From: Christoph Hellwig <hch@lst.de>
To: Logan Gunthorpe <logang@deltatee.com>
Cc: 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,
"Stephen Bates" <sbates@raithlin.com>,
"Christoph Hellwig" <hch@lst.de>,
"Dan Williams" <dan.j.williams@intel.com>,
"Jason Gunthorpe" <jgg@ziepe.ca>,
"Christian König" <christian.koenig@amd.com>,
"John Hubbard" <jhubbard@nvidia.com>,
"Don Dutile" <ddutile@redhat.com>,
"Matthew Wilcox" <willy@infradead.org>,
"Daniel Vetter" <daniel.vetter@ffwll.ch>,
"Jakowski Andrzej" <andrzej.jakowski@intel.com>,
"Minturn Dave B" <dave.b.minturn@intel.com>,
"Jason Ekstrand" <jason@jlekstrand.net>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"Xiong Jianxin" <jianxin.xiong@intel.com>,
"Bjorn Helgaas" <helgaas@kernel.org>,
"Ira Weiny" <ira.weiny@intel.com>,
"Robin Murphy" <robin.murphy@arm.com>
Subject: Re: [PATCH v2 15/22] dma-direct: Support PCI P2PDMA pages in dma-direct map_sg
Date: Fri, 14 May 2021 15:57:12 +0200 [thread overview]
Message-ID: <20210514135712.GD4715@lst.de> (raw)
In-Reply-To: <20210513223203.5542-16-logang@deltatee.com>
> + for_each_sg(sgl, sg, nents, i) {
> + if (sg_is_dma_pci_p2pdma(sg)) {
> + sg_dma_unmark_pci_p2pdma(sg);
> + } else {
Double space here. We also don't really need the curly braces to start
with.
> + struct pci_p2pdma_map_state p2pdma_state = {};
> + enum pci_p2pdma_map_type map;
> struct scatterlist *sg;
> + int i, ret;
>
> for_each_sg(sgl, sg, nents, i) {
> + if (is_pci_p2pdma_page(sg_page(sg))) {
> + map = pci_p2pdma_map_segment(&p2pdma_state, dev, sg);
> + switch (map) {
Why not just:
switch (pci_p2pdma_map_segment(&p2pdma_state, dev,
sg)) {
(even better with a shorter name for p2pdma_state so that it all fits on
a single line)?
> + case PCI_P2PDMA_MAP_BUS_ADDR:
> + continue;
> + case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE:
> + /*
> + * Mapping through host bridge should be
> + * mapped normally, thus we do nothing
> + * and continue below.
> + */
I have a bit of a hard time parsing this comment.
> + if (sg->dma_address == DMA_MAPPING_ERROR) {
> + ret = -EINVAL;
> goto out_unmap;
> + }
> sg_dma_len(sg) = sg->length;
> }
>
> @@ -411,7 +443,7 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
>
> out_unmap:
> dma_direct_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC);
> - return -EINVAL;
> + return ret;
Maybe just initialize ret to -EINVAL at declaration time to simplify this
a bit?
next prev parent reply other threads:[~2021-05-14 13:57 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-13 22:31 [PATCH v2 00/22] Add new DMA mapping operation for P2PDMA Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 01/22] PCI/P2PDMA: Rename upstream_bridge_distance() and rework documentation Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 02/22] PCI/P2PDMA: Use a buffer on the stack for collecting the acs list Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 03/22] PCI/P2PDMA: Cleanup type for return value of calc_map_type_and_dist() Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 04/22] PCI/P2PDMA: Avoid pci_get_slot() which sleeps Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 05/22] PCI/P2PDMA: Print a warning if the host bridge is not in the whitelist Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 06/22] PCI/P2PDMA: Attempt to set map_type if it has not been set Logan Gunthorpe
2021-05-14 13:49 ` Christoph Hellwig
2021-05-14 16:15 ` Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 07/22] PCI/P2PDMA: Refactor pci_p2pdma_map_type() to take pagemap and device Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 08/22] dma-mapping: Allow map_sg() ops to return negative error codes Logan Gunthorpe
2021-05-14 13:51 ` Christoph Hellwig
2021-05-14 16:15 ` Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 09/22] dma-direct: Return appropriate error code from dma_direct_map_sg() Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 10/22] iommu: Return full error code from iommu_map_sg[_atomic]() Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 11/22] dma-iommu: Return error code from iommu_dma_map_sg() Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 12/22] lib/scatterlist: Add flag for indicating P2PDMA segments in an SGL Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 13/22] PCI/P2PDMA: Make pci_p2pdma_map_type() non-static Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 14/22] PCI/P2PDMA: Introduce helpers for dma_map_sg implementations Logan Gunthorpe
2021-05-14 13:53 ` Christoph Hellwig
2021-05-14 16:16 ` Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 15/22] dma-direct: Support PCI P2PDMA pages in dma-direct map_sg Logan Gunthorpe
2021-05-14 13:57 ` Christoph Hellwig [this message]
2021-05-14 16:17 ` Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 16/22] dma-mapping: Add flags to dma_map_ops to indicate PCI P2PDMA support Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 17/22] iommu/dma: Support PCI P2PDMA pages in dma-iommu map_sg Logan Gunthorpe
2021-05-13 22:31 ` [PATCH v2 18/22] nvme-pci: Check DMA ops when indicating support for PCI P2PDMA Logan Gunthorpe
2021-05-13 22:32 ` [PATCH v2 19/22] nvme-pci: Convert to using dma_map_sgtable() Logan Gunthorpe
2021-05-13 22:32 ` [PATCH v2 20/22] RDMA/core: Introduce ib_dma_pci_p2p_dma_supported() Logan Gunthorpe
2021-05-13 22:32 ` [PATCH v2 21/22] RDMA/rw: use dma_map_sgtable() Logan Gunthorpe
2021-05-13 22:32 ` [PATCH v2 22/22] PCI/P2PDMA: Remove pci_p2pdma_[un]map_sg() Logan Gunthorpe
2021-05-14 14:00 ` [PATCH v2 00/22] Add new DMA mapping operation for P2PDMA Christoph Hellwig
2021-05-14 16:30 ` Logan Gunthorpe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210514135712.GD4715@lst.de \
--to=hch@lst.de \
--cc=andrzej.jakowski@intel.com \
--cc=christian.koenig@amd.com \
--cc=dan.j.williams@intel.com \
--cc=daniel.vetter@ffwll.ch \
--cc=dave.b.minturn@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=ddutile@redhat.com \
--cc=helgaas@kernel.org \
--cc=iommu@lists.linux-foundation.org \
--cc=ira.weiny@intel.com \
--cc=jason@jlekstrand.net \
--cc=jgg@ziepe.ca \
--cc=jhubbard@nvidia.com \
--cc=jianxin.xiong@intel.com \
--cc=linux-block@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-nvme@lists.infradead.org \
--cc=linux-pci@vger.kernel.org \
--cc=logang@deltatee.com \
--cc=robin.murphy@arm.com \
--cc=sbates@raithlin.com \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).