From: Christoph Hellwig <hch@infradead.org>
To: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: virtualization@lists.linux-foundation.org,
linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
aik@ozlabs.ru, robh@kernel.org, joe@perches.com,
elfring@users.sourceforge.net, david@gibson.dropbear.id.au,
jasowang@redhat.com, benh@kernel.crashing.org,
mpe@ellerman.id.au, mst@redhat.com, hch@infradead.org,
linuxram@us.ibm.com, haren@linux.vnet.ibm.com, paulus@samba.org,
srikar@linux.vnet.ibm.com
Subject: Re: [RFC 1/4] virtio: Define virtio_direct_dma_ops structure
Date: Mon, 30 Jul 2018 02:24:19 -0700 [thread overview]
Message-ID: <20180730092419.GA26245@infradead.org> (raw)
In-Reply-To: <20180720035941.6844-2-khandual@linux.vnet.ibm.com>
> +/*
> + * Virtio direct mapping DMA API operations structure
> + *
> + * This defines DMA API structure for all virtio devices which would not
> + * either bring in their own DMA OPS from architecture or they would not
> + * like to use architecture specific IOMMU based DMA OPS because QEMU
> + * expects GPA instead of an IOVA in absence of VIRTIO_F_IOMMU_PLATFORM.
> + */
> +dma_addr_t virtio_direct_map_page(struct device *dev, struct page *page,
> + unsigned long offset, size_t size,
> + enum dma_data_direction dir,
> + unsigned long attrs)
All these functions should probably be marked static.
> +void virtio_direct_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
> + size_t size, enum dma_data_direction dir,
> + unsigned long attrs)
> +{
> +}
No need to implement no-op callbacks in struct dma_map_ops.
> +
> +int virtio_direct_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
> +{
> + return 0;
> +}
Including this one.
> +void *virtio_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
> + gfp_t gfp, unsigned long attrs)
> +{
> + void *queue = alloc_pages_exact(PAGE_ALIGN(size), gfp);
> +
> + if (queue) {
> + phys_addr_t phys_addr = virt_to_phys(queue);
> + *dma_handle = (dma_addr_t)phys_addr;
> +
> + if (WARN_ON_ONCE(*dma_handle != phys_addr)) {
> + free_pages_exact(queue, PAGE_ALIGN(size));
> + return NULL;
> + }
> + }
> + return queue;
queue is a very odd name in a generic memory allocator.
> +void virtio_direct_free(struct device *dev, size_t size, void *vaddr,
> + dma_addr_t dma_addr, unsigned long attrs)
> +{
> + free_pages_exact(vaddr, PAGE_ALIGN(size));
> +}
> +
> +const struct dma_map_ops virtio_direct_dma_ops = {
> + .alloc = virtio_direct_alloc,
> + .free = virtio_direct_free,
> + .map_page = virtio_direct_map_page,
> + .unmap_page = virtio_direct_unmap_page,
> + .mapping_error = virtio_direct_mapping_error,
> +};
This is missing a dma_map_sg implementation. In general this is
mandatory for dma_ops. So either you implement it or explain in
a common why you think you can skip it.
> +EXPORT_SYMBOL(virtio_direct_dma_ops);
EXPORT_SYMBOL_GPL like all virtio symbols, please.
