From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ale.deltatee.com (ale.deltatee.com [207.54.116.67]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 489A121BC6A24 for ; Fri, 31 Mar 2017 08:42:01 -0700 (PDT) References: <1490911959-5146-1-git-send-email-logang@deltatee.com> <1490911959-5146-6-git-send-email-logang@deltatee.com> <20170331070950.GA9059@infradead.org> From: Logan Gunthorpe Message-ID: <435d4471-436b-87e6-8827-c9fc6cbdde2c@deltatee.com> Date: Fri, 31 Mar 2017 09:41:56 -0600 MIME-Version: 1.0 In-Reply-To: <20170331070950.GA9059@infradead.org> Subject: Re: [RFC 5/8] scatterlist: Modify SG copy functions to support io memory. List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Christoph Hellwig Cc: Jens Axboe , Jason Gunthorpe , "James E.J. Bottomley" , "Martin K. Petersen" , linux-nvdimm@lists.01.org, linux-rdma@vger.kernel.org, linux-pci@vger.kernel.org, Steve Wise , linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, Keith Busch , linux-scsi@vger.kernel.org, Max Gurtovoy , Christoph Hellwig List-ID: On 31/03/17 01:09 AM, Christoph Hellwig wrote: > You're calling memcpy_{to,from}_iomem on non-__iomem pointers. This > is a fundamental no-go as we keep I/O memory separate from kernel > pointers. Yes, that's true, however I don't know how we could get around that when the iomem is referenced by struct pages inside a scatter gather list. Do we need to now have special __iomem sgls? And even still, I'm not sure how that could work when the nvme target code is using the same sgls to sometimes point to iomem and sometimes point to regular memory. I'm certainly open to suggestions, though. Logan _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm From mboxrd@z Thu Jan 1 00:00:00 1970 From: Logan Gunthorpe Subject: Re: [RFC 5/8] scatterlist: Modify SG copy functions to support io memory. Date: Fri, 31 Mar 2017 09:41:56 -0600 Message-ID: <435d4471-436b-87e6-8827-c9fc6cbdde2c@deltatee.com> References: <1490911959-5146-1-git-send-email-logang@deltatee.com> <1490911959-5146-6-git-send-email-logang@deltatee.com> <20170331070950.GA9059@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170331070950.GA9059-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Christoph Hellwig Cc: Christoph Hellwig , Sagi Grimberg , "James E.J. Bottomley" , "Martin K. Petersen" , Jens Axboe , Steve Wise , Stephen Bates , Max Gurtovoy , Dan Williams , Keith Busch , Jason Gunthorpe , linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org On 31/03/17 01:09 AM, Christoph Hellwig wrote: > You're calling memcpy_{to,from}_iomem on non-__iomem pointers. This > is a fundamental no-go as we keep I/O memory separate from kernel > pointers. Yes, that's true, however I don't know how we could get around that when the iomem is referenced by struct pages inside a scatter gather list. Do we need to now have special __iomem sgls? And even still, I'm not sure how that could work when the nvme target code is using the same sgls to sometimes point to iomem and sometimes point to regular memory. I'm certainly open to suggestions, though. Logan -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933447AbdCaPmG (ORCPT ); Fri, 31 Mar 2017 11:42:06 -0400 Received: from ale.deltatee.com ([207.54.116.67]:46602 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933114AbdCaPmD (ORCPT ); Fri, 31 Mar 2017 11:42:03 -0400 To: Christoph Hellwig References: <1490911959-5146-1-git-send-email-logang@deltatee.com> <1490911959-5146-6-git-send-email-logang@deltatee.com> <20170331070950.GA9059@infradead.org> Cc: Christoph Hellwig , Sagi Grimberg , "James E.J. Bottomley" , "Martin K. Petersen" , Jens Axboe , Steve Wise , Stephen Bates , Max Gurtovoy , Dan Williams , Keith Busch , Jason Gunthorpe , linux-pci@vger.kernel.org, linux-scsi@vger.kernel.org, linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org, linux-nvdimm@ml01.01.org, linux-kernel@vger.kernel.org From: Logan Gunthorpe Message-ID: <435d4471-436b-87e6-8827-c9fc6cbdde2c@deltatee.com> Date: Fri, 31 Mar 2017 09:41:56 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.6.0 MIME-Version: 1.0 In-Reply-To: <20170331070950.GA9059@infradead.