From patchwork Tue Oct 25 10:17:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Garry X-Patchwork-Id: 619472 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 AA866C04A95 for ; Tue, 25 Oct 2022 09:48:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231585AbiJYJsQ (ORCPT ); Tue, 25 Oct 2022 05:48:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33026 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230360AbiJYJsI (ORCPT ); Tue, 25 Oct 2022 05:48:08 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 73DCE4E625; Tue, 25 Oct 2022 02:48:07 -0700 (PDT) Received: from fraeml704-chm.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4MxRqR2sY4z689TS; Tue, 25 Oct 2022 17:44:35 +0800 (CST) Received: from lhrpeml500003.china.huawei.com (7.191.162.67) by fraeml704-chm.china.huawei.com (10.206.15.53) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2375.31; Tue, 25 Oct 2022 11:48:05 +0200 Received: from localhost.localdomain (10.69.192.58) by lhrpeml500003.china.huawei.com (7.191.162.67) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 25 Oct 2022 10:48:01 +0100 From: John Garry To: , , , , , , , , , CC: , , , , , John Garry Subject: [PATCH RFC v3 03/22] scsi: core: Implement reserved command handling Date: Tue, 25 Oct 2022 18:17:57 +0800 Message-ID: <1666693096-180008-4-git-send-email-john.garry@huawei.com> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1666693096-180008-1-git-send-email-john.garry@huawei.com> References: <1666693096-180008-1-git-send-email-john.garry@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.69.192.58] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To lhrpeml500003.china.huawei.com (7.191.162.67) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Hannes Reinecke Quite some drivers are using management commands internally, which typically use the same hardware tag pool (ie they are being allocated from the same hardware resources) as the 'normal' I/O commands. These commands are set aside before allocating the block-mq tag bitmap, so they'll never show up as busy in the tag map. The block-layer, OTOH, already has 'reserved_tags' to handle precisely this situation. So this patch adds a new field 'nr_reserved_cmds' to the SCSI host template to instruct the block layer to set aside a tag space for these management commands by using reserved tags. Signed-off-by: Hannes Reinecke #jpg: Set tag_set->queue_depth = shost->can_queue, and not = shost->can_queue + shost->nr_reserved_cmds; Signed-off-by: John Garry --- drivers/scsi/hosts.c | 3 +++ drivers/scsi/scsi_lib.c | 2 ++ include/scsi/scsi_host.h | 15 ++++++++++++++- 3 files changed, 19 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 12346e2297fd..db89afc37bc9 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -489,6 +489,9 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) if (sht->virt_boundary_mask) shost->virt_boundary_mask = sht->virt_boundary_mask; + if (sht->nr_reserved_cmds) + shost->nr_reserved_cmds = sht->nr_reserved_cmds; + device_initialize(&shost->shost_gendev); dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); shost->shost_gendev.bus = &scsi_bus_type; diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 39d4fd124375..a8c4e7c037ae 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1978,6 +1978,8 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost) tag_set->nr_hw_queues = shost->nr_hw_queues ? : 1; tag_set->nr_maps = shost->nr_maps ? : 1; tag_set->queue_depth = shost->can_queue; + tag_set->reserved_tags = shost->nr_reserved_cmds; + tag_set->cmd_size = cmd_size; tag_set->numa_node = dev_to_node(shost->dma_dev); tag_set->flags = BLK_MQ_F_SHOULD_MERGE; diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 750ccf126377..91678c77398e 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -360,10 +360,17 @@ struct scsi_host_template { /* * This determines if we will use a non-interrupt driven * or an interrupt driven scheme. It is set to the maximum number - * of simultaneous commands a single hw queue in HBA will accept. + * of simultaneous commands a single hw queue in HBA will accept + * including reserved commands. */ int can_queue; + /* + * This determines how many commands the HBA will set aside + * for reserved commands. + */ + int nr_reserved_cmds; + /* * In many instances, especially where disconnect / reconnect are * supported, our host also has an ID on the SCSI bus. If this is @@ -611,6 +618,12 @@ struct Scsi_Host { */ unsigned nr_hw_queues; unsigned nr_maps; + + /* + * Number of reserved commands to allocate, if any. + */ + unsigned int nr_reserved_cmds; + unsigned active_mode:2; /*