net: fbnic: Fix page chunking logic when PAGE_SIZE > 4K

The HW always works on a 4K page size. When the OS supports larger
pages, we fragment them across multiple BDQ descriptors.
We were not properly incrementing the descriptor, which resulted in us
specifying the last chunks id/addr and then 15 zero descriptors. This
would cause packet loss and driver crashes. This is not a fix since the
Kconfig prevents use outside of x86.

Signed-off-by: Dimitri Daskalakis <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

Author: Dimitri Daskalakis

drivers/net/ethernet/meta/fbnic/fbnic_txrx.c

@@ -887,6 +887,7 @@ static void fbnic_bd_prep(struct fbnic_ring *bdq, u16 id, netmem_ref netmem)
 		*bdq_desc = cpu_to_le64(bd);
 		bd += FIELD_PREP(FBNIC_BD_DESC_ADDR_MASK, 1) |
 		      FIELD_PREP(FBNIC_BD_DESC_ID_MASK, 1);
+		bdq_desc++;
 	} while (--i);
 }