From patchwork Sun Mar 17 10:05:42 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Gu X-Patchwork-Id: 13594533 X-Patchwork-Delegate: kuba@kernel.org Received: from out30-113.freemail.mail.aliyun.com (out30-113.freemail.mail.aliyun.com [115.124.30.113]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1D3D31CD15; Sun, 17 Mar 2024 10:06:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.113 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710669969; cv=none; b=tjFntxyG+Mr/m+zhLottZ/Vw7GjMJMMPk8l76Nol7hUcjuwchjtEVUbLAgnMEHBFvHez+1nb8OjI/drzJOCpIE245LnUMwc+lpih6YzQgT8GkIuwFEEXVFvrg5tWPYkTRZOsGQAt1CjdZSkXKwB2A2wRlUq/wTtxGKLO8BRKurk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710669969; c=relaxed/simple; bh=PUGkVStuetsMke/VaEeAh7P6q9BaVMTgmXwXUKLgTNk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=r22r3aTlSwZ1M606QD6/7LiWfp0/3gfDHPJeHIz3/8p1q4ZoDAcrVrSU/GnJqqB/peYHLK3KWiLH9akgkfMABcnlhLssnKJfrxuYtWlQK5p/rtlw+x5Jzn3w02KkmD0gPvjqff6OODxdQUh8r1siM6Ah6AfxVsEv81R2tYEvosA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=X+qLtpTA; arc=none smtp.client-ip=115.124.30.113 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="X+qLtpTA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1710669965; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=cXxkfew4pLmEZxVFDkURa/WPZ9twZw4K1banM7Wm1Jc=; b=X+qLtpTAWw4K4ciXX7RNQnrqG4dp3dveD6JIFamUJ/ic1ogoV3EEr0hcT3/RG3MYMCh/fNJ+Ego5efUGO1h+DFUv0QgQtR0v8DwESOG2MSGbyfNgMqczZgIIwdc+bJiDHERa21V5Fp4BLBefmWDL3X6ueN5vPlxi6jEdtKENYSI= X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R581e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046056;MF=guwen@linux.alibaba.com;NM=1;PH=DS;RN=19;SR=0;TI=SMTPD_---0W2c7m5w_1710669963; Received: from localhost(mailfrom:guwen@linux.alibaba.com fp:SMTPD_---0W2c7m5w_1710669963) by smtp.aliyun-inc.com; Sun, 17 Mar 2024 18:06:04 +0800 From: Wen Gu To: wintera@linux.ibm.com, twinkler@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, wenjia@linux.ibm.com, jaka@linux.ibm.com Cc: borntraeger@linux.ibm.com, svens@linux.ibm.com, alibuda@linux.alibaba.com, tonylu@linux.alibaba.com, guwen@linux.alibaba.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org Subject: [RFC PATCH net-next v4 08/11] net/smc: add operations to merge sndbuf with peer DMB Date: Sun, 17 Mar 2024 18:05:42 +0800 Message-Id: <20240317100545.96663-9-guwen@linux.alibaba.com> X-Mailer: git-send-email 2.32.0.3.g01195cf9f In-Reply-To: <20240317100545.96663-1-guwen@linux.alibaba.com> References: <20240317100545.96663-1-guwen@linux.alibaba.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC In some scenarios using Emulated-ISM device, sndbuf can share the same physical memory region with peer DMB to avoid data copy from one side to the other. In such case the sndbuf is only a descriptor that describes the shared memory and does not actually occupy memory, it's more like a ghost buffer. +----------+ +----------+ | socket A | | socket B | +----------+ +----------+ | | +--------+ +--------+ | sndbuf | | DMB | | desc | | desc | +--------+ +--------+ | | | +----v-----+ +--------------------------> memory | +----------+ So here introduces three new SMC-D device operations to check if this feature is supported by device, and to {attach|detach} ghost sndbuf to peer DMB. For now only loopback-ism supports this. Signed-off-by: Wen Gu --- include/net/smc.h | 3 +++ net/smc/smc_ism.c | 40 ++++++++++++++++++++++++++++++++++++++++ net/smc/smc_ism.h | 4 ++++ 3 files changed, 47 insertions(+) diff --git a/include/net/smc.h b/include/net/smc.h index 6273c3a8b24a..01387631d8a6 100644 --- a/include/net/smc.h +++ b/include/net/smc.h @@ -62,6 +62,9 @@ struct smcd_ops { int (*register_dmb)(struct smcd_dev *dev, struct smcd_dmb *dmb, void *client); int (*unregister_dmb)(struct smcd_dev *dev, struct smcd_dmb *dmb); + int (*support_dmb_nocopy)(struct smcd_dev *dev); + int (*attach_dmb)(struct smcd_dev *dev, struct smcd_dmb *dmb); + int (*detach_dmb)(struct smcd_dev *dev, u64 token); int (*add_vlan_id)(struct smcd_dev *dev, u64 vlan_id); int (*del_vlan_id)(struct smcd_dev *dev, u64 vlan_id); int (*set_vlan_required)(struct smcd_dev *dev); diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c index 38469ff53346..182748927681 100644 --- a/net/smc/smc_ism.c +++ b/net/smc/smc_ism.c @@ -246,6 +246,46 @@ int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len, return rc; } +bool smc_ism_support_dmb_nocopy(struct smcd_dev *smcd) +{ + /* for now only loopback-ism supports + * merging sndbuf with peer DMB to avoid + * data copies between them. + */ + return (smcd->ops->support_dmb_nocopy && + smcd->ops->support_dmb_nocopy(smcd)); +} + +int smc_ism_attach_dmb(struct smcd_dev *dev, u64 token, + struct smc_buf_desc *dmb_desc) +{ + struct smcd_dmb dmb; + int rc = 0; + + if (!dev->ops->attach_dmb) + return -EINVAL; + + memset(&dmb, 0, sizeof(dmb)); + dmb.dmb_tok = token; + rc = dev->ops->attach_dmb(dev, &dmb); + if (!rc) { + dmb_desc->sba_idx = dmb.sba_idx; + dmb_desc->token = dmb.dmb_tok; + dmb_desc->cpu_addr = dmb.cpu_addr; + dmb_desc->dma_addr = dmb.dma_addr; + dmb_desc->len = dmb.dmb_len; + } + return rc; +} + +int smc_ism_detach_dmb(struct smcd_dev *dev, u64 token) +{ + if (!dev->ops->detach_dmb) + return -EINVAL; + + return dev->ops->detach_dmb(dev, token); +} + static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd, struct sk_buff *skb, struct netlink_callback *cb) diff --git a/net/smc/smc_ism.h b/net/smc/smc_ism.h index e6f57e5e1ef9..6763133dd8d0 100644 --- a/net/smc/smc_ism.h +++ b/net/smc/smc_ism.h @@ -48,6 +48,10 @@ int smc_ism_put_vlan(struct smcd_dev *dev, unsigned short vlan_id); int smc_ism_register_dmb(struct smc_link_group *lgr, int buf_size, struct smc_buf_desc *dmb_desc); int smc_ism_unregister_dmb(struct smcd_dev *dev, struct smc_buf_desc *dmb_desc); +bool smc_ism_support_dmb_nocopy(struct smcd_dev *smcd); +int smc_ism_attach_dmb(struct smcd_dev *dev, u64 token, + struct smc_buf_desc *dmb_desc); +int smc_ism_detach_dmb(struct smcd_dev *dev, u64 token); int smc_ism_signal_shutdown(struct smc_link_group *lgr); void smc_ism_get_system_eid(u8 **eid); u16 smc_ism_get_chid(struct smcd_dev *dev);