Re: [PATCH] lib/scatterlist: Add SG_CHAIN and SG_EMARK macros for LSB encodings

From: Anshuman Khandual
Date: Wed Feb 14 2018 - 21:53:28 EST


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@xxxxxxxxxxxxxxxxxx>
>>> ---
>>> 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.