for the virtual net device such as veth, there is
no need to do dma check if we support zero copy.
add this flag after unaligned. beacause there is 4 bytes hole
pahole -V ./net/xdp/xsk_buff_pool.o:
-----------
...
/* --- cacheline 3 boundary (192 bytes) --- */
u32 chunk_size; /* 192 4 */
u32 frame_len; /* 196 4 */
u8 cached_need_wakeup; /* 200 1 */
bool uses_need_wakeup; /* 201 1 */
bool dma_need_sync; /* 202 1 */
bool unaligned; /* 203 1 */
/* XXX 4 bytes hole, try to pack */
void * addrs; /* 208 8 */
spinlock_t cq_lock; /* 216 4 */
...
-----------
Signed-off-by: Albert Huang <[email protected]>
---
include/net/xsk_buff_pool.h | 1 +
net/xdp/xsk_buff_pool.c | 3 ++-
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h
index b0bdff26fc88..fe31097dc11b 100644
--- a/include/net/xsk_buff_pool.h
+++ b/include/net/xsk_buff_pool.h
@@ -81,6 +81,7 @@ struct xsk_buff_pool {
bool uses_need_wakeup;
bool dma_need_sync;
bool unaligned;
+ bool dma_check_skip;
void *addrs;
/* Mutual exclusion of the completion ring in the SKB mode. Two cases to protect:
* NAPI TX thread and sendmsg error paths in the SKB destructor callback and when
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index b3f7b310811e..ed251b8e8773 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -85,6 +85,7 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
XDP_PACKET_HEADROOM;
pool->umem = umem;
pool->addrs = umem->addrs;
+ pool->dma_check_skip = false;
INIT_LIST_HEAD(&pool->free_list);
INIT_LIST_HEAD(&pool->xskb_list);
INIT_LIST_HEAD(&pool->xsk_tx_list);
@@ -202,7 +203,7 @@ int xp_assign_dev(struct xsk_buff_pool *pool,
if (err)
goto err_unreg_pool;
- if (!pool->dma_pages) {
+ if (!pool->dma_pages && !pool->dma_check_skip) {
WARN(1, "Driver did not DMA map zero-copy buffers");
err = -EINVAL;
goto err_unreg_xsk;
--
2.20.1