next prev parent reply other threads:[~2018-07-30 9:24 UTC|newest]
Thread overview: 119+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-20 3:59 [RFC 0/4] Virtio uses DMA API for all devices Anshuman Khandual
2018-07-20 3:59 ` [RFC 1/4] virtio: Define virtio_direct_dma_ops structure Anshuman Khandual
2018-07-30 9:24 ` Christoph Hellwig [this message]
2018-07-31 4:01 ` Anshuman Khandual
2018-07-20 3:59 ` [RFC 2/4] virtio: Override device's DMA OPS with virtio_direct_dma_ops selectively Anshuman Khandual
2018-07-28 8:56 ` Anshuman Khandual
2018-07-28 21:16 ` Michael S. Tsirkin
2018-07-30 4:15 ` Anshuman Khandual
2018-07-30 9:30 ` Christoph Hellwig
2018-07-31 6:39 ` Anshuman Khandual
2018-07-30 9:25 ` Christoph Hellwig
2018-07-31 7:00 ` Anshuman Khandual
2018-07-20 3:59 ` [RFC 3/4] virtio: Force virtio core to use DMA API callbacks for all virtio devices Anshuman Khandual
2018-07-20 3:59 ` [RFC 4/4] virtio: Add platform specific DMA API translation for virito devices Anshuman Khandual
2018-07-20 13:15 ` Michael S. Tsirkin
2018-07-23 2:16 ` Anshuman Khandual
2018-07-25 4:30 ` Anshuman Khandual
2018-07-25 13:31 ` Michael S. Tsirkin
2018-07-20 13:16 ` [RFC 0/4] Virtio uses DMA API for all devices Michael S. Tsirkin
2018-07-23 6:28 ` Anshuman Khandual
2018-07-23 9:08 ` Michael S. Tsirkin
2018-07-25 3:26 ` Anshuman Khandual
2018-07-27 11:31 ` Michael S. Tsirkin
2018-07-28 8:37 ` Anshuman Khandual
2018-07-27 9:58 ` Will Deacon
2018-07-27 10:58 ` Anshuman Khandual
2018-07-30 9:34 ` Christoph Hellwig
2018-07-30 10:28 ` Michael S. Tsirkin
2018-07-30 11:18 ` Christoph Hellwig
2018-07-30 13:26 ` Michael S. Tsirkin
2018-07-31 17:30 ` Christoph Hellwig
2018-07-31 20:36 ` Benjamin Herrenschmidt
2018-08-01 8:16 ` Will Deacon
2018-08-01 8:36 ` Christoph Hellwig
2018-08-01 9:05 ` Will Deacon
2018-08-01 22:41 ` Michael S. Tsirkin
2018-08-01 22:35 ` Michael S. Tsirkin
2018-08-02 15:24 ` Benjamin Herrenschmidt
2018-08-02 15:41 ` Michael S. Tsirkin
2018-08-02 16:01 ` Benjamin Herrenschmidt
2018-08-02 17:19 ` Michael S. Tsirkin
2018-08-02 17:53 ` Benjamin Herrenschmidt
2018-08-02 20:52 ` Michael S. Tsirkin
2018-08-02 21:13 ` Benjamin Herrenschmidt
2018-08-02 21:51 ` Michael S. Tsirkin
2018-08-03 7:05 ` Christoph Hellwig
2018-08-03 15:58 ` Benjamin Herrenschmidt
2018-08-03 16:02 ` Christoph Hellwig
2018-08-03 18:58 ` Benjamin Herrenschmidt
2018-08-04 8:21 ` Christoph Hellwig
2018-08-05 1:10 ` Benjamin Herrenschmidt
2018-08-05 7:29 ` Christoph Hellwig
2018-08-05 21:16 ` Benjamin Herrenschmidt
2018-08-05 21:30 ` Benjamin Herrenschmidt
2018-08-06 9:42 ` Christoph Hellwig
2018-08-06 19:52 ` Benjamin Herrenschmidt
2018-08-07 6:21 ` Christoph Hellwig
2018-08-07 6:42 ` Benjamin Herrenschmidt
2018-08-07 13:55 ` Christoph Hellwig
2018-08-07 20:32 ` Benjamin Herrenschmidt
2018-08-08 6:31 ` Christoph Hellwig
