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| author | James Morris <jmorris@namei.org> | 2011-11-16 12:39:48 +1100 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2011-11-16 12:39:48 +1100 |
| commit | 24942c8e5cc8696064ee207ff29d4cf21f70dafc (patch) | |
| tree | 08a8221eb72ec3da7746d7d76f6f5915ce77cde7 /arch/powerpc/kernel/iommu.c | |
| parent | e163bc8e4a0cd1cdffadb58253f7651201722d56 (diff) | |
| parent | ff0ff78068dd8a962358dbbdafa9d6f24540d3e5 (diff) | |
Merge branch 'master'; commit 'v3.2-rc2' into next
Diffstat (limited to 'arch/powerpc/kernel/iommu.c')
| -rw-r--r-- | arch/powerpc/kernel/iommu.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index 961bb03413f3..0cfcf98aafca 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/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); |