[PATCH 0/2] ethdev: support single queue per port

[Morten Brørup]

When configuring DPDK for one queue per port
(#define RTE_MAX_QUEUES_PER_PORT 1), compilation of some network drivers
fails with e.g.:

../drivers/net/bnxt/bnxt_rxq.c: In function 'bnxt_rx_queue_stop':
../drivers/net/bnxt/bnxt_rxq.c:587:34: error: array subscript 1 is above array bounds of 'uint8_t[1]' {aka 'unsigned char[1]'} [-Werror=array-bounds=]
  587 |         dev->data->rx_queue_state[q_id] = RTE_ETH_QUEUE_STATE_STOPPED;
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
In file included from ../drivers/net/bnxt/bnxt.h:16,
                 from ../drivers/net/bnxt/bnxt_rxq.c:10:
../lib/ethdev/ethdev_driver.h:168:17: note: while referencing 'rx_queue_state'
  168 |         uint8_t rx_queue_state[RTE_MAX_QUEUES_PER_PORT];
      |                 ^~~~~~~~~~~~~~

This series fixes those compiler emitted errros as follows:
1. A precondition hint macro is introduced, which can be used to prevent
   the compiler/optimizer from considering scenarios that cannot occur.
2. The hint is added to the network drivers where a compiler in the CI has
   been seen to emit the above error when DPDK is configured for one queue
   per port, but we know that the error cannot occur.

Morten Brørup (2):
  eal: add unreachable and precondition hints
  drivers/net: support single queue per port

 drivers/net/bnxt/bnxt_ethdev.c      |  2 ++
 drivers/net/bnxt/bnxt_rxq.c         |  1 +
 drivers/net/e1000/igb_rxtx.c        |  2 ++
 drivers/net/failsafe/failsafe_ops.c | 10 ++++++++--
 drivers/net/hns3/hns3_rxtx.c        |  2 ++
 drivers/net/mana/tx.c               |  1 +
 lib/eal/include/rte_common.h        | 27 +++++++++++++++++++++++++++
 7 files changed, 43 insertions(+), 2 deletions(-)

-- 
2.43.0