[PATCH net-next v4 3/5] page_pool: Set `dma_sync` to false for devmem memory provider

[Mina Almasry <almasrymina@google.com>]

From: Samiullah Khawaja <skhawaja@google.com>

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@ziepe.ca>
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Signed-off-by: Mina Almasry <almasrymina@google.com>

---

v4:
- Improve comment (Jakub)

---
 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..3ebdeed2bf18 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 do not need and 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