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Date:   Tue, 11 Dec 2018 23:40:17 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     Parshuram Raju Thombare <pthombar@cadence.com>
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Subject: Re: [PATCH 0/2] scsi: ufs: add real time/inline crypto support to
 UFS HCD
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On Tue, Dec 11, 2018 at 06:22:27PM +0000, Parshuram Raju Thombare wrote:
> One reason of using device mapper here is to use existing tools like
> 'dmsetup', otherwise some user space application is needed and may be
> some changes in block layer to pass the crypto information (crypto
> algorithm, key etc) till ufs driver.

Yes, so what?  We also don't use dmsetup to set up TCG OPAL based
encryption either.

> Another reason is supporting multiple UFS devices. I think, as you said
> UFS crypto support can be added by some change in ufs driver and block
> layer glue. But to support multiple UFS crypto devices having different
> crypto configs (crypto algorithms, key size etc), crypto context need to
> be saved per crypto device which may need some changes in block layer code.

I don't think we need device mapper for that.  We can hav the crypto
state hanging off the ufs host, or request_queue if we decide to
implement it generic in the block layer.