ice: xsk: do not use xdp_return_frame() on tx_buf->raw_buf

[ Upstream commit 53fc61be273a1e76dd5e356f91805dce00ff2d2c ]

Previously ice XDP xmit routine was changed in a way that it avoids
xdp_buff->xdp_frame conversion as it is simply not needed for handling
XDP_TX action and what is more it saves us CPU cycles. This routine is
re-used on ZC driver to handle XDP_TX action.

Although for XDP_TX on Rx ZC xdp_buff that comes from xsk_buff_pool is
converted to xdp_frame, xdp_frame itself is not stored inside
ice_tx_buf, we only store raw data pointer. Casting this pointer to
xdp_frame and calling against it xdp_return_frame in
ice_clean_xdp_tx_buf() results in undefined behavior.

To fix this, simply call page_frag_free() on tx_buf->raw_buf.
Later intention is to remove the buff->frame conversion in order to
simplify the codebase and improve XDP_TX performance on ZC.

Fixes: 126cdfe1007a ("ice: xsk: Improve AF_XDP ZC Tx and use batching API")
Reported-and-tested-by: Robin Cowley <robin.cowley@thehutgroup.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Chandan Kumar Rout <chandanx.rout@intel.com> (A Contingent Worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Reviewed-by: Piotr Raczynski <piotr.raczynski@.intel.com>
Link: https://lore.kernel.org/r/20221220175448.693999-1-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
index 056c904..79fa65d 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -772,7 +772,7 @@ construct_skb:
 static void
 ice_clean_xdp_tx_buf(struct ice_tx_ring *xdp_ring, struct ice_tx_buf *tx_buf)
 {
-       xdp_return_frame((struct xdp_frame *)tx_buf->raw_buf);
+       page_frag_free(tx_buf->raw_buf);
        xdp_ring->xdp_tx_active--;
        dma_unmap_single(xdp_ring->dev, dma_unmap_addr(tx_buf, dma),
                         dma_unmap_len(tx_buf, len), DMA_TO_DEVICE);