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Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.9.0 MIME-Version: 1.0 In-Reply-To: <78a165e1-657b-c284-d31a-adc8c9ded55d@nvidia.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-CA Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 172.16.1.162 X-SA-Exim-Rcpt-To: 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, 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, jhubbard@nvidia.com X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [PATCH 13/16] nvme-pci: Convert to using dma_map_sg_p2pdma for p2pdma pages 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) X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 198ACE00012F Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=deltatee.com header.s=20200525 header.b=QqAwmeJn; dmarc=none; spf=pass (imf13.hostedemail.com: domain of logang@deltatee.com designates 204.191.154.188 as permitted sender) smtp.mailfrom=logang@deltatee.com X-Stat-Signature: 1tktx3h8ho3stnagnhjwy96bma6nwcoy Received-SPF: none (deltatee.com>: No applicable sender policy available) receiver=imf13; identity=mailfrom; envelope-from=""; helo=ale.deltatee.com; client-ip=204.191.154.188 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1620062370-495497 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2021-05-02 7:34 p.m., John Hubbard wrote: >> if (iod->npages == 0) >> dma_pool_free(dev->prp_small_pool, nvme_pci_iod_list(req)[0], >> iod->first_dma); >> @@ -868,14 +857,13 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req, >> if (!iod->nents) >> goto out_free_sg; >> >> - if (is_pci_p2pdma_page(sg_page(iod->sg))) >> - nr_mapped = pci_p2pdma_map_sg_attrs(dev->dev, iod->sg, >> - iod->nents, rq_dma_dir(req), DMA_ATTR_NO_WARN); >> - else >> - nr_mapped = dma_map_sg_attrs(dev->dev, iod->sg, iod->nents, >> - rq_dma_dir(req), DMA_ATTR_NO_WARN); >> - if (!nr_mapped) >> + nr_mapped = dma_map_sg_p2pdma_attrs(dev->dev, iod->sg, iod->nents, >> + rq_dma_dir(req), DMA_ATTR_NO_WARN); >> + if (nr_mapped < 0) { >> + if (nr_mapped != -ENOMEM) >> + ret = BLK_STS_TARGET; >> goto out_free_sg; >> + } > > But now the "nr_mapped == 0" case is no longer doing an early out_free_sg. > Is that OK? dma_map_sg_p2pdma_attrs() never returns zero. It will return -ENOMEM in the same situation and results in the same goto out_free_sg. Logan