the second stage invocations of the destroy function.
I think that besides this being a real issue with Xen (where
unmap_page_from_agp() is not just a page table attribute change), this
also is invalid from a theoretical perspective: One should not assume that
gart_to_virt() is still valid after unmapping a page. So minimally (keeping
the 2-stage mechanism) a patch like the one below would be needed.

Jan

Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Jan Beulich
2008-06-18 09:28:00 +01:00
committed by Dave Airlie
parent dcd981a77b
commit da503fa60b
3 changed files with 17 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/char/agp/intel-agp.c
View File

@@ -418,9 +418,11 @@ static void intel_i810_free_by_type(struct agp_memory *curr)
if (curr->page_count == 4)
i8xx_destroy_pages(gart_to_virt(curr->memory[0]));
else {
agp_bridge->driver->agp_destroy_page(gart_to_virt(curr->memory[0]),
void *va = gart_to_virt(curr->memory[0]);
agp_bridge->driver->agp_destroy_page(va,
AGP_PAGE_DESTROY_UNMAP);
agp_bridge->driver->agp_destroy_page(gart_to_virt(curr->memory[0]),
agp_bridge->driver->agp_destroy_page(va,
AGP_PAGE_DESTROY_FREE);
}
agp_free_page_array(curr);