From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755626AbdLGRAY (ORCPT ); Thu, 7 Dec 2017 12:00:24 -0500 Received: from fldsmtpe03.verizon.com ([140.108.26.142]:49829 "EHLO fldsmtpe03.verizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756374AbdLGPwf (ORCPT ); Thu, 7 Dec 2017 10:52:35 -0500 From: alexander.levin@verizon.com Cc: Parav Pandit , Leon Romanovsky , "Doug Ledford" , alexander.levin@verizon.com X-Host: surveyor.tdc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH AUTOSEL for 4.9 143/156] IB/core: Fix calculation of maximum RoCE MTU Thread-Topic: [PATCH AUTOSEL for 4.9 143/156] IB/core: Fix calculation of maximum RoCE MTU Thread-Index: AQHTb3L58Wyml/sPk0iHU92T7+lVow== Date: Thu, 7 Dec 2017 15:49:31 +0000 Message-ID: <20171207154845.4814-143-alexander.levin@verizon.com> References: <20171207154845.4814-1-alexander.levin@verizon.com> In-Reply-To: <20171207154845.4814-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id vB7H0SPN020809 From: Parav Pandit [ Upstream commit 99260132fde7bddc6e0132ce53da94d1c9ccabcb ] The original code only took into consideration the largest header possible after the IB_BTH_BYTES. This was incorrect, as the largest possible header size is the largest possible combination of headers we might run into. The new code accounts for all possible headers in the largest possible combination and subtracts that from the MTU to make sure that all packets will fit on the wire. Link: https://www.spinics.net/lists/linux-rdma/msg54558.html Fixes: 3c86aa70bf67 ("RDMA/cm: Add RDMA CM support for IBoE devices") Signed-off-by: Parav Pandit Reviewed-by: Daniel Jurgens Reported-by: Roland Dreier Signed-off-by: Leon Romanovsky Signed-off-by: Doug Ledford Signed-off-by: Sasha Levin --- include/rdma/ib_addr.h | 7 ++++--- include/rdma/ib_pack.h | 19 +++++++++++-------- 2 files changed, 15 insertions(+), 11 deletions(-) diff --git a/include/rdma/ib_addr.h b/include/rdma/ib_addr.h index 1beab5532035..818a38f99221 100644 --- a/include/rdma/ib_addr.h +++ b/include/rdma/ib_addr.h @@ -243,10 +243,11 @@ static inline void rdma_addr_set_dgid(struct rdma_dev_addr *dev_addr, union ib_g static inline enum ib_mtu iboe_get_mtu(int mtu) { /* - * reduce IB headers from effective IBoE MTU. 28 stands for - * atomic header which is the biggest possible header after BTH + * Reduce IB headers from effective IBoE MTU. */ - mtu = mtu - IB_GRH_BYTES - IB_BTH_BYTES - 28; + mtu = mtu - (IB_GRH_BYTES + IB_UDP_BYTES + IB_BTH_BYTES + + IB_EXT_XRC_BYTES + IB_EXT_ATOMICETH_BYTES + + IB_ICRC_BYTES); if (mtu >= ib_mtu_enum_to_int(IB_MTU_4096)) return IB_MTU_4096; diff --git a/include/rdma/ib_pack.h b/include/rdma/ib_pack.h index b13419ce99ff..e02b78a38eba 100644 --- a/include/rdma/ib_pack.h +++ b/include/rdma/ib_pack.h @@ -37,14 +37,17 @@ #include enum { - IB_LRH_BYTES = 8, - IB_ETH_BYTES = 14, - IB_VLAN_BYTES = 4, - IB_GRH_BYTES = 40, - IB_IP4_BYTES = 20, - IB_UDP_BYTES = 8, - IB_BTH_BYTES = 12, - IB_DETH_BYTES = 8 + IB_LRH_BYTES = 8, + IB_ETH_BYTES = 14, + IB_VLAN_BYTES = 4, + IB_GRH_BYTES = 40, + IB_IP4_BYTES = 20, + IB_UDP_BYTES = 8, + IB_BTH_BYTES = 12, + IB_DETH_BYTES = 8, + IB_EXT_ATOMICETH_BYTES = 28, + IB_EXT_XRC_BYTES = 4, + IB_ICRC_BYTES = 4 }; struct ib_field { -- 2.11.0