From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hal Rosenstock Subject: Re: [PATCH v4 14/19] IB/core: Add IB_DEVICE_OPA_MAD_SUPPORT device cap flag Date: Fri, 06 Feb 2015 15:35:21 -0500 Message-ID: <54D52589.8020305@dev.mellanox.co.il> References: <1423092585-26692-1-git-send-email-ira.weiny@intel.com> <1423092585-26692-15-git-send-email-ira.weiny@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1423092585-26692-15-git-send-email-ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org Cc: roland-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org On 2/4/2015 6:29 PM, ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org wrote: > From: Ira Weiny >=20 > OPA MADs share a common header with IBTA MADs but with a different ba= se version > and an extended length. These "jumbo" MADs increase the performance = of > management traffic. >=20 > Sharing a common header with IBTA MADs allows us to share most of the= MAD > processing code when dealing with OPA MADs in addition to supporting = some IBTA > MADs on OPA devices. >=20 > Add a device capability flag to indicate OPA MAD support on the devic= e. >=20 > Signed-off-by: Ira Weiny >=20 > --- > include/rdma/ib_verbs.h | 5 +++++ > 1 file changed, 5 insertions(+) >=20 > diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h > index 3ab4033..2614233 100644 > --- a/include/rdma/ib_verbs.h > +++ b/include/rdma/ib_verbs.h > @@ -128,6 +128,10 @@ enum ib_device_cap_flags { > IB_DEVICE_ON_DEMAND_PAGING =3D (1<<31), > }; > =20 > +enum ib_device_cap_flags2 { > + IB_DEVICE_OPA_MAD_SUPPORT =3D 1 > +}; > + > enum ib_signature_prot_cap { > IB_PROT_T10DIF_TYPE_1 =3D 1, > IB_PROT_T10DIF_TYPE_2 =3D 1 << 1, > @@ -210,6 +214,7 @@ struct ib_device_attr { > int sig_prot_cap; > int sig_guard_cap; > struct ib_odp_caps odp_caps; > + u64 device_cap_flags2; > u32 max_mad_size; > }; > =20 Why is OPA support determined via a device capability flag ? What are the tradeoffs for doing it this way versus the other choices that have been used in the past for other RDMA technologies like RoCE, iWARP, usNIC, =85 ? -- Hal -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html