RE: swiotlb/caamjr regression (Was: [GIT PULL] (swiotlb) stable/for-linus-5.12)

From: "Chanho Park" <chanho61.park@samsung.com>
To: "'Dominique MARTINET'" <dominique.martinet@atmark-techno.com>,
	"'Jianxiong Gao'" <jxgao@google.com>
Cc: "'Christoph Hellwig'" <hch@lst.de>,
	"'Konrad Rzeszutek Wilk'" <konrad@darnok.org>,
	"'Konrad Rzeszutek Wilk'" <konrad.wilk@oracle.com>,
	"'Linus Torvalds'" <torvalds@linux-foundation.org>,
	"'Horia Geantă'" <horia.geanta@nxp.com>,
	linux-kernel@vger.kernel.org,
	"'Lukas Hartmann'" <lukas@mntmn.com>,
	"'Aymen Sghaier'" <aymen.sghaier@nxp.com>,
	"'Herbert Xu'" <herbert@gondor.apana.org.au>,
	"'David S. Miller'" <davem@davemloft.net>,
	linux-crypto@vger.kernel.org, iommu@lists.linux-foundation.org,
	"'Marc Orr'" <marcorr@google.com>,
	"'Erdem Aktas'" <erdemaktas@google.com>,
	"'Peter Gonda'" <pgonda@google.com>,
	"'Bumyong Lee'" <bumyong.lee@samsung.com>
Subject: RE: swiotlb/caamjr regression (Was: [GIT PULL] (swiotlb) stable/for-linus-5.12)
Date: Mon, 21 Jun 2021 11:55:22 +0900	[thread overview]
Message-ID: <2038148563.21624247281621.JavaMail.epsvc@epcpadp4> (raw)
In-Reply-To: <YM/zWyZlk1bzHWgI@atmark-techno.com>

+ Bumyong who is the original author of the patch. 

Hi Dominique,

> Thanks!
> (a bit late, but added Chanho Park in Cc...)
> 
> I can confirm it also works for our caam problem, as Horia said.
> 
> I've also come to term with the use of swiotlb_align_offset() through
> testing, or rather many devices seem to have a 0 mask so it will almost
> always be cancelled out, so if it works for Jianxiong then it's probably
> good enough and I'll just assume that's how the orig_addr has been
> designed...
> 
> I think it's missing a couple of checks like the one Linus had in his
> patch, and would be comfortable with something like the attached patch (in
> practice for me exactly the same as the original patch, except I've added
> two checks: offsets smaller than orig addr offset are refused as well as
> offsets bigger than the mapping size)
> 
> I'm sorry Jianxiong but would you be willing to take the time to test
> again just to make sure there were no such offsets in your case?
> 
> 
> If we're good with that I'll send it as an official v2 keeping Chanho's
> from, unless he wants to.
> 

Sure. No problem. But, the patch was already stacked on Konrad's tree
and linux-next as well.

https://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb.git/commit/?h=devel/for-linus-5.14&id=33d1641f38f0c327bc3e5c21de585c77a6512bc6 

Best Regards, 
Chanho Park