---

yaml --- r: 274204 b: refs/heads/master c: d12b524 h: refs/heads/master v: v3
git-mirror · Sep 23, 2011 · 7bbc01f · 7bbc01f
1 parent 86c5662
commit 7bbc01f
Show file tree

Hide file tree

Showing 2 changed files with 9 additions and 1 deletion.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 25c29f9e3242071bca1bee7ad919baf1888ae436
+refs/heads/master: d12b524f8b2f4e45cabe8bc1501e8b967d543111
diff --git a/trunk/arch/powerpc/kernel/iommu.c b/trunk/arch/powerpc/kernel/iommu.c
@@ -501,6 +501,14 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid)
 	tbl->it_map = page_address(page);
 	memset(tbl->it_map, 0, sz);
 
+	/*
+	 * Reserve page 0 so it will not be used for any mappings.
+	 * This avoids buggy drivers that consider page 0 to be invalid
+	 * to crash the machine or even lose data.
+	 */
+	if (tbl->it_offset == 0)
+		set_bit(0, tbl->it_map);
+
 	tbl->it_hint = 0;
 	tbl->it_largehint = tbl->it_halfpoint;
 	spin_lock_init(&tbl->it_lock);