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 172.16.1.111 X-SA-Exim-Rcpt-To: linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-rdma@vger.kernel.org, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, linux-pci@vger.kernel.org, jgunthorpe@obsidianresearch.com, keith.busch@intel.com, dan.j.williams@intel.com, maxg@mellanox.com, sbates@raithlin.com, swise@opengridcomputing.com, axboe@kernel.dk, martin.petersen@oracle.com, jejb@linux.vnet.ibm.com, sagi@grimberg.me, hch@lst.de, hch@infradead.org X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [RFC 5/8] scatterlist: Modify SG copy functions to support io memory. X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 31/03/17 01:09 AM, Christoph Hellwig wrote: > You're calling memcpy_{to,from}_iomem on non-__iomem pointers. This > is a fundamental no-go as we keep I/O memory separate from kernel > pointers. Yes, that's true, however I don't know how we could get around that when the iomem is referenced by struct pages inside a scatter gather list. Do we need to now have special __iomem sgls? And even still, I'm not sure how that could work when the nvme target code is using the same sgls to sometimes point to iomem and sometimes point to regular memory. I'm certainly open to suggestions, though. Logan From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ale.deltatee.com ([207.54.116.67]:46602 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933114AbdCaPmD (ORCPT ); Fri, 31 Mar 2017 11:42:03 -0400 To: Christoph Hellwig References: <1490911959-5146-1-git-send-email-logang@deltatee.com> <1490911959-5146-6-git-send-email-logang@deltatee.com> <20170331070950.GA9059@infradead.org> Cc: Christoph Hellwig , Sagi Grimberg , "James E.J. Bottomley" , "Martin K. Petersen" , Jens Axboe , Steve Wise , Stephen Bates , Max Gurtovoy , Dan Williams , Keith Busch , Jason Gunthorpe , linux-pci@vger.kernel.org, linux-scsi@vger.kernel.org, linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org From: Logan Gunthorpe Message-ID: <435d4471-436b-87e6-8827-c9fc6cbdde2c@deltatee.com> Date: Fri, 31 Mar 2017 09:41:56 -0600 MIME-Version: 1.0 In-Reply-To: <20170331070950.GA9059@infradead.org> Content-Type: text/plain; charset=windows-1252 Subject: Re: [RFC 5/8] scatterlist: Modify SG copy functions to support io memory. Sender: linux-pci-owner@vger.kernel.org List-ID: On 31/03/17 01:09 AM, Christoph Hellwig wrote: > You're calling memcpy_{to,from}_iomem on non-__iomem pointers. This > is a fundamental no-go as we keep I/O memory separate from kernel > pointers. Yes, that's true, however I don't know how we could get around that when the iomem is referenced by struct pages inside a scatter gather list. Do we need to now have special __iomem sgls? And even still, I'm not sure how that could work when the nvme target code is using the same sgls to sometimes point to iomem and sometimes point to regular memory. I'm certainly open to suggestions, though. Logan From mboxrd@z Thu Jan 1 00:00:00 1970 From: logang@deltatee.com (Logan Gunthorpe) Date: Fri, 31 Mar 2017 09:41:56 -0600 Subject: [RFC 5/8] scatterlist: Modify SG copy functions to support io memory. In-Reply-To: <20170331070950.GA9059@infradead.org> References: <1490911959-5146-1-git-send-email-logang@deltatee.com> <1490911959-5146-6-git-send-email-logang@deltatee.com> <20170331070950.GA9059@infradead.org> Message-ID: <435d4471-436b-87e6-8827-c9fc6cbdde2c@deltatee.com> On 31/03/17 01:09 AM, Christoph Hellwig wrote: > You're calling memcpy_{to,from}_iomem on non-__iomem pointers. This > is a fundamental no-go as we keep I/O memory separate from kernel > pointers. Yes, that's true, however I don't know how we could get around that when the iomem is referenced by struct pages inside a scatter gather list. Do we need to now have special __iomem sgls? And even still, I'm not sure how that could work when the nvme target code is using the same sgls to sometimes point to iomem and sometimes point to regular memory. I'm certainly open to suggestions, though. Logan