[RFC PATCH v3 19/20] net: page pool: generalise ppiov dma address get

David Wei
2023-12-19T21:04:23Z

From: Pavel Begunkov <asml.silence@gmail.com>

io_uring pp memory provider doesn't have contiguous dma addresses,
implement page_pool_iov_dma_addr() via callbacks.

Note: it might be better to stash dma address into struct page_pool_iov.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David Wei <dw@davidwei.uk>
---
include/net/page_pool/helpers.h | 5 +----
include/net/page_pool/types.h | 2 ++
io_uring/zc_rx.c | 8 ++++++++
net/core/page_pool.c | 9 +++++++++
4 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h
index aca3a52d0e22..10dba1f2aa0c 100644
--- a/include/net/page_pool/helpers.h
+++ b/include/net/page_pool/helpers.h
@@ -105,10 +105,7 @@ static inline unsigned int page_pool_iov_idx(const struct page_pool_iov *ppiov)
static inline dma_addr_t
page_pool_iov_dma_addr(const struct page_pool_iov *ppiov)
{
- struct dmabuf_genpool_chunk_owner *owner = page_pool_iov_owner(ppiov);
-
- return owner->base_dma_addr +
- ((dma_addr_t)page_pool_iov_idx(ppiov) << PAGE_SHIFT);
+ return ppiov->pp->mp_ops->ppiov_dma_addr(ppiov);
}

static inline unsigned long
diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index f54ee759e362..1b9266835ab6 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -125,6 +125,7 @@ struct page_pool_stats {
#endif

struct mem_provider;
+struct page_pool_iov;

enum pp_memory_provider_type {
__PP_MP_NONE, /* Use system allocator directly */
@@ -138,6 +139,7 @@ struct pp_memory_provider_ops {
void (*scrub)(struct page_pool *pool);
struct page *(*alloc_pages)(struct page_pool *pool, gfp_t gfp);
bool (*release_page)(struct page_pool *pool, struct page *page);
+ dma_addr_t (*ppiov_dma_addr)(const struct page_pool_iov *ppiov);
};

extern const struct pp_memory_provider_ops dmabuf_devmem_ops;
diff --git a/io_uring/zc_rx.c b/io_uring/zc_rx.c
index f7d99d569885..20fb89e6bad7 100644
--- a/io_uring/zc_rx.c
+++ b/io_uring/zc_rx.c
@@ -600,12 +600,20 @@ static void io_pp_zc_destroy(struct page_pool *pp)
percpu_ref_put(&ifq->ctx->refs);
}

+static dma_addr_t io_pp_zc_ppiov_dma_addr(const struct page_pool_iov *ppiov)
+{
+ struct io_zc_rx_buf *buf = io_iov_to_buf((struct page_pool_iov *)ppiov);
+
+ return buf->dma;
+}
+
const struct pp_memory_provider_ops io_uring_pp_zc_ops = {
.alloc_pages = io_pp_zc_alloc_pages,
.release_page = io_pp_zc_release_page,
.init = io_pp_zc_init,
.destroy = io_pp_zc_destroy,
.scrub = io_pp_zc_scrub,
+ .ppiov_dma_addr = io_pp_zc_ppiov_dma_addr,
};
EXPORT_SYMBOL(io_uring_pp_zc_ops);

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index ebf5ff009d9d..6586631ecc2e 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -1105,10 +1105,19 @@ static bool mp_dmabuf_devmem_release_page(struct page_pool *pool,
return true;
}

+static dma_addr_t mp_dmabuf_devmem_ppiov_dma_addr(const struct page_pool_iov *ppiov)
+{
+ struct dmabuf_genpool_chunk_owner *owner = page_pool_iov_owner(ppiov);
+
+ return owner->base_dma_addr +
+ ((dma_addr_t)page_pool_iov_idx(ppiov) << PAGE_SHIFT);
+}
+
const struct pp_memory_provider_ops dmabuf_devmem_ops = {
.init = mp_dmabuf_devmem_init,
.destroy = mp_dmabuf_devmem_destroy,
.alloc_pages = mp_dmabuf_devmem_alloc_pages,
.release_page = mp_dmabuf_devmem_release_page,
+ .ppiov_dma_addr = mp_dmabuf_devmem_ppiov_dma_addr,
};
EXPORT_SYMBOL(dmabuf_devmem_ops);
--
2.39.3