From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: [PATCH 4/7] MIPS: Octeon: Add Free Pointer Unit (FPA) support. Date: Thu, 2 Nov 2017 11:04:26 -0700 Message-ID: <70fa7ec2-3e6d-e420-ff57-b34dc7ec311e@gmail.com> References: <20171102003606.19913-1-david.daney@cavium.com> <20171102003606.19913-5-david.daney@cavium.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Content-Language: en-US Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: David Daney , David Daney , linux-mips-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org, ralf-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org, James Hogan , netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "David S. Miller" , Rob Herring , Mark Rutland Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Steven J. Hill" , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Carlos Munoz List-Id: devicetree@vger.kernel.org On 11/02/2017 09:27 AM, David Daney wrote: > On 11/01/2017 08:29 PM, Florian Fainelli wrote: >> Le 