[PATCH net-next v3 3/5] page_pool: Set `dma_sync` to false for devmem memory provider

From: Mina Almasry
Date: Mon Dec 09 2024 - 12:24:08 EST


From: Samiullah Khawaja <skhawaja@xxxxxxxxxx>

Move the `dma_map` and `dma_sync` checks to `page_pool_init` to make
them generic. Set dma_sync to false for devmem memory provider because
the dma_sync APIs should not be used for dma_buf backed devmem memory
provider.

Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Signed-off-by: Samiullah Khawaja <skhawaja@xxxxxxxxxx>
Signed-off-by: Mina Almasry <almasrymina@xxxxxxxxxx>

---
net/core/devmem.c | 9 ++++-----
net/core/page_pool.c | 3 +++
2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/net/core/devmem.c b/net/core/devmem.c
index 11b91c12ee11..826d0b00159f 100644
--- a/net/core/devmem.c
+++ b/net/core/devmem.c
@@ -331,11 +331,10 @@ int mp_dmabuf_devmem_init(struct page_pool *pool)
if (!binding)
return -EINVAL;

- if (!pool->dma_map)
- return -EOPNOTSUPP;
-
- if (pool->dma_sync)
- return -EOPNOTSUPP;
+ /* dma-buf dma addresses should not be used with
+ * dma_sync_for_cpu/device. Force disable dma_sync.
+ */
+ pool->dma_sync = false;

if (pool->p.order != 0)
return -E2BIG;
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 3c0e19e13e64..060450082342 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -287,6 +287,9 @@ static int page_pool_init(struct page_pool *pool,
}

if (pool->mp_priv) {
+ if (!pool->dma_map || !pool->dma_sync)
+ return -EOPNOTSUPP;
+
err = mp_dmabuf_devmem_init(pool);
if (err) {
pr_warn("%s() mem-provider init failed %d\n", __func__,
--
2.47.0.338.g60cca15819-goog