i40e: Fix the inability to attach XDP program on downed interface

[ Upstream commit 0c87b545a2ed5cd8a6318011f1c92b188c2d74bc ]

Whenever trying to load XDP prog on downed interface, function i40e_xdp
was passing vsi->rx_buf_len field to i40e_xdp_setup() which was equal 0.
i40e_open() calls i40e_vsi_configure_rx() which configures that field,
but that only happens when interface is up. When it is down, i40e_open()
is not being called, thus vsi->rx_buf_len is not set.

Solution for this is calculate buffer length in newly created
function - i40e_calculate_vsi_rx_buf_len() that return actual buffer
length. Buffer length is being calculated based on the same rules
applied previously in i40e_vsi_configure_rx() function.

Fixes: 613142b0bb88 ("i40e: Log error for oversized MTU on device")
Fixes: 0c8493d90b6b ("i40e: add XDP support for pass and drop actions")
Signed-off-by: Bartosz Staszewski <bartoszx.staszewski@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: Shwetha Nagaraju <Shwetha.nagaraju@intel.com>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Reviewed-by: Saeed Mahameed <saeed@kernel.com>
Link: https://lore.kernel.org/r/20221209185411.2519898-1-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/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 6416322..e6e349f 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3694,6 +3694,24 @@ static int i40e_vsi_configure_tx(struct i40e_vsi *vsi)
 }
 
 /**
+ * i40e_calculate_vsi_rx_buf_len - Calculates buffer length
+ *
+ * @vsi: VSI to calculate rx_buf_len from
+ */
+static u16 i40e_calculate_vsi_rx_buf_len(struct i40e_vsi *vsi)
+{
+       if (!vsi->netdev || (vsi->back->flags & I40E_FLAG_LEGACY_RX))
+               return I40E_RXBUFFER_2048;
+
+#if (PAGE_SIZE < 8192)
+       if (!I40E_2K_TOO_SMALL_WITH_PADDING && vsi->netdev->mtu <= ETH_DATA_LEN)
+               return I40E_RXBUFFER_1536 - NET_IP_ALIGN;
+#endif
+
+       return PAGE_SIZE < 8192 ? I40E_RXBUFFER_3072 : I40E_RXBUFFER_2048;
+}
+
+/**
  * i40e_vsi_configure_rx - Configure the VSI for Rx
  * @vsi: the VSI being configured
  *
@@ -3704,20 +3722,14 @@ static int i40e_vsi_configure_rx(struct i40e_vsi *vsi)
        int err = 0;
        u16 i;
 
-       if (!vsi->netdev || (vsi->back->flags & I40E_FLAG_LEGACY_RX)) {
-               vsi->max_frame = I40E_MAX_RXBUFFER;
-               vsi->rx_buf_len = I40E_RXBUFFER_2048;
+       vsi->max_frame = I40E_MAX_RXBUFFER;
+       vsi->rx_buf_len = i40e_calculate_vsi_rx_buf_len(vsi);
+
 #if (PAGE_SIZE < 8192)
-       } else if (!I40E_2K_TOO_SMALL_WITH_PADDING &&
-                  (vsi->netdev->mtu <= ETH_DATA_LEN)) {
+       if (vsi->netdev && !I40E_2K_TOO_SMALL_WITH_PADDING &&
+           vsi->netdev->mtu <= ETH_DATA_LEN)
                vsi->max_frame = I40E_RXBUFFER_1536 - NET_IP_ALIGN;
-               vsi->rx_buf_len = I40E_RXBUFFER_1536 - NET_IP_ALIGN;
 #endif
-       } else {
-               vsi->max_frame = I40E_MAX_RXBUFFER;
-               vsi->rx_buf_len = (PAGE_SIZE < 8192) ? I40E_RXBUFFER_3072 :
-                                                      I40E_RXBUFFER_2048;
-       }
 
        /* set up individual rings */
        for (i = 0; i < vsi->num_queue_pairs && !err; i++)
@@ -13282,7 +13294,7 @@ static int i40e_xdp_setup(struct i40e_vsi *vsi, struct bpf_prog *prog,
        int i;
 
        /* Don't allow frames that span over multiple buffers */
-       if (frame_size > vsi->rx_buf_len) {
+       if (frame_size > i40e_calculate_vsi_rx_buf_len(vsi)) {
                NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
                return -EINVAL;
        }