From patchwork Sun Dec 10 13:24:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Gu X-Patchwork-Id: 13486418 X-Patchwork-Delegate: kuba@kernel.org Received: from out30-131.freemail.mail.aliyun.com (out30-131.freemail.mail.aliyun.com [115.124.30.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6F591BEF; Sun, 10 Dec 2023 05:24:48 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R371e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045176;MF=guwen@linux.alibaba.com;NM=1;PH=DS;RN=19;SR=0;TI=SMTPD_---0Vy8DodD_1702214684; Received: from localhost(mailfrom:guwen@linux.alibaba.com fp:SMTPD_---0Vy8DodD_1702214684) by smtp.aliyun-inc.com; Sun, 10 Dec 2023 21:24:46 +0800 From: Wen Gu To: wintera@linux.ibm.com, wenjia@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, kgraul@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-s390@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH net-next 13/13] net/smc: implement {at|de}tach_dmb interfaces of loopback-ism Date: Sun, 10 Dec 2023 21:24:14 +0800 Message-Id: <1702214654-32069-14-git-send-email-guwen@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1702214654-32069-1-git-send-email-guwen@linux.alibaba.com> References: <1702214654-32069-1-git-send-email-guwen@linux.alibaba.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC This implements attach_dmb and detach_dmb interfaces of loopback-ism. The DMB won't be unregistered by loopback-ism until no sndbuf is attached to it. Signed-off-by: Wen Gu --- net/smc/smc_loopback.c | 107 +++++++++++++++++++++++++++++++++++++++++++------ net/smc/smc_loopback.h | 4 ++ 2 files changed, 99 insertions(+), 12 deletions(-) diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c index 057ea6a..909c069 100644 --- a/net/smc/smc_loopback.c +++ b/net/smc/smc_loopback.c @@ -198,6 +198,7 @@ static int smc_lo_register_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb, } dmb_node->len = dmb->dmb_len; dmb_node->dma_addr = SMC_DMA_ADDR_INVALID; + refcount_set(&dmb_node->refcnt, 1); again: /* add new dmb into hash table */ @@ -211,6 +212,7 @@ static int smc_lo_register_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb, } hash_add(ldev->dmb_ht, &dmb_node->list, dmb_node->token); write_unlock(&ldev->dmb_ht_lock); + atomic_inc(&ldev->dmb_cnt); SMC_LO_STAT_DMBS_INC(ldev); dmb->sba_idx = dmb_node->sba_idx; @@ -233,8 +235,8 @@ static int smc_lo_unregister_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; - /* remove dmb from hash table */ - write_lock(&ldev->dmb_ht_lock); + /* find dmb from hash table */ + 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; @@ -242,9 +244,18 @@ static int smc_lo_unregister_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb) } } if (!dmb_node) { - write_unlock(&ldev->dmb_ht_lock); + read_unlock(&ldev->dmb_ht_lock); return -EINVAL; } + read_unlock(&ldev->dmb_ht_lock); + + /* wait for peer sndbuf to detach from this dmb */ + if (!refcount_dec_and_test(&dmb_node->refcnt)) + wait_event(ldev->dmbs_release, + !refcount_read(&dmb_node->refcnt)); + + /* remove dmb from hash table */ + write_lock(&ldev->dmb_ht_lock); hash_del(&dmb_node->list); write_unlock(&ldev->dmb_ht_lock); @@ -253,6 +264,66 @@ static int smc_lo_unregister_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb) kfree(dmb_node); SMC_LO_STAT_DMBS_DEC(ldev); + 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); + + if (!refcount_inc_not_zero(&dmb_node->refcnt)) + /* the dmb is being unregistered, but has + * not been removed from the hash table. + */ + return -EINVAL; + + /* 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; } @@ -288,7 +359,15 @@ static int smc_lo_move_data(struct smcd_dev *smcd, u64 dmb_tok, { struct smc_lo_dmb_node *rmb_node = NULL, *tmp_node; struct smc_lo_dev *ldev = smcd->priv; - + struct smc_connection *conn; + + if (!sf) { + /* Since ghost sndbuf shares the same memory region + * with peer DMB, there is no need to 'transfer' data + * from sndbuf to peer DMB. + */ + 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) { @@ -305,14 +384,10 @@ static int smc_lo_move_data(struct smcd_dev *smcd, u64 dmb_tok, memcpy((char *)rmb_node->cpu_addr + offset, data, size); SMC_LO_STAT_TX_BYTES(ldev, size); - if (sf) { - struct smc_connection *conn = - smcd->conn[rmb_node->sba_idx]; - - if (conn && !conn->killed) { - SMC_LO_STAT_RX_BYTES(ldev, size); - smcd_cdc_rx_handler(conn); - } + conn = smcd->conn[rmb_node->sba_idx]; + if (conn && !conn->killed) { + SMC_LO_STAT_RX_BYTES(ldev, size); + smcd_cdc_rx_handler(conn); } return 0; } @@ -345,6 +420,8 @@ 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, @@ -426,12 +503,18 @@ static int smc_lo_dev_init(struct smc_lo_dev *ldev) smc_lo_generate_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); } 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_release(struct device *dev) diff --git a/net/smc/smc_loopback.h b/net/smc/smc_loopback.h index ad0feaa..df6c252 100644 --- a/net/smc/smc_loopback.h +++ b/net/smc/smc_loopback.h @@ -30,6 +30,7 @@ struct smc_lo_dmb_node { u32 sba_idx; void *cpu_addr; dma_addr_t dma_addr; + refcount_t refcnt; }; struct smc_lo_dev_stats64 { @@ -45,9 +46,12 @@ struct smc_lo_dev { u16 chid; struct smcd_gid local_gid; struct smc_lo_dev_stats64 __percpu *stats; + atomic_t dmb_cnt; rwlock_t dmb_ht_lock; DECLARE_BITMAP(sba_idx_mask, SMC_LO_MAX_DMBS); DECLARE_HASHTABLE(dmb_ht, SMC_LO_DMBS_HASH_BITS); + wait_queue_head_t dmbs_release; + wait_queue_head_t ldev_release; }; #define SMC_LO_STAT_SUB(ldev, key, val) \