Messages in this thread | | | Date | Wed, 27 Mar 2024 23:35:19 -0700 | From | Christoph Hellwig <> | Subject | Re: [PATCH v2] scsi: libsas: Allocation SMP request is aligned to ARCH_DMA_MINALIGN |
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On Tue, Mar 26, 2024 at 01:32:09PM +0000, John Garry wrote: > > > + u8 *p; > > > + > > > + size = ALIGN(size, ARCH_DMA_MINALIGN); > > > If this is a hisi_sas requirement, then why use ARCH_DMA_MINALIGN and not > 16B as minimum alignment? > > Or are we really talking about an arch requirement?
One thing is that we should never allocate unaligned memory for anything DMA mapped, or data will be corrupted by non-coherent DMA. So ARCH_DMA_MINALIGN needs to be here. If specific hardware has further requirements we'll need to communicated it through a field or op vector.
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