From patchwork Thu Jan 11 12:00:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Gu X-Patchwork-Id: 13517321 X-Patchwork-Delegate: kuba@kernel.org Received: from out30-118.freemail.mail.aliyun.com (out30-118.freemail.mail.aliyun.com [115.124.30.118]) (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 B4FCC22093; Thu, 11 Jan 2024 12:01:39 +0000 (UTC) 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 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R421e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046059;MF=guwen@linux.alibaba.com;NM=1;PH=DS;RN=18;SR=0;TI=SMTPD_---0W-PfInN_1704974495; Received: from localhost(mailfrom:guwen@linux.alibaba.com fp:SMTPD_---0W-PfInN_1704974495) by smtp.aliyun-inc.com; Thu, 11 Jan 2024 20:01:36 +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, 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: [PATCH net-next 15/15] net/smc: implement DMB-merged operations of loopback-ism Date: Thu, 11 Jan 2024 20:00:36 +0800 Message-Id: <20240111120036.109903-16-guwen@linux.alibaba.com> X-Mailer: git-send-email 2.32.0.3.g01195cf9f In-Reply-To: <20240111120036.109903-1-guwen@linux.alibaba.com> References: <20240111120036.109903-1-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 This implements operations related to merging sndbuf with peer DMB in loopback-ism. The DMB won't be unregistered until no sndbuf is attached to it. Signed-off-by: Wen Gu --- net/smc/smc_loopback.c | 101 +++++++++++++++++++++++++++++++++++++++-- net/smc/smc_loopback.h | 4 ++ 2 files changed, 102 insertions(+), 3 deletions(-) diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c index bfbb346ef01a..296a4d1f1a33 100644 --- a/net/smc/smc_loopback.c +++ b/net/smc/smc_loopback.c @@ -298,6 +298,7 @@ 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 */ @@ -311,6 +312,7 @@ 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; @@ -333,8 +335,8 @@ 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; @@ -342,9 +344,18 @@ 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); @@ -353,6 +364,73 @@ 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_support_dmb_nocopy(struct smcd_dev *smcd) +{ + struct smc_lo_dev *ldev = smcd->priv; + + return (ldev->dmb_copy == SMC_LO_DMB_NOCOPY); +} + +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; } @@ -389,6 +467,14 @@ 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; + /* if sndbuf is merged with peer DMB, there is + * no need to copy data from sndbuf to peer DMB. + */ + if (!sf && smc_lo_support_dmb_nocopy(smcd)) { + SMC_LO_STAT_XFER_BYTES(ldev, size); + 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) { @@ -444,6 +530,9 @@ static const struct smcd_ops lo_ops = { .query_remote_gid = smc_lo_query_rgid, .register_dmb = smc_lo_register_dmb, .unregister_dmb = smc_lo_unregister_dmb, + .support_dmb_nocopy = smc_lo_support_dmb_nocopy, + .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, @@ -529,12 +618,18 @@ 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 7ecb4a35eb36..19a1eace2255 100644 --- a/net/smc/smc_loopback.h +++ b/net/smc/smc_loopback.h @@ -40,6 +40,7 @@ struct smc_lo_dmb_node { u32 sba_idx; void *cpu_addr; dma_addr_t dma_addr; + refcount_t refcnt; }; struct smc_lo_dev_stats64 { @@ -56,9 +57,12 @@ 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) \