[PATCH 7/8] arm64: update arch_zone_dma_bits to fine tune dma-direct min mask

[Nicolas Saenz Julienne]

With the introduction of ZONE_DMA in arm64 devices are not forced to
support 32 bit DMA masks. We have to inform dma-direct of this
limitation whenever it happens.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulie...@suse.de>
---

 arch/arm64/mm/init.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index f5279ef85756..b809f3259340 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -22,6 +22,7 @@
 #include <linux/of_fdt.h>
 #include <linux/dma-mapping.h>
 #include <linux/dma-contiguous.h>
+#include <linux/dma-direct.h>
 #include <linux/efi.h>
 #include <linux/swiotlb.h>
 #include <linux/vmalloc.h>
@@ -439,10 +440,14 @@ void __init arm64_memblock_init(void)
 
        early_init_fdt_scan_reserved_mem();
 
-       if (IS_ENABLED(CONFIG_ZONE_DMA))
+       if (IS_ENABLED(CONFIG_ZONE_DMA)) {
                arm64_dma_phys_limit = max_zone_dma_phys();
-       else
+
+               if (arm64_dma_phys_limit)
+                       arch_zone_dma_bits = ilog2(arm64_dma_phys_limit) + 1;
+       } else {
                arm64_dma_phys_limit = 0;
+       }
 
        /* 4GB maximum for 32-bit only capable devices */
        if (IS_ENABLED(CONFIG_ZONE_DMA32))
-- 
2.22.0