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authorJan Beulich <jbeulich@novell.com>2008-06-18 04:28:00 -0400
committerDave Airlie <airlied@redhat.com>2008-06-18 19:56:16 -0400
commitda503fa60b84d5945deb3ab74efdd0bec61df4a1 (patch)
tree9883d28cabdab419567a2c0689d06c938460eaa1 /drivers/char/agp/generic.c
parentdcd981a77b2b35d169656d4b9cee208096ed7ccf (diff)
agp: two-stage page destruction issue
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>
Diffstat (limited to 'drivers/char/agp/generic.c')
-rw-r--r--drivers/char/agp/generic.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index 7fc0c99a3a58..b6650a63197d 100644
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -202,10 +202,13 @@ void agp_free_memory(struct agp_memory *curr)
202 } 202 }
203 if (curr->page_count != 0) { 203 if (curr->page_count != 0) {
204 for (i = 0; i < curr->page_count; i++) { 204 for (i = 0; i < curr->page_count; i++) {
205 curr->bridge->driver->agp_destroy_page(gart_to_virt(curr->memory[i]), AGP_PAGE_DESTROY_UNMAP); 205 curr->memory[i] = (unsigned long)gart_to_virt(curr->memory[i]);
206 curr->bridge->driver->agp_destroy_page((void *)curr->memory[i],
207 AGP_PAGE_DESTROY_UNMAP);
206 } 208 }
207 for (i = 0; i < curr->page_count; i++) { 209 for (i = 0; i < curr->page_count; i++) {
208 curr->bridge->driver->agp_destroy_page(gart_to_virt(curr->memory[i]), AGP_PAGE_DESTROY_FREE); 210 curr->bridge->driver->agp_destroy_page((void *)curr->memory[i],
211 AGP_PAGE_DESTROY_FREE);
209 } 212 }
210 } 213 }
211 agp_free_key(curr->key); 214 agp_free_key(curr->key);