On Thu, Oct 31, 2019 at 04:53:13PM +0100, Nicolas Saenz Julienne wrote:

quoted

quoted

+#define ARM64_ZONE_DMA_BITS	30
+
 /*
  * We need to be able to catch inadvertent references to memstart_addr
  * that occur (potentially in generic code) before arm64_memblock_init()

@@ -424,6 +427,8 @@ void __init arm64_memblock_init(void)
 	else
 		arm64_dma_phys_limit = PHYS_MASK + 1;
 
+	zone_dma_bits = ARM64_ZONE_DMA_BITS;
+
 	reserve_crashkernel();

This actually adds a new limit, as there wasn't one before for arm64.

Well, as zone_dma_bits is only relevant in dma/direct when ZONE_DMA is defined
I figured it doesn't matter if the variable is set conditionally to ZONE_DMA or
not.

I'd much prefer that to do separately.