From patchwork Wed Feb 15 16:18:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Gu X-Patchwork-Id: 13141903 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65683C64EC4 for ; Wed, 15 Feb 2023 16:19:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230071AbjBOQT0 (ORCPT ); Wed, 15 Feb 2023 11:19:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230100AbjBOQTL (ORCPT ); Wed, 15 Feb 2023 11:19:11 -0500 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 772E13B0DF; Wed, 15 Feb 2023 08:18:55 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R991e4;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=10;SR=0;TI=SMTPD_---0Vbl2fgZ_1676477929; Received: from localhost(mailfrom:guwen@linux.alibaba.com fp:SMTPD_---0Vbl2fgZ_1676477929) by smtp.aliyun-inc.com; Thu, 16 Feb 2023 00:18:51 +0800 From: Wen Gu To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@linux.ibm.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: linux-s390@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH net-next v3 9/9] net/smc: Add interface implementation of loopback device Date: Thu, 16 Feb 2023 00:18:25 +0800 Message-Id: <1676477905-88043-10-git-send-email-guwen@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1676477905-88043-1-git-send-email-guwen@linux.alibaba.com> References: <1676477905-88043-1-git-send-email-guwen@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC This patch completes the specific implementation of loopback device for the newly added SMC-D DMB-related interface. The loopback device always provides mappable DMB because the device users are in the same OS instance. Signed-off-by: Wen Gu --- net/smc/smc_loopback.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++---- net/smc/smc_loopback.h | 4 +++ 2 files changed, 90 insertions(+), 7 deletions(-) diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c index 38bacd8..2fa2a73 100644 --- a/net/smc/smc_loopback.c +++ b/net/smc/smc_loopback.c @@ -77,6 +77,7 @@ static int smc_lo_register_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb, goto err_node; } dmb_node->len = dmb->dmb_len; + refcount_set(&dmb_node->refcnt, 1); /* TODO: token is random but not exclusive ! * suppose to find token in dmb hask table, if has this token @@ -87,6 +88,7 @@ static int smc_lo_register_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb, write_lock(&ldev->dmb_ht_lock); hash_add(ldev->dmb_ht, &dmb_node->list, dmb_node->token); write_unlock(&ldev->dmb_ht_lock); + atomic_inc(&ldev->dmb_cnt); dmb->sba_idx = dmb_node->sba_idx; dmb->dmb_tok = dmb_node->token; @@ -124,12 +126,76 @@ static int smc_lo_unregister_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb) write_unlock(&ldev->dmb_ht_lock); clear_bit(dmb_node->sba_idx, ldev->sba_idx_mask); + + /* wait for dmb refcnt to be 0 */ + if (!refcount_dec_and_test(&dmb_node->refcnt)) + wait_event(ldev->dmbs_release, !refcount_read(&dmb_node->refcnt)); kfree(dmb_node->cpu_addr); kfree(dmb_node); + if (atomic_dec_and_test(&ldev->dmb_cnt)) + wake_up(&ldev->ldev_release); + return 0; +} + +static int smc_lo_attach_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb) +{ + struct smc_lo_dmb_node *dmb_node = NULL, *tmp_node; + struct smc_lo_dev *ldev = smcd->priv; + + /* find dmb_node according to dmb->dmb_tok */ + read_lock(&ldev->dmb_ht_lock); + hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb->dmb_tok) { + if (tmp_node->token == dmb->dmb_tok) { + dmb_node = tmp_node; + break; + } + } + if (!dmb_node) { + read_unlock(&ldev->dmb_ht_lock); + return -EINVAL; + } + read_unlock(&ldev->dmb_ht_lock); + refcount_inc(&dmb_node->refcnt); + + /* provide dmb information */ + dmb->sba_idx = dmb_node->sba_idx; + dmb->dmb_tok = dmb_node->token; + dmb->cpu_addr = dmb_node->cpu_addr; + dmb->dma_addr = dmb_node->dma_addr; + dmb->dmb_len = dmb_node->len; + return 0; +} + +static int smc_lo_detach_dmb(struct smcd_dev *smcd, u64 token) +{ + struct smc_lo_dmb_node *dmb_node = NULL, *tmp_node; + struct smc_lo_dev *ldev = smcd->priv; + + /* find dmb_node according to dmb->dmb_tok */ + read_lock(&ldev->dmb_ht_lock); + hash_for_each_possible(ldev->dmb_ht, tmp_node, list, token) { + if (tmp_node->token == token) { + dmb_node = tmp_node; + break; + } + } + if (!dmb_node) { + read_unlock(&ldev->dmb_ht_lock); + return -EINVAL; + } + read_unlock(&ldev->dmb_ht_lock); + + if (refcount_dec_and_test(&dmb_node->refcnt)) + wake_up_all(&ldev->dmbs_release); return 0; } +static int smc_lo_get_dev_dmb_attr(struct smcd_dev *smcd) +{ + return (1 << ISM_DMB_MAPPABLE); +} + static int smc_lo_add_vlan_id(struct smcd_dev *smcd, u64 vlan_id) { return -EOPNOTSUPP; @@ -156,7 +222,15 @@ static int smc_lo_move_data(struct smcd_dev *smcd, u64 dmb_tok, unsigned int idx { struct smc_lo_dmb_node *rmb_node = NULL, *tmp_node; struct smc_lo_dev *ldev = smcd->priv; - + struct smc_connection *conn; + + if (!sf) { + /* local sndbuf shares the same physical memory with + * peer RMB, so no need to copy data from local sndbuf + * to peer RMB. + */ + return 0; + } read_lock(&ldev->dmb_ht_lock); hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb_tok) { if (tmp_node->token == dmb_tok) { @@ -172,13 +246,10 @@ static int smc_lo_move_data(struct smcd_dev *smcd, u64 dmb_tok, unsigned int idx memcpy((char *)rmb_node->cpu_addr + offset, data, size); - if (sf) { - struct smc_connection *conn = - smcd->conn[rmb_node->sba_idx]; + conn = smcd->conn[rmb_node->sba_idx]; + if (conn && !conn->killed) + smcd_cdc_rx_handler(conn); - if (conn && !conn->killed) - smcd_cdc_rx_handler(conn); - } return 0; } @@ -206,6 +277,8 @@ static struct device *smc_lo_get_dev(struct smcd_dev *smcd) .query_remote_gid = smc_lo_query_rgid, .register_dmb = smc_lo_register_dmb, .unregister_dmb = smc_lo_unregister_dmb, + .attach_dmb = smc_lo_attach_dmb, + .detach_dmb = smc_lo_detach_dmb, .add_vlan_id = smc_lo_add_vlan_id, .del_vlan_id = smc_lo_del_vlan_id, .set_vlan_required = smc_lo_set_vlan_required, @@ -216,6 +289,7 @@ static struct device *smc_lo_get_dev(struct smcd_dev *smcd) .get_local_gid = smc_lo_get_local_gid, .get_chid = smc_lo_get_chid, .get_dev = smc_lo_get_dev, + .get_dev_dmb_attr = smc_lo_get_dev_dmb_attr, }; static struct smcd_dev *smcd_lo_alloc_dev(const struct smcd_ops *ops, @@ -296,6 +370,9 @@ static int smc_lo_dev_init(struct smc_lo_dev *ldev) smc_lo_gen_id(ldev); rwlock_init(&ldev->dmb_ht_lock); hash_init(ldev->dmb_ht); + atomic_set(&ldev->dmb_cnt, 0); + init_waitqueue_head(&ldev->dmbs_release); + init_waitqueue_head(&ldev->ldev_release); return smcd_lo_register_dev(ldev); } @@ -334,6 +411,8 @@ static int smc_lo_dev_probe(void) static void smc_lo_dev_exit(struct smc_lo_dev *ldev) { smcd_lo_unregister_dev(ldev); + if (atomic_read(&ldev->dmb_cnt)) + wait_event(ldev->ldev_release, !atomic_read(&ldev->dmb_cnt)); } static void smc_lo_dev_remove(void) diff --git a/net/smc/smc_loopback.h b/net/smc/smc_loopback.h index 9d34aba..0a09330 100644 --- a/net/smc/smc_loopback.h +++ b/net/smc/smc_loopback.h @@ -33,6 +33,7 @@ struct smc_lo_dmb_node { u32 sba_idx; void *cpu_addr; dma_addr_t dma_addr; + refcount_t refcnt; }; struct smc_lo_dev { @@ -43,6 +44,9 @@ struct smc_lo_dev { DECLARE_BITMAP(sba_idx_mask, SMC_LODEV_MAX_DMBS); rwlock_t dmb_ht_lock; DECLARE_HASHTABLE(dmb_ht, SMC_LODEV_MAX_DMBS_BUCKETS); + atomic_t dmb_cnt; + wait_queue_head_t dmbs_release; + wait_queue_head_t ldev_release; }; int smc_loopback_init(void);