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author | 2020-08-18 16:13:41 +0900 | |
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committer | 2020-08-18 10:01:44 +0200 | |
commit | a0308938ec81cd0dca9d75833ec0dd1b8708917e (patch) | |
tree | a7a8c3421f26b9ce09dd86ddc1004813793c2a25 /drivers/virtio | |
parent | drm/qxl: Replace deprecated function in qxl_display (diff) | |
download | linux-a0308938ec81cd0dca9d75833ec0dd1b8708917e.tar.gz linux-a0308938ec81cd0dca9d75833ec0dd1b8708917e.tar.bz2 linux-a0308938ec81cd0dca9d75833ec0dd1b8708917e.zip |
virtio: add dma-buf support for exported objects
This change adds a new flavor of dma-bufs that can be used by virtio
drivers to share exported objects. A virtio dma-buf can be queried by
virtio drivers to obtain the UUID which identifies the underlying
exported object.
Signed-off-by: David Stevens <stevensd@chromium.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200818071343.3461203-2-stevensd@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Diffstat (limited to 'drivers/virtio')
-rw-r--r-- | drivers/virtio/Makefile | 2 | ||||
-rw-r--r-- | drivers/virtio/virtio.c | 6 | ||||
-rw-r--r-- | drivers/virtio/virtio_dma_buf.c | 85 |
3 files changed, 92 insertions, 1 deletions
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile index 4d993791f2d7..49da768ee7fd 100644 --- a/drivers/virtio/Makefile +++ b/drivers/virtio/Makefile @@ -1,5 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o +obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o virtio_dma_buf.o obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index a977e32a88f2..5d46f0ded92d 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -357,6 +357,12 @@ out: } EXPORT_SYMBOL_GPL(register_virtio_device); +bool is_virtio_device(struct device *dev) +{ + return dev->bus == &virtio_bus; +} +EXPORT_SYMBOL_GPL(is_virtio_device); + void unregister_virtio_device(struct virtio_device *dev) { int index = dev->index; /* save for after device release */ diff --git a/drivers/virtio/virtio_dma_buf.c b/drivers/virtio/virtio_dma_buf.c new file mode 100644 index 000000000000..45d6e8647dcf --- /dev/null +++ b/drivers/virtio/virtio_dma_buf.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * dma-bufs for virtio exported objects + * + * Copyright (C) 2020 Google, Inc. + */ + +#include <linux/virtio_dma_buf.h> + +/** + * virtio_dma_buf_export - Creates a new dma-buf for a virtio exported object + * @exp_info: [in] see dma_buf_export(). ops MUST refer to a dma_buf_ops + * struct embedded in a virtio_dma_buf_ops. + * + * This wraps dma_buf_export() to allow virtio drivers to create a dma-buf + * for an virtio exported object that can be queried by other virtio drivers + * for the object's UUID. + */ +struct dma_buf *virtio_dma_buf_export + (const struct dma_buf_export_info *exp_info) +{ + const struct virtio_dma_buf_ops *virtio_ops = + container_of(exp_info->ops, + const struct virtio_dma_buf_ops, ops); + + if (!exp_info->ops || + exp_info->ops->attach != &virtio_dma_buf_attach || + !virtio_ops->get_uuid) { + return ERR_PTR(-EINVAL); + } + + return dma_buf_export(exp_info); +} +EXPORT_SYMBOL(virtio_dma_buf_export); + +/** + * virtio_dma_buf_attach - mandatory attach callback for virtio dma-bufs + */ +int virtio_dma_buf_attach(struct dma_buf *dma_buf, + struct dma_buf_attachment *attach) +{ + int ret; + const struct virtio_dma_buf_ops *ops = + container_of(dma_buf->ops, + const struct virtio_dma_buf_ops, ops); + + if (ops->device_attach) { + ret = ops->device_attach(dma_buf, attach); + if (ret) + return ret; + } + return 0; +} +EXPORT_SYMBOL(virtio_dma_buf_attach); + +/** + * is_virtio_dma_buf - returns true if the given dma-buf is a virtio dma-buf + * @dma_buf: buffer to query + */ +bool is_virtio_dma_buf(struct dma_buf *dma_buf) +{ + return dma_buf->ops->attach == &virtio_dma_buf_attach; +} +EXPORT_SYMBOL(is_virtio_dma_buf); + +/** + * virtio_dma_buf_get_uuid - gets a virtio dma-buf's exported object's uuid + * @dma_buf: [in] buffer to query + * @uuid: [out] the uuid + * + * Returns: 0 on success, negative on failure. + */ +int virtio_dma_buf_get_uuid(struct dma_buf *dma_buf, + uuid_t *uuid) +{ + const struct virtio_dma_buf_ops *ops = + container_of(dma_buf->ops, + const struct virtio_dma_buf_ops, ops); + + if (!is_virtio_dma_buf(dma_buf)) + return -EINVAL; + + return ops->get_uuid(dma_buf, uuid); +} +EXPORT_SYMBOL(virtio_dma_buf_get_uuid); |