From: Dave Jiang <dave.jiang@intel.com>
To: Borislav Petkov <bp@alien8.de>
Cc: "dmaengine@vger.kernel.org" <dmaengine@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"vkoul@kernel.org" <vkoul@kernel.org>,
"Williams, Dan J" <dan.j.williams@intel.com>,
"Luck, Tony" <tony.luck@intel.com>,
"Lin, Jing" <jing.lin@intel.com>,
"Raj, Ashok" <ashok.raj@intel.com>,
"Kumar, Sanjay K" <sanjay.k.kumar@intel.com>,
"Dey, Megha" <megha.dey@intel.com>,
"Pan, Jacob jun" <jacob.jun.pan@intel.com>,
"Liu, Yi L" <yi.l.liu@intel.com>,
"axboe@kernel.dk" <axboe@kernel.dk>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"mingo@redhat.com" <mingo@redhat.com>,
"Yu, Fenghua" <fenghua.yu@intel.com>,
"hpa@zytor.com" <hpa@zytor.com>
Subject: Re: [PATCH RFC 01/14] x86/asm: add iosubmit_cmds512() based on movdir64b CPU instruction
Date: Thu, 21 Nov 2019 09:52:19 -0700 [thread overview]
Message-ID: <ef6bc4a4-b307-9bc4-f3be-f7ab7232d303@intel.com> (raw)
In-Reply-To: <20191121105913.GB6540@zn.tnic>
On 11/21/19 3:59 AM, Borislav Petkov wrote:
> On Wed, Nov 20, 2019 at 05:10:41PM -0700, Dave Jiang wrote:
>> I'll add the check on the destination address. The call is modeled after
>> __iowrite64_copy() / __iowrite32_copy() in lib/iomap_copy.c. Looks like
>> those functions do not check for the alignment requirements either.
>
> So just because they don't check, you don't need to check either?
No what I mean was those primitives are missing the checks and we should
probably address that at some point.
>
> Can you guarantee that all callers will always do the right thing?
>
> I mean, if you don't care too much, why even write "(must be 512-bit
> aligned)"? Who cares then if the data is aligned or not...
>
>>>> + * @dst: destination, in MMIO space (must be 512-bit aligned)
>>>> + * @src: source
>>>> + * @count: number of 512 bits quantities to submit
>>>
>>> Where's that check on the data?
>>
>> I don't follow?
>
> What do you do if the caller doesn't submit data in 512 bits quantities?
>
How would I detect that? Add a size (in bytes) parameter for the total
source data?
next prev parent reply other threads:[~2019-11-21 16:52 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-20 21:23 [PATCH RFC 00/14] idxd driver for Intel Data Streaming Accelerator Dave Jiang
2019-11-20 21:23 ` [PATCH RFC 01/14] x86/asm: add iosubmit_cmds512() based on movdir64b CPU instruction Dave Jiang
2019-11-20 21:50 ` Dave Hansen
2019-11-20 23:46 ` Dave Jiang
2019-11-20 21:53 ` Borislav Petkov
2019-11-20 23:19 ` Luck, Tony
2019-11-20 23:26 ` Borislav Petkov
2019-11-21 0:15 ` Luck, Tony
2019-11-21 0:27 ` Dan Williams
2019-11-21 0:53 ` Thomas Gleixner
2019-11-21 1:32 ` Dan Williams
2019-11-21 10:37 ` Borislav Petkov
2019-11-21 0:21 ` Dan Williams
2019-11-21 0:22 ` Thomas Gleixner
2019-11-21 0:27 ` Dave Jiang
2019-11-21 0:10 ` Dave Jiang
2019-11-21 10:59 ` Borislav Petkov
2019-11-21 16:52 ` Dave Jiang [this message]
2019-11-22 8:59 ` Borislav Petkov
2019-11-22 17:20 ` Dan Williams
2019-11-22 18:44 ` Borislav Petkov
2019-11-22 18:50 ` Dan Williams
2019-11-20 21:23 ` [PATCH RFC 02/14] dmaengine: break out channel registration Dave Jiang
2019-11-20 21:24 ` [PATCH RFC 03/14] dmaengine: add new dma device registration Dave Jiang
2019-11-20 21:24 ` [PATCH RFC 04/14] mm: create common code from request allocation based from blk-mq code Dave Jiang
2019-11-20 21:24 ` [PATCH RFC 05/14] dmaengine: add dma_request support functions Dave Jiang
2019-11-20 21:24 ` [PATCH RFC 06/14] dmaengine: add dma request submit and completion path support Dave Jiang
2019-11-20 21:24 ` [PATCH RFC 07/14] dmaengine: update dmatest to support dma request Dave Jiang
2019-11-20 21:24 ` [PATCH RFC 08/14] dmaengine: idxd: Init and probe for Intel data accelerators Dave Jiang
2019-11-20 21:24 ` [PATCH RFC 09/14] dmaengine: idxd: add configuration component of driver Dave Jiang
2019-11-20 21:24 ` [PATCH RFC 10/14] dmaengine: idxd: add descriptor manipulation routines Dave Jiang
2019-11-20 21:24 ` [PATCH RFC 11/14] dmaengine: idxd: connect idxd to dmaengine subsystem Dave Jiang
2019-11-20 21:24 ` [PATCH RFC 12/14] dmaengine: request submit optimization Dave Jiang
2019-11-20 21:25 ` [PATCH RFC 13/14] dmaengine: idxd: add char driver to expose submission portal to userland Dave Jiang
2019-11-20 21:25 ` [PATCH RFC 14/14] dmaengine: idxd: add sysfs ABI for idxd driver Dave Jiang
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