cxgb4/cxgb4vf: Add code to calculate T5 BAR2 Offsets for SGE Queue Registers
Hello Hariprasad Shenai,
The patch e85c9a7abfa4: "cxgb4/cxgb4vf: Add code to calculate T5 BAR2 Offsets for SGE Queue Registers" from Dec 3, 2014, leads to the following static checker warning:
drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:5358 t4_bar2_sge_qregs() warn: should '(qid >> qpp_shift) << page_shift' be a 64 bit type?
drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
5326 int t4_bar2_sge_qregs(struct adapter *adapter,
5327 unsigned int qid,
5328 enum t4_bar2_qtype qtype,
5329 u64 *pbar2_qoffset,
5330 unsigned int *pbar2_qid)
5331 {
5332 unsigned int page_shift, page_size, qpp_shift, qpp_mask;
5333 u64 bar2_page_offset, bar2_qoffset;
5334 unsigned int bar2_qid, bar2_qid_offset, bar2_qinferred;
5335
5336 /* T4 doesn't support BAR2 SGE Queue registers.
5337 */
5338 if (is_t4(adapter->params.chip))
5339 return -EINVAL;
5340
5341 /* Get our SGE Page Size parameters.
5342 */
5343 page_shift = adapter->params.sge.hps + 10;
5344 page_size = 1 << page_shift;
5345
5346 /* Get the right Queues per Page parameters for our Queue.
5347 */
5348 qpp_shift = (qtype = T4_BAR2_QTYPE_EGRESS
5349 ? adapter->params.sge.eq_qpp
5350 : adapter->params.sge.iq_qpp);
5351 qpp_mask = (1 << qpp_shift) - 1;
5352
5353 /* Calculate the basics of the BAR2 SGE Queue register area:
5354 * o The BAR2 page the Queue registers will be in.
5355 * o The BAR2 Queue ID.
5356 * o The BAR2 Queue ID Offset into the BAR2 page.
5357 */
5358 bar2_page_offset = ((qid >> qpp_shift) << page_shift);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^The static checker is complaining that it can not use the high 32 bytes unless we add a cast. This is using custom page sizes here so I'm not sure exactly what's going on or if declaring this as u64 was necessary.
5359 bar2_qid = qid & qpp_mask; 5360 bar2_qid_offset = bar2_qid * SGE_UDB_SIZE;
regards,
dan carpenter