On Thu, Mar 21, 2024 at 04:27:26PM +0000, Ferruh Yigit wrote: > On 3/5/2024 8:10 AM, Jiawen Wu wrote: > > <...> > > >>> +++ b/drivers/net/txgbe/txgbe_rxtx_vec_neon.c > >>> @@ -0,0 +1,604 @@ > >>> +/* SPDX-License-Identifier: BSD-3-Clause > >>> + * Copyright(c) 2015-2024 Beijing WangXun Technology Co., Ltd. > >>> + * Copyright(c) 2010-2015 Intel Corporation > >>> + */ > >>> + > >>> +#include <ethdev_driver.h> > >>> +#include <rte_malloc.h> > >>> +#include <rte_vect.h> > >>> + > >>> +#include "txgbe_ethdev.h" > >>> +#include "txgbe_rxtx.h" > >>> +#include "txgbe_rxtx_vec_common.h" > >>> + > >>> +#pragma GCC diagnostic ignored "-Wcast-qual" > >>> + > >> > >> Is this pragma really required? > > > > Yes. Otherwise, there are warnings in the compilation: > > > > [1909/2921] Compiling C object > > drivers/libtmp_rte_net_txgbe.a.p/net_txgbe_txgbe_rxtx_vec_neon.c.o > > ../drivers/net/txgbe/txgbe_rxtx_vec_neon.c: In function ‘txgbe_rxq_rearm’: > > ../drivers/net/txgbe/txgbe_rxtx_vec_neon.c:37:15: warning: cast discards > > ‘volatile’ qualifier from pointer target type [-Wcast-qual] > > vst1q_u64((uint64_t *)&rxdp[i], zero); > > ^ > > ../drivers/net/txgbe/txgbe_rxtx_vec_neon.c:60:13: warning: cast discards > > ‘volatile’ qualifier from pointer target type [-Wcast-qual] > > vst1q_u64((uint64_t *)rxdp++, dma_addr0); > > ^ > > ../drivers/net/txgbe/txgbe_rxtx_vec_neon.c:65:13: warning: cast discards > > ‘volatile’ qualifier from pointer target type [-Wcast-qual] > > vst1q_u64((uint64_t *)rxdp++, dma_addr1); > > > > Hi Honnappa, > > There are multiple drivers ignores "-Wcast-qual" for neon implementation. > > Is there a better, more proper way to address this warning?
rather than suppress the warning you could just cast away the volatile qualifier the common approach is to cast through uintptr_t to discard. volatile uint64_t *vp; uint64_t *p = (uint64_t *)(uintptr_t)vp; perhaps better than broad suppression of warnings. but does require code be reviewed to be certain it is okay to have the qualifier removed which i suspect is okay in functions that are inline assembly or intrinsics. > > > Thanks, > ferruh
