From 7bbc01f327d15cd816ec956ac33669b27f67230d Mon Sep 17 00:00:00 2001 From: Thadeu Lima de Souza Cascardo Date: Tue, 20 Sep 2011 03:07:24 +0000 Subject: [PATCH] --- yaml --- r: 274204 b: refs/heads/master c: d12b524f8b2f4e45cabe8bc1501e8b967d543111 h: refs/heads/master v: v3 --- [refs] | 2 +- trunk/arch/powerpc/kernel/iommu.c | 8 ++++++++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/[refs] b/[refs] index ef707e9a3cce..87c81f0b3409 100644 --- 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 index 961bb03413f3..0cfcf98aafca 100644 --- 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);