DPDK patches and discussions
 help / color / mirror / Atom feed
From: "Chautru, Nicolas" <nicolas.chautru@intel.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>,
	"dev@dpdk.org" <dev@dpdk.org>
Cc: "hemant.agrawal@nxp.com" <hemant.agrawal@nxp.com>,
	"david.marchand@redhat.com" <david.marchand@redhat.com>,
	"Vargas, Hernan" <hernan.vargas@intel.com>
Subject: RE: [PATCH v1 1/7] bbdev: add FFT version member in driver info
Date: Tue, 19 Sep 2023 20:51:58 +0000	[thread overview]
Message-ID: <BY5PR11MB445132533199719F4B2FD341F8FAA@BY5PR11MB4451.namprd11.prod.outlook.com> (raw)
In-Reply-To: <4295bcc3-145d-2bb2-8ce1-4689e7ef7d22@redhat.com>

Hi Maxime, 

This is neither part of 3GPP per se, nor specific to VRB device. Let me provide more context. 
The SRS processing chain (https://doc.dpdk.org/guides/prog_guide/bbdev.html#bbdev-fft-operation) includes a pointwise multiplication by time window. 
The generic API include some control of these windowing function but still the actual shape need to be programmed onto any device (ie. rectangular, taped, sinc, different width or offset, any abritraty shape defined as an array of scalars). These degrees of liberties cannot be exposed through a generic API (information is multi-kB, ie the data itself) and can be user specific (external to the HW IP itself or outside of Intel control).
As an illustration for VRB device pf_bb_config provides to user an option to include such windowing data as an input ("FFT LUT bin file"), but more generally at platform level for any bb device this big Look-Up Table or big array can be configured on the host during platform initialization for a given deployment or vendor. 
What is required here is for the user application to have knowledge of what version of such array is being used on the given platform, as this information would be relevant to processing done outside of bbdev (notably for noise estimate). Through that mechanism, the user can now map through that API which possible file was being used, and act accordingly.
The content itself is not specified, for VRB we just use the md5sum of that binary file (which is just a big array of int16 for point wise multiplication) so that this can be used to share knowledge between initialized platform configuration and at run-time user application assumption. 
It is also important to under that the user/vendor may use any array or shape (based on their algorithm) regardless of Intel or IP, and still be able to share information mapping between what is configured on the platform (multiple versions possible) and what the application enumerates. 

I can add more details in the documentation indeed but above should arguably make sense. The name FFT_version naming may be quite vague, this is more related to the FFT pointwise windowing array variant assumed on the platform. I did not want to impose for it to be an md5sum necessarily, hence the vagueness, as it could be any hash shared between the device programming and the user application related to the semi-static FFT processing programming. 

Let me know if unclear or if any other thought, 
Thanks
Nic

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Tuesday, September 19, 2023 2:56 AM
> To: Chautru, Nicolas <nicolas.chautru@intel.com>; dev@dpdk.org
> Cc: hemant.agrawal@nxp.com; david.marchand@redhat.com; Vargas, Hernan
> <hernan.vargas@intel.com>
> Subject: Re: [PATCH v1 1/7] bbdev: add FFT version member in driver info
> 
> 
> 
> On 9/19/23 03:21, Nicolas Chautru wrote:
> > This can be used to distinguish different version of the flexible
> > pointwise windowing applied to the FFT and expose this to the
> > application.
> 
> Does this version relates to a standard, or is this specific to the
> implementation of your VRB devices?
> 
> > Signed-off-by: Nicolas Chautru <nicolas.chautru@intel.com>
> > ---
> >   lib/bbdev/rte_bbdev.h | 2 ++
> >   1 file changed, 2 insertions(+)
> >
> > diff --git a/lib/bbdev/rte_bbdev.h b/lib/bbdev/rte_bbdev.h index
> > a5bcc09f10..d6e54ee9a4 100644
> > --- a/lib/bbdev/rte_bbdev.h
> > +++ b/lib/bbdev/rte_bbdev.h
> > @@ -349,6 +349,8 @@ struct rte_bbdev_driver_info {
> >   	const struct rte_bbdev_op_cap *capabilities;
> >   	/** Device cpu_flag requirements */
> >   	const enum rte_cpu_flag_t *cpu_flag_reqs;
> > +	/** Versioning number for the FFT operation type. */
> > +	uint16_t fft_version;
> >   };
> >
> >   /** Macro used at end of bbdev PMD list */


  reply	other threads:[~2023-09-19 20:52 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-19  1:21 [PATCH v1 0/7] VRB2 BBDEV PMD introduction Nicolas Chautru
2023-09-19  1:21 ` [PATCH v1 1/7] bbdev: add FFT version member in driver info Nicolas Chautru
2023-09-19  9:55   ` Maxime Coquelin
2023-09-19 20:51     ` Chautru, Nicolas [this message]
2023-09-22  8:14       ` Maxime Coquelin
2023-09-22 16:41         ` Chautru, Nicolas
2023-09-26 10:00           ` Maxime Coquelin
2023-09-27 23:50             ` Chautru, Nicolas
2023-09-28  8:27               ` Maxime Coquelin
2023-09-28 16:33                 ` Chautru, Nicolas
2023-10-03 11:46                   ` Maxime Coquelin
2023-09-19  1:21 ` [PATCH v1 2/7] baseband/acc: add FFT version in the VRM PMD Nicolas Chautru
2023-09-19  1:21 ` [PATCH v1 3/7] baseband/acc: remove the 4G SO capability for VRB1 Nicolas Chautru
2023-09-19 15:20   ` David Marchand
2023-09-19 20:32     ` Chautru, Nicolas
2023-09-21  7:13       ` David Marchand
2023-09-21 17:18         ` Chautru, Nicolas
2023-09-27  7:08           ` Maxime Coquelin
2023-09-27  7:32             ` Maxime Coquelin
2023-09-19  1:21 ` [PATCH v1 4/7] baseband/acc: allocate FCW memory separately Nicolas Chautru
2023-09-19  1:21 ` [PATCH v1 5/7] baseband/acc: add support for MLD operation Nicolas Chautru
2023-09-19  1:21 ` [PATCH v1 6/7] baseband/acc: introduce the new VRB2 variant Nicolas Chautru
2023-09-19  1:21 ` [PATCH v1 7/7] baseband/acc: add configure helper for VRB2 Nicolas Chautru
2023-09-21  7:25 ` [PATCH v1 0/7] VRB2 BBDEV PMD introduction David Marchand

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=BY5PR11MB445132533199719F4B2FD341F8FAA@BY5PR11MB4451.namprd11.prod.outlook.com \
    --to=nicolas.chautru@intel.com \
    --cc=david.marchand@redhat.com \
    --cc=dev@dpdk.org \
    --cc=hemant.agrawal@nxp.com \
    --cc=hernan.vargas@intel.com \
    --cc=maxime.coquelin@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).