[PATCH vhost 14/17] virtio_ring: introduce dma map api for page
From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Date: 2024-01-30 11:42:52
Also in:
bpf, kvm, linux-remoteproc, linux-s390, linux-um, platform-driver-x86, virtualization
Subsystem:
the rest, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
The virtio-net sq will use these APIs to map the scatterlist.
For scatterlist, the page dma APIs are more appropriate.
dma_addr_t virtqueue_dma_map_page_attrs(struct virtqueue *_vq, struct page *page,
size_t offset, size_t size,
enum dma_data_direction dir,
unsigned long attrs);
void virtqueue_dma_unmap_page_attrs(struct virtqueue *_vq, dma_addr_t addr,
size_t size, enum dma_data_direction dir,
unsigned long attrs);
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 52 ++++++++++++++++++++++++++++++++++++
include/linux/virtio.h | 7 +++++
2 files changed, 59 insertions(+)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index ccdd6dd3062f..47aa31ce69e7 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c@@ -3117,6 +3117,58 @@ void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr, } EXPORT_SYMBOL_GPL(virtqueue_dma_unmap_single_attrs); +/** + * virtqueue_dma_map_page_attrs - map DMA for _vq + * @_vq: the struct virtqueue we're talking about. + * @page: the page to do dma + * @offset: the offset inside the page + * @size: the size of the page to do dma + * @dir: DMA direction + * @attrs: DMA Attrs + * + * The caller calls this to do dma mapping in advance. The DMA address can be + * passed to this _vq when it is in pre-mapped mode. + * + * return DMA address. Caller should check that by virtqueue_dma_mapping_error(). + */ +dma_addr_t virtqueue_dma_map_page_attrs(struct virtqueue *_vq, struct page *page, + size_t offset, size_t size, + enum dma_data_direction dir, + unsigned long attrs) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + + if (!vq->use_dma_api) + return page_to_phys(page) + offset; + + return dma_map_page_attrs(vring_dma_dev(vq), page, offset, size, dir, attrs); +} +EXPORT_SYMBOL_GPL(virtqueue_dma_map_page_attrs); + +/** + * virtqueue_dma_unmap_page_attrs - unmap DMA for _vq + * @_vq: the struct virtqueue we're talking about. + * @addr: the dma address to unmap + * @size: the size of the buffer + * @dir: DMA direction + * @attrs: DMA Attrs + * + * Unmap the address that is mapped by the virtqueue_dma_map_* APIs. + * + */ +void virtqueue_dma_unmap_page_attrs(struct virtqueue *_vq, dma_addr_t addr, + size_t size, enum dma_data_direction dir, + unsigned long attrs) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + + if (!vq->use_dma_api) + return; + + dma_unmap_page_attrs(vring_dma_dev(vq), addr, size, dir, attrs); +} +EXPORT_SYMBOL_GPL(virtqueue_dma_unmap_page_attrs); + /** * virtqueue_dma_mapping_error - check dma address * @_vq: the struct virtqueue we're talking about.
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 7f16bacc6c49..8a8d282982ad 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h@@ -216,6 +216,13 @@ dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr, size void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr, size_t size, enum dma_data_direction dir, unsigned long attrs); +dma_addr_t virtqueue_dma_map_page_attrs(struct virtqueue *_vq, struct page *page, + size_t offset, size_t size, + enum dma_data_direction dir, + unsigned long attrs); +void virtqueue_dma_unmap_page_attrs(struct virtqueue *_vq, dma_addr_t addr, + size_t size, enum dma_data_direction dir, + unsigned long attrs); int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr); bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr);
--
2.32.0.3.g01195cf9f