From: Christoph Hellwig <hch@infradead.org>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Casey Leedom <leedom@chelsio.com>,
Robin Murphy <robin.murphy@arm.com>,
Harsh Jain <Harsh@chelsio.com>,
"Raj, Ashok" <ashok.raj@intel.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
David Woodhouse <David.Woodhouse@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
"linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
"dwmw2@infradead.org" <dwmw2@infradead.org>,
Michael Werner <werner@chelsio.com>
Subject: Re: DMA error when sg->offset value is greater than PAGE_SIZE in Intel IOMMU
Date: Sun, 1 Oct 2017 01:59:13 -0700 [thread overview]
Message-ID: <20171001085913.GA29880@infradead.org> (raw)
In-Reply-To: <CAPcyv4hL92Ru5x-b_5s80EwO=w37M=KEr289zrCRSM_8juvDzw@mail.gmail.com>
On Wed, Sep 27, 2017 at 10:13:51AM -0700, Dan Williams wrote:
> As far as I can see "Offset can be greater than PAGE_SIZE" is the only
> safe assumption for core code.
It seems completely bogus to me, but if it is the current assumption
we'll have to document it. But this brings me back to that
our scatterlists are a pretty horrible data structure to start
with as they try to mix virtual and physical addressing together.
We'd be much better of by passing a chain of bio_vecs where we
just need virtual addresses, a chain of [bus_addr,len] pairs where
we just need a physical address, and both where we need both instead
of this giant structure that tries to do both at the same time..
next prev parent reply other threads:[~2017-10-01 8:59 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-16 6:11 DMA error when sg->offset value is greater than PAGE_SIZE in Intel IOMMU Harsh Jain
2017-09-20 8:01 ` Herbert Xu
2017-09-20 10:12 ` Robin Murphy
2017-09-20 11:20 ` Harsh Jain
2017-09-25 17:46 ` Casey Leedom
2017-09-25 15:54 ` Raj, Ashok
2017-09-25 18:46 ` Casey Leedom
2017-09-26 3:46 ` Harsh Jain
[not found] ` <afa02763-4556-0e14-7d1b-1c044cdc1ff7-ut6Up61K2wZBDgjK7y7TUQ@public.gmane.org>
2017-09-26 12:21 ` Harsh Jain
2017-09-26 14:22 ` Robin Murphy
2017-09-26 14:34 ` Raj, Ashok
2017-09-26 14:40 ` Raj, Ashok
2017-09-26 20:50 ` Casey Leedom
2017-09-26 18:15 ` Robin Murphy
[not found] ` <437a9bd8-d4d6-22ca-1a64-1a3e73f1101a-5wv7dgnIgG8@public.gmane.org>
2017-09-26 16:06 ` Casey Leedom
2017-09-26 16:10 ` Dan Williams
2017-09-27 16:31 ` Casey Leedom
[not found] ` <MWHPR12MB160060436AC70CB5BE8C0C6EC8780-Gy0DoCVfaSVsWITs4OkDoAdYzm3356FpvxpqHgZTriW3zl9H0oFU5g@public.gmane.org>
2017-09-27 17:13 ` Dan Williams
2017-10-01 8:59 ` Christoph Hellwig [this message]
2017-09-27 17:18 ` Robin Murphy
[not found] ` <20170927181802.3dcd7efb-h2/QxWiDqNo@public.gmane.org>
2017-09-27 14:48 ` Raj, Ashok
2017-09-27 21:29 ` Casey Leedom
[not found] ` <MWHPR12MB16005D59D7A33F3D5BE43395C8780-Gy0DoCVfaSVsWITs4OkDoAdYzm3356FpvxpqHgZTriW3zl9H0oFU5g@public.gmane.org>
2017-09-27 19:07 ` Raj, Ashok
2017-09-27 22:13 ` Casey Leedom
2017-09-28 5:01 ` Harsh Jain
[not found] ` <MWHPR12MB16007E5363E79173C52BFA19C8780-Gy0DoCVfaSVsWITs4OkDoAdYzm3356FpvxpqHgZTriW3zl9H0oFU5g@public.gmane.org>
2017-09-28 10:33 ` Herbert Xu
[not found] ` <20170928103312.GB8118-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2017-09-28 11:11 ` Harsh Jain
2017-09-28 13:38 ` Harsh Jain
2017-09-28 13:05 ` Raj, Ashok
2017-09-29 5:37 ` Harsh Jain
2017-09-27 17:30 ` Casey Leedom
2017-09-26 17:30 ` Casey Leedom
2017-09-25 19:31 ` Dan Williams
[not found] ` <CAPcyv4j3J41eY2eR07nTvo75F0yCbL9bNHM8GmXEFOHDQUuf8Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-09-25 20:05 ` Casey Leedom
[not found] ` <MWHPR12MB1600948B2F57696189FC7C22C87A0-Gy0DoCVfaSVsWITs4OkDoAdYzm3356FpvxpqHgZTriW3zl9H0oFU5g@public.gmane.org>
2017-09-25 20:11 ` Dan Williams
2017-09-25 19:03 ` Raj, Ashok
2017-09-25 23:41 ` Casey Leedom
2017-09-26 13:04 ` Harsh Jain
2017-09-20 11:30 ` Harsh Jain
2017-09-25 18:45 ` David Woodhouse
2017-09-25 20:19 ` Casey Leedom
2017-09-26 11:17 ` Harsh Jain
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