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From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH 3/4] net: qcom/emac: enforce DMA address restrictions
Date: Thu, 12 Oct 2017 09:58:37 -0700 (PDT)
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From: Timur Tabi <timur@codeaurora.org>
Date: Thu, 12 Oct 2017 09:13:25 -0500

> On 10/12/17 4:30 AM, David Laight wrote:
>> Isn't the memory allocated by a single kzalloc() call?
> 
> dma_alloc_coherenent, actually.
> 
>> IIRC that guarantees it doesn't cross a power or 2 boundary less than
>> the size.
> 
> I'm pretty sure that kzalloc does not make that guarantee, and I don't
> think dma_alloc_coherent does either.

Both make that guarantee, even when an IOMMU is used.