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-rw-r--r--drivers/xen/gntdev.c24
1 files changed, 13 insertions, 11 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index a36b71286bcf..aece224a4e70 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -309,18 +309,25 @@ int gntdev_map_grant_pages(struct gntdev_grant_map *map)
* to the kernel linear addresses of the struct pages.
* These ptes are completely different from the user ptes dealt
* with find_grant_ptes.
+ * Note that GNTMAP_device_map isn't needed here: The
+ * dev_bus_addr output field gets consumed only from ->map_ops,
+ * and by not requesting it when mapping we also avoid needing
+ * to mirror dev_bus_addr into ->unmap_ops (and holding an extra
+ * reference to the page in the hypervisor).
*/
+ unsigned int flags = (map->flags & ~GNTMAP_device_map) |
+ GNTMAP_host_map;
+
for (i = 0; i < map->count; i++) {
unsigned long address = (unsigned long)
pfn_to_kaddr(page_to_pfn(map->pages[i]));
BUG_ON(PageHighMem(map->pages[i]));
- gnttab_set_map_op(&map->kmap_ops[i], address,
- map->flags | GNTMAP_host_map,
+ gnttab_set_map_op(&map->kmap_ops[i], address, flags,
map->grants[i].ref,
map->grants[i].domid);
gnttab_set_unmap_op(&map->kunmap_ops[i], address,
- map->flags | GNTMAP_host_map, -1);
+ flags, -1);
}
}
@@ -336,17 +343,12 @@ int gntdev_map_grant_pages(struct gntdev_grant_map *map)
continue;
}
+ if (map->flags & GNTMAP_device_map)
+ map->unmap_ops[i].dev_bus_addr = map->map_ops[i].dev_bus_addr;
+
map->unmap_ops[i].handle = map->map_ops[i].handle;
if (use_ptemod)
map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
-#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
- else if (map->dma_vaddr) {
- unsigned long bfn;
-
- bfn = pfn_to_bfn(page_to_pfn(map->pages[i]));
- map->unmap_ops[i].dev_bus_addr = __pfn_to_phys(bfn);
- }
-#endif
}
return err;
}