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Subject: Re: [PATCH] lib/scatterlist: Add SG_CHAIN and SG_EMARK macros for LSB
 encodings
To:     Tvrtko Ursulin <tursulin@ursulin.net>,
        Johannes Thumshirn <jthumshirn@suse.de>,
        linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org,
        bart.vanassche@wdc.com, axboe@kernel.dk, chris@chris-wilson.co.uk,
        tvrtko.ursulin@intel.com
References: <20180214045804.9113-1-khandual@linux.vnet.ibm.com>
 <1518597168.24629.4.camel@suse.de>
 <ebbfc01c-3f42-483e-a281-1b4572bc8ac2@ursulin.net>
From:   Anshuman Khandual <khandual@linux.vnet.ibm.com>
Date:   Thu, 15 Feb 2018 08:23:11 +0530
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On 02/14/2018 09:41 PM, Tvrtko Ursulin wrote:
> 
> On 14/02/18 08:32, Johannes Thumshirn wrote:
>> On Wed, 2018-02-14 at 10:28 +0530, Anshuman Khandual wrote:
>>> This replaces scatterlist->page_link LSB encodings with SG_CHAIN and
>>> SG_EMARK definitions without any functional change.
>>>
>>> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
>>> ---
>>>   include/linux/scatterlist.h | 23 +++++++++++++----------
>>>   1 file changed, 13 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/include/linux/scatterlist.h
>>> b/include/linux/scatterlist.h
>>> index 22b2131bcdcd..63d00bdb2fb3 100644
>>> --- a/include/linux/scatterlist.h
>>> +++ b/include/linux/scatterlist.h
>>> @@ -65,16 +65,18 @@ struct sg_table {
>>>    */
>>>     #define SG_MAGIC    0x87654321
>>> +#define SG_CHAIN    0x01
>>> +#define SG_EMARK    0x02
>>
>> SG_EMARK sounds strange, what about SG_END?
> 
> +1 on SG_END.
> 
> Btw, just a cleanup for readability or you have further work in this area?

Sure, will replace with SG_END. I was trying something else on virtio drivers
on POWER platform and just came across this.