Commit b84621d9 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring/zcrx: allocate sgtable for umem areas 



Currently, dma addresses for umem areas are stored directly in niovs.
It's memory efficient but inconvenient. I need a better format 1) to
share code with dmabuf areas, and 2) for disentangling page, folio and
niov sizes. dmabuf already provides sg_table, create one for user memory
as well.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Reviewed-by: default avatarDavid Wei <dw@davidwei.uk>
Link: https://lore.kernel.org/r/f3c15081827c1bf5427d3a2e693bc526476b87ee.1751466461.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 54e89a93

io_uring/zcrx.c

+27 −51
Original line number Diff line number Diff line
@@ -161,7 +161,7 @@ static int io_import_umem(struct io_zcrx_ifq *ifq, 
			  struct io_uring_zcrx_area_reg *area_reg)

{

	struct page **pages;

	int nr_pages;

	int nr_pages, ret;



	if (area_reg->dmabuf_fd)

		return -EINVAL;
@@ -172,6 +172,12 @@ static int io_import_umem(struct io_zcrx_ifq *ifq, 
	if (IS_ERR(pages))

		return PTR_ERR(pages);



	ret = sg_alloc_table_from_pages(&mem->page_sg_table, pages, nr_pages,

					0, nr_pages << PAGE_SHIFT,

					GFP_KERNEL_ACCOUNT);

	if (ret)

		return ret;



	mem->pages = pages;

	mem->nr_folios = nr_pages;

	mem->size = area_reg->len;
@@ -186,6 +192,7 @@ static void io_release_area_mem(struct io_zcrx_mem *mem) 
	}

	if (mem->pages) {

		unpin_user_pages(mem->pages, mem->nr_folios);

		sg_free_table(&mem->page_sg_table);

		kvfree(mem->pages);

	}

}
@@ -207,67 +214,36 @@ static int io_import_area(struct io_zcrx_ifq *ifq, 
	return io_import_umem(ifq, mem, area_reg);

}



static void io_zcrx_unmap_umem(struct io_zcrx_ifq *ifq,

				struct io_zcrx_area *area, int nr_mapped)

{

	int i;



	for (i = 0; i < nr_mapped; i++) {

		netmem_ref netmem = net_iov_to_netmem(&area->nia.niovs[i]);

		dma_addr_t dma = page_pool_get_dma_addr_netmem(netmem);



		dma_unmap_page_attrs(ifq->dev, dma, PAGE_SIZE,

				     DMA_FROM_DEVICE, IO_DMA_ATTR);

	}

}



static void __io_zcrx_unmap_area(struct io_zcrx_ifq *ifq,

				 struct io_zcrx_area *area, int nr_mapped)

static void io_zcrx_unmap_area(struct io_zcrx_ifq *ifq,

				struct io_zcrx_area *area)

{

	int i;



	if (area->mem.is_dmabuf)

		io_release_dmabuf(&area->mem);

	else

		io_zcrx_unmap_umem(ifq, area, nr_mapped);

	guard(mutex)(&ifq->dma_lock);

	if (!area->is_mapped)

		return;

	area->is_mapped = false;



	for (i = 0; i < area->nia.num_niovs; i++)

		net_mp_niov_set_dma_addr(&area->nia.niovs[i], 0);

}



static void io_zcrx_unmap_area(struct io_zcrx_ifq *ifq, struct io_zcrx_area *area)

{

	guard(mutex)(&ifq->dma_lock);



	if (area->is_mapped)

		__io_zcrx_unmap_area(ifq, area, area->nia.num_niovs);

	area->is_mapped = false;

	if (area->mem.is_dmabuf) {

		io_release_dmabuf(&area->mem);

	} else {

		dma_unmap_sgtable(ifq->dev, &area->mem.page_sg_table,

				  DMA_FROM_DEVICE, IO_DMA_ATTR);

	}

}



static int io_zcrx_map_area_umem(struct io_zcrx_ifq *ifq, struct io_zcrx_area *area)

static unsigned io_zcrx_map_area_umem(struct io_zcrx_ifq *ifq, struct io_zcrx_area *area)

{

	int i;



	for (i = 0; i < area->nia.num_niovs; i++) {

		struct net_iov *niov = &area->nia.niovs[i];

		dma_addr_t dma;

	int ret;



		dma = dma_map_page_attrs(ifq->dev, area->mem.pages[i], 0,

					 PAGE_SIZE, DMA_FROM_DEVICE, IO_DMA_ATTR);

		if (dma_mapping_error(ifq->dev, dma))

			break;

		if (net_mp_niov_set_dma_addr(niov, dma)) {

			dma_unmap_page_attrs(ifq->dev, dma, PAGE_SIZE,

	ret = dma_map_sgtable(ifq->dev, &area->mem.page_sg_table,

				DMA_FROM_DEVICE, IO_DMA_ATTR);

			break;

		}

	}



	if (i != area->nia.num_niovs) {

		__io_zcrx_unmap_area(ifq, area, i);

		return -EINVAL;

	}

	return 0;

	if (ret < 0)

		return ret;

	return io_populate_area_dma(ifq, area, &area->mem.page_sg_table, 0);

}



static int io_zcrx_map_area(struct io_zcrx_ifq *ifq, struct io_zcrx_area *area)

io_uring/zcrx.h

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ struct io_zcrx_mem { 


	struct page			**pages;

	unsigned long			nr_folios;

	struct sg_table			page_sg_table;



	struct dma_buf_attachment	*attach;

	struct dma_buf			*dmabuf;