lkml.org 
[lkml]   [2019]   [Nov]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [EXT] Re: [net-next] enetc: add support Credit Based Shaper(CBS) for hardware offload
Date
Hi Jakub,

Thanks!


Br,
Po Liu

> -----Original Message-----
> From: Jakub Kicinski <jakub.kicinski@netronome.com>
> Sent: 2019年11月25日 7:35
> To: Po Liu <po.liu@nxp.com>
> Cc: davem@davemloft.net; linux-kernel@vger.kernel.org;
> netdev@vger.kernel.org; vinicius.gomes@intel.com; Claudiu Manoil
> <claudiu.manoil@nxp.com>; Vladimir Oltean <vladimir.oltean@nxp.com>;
> Alexandru Marginean <alexandru.marginean@nxp.com>; Xiaoliang Yang
> <xiaoliang.yang_1@nxp.com>; Roy Zang <roy.zang@nxp.com>; Mingkai Hu
> <mingkai.hu@nxp.com>; Jerry Huang <jerry.huang@nxp.com>; Leo Li
> <leoyang.li@nxp.com>
> Subject: [EXT] Re: [net-next] enetc: add support Credit Based Shaper(CBS) for
> hardware offload
>
> Caution: EXT Email
>
> On Sat, 23 Nov 2019 19:02:09 -0800, Jakub Kicinski wrote:
> > On Fri, 22 Nov 2019 07:17:18 +0000, Po Liu wrote:
> > > + if (tc == prio_top) {
> > > + max_interference_size = port_frame_max_size * 8;
> > > + } else {
> > > + u32 m0, ma, r0, ra;
> > > +
> > > + m0 = port_frame_max_size * 8;
> > > + ma = enetc_port_rd(&si->hw, ENETC_PTCMSDUR(prio_top)) * 8;
> > > + ra = enetc_get_cbs_bw(&si->hw, prio_top) *
> > > + port_transmit_rate * 10000ULL;
> > > + r0 = port_transmit_rate * 1000000ULL;
> > > + max_interference_size = m0 + ma + (u64)ra * m0 / (r0 - ra);
> > > + }
> > > +
> > > + /* hiCredit bits calculate by:
> > > + *
> > > + * maxSizedFrame * (idleSlope/portTxRate)
> > > + */
> > > + hi_credit_bit = max_interference_size * bw / 100;
> > > +
> > > + /* hiCredit bits to hiCredit register need to calculated as:
> > > + *
> > > + * (enetClockFrequency / portTransmitRate) * 100
> > > + */
> > > + hi_credit_reg = (ENETC_CLK * 100ULL) * hi_credit_bit
> > > + / (port_transmit_rate * 1000000ULL);
> >
> > Hi! The patch looks good to me, but I'm concerned about those 64bit
> > divisions here. Don't these need to be div_u64() & co.? Otherwise we
> > may see one of the:
> >
> > ERROR: "__udivdi3" [drivers/net/ethernet/freescale/enetc/fsl-enetc.ko]
> undefined!
> >
> > messages from the build bot..
> >
> > I could be wrong, I haven't actually tested..
>
> Yup:
>
> drivers/net/ethernet/freescale/enetc/enetc_qos.o: In function
> `enetc_setup_tc_cbs':
> enetc_qos.c:(.text+0x5b4): undefined reference to `__udivdi3'
> enetc_qos.c:(.text+0x608): undefined reference to `__udivdi3'
> /home/jkicinski/devel/linux/Makefile:1077: recipe for target 'vmlinux' failed
> make[1]: *** [vmlinux] Error 1
> make[1]: Leaving directory '/home/jkicinski/devel/linux/build_tmp2'
> Makefile:179: recipe for target 'sub-make' failed
> make: *** [sub-make] Error 2
>
> Please fix and repost.

Will update to div_u64().
\
 
 \ /
  Last update: 2019-11-25 04:04    [W:0.044 / U:0.372 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site