arm_vmregion_alloc call

[Robert Beckett]

Hello all,

I just debugged a problem with a USB driver where it was calling
dma_alloc_coherent with a GFP_DMA32 flag.
It turned out that in __dma_alloc_remap, it clears the GFP_DMA and
GFP_HIGHMEM flags when calling arm_vmregion_alloc so that it does not clash
with the slab allocator flag requirements, but it does not clear GFP_DMA32.
The GFP_SLAB_BUG_MASK includes GFP_DMA32, so this looks like a bug to me.
Should it be clearing GFP_DMA32 as well as GFP_DMA and GFP_HIGHMEM ?

I checked in the latest kernel.org code, and the issue is still there.

Is this a bug, or should it just be calling with GFP_DMA instead of
GFP_DMA32?

For now, I am working around it by using GFP_DMA in the dma_alloc_coherent
call as we have no GFP_DMA lower limit, so GFP_DMA and GFP_DMA32 are the
same on my architecture.

Any advice appreciated,

Thanks

Bob
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