[PATCH 4.8 53/92] iommu/io-pgtable-arm: Check for v7s-incapable systems

[Greg Kroah-Hartman]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Robin Murphy <robin.murphy@xxxxxxx>

commit 82db33dc5e49fb625262d81125625d07a0d6184e upstream.

On machines with no 32-bit addressable RAM whatsoever, we shouldn't
even touch the v7s format as it's never going to work.

Fixes: e5fc9753b1a8 ("iommu/io-pgtable: Add ARMv7 short descriptor support")
Reported-by: Eric Auger <eric.auger@xxxxxxxxxx>
Tested-by: Eric Auger <eric.auger@xxxxxxxxxx>
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/iommu/io-pgtable-arm-v7s.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -633,6 +633,10 @@ static struct io_pgtable *arm_v7s_alloc_
 {
 	struct arm_v7s_io_pgtable *data;
 
+#ifdef PHYS_OFFSET
+	if (upper_32_bits(PHYS_OFFSET))
+		return NULL;
+#endif
 	if (cfg->ias > ARM_V7S_ADDR_BITS || cfg->oas > ARM_V7S_ADDR_BITS)
 		return NULL;