From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48045C433F5 for ; Thu, 30 Sep 2021 16:51:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 301B961247 for ; Thu, 30 Sep 2021 16:51:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352460AbhI3QxW (ORCPT ); Thu, 30 Sep 2021 12:53:22 -0400 Received: from ale.deltatee.com ([204.191.154.188]:44024 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352384AbhI3QxT (ORCPT ); Thu, 30 Sep 2021 12:53:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:In-Reply-To:MIME-Version:Date: Message-ID:From:References:Cc:To:content-disposition; bh=DY98l6f/p37o1n6z2SAmaZFkiMoprnW0+Juc+mDOhCo=; b=pTfd2cTcyBzH2LpKD5iE+L5qG5 1YxVv6haFuR4tVxbCWzg77WlnQgwPvUMZwmaeKZ/dooUcIP5nxEHrl6iUZij4mssaKTc1px7tpQdx UMyTxmWTfEjMtRe2GIkYjVgqlDS1F3IkTZYJ19rOxetGBvpeebtdTkcvo2LLMm8BaIdwZQW6M+yDA xwkZTQaVYuM6i+YEvgQv3b/vT6jMo3j0z9ni8dqNTUIbj+9inuXDYYSM/W4MlssDZdeD33aXoOrpZ tIrW+L7X4llhAn1S/KznAKSdwTbT4O7Y3kK3KgNwTuziND3TP1yUKnxXkkTO5ob60fRu9UHxzZrhf 5AMobH0g==; Received: from s0106a84e3fe8c3f3.cg.shawcable.net ([24.64.144.200] helo=[192.168.0.10]) by ale.deltatee.com with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1mVzHI-0004dm-2w; Thu, 30 Sep 2021 10:51:25 -0600 To: Chaitanya Kulkarni , "linux-kernel@vger.kernel.org" , "linux-nvme@lists.infradead.org" , "linux-block@vger.kernel.org" , "linux-pci@vger.kernel.org" , "linux-mm@kvack.org" , "iommu@lists.linux-foundation.org" Cc: Stephen Bates , Christoph Hellwig , Dan Williams , Jason Gunthorpe , =?UTF-8?Q?Christian_K=c3=b6nig?= , John Hubbard , Don Dutile , Matthew Wilcox , Daniel Vetter , Jakowski Andrzej , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy , Martin Oliveira , Chaitanya Kulkarni References: <20210916234100.122368-1-logang@deltatee.com> <20210916234100.122368-10-logang@deltatee.com> From: Logan Gunthorpe Message-ID: Date: Thu, 30 Sep 2021 10:51:22 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-CA Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 24.64.144.200 X-SA-Exim-Rcpt-To: ckulkarnilinux@gmail.com, martin.oliveira@eideticom.com, robin.murphy@arm.com, ira.weiny@intel.com, helgaas@kernel.org, jianxin.xiong@intel.com, dave.hansen@linux.intel.com, jason@jlekstrand.net, dave.b.minturn@intel.com, andrzej.jakowski@intel.com, daniel.vetter@ffwll.ch, willy@infradead.org, ddutile@redhat.com, jhubbard@nvidia.com, christian.koenig@amd.com, jgg@ziepe.ca, dan.j.williams@intel.com, hch@lst.de, sbates@raithlin.com, iommu@lists.linux-foundation.org, linux-mm@kvack.org, linux-pci@vger.kernel.org, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, chaitanyak@nvidia.com X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [PATCH v3 09/20] nvme-pci: check DMA ops when indicating support for PCI P2PDMA X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-09-29 11:06 p.m., Chaitanya Kulkarni wrote: > Logan, > >> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c >> index 7efb31b87f37..916750a54f60 100644 >> --- a/drivers/nvme/host/core.c >> +++ b/drivers/nvme/host/core.c >> @@ -3771,7 +3771,8 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid, >> blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, ns->queue); >> >> blk_queue_flag_set(QUEUE_FLAG_NONROT, ns->queue); >> - if (ctrl->ops->flags & NVME_F_PCI_P2PDMA) >> + if (ctrl->ops->supports_pci_p2pdma && >> + ctrl->ops->supports_pci_p2pdma(ctrl)) >> blk_queue_flag_set(QUEUE_FLAG_PCI_P2PDMA, ns->queue); >> >> ns->ctrl = ctrl; >> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h >> index 9871c0c9374c..fb9bfc52a6d7 100644 >> --- a/drivers/nvme/host/nvme.h >> +++ b/drivers/nvme/host/nvme.h >> @@ -477,7 +477,6 @@ struct nvme_ctrl_ops { >> unsigned int flags; >> #define NVME_F_FABRICS (1 << 0) >> #define NVME_F_METADATA_SUPPORTED (1 << 1) >> -#define NVME_F_PCI_P2PDMA (1 << 2) >> int (*reg_read32)(struct nvme_ctrl *ctrl, u32 off, u32 *val); >> int (*reg_write32)(struct nvme_ctrl *ctrl, u32 off, u32 val); >> int (*reg_read64)(struct nvme_ctrl *ctrl, u32 off, u64 *val); >> @@ -485,6 +484,7 @@ struct nvme_ctrl_ops { >> void (*submit_async_event)(struct nvme_ctrl *ctrl); >> void (*delete_ctrl)(struct nvme_ctrl *ctrl); >> int (*get_address)(struct nvme_ctrl *ctrl, char *buf, int size); >> + bool (*supports_pci_p2pdma)(struct nvme_ctrl *ctrl); >> }; >> > > Is this new ops only needed for the PCIe transport ? or do you have > following patches to use this op for the other transports ? No, I don't think this will make sense for transports that are not based on PCI devices. > If it is only needed for the PCIe then we need to find a way to > not add this somehow... I don't see how we can do that. The core code needs to know whether the transport supports this and must have an operation to query it. Logan