Re: [dpdk-dev] [PATCH] net/nfp: add CPP bridge as service

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 1/10/2019 11:55 AM, Alejandro Lucero wrote:
> 
> 
> On Wed, Jan 9, 2019 at 4:15 PM Ferruh Yigit <ferruh.yigit@intel.com
> <mailto:ferruh.yigit@intel.com>> wrote:
> 
>     On 1/9/2019 2:20 PM, Alejandro Lucero wrote:
>     >
>     >
>     > On Wed, Jan 9, 2019 at 10:54 AM Ferruh Yigit <ferruh.yigit@intel.com
>     <mailto:ferruh.yigit@intel.com>
>     > <mailto:ferruh.yigit@intel.com <mailto:ferruh.yigit@intel.com>>> wrote:
>     >
>     >     On 1/3/2019 8:56 AM, Alejandro Lucero wrote:
>     >     > The Netronome's Network Flow Processor chip is highly programmable
>     >     > with the goal of processing packets at high speed. Processing units
>     >     > and other chip components are available from the host through the
>     >     > PCIe CPP(Command Push Pull bus) interface. The NFP PF PMD configures
>     >     > a CPP handler for setting up and working with vNICs, perform actions
>     >     > like link up or down, or accessing extended stats from the MAC
>     component.
>     >     >
>     >     > There exist NFP host tools which access the NFP components for
>     >     > programming and debugging but they require the CPP interface. When the
>     >     > PMD is bound to the PF, the DPDK app owns the CPP interface, so these
>     >     > host tools can not access the NFP through other means like NFP kernel
>     >     > drivers.
>     >     >
>     >     > This patch adds a CPP bridge using the rte_service API which can be
>     >     > enabled by a DPDK app. Interestingly, DPDK clients like OVS will not
>     >     > enable specific service cores, but this can be performed with a
>     >     > secondary process specifically enabling this CPP bridge service and
>     >     > therefore giving access to the NFP to those host tools.
>     >
>     >     Hi Alejandro,
>     >
>     >
>     > Hi Ferruh,
>     >  
>     >
>     >     Getting a few build errors, more details below.
>     >
>     >     >
>     >     > Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com
>     <mailto:alejandro.lucero@netronome.com>
>     >     <mailto:alejandro.lucero@netronome.com
>     <mailto:alejandro.lucero@netronome.com>>>
>     >     <...>
>     >
>     >     > +     /* Obtain target's CPP ID and offset in target */
>     >     > +     cpp_id = (offset >> 40) << 8;
>     >
>     >     With icc, i686 getting [1], it seems 'off_t' is 32bits long on 32bit
>     build.
>     >
>     >     [1]
>     >     error #63: shift count is too large
>     >
>     >
>     > We do not support 32 bits. I thought our PMD was not built in that case.
> 
>     If PMD doesn't support 32 bits, above is OK, I will update my script
>     accordingly.
> 
>     >  
>     >
>     >     <...>
>     >
>     >     > +                     if (err != (int)len) {
>     >     > +                             printf("%s: error when receiving, %d
>     of %lu\n",
>     >     > +                                     __func__, err, count);
>     >
>     >     Giving build error for 32bits [3], and can you please use logging
>     macros instead
>     >     of printf?
>     >
>     >
>     > Sure.
>     >  
>     >
>     >     [3]
>     >     error: format ‘%lu’ expects argument of type ‘long unsigned int’, but
>     argument 4
>     >     has type ‘size_t’ {aka ‘unsigned int’} [-Werror=format=] 
>     >
>     >     <...>
>     >
>     >     > +     /* Obtain target's CPP ID and offset in target */
>     >     > +     cpp_id = (offset >> 40) << 8;
>     >
>     >     Same as above [1].
>     >
>     >     <...>
>     >
>     >     > +                     if (err != (int)len) {
>     >     > +                             printf("%s: error when sending: %d of
>     %lu\n",
>     >     > +                                     __func__, err, count);
>     >
>     >     Same build error with above [3].
>     >
>     >     <...>
>     >
>     >     > +nfp_cpp_bridge_serve_ioctl(int sockfd, struct nfp_cpp *cpp)
>     >     > +{
>     >     > +     int cmd, err;
>     >     > +     uint32_t ident_size, tmp;
>     >     > +
>     >     > +     /* Reading now the IOCTL command */
>     >     > +     err = recv(sockfd, &cmd, 4, 0);
>     >     > +     if (err != 4) {
>     >     > +             printf("%s: read error from socket\n", __func__);
>     >     > +             return -EIO;
>     >     > +     }
>     >     > +
>     >     > +     /* Only supporting NFP_IOCTL_CPP_IDENTIFICATION */
>     >     > +     if (cmd != NFP_IOCTL_CPP_IDENTIFICATION) {
>     >
>     >     Giving build error with ppc_64-power8-linuxapp-gcc [2].
>     >
>     >
>     > We do not support power architecture.
> 
>     Yes but issue seems not exactly ppc issue, more like signed - unsigned
>     comparison. Can you please check if is there any valid issue here?
> 
> 
> This is a funny one. NFP_IOCTL_CPP_IDENTIFICATION is not zero, and cmd could be
> anything. 
> And it does work with other compilers!
> 
> Talking with a compiler guy in the office, and it is hard to know why the
> compiler is triggering an error here. I suspect this is some sort of endianness
> mess, and he thinks the compiler could be assuming the cmd variable after recv
> call is always negative or positive, and the macro always being the opposite in
> powerpc, so the comparison is always true, what is what the error message says.
> 
> Anyway, it is not clear how to fix this. Maybe defining cmd as uint32_t could
> help. Any change we can test this before sending another patch version?

I am using a cross compiler for ppc, it is freely available, you should be able
to get and test with it, or I can test for you if you prefer.

> 
>  
> 
>     >  
>     >
>     >     [2]
>     >     error: comparison is always true due to limited range of data type
>     >     [-Werror=type-limits]
>     >
>