agp: don't lock pages

AGP should not need to lock pages. They are not protecting any race
because there is no lock_page calls, only SetPageLocked.

This is causing hangs with d00806b183152af6d24f46f0c33f14162ca1262a.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/char/agp/generic.c

@@ -1170,7 +1170,6 @@ void *agp_generic_alloc_page(struct agp_bridge_data *bridge)
 	map_page_into_agp(page);
 
 	get_page(page);
-	SetPageLocked(page);
 	atomic_inc(&agp_bridge->current_memory_agp);
 	return page_address(page);
 }
@@ -1187,7 +1186,6 @@ void agp_generic_destroy_page(void *addr)
 	page = virt_to_page(addr);
 	unmap_page_from_agp(page);
 	put_page(page);
-	unlock_page(page);
 	free_page((unsigned long)addr);
 	atomic_dec(&agp_bridge->current_memory_agp);
 }

drivers/char/agp/intel-agp.c

@@ -213,7 +213,6 @@ static void *i8xx_alloc_pages(void)
 	}
 	global_flush_tlb();
 	get_page(page);
-	SetPageLocked(page);
 	atomic_inc(&agp_bridge->current_memory_agp);
 	return page_address(page);
 }
@@ -229,7 +228,6 @@ static void i8xx_destroy_pages(void *addr)
 	change_page_attr(page, 4, PAGE_KERNEL);
 	global_flush_tlb();
 	put_page(page);
-	unlock_page(page);
 	__free_pages(page, 2);
 	atomic_dec(&agp_bridge->current_memory_agp);
 }

drivers/char/agp/sgi-agp.c

@@ -51,7 +51,6 @@ static void *sgi_tioca_alloc_page(struct agp_bridge_data *bridge)
 		return NULL;
 
 	get_page(page);
-	SetPageLocked(page);
 	atomic_inc(&agp_bridge->current_memory_agp);
 	return page_address(page);
 }