From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Moyer Subject: Re: [PATCH 1/2] added stream id write support Date: Tue, 21 Apr 2015 09:44:44 -0400 Message-ID: References: <1429580863-3451-1-git-send-email-kwan.huen@samsung.com> <1429580863-3451-2-git-send-email-kwan.huen@samsung.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1429580863-3451-2-git-send-email-kwan.huen-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org> (kwan huen's message of "Mon, 20 Apr 2015 18:47:42 -0700") Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "kwan.huen" Cc: Matthew Wilcox , Keith Busch , Jens Axboe , Dimitri John Ledkov , linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-api@vger.kernel.org "kwan.huen" writes: > --- > drivers/block/nvme-core.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c > index 85b8036..332341a 100644 > --- a/drivers/block/nvme-core.c > +++ b/drivers/block/nvme-core.c > @@ -769,6 +769,9 @@ static int nvme_submit_iod(struct nvme_queue *nvmeq, struct nvme_iod *iod, > if (req->cmd_flags & REQ_RAHEAD) > dsmgmt |= NVME_RW_DSM_FREQ_PREFETCH; > > + if (rq_data_dir(req)) > + dsmgmt |= bio_get_streamid(req->bio) << 8; > + There's no public specification for this, yet. How many bits are set aside for the stream id? Do you need to do bounds checking/input validation? What happens on adapters with older firmware when these bits are set? Cheers, Jeff