MIPS: Octeon: Put restrictions on DMA descriptors.

Set the DMA mask such that all descriptors stay in the
lower 4GB of memory.

Signed-off-by: Steven J. Hill <steven.hill@cavium.com>
Acked-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13830/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/cavium-octeon/octeon-platform.c b/arch/mips/cavium-octeon/octeon-platform.c
index 7aeafed..c9359fd 100644
--- a/arch/mips/cavium-octeon/octeon-platform.c
+++ b/arch/mips/cavium-octeon/octeon-platform.c
@@ -311,7 +311,11 @@
 #ifdef __BIG_ENDIAN
 	.big_endian_mmio	= 1,
 #endif
-	.dma_mask_64	= 1,
+	/*
+	 * We can DMA from anywhere. But the descriptors must be in
+	 * the lower 4GB.
+	 */
+	.dma_mask_64	= 0,
 	.power_on	= octeon_ehci_power_on,
 	.power_off	= octeon_ehci_power_off,
 };