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Date: Thu, 8 Nov 2018 07:04:45 -0800
From: Christoph Hellwig <hch@infradead.org>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Sagi Grimberg <sagi@grimberg.me>,
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Subject: Re: [PATCH] block: respect virtual boundary mask in bvecs
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On Wed, Nov 07, 2018 at 08:10:19AM -0800, Bart Van Assche wrote:
> > I personally not a huge fan of decoding complicated expressions. But if
> > others are fine with it then I am too...
> 
> What I proposed is not a new pattern. It is a pattern that is already used
> elsewhere in the Linux kernel. A few examples:
> 
> >From dmabounce.c:
> 
> 		/* Figure out if we need to bounce from the DMA mask. */
> 		if ((dma_addr | (dma_addr + size - 1)) & ~mask)
> 			return 1;
> 
> >From dma-direct.h:
> 
> 	if ((addr | (addr + size - 1)) & ~mask)
> 		return 0;

Time for a well documented helper :)