2018-08-08 10:07 ` Benjamin Herrenschmidt
2018-08-08 12:30 ` Christoph Hellwig
2018-08-08 13:18 ` Benjamin Herrenschmidt
2018-08-08 20:31 ` Michael S. Tsirkin
2018-08-08 22:13 ` Benjamin Herrenschmidt
2018-08-09 2:00 ` Benjamin Herrenschmidt
2018-08-09 5:40 ` Christoph Hellwig
2018-09-07 0:09 ` Jiandi An
2018-09-10 6:19 ` Christoph Hellwig
2018-09-10 8:53 ` Gerd Hoffmann
2018-08-03 19:07 ` Michael S. Tsirkin
2018-08-04 1:11 ` Benjamin Herrenschmidt
2018-08-04 1:16 ` Benjamin Herrenschmidt
2018-08-05 0:22 ` Michael S. Tsirkin
2018-08-05 4:52 ` Benjamin Herrenschmidt
2018-08-06 13:46 ` Michael S. Tsirkin
2018-08-06 19:56 ` Benjamin Herrenschmidt
2018-08-06 20:35 ` Michael S. Tsirkin
2018-08-06 21:26 ` Benjamin Herrenschmidt
2018-08-06 21:46 ` Michael S. Tsirkin
2018-08-06 22:13 ` Benjamin Herrenschmidt
2018-08-06 23:16 ` Benjamin Herrenschmidt
2018-08-06 23:45 ` Michael S. Tsirkin
2018-08-07 0:18 ` Benjamin Herrenschmidt
2018-08-07 6:32 ` Christoph Hellwig
2018-08-07 6:27 ` Christoph Hellwig
2018-08-07 6:44 ` Benjamin Herrenschmidt
2018-08-07 6:18 ` Christoph Hellwig
2018-08-07 6:16 ` Christoph Hellwig
2018-08-06 23:18 ` Benjamin Herrenschmidt
2018-08-07 6:12 ` Christoph Hellwig
2018-08-04 1:18 ` Benjamin Herrenschmidt
2018-08-04 1:22 ` Benjamin Herrenschmidt
2018-08-05 0:23 ` Michael S. Tsirkin
2018-08-03 19:17 ` Michael S. Tsirkin
2018-08-04 8:15 ` Christoph Hellwig
2018-08-05 0:09 ` Michael S. Tsirkin
2018-08-05 1:11 ` Benjamin Herrenschmidt
2018-08-05 7:25 ` Christoph Hellwig
2018-08-05 0:53 ` Benjamin Herrenschmidt
2018-08-05 0:27 ` Michael S. Tsirkin
2018-08-06 14:05 ` Will Deacon
2018-08-01 21:56 ` Michael S. Tsirkin
2018-08-02 15:33 ` Benjamin Herrenschmidt
2018-08-02 20:53 ` Michael S. Tsirkin
2018-08-03 7:06 ` Christoph Hellwig
2018-08-02 20:55 ` Michael S. Tsirkin
2018-08-03 2:41 ` Jason Wang
2018-08-03 19:08 ` Michael S. Tsirkin
2018-08-04 1:21 ` Benjamin Herrenschmidt
2018-08-05 0:24 ` Michael S. Tsirkin
2018-08-06 9:02 ` Anshuman Khandual
2018-08-06 13:36 ` Michael S. Tsirkin
2018-08-06 15:24 ` Christoph Hellwig
2018-08-06 16:06 ` Michael S. Tsirkin
2018-08-06 16:10 ` Christoph Hellwig
2018-08-06 16:13 ` Michael S. Tsirkin
2018-08-06 16:34 ` Christoph Hellwig
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=20180730092419.GA26245@infradead.org \
--to=hch@infradead.org \
--cc=aik@ozlabs.ru \
--cc=benh@kernel.crashing.org \
--cc=david@gibson.dropbear.id.au \
--cc=elfring@users.sourceforge.net \
--cc=haren@linux.vnet.ibm.com \
--cc=jasowang@redhat.com \
--cc=joe@perches.com \
--cc=khandual@linux.vnet.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=linuxram@us.ibm.com \
--cc=mpe@ellerman.id.au \
--cc=mst@redhat.com \
--cc=paulus@samba.org \
--cc=robh@kernel.org \
--cc=srikar@linux.vnet.ibm.com \
--cc=virtualization@lists.linux-foundation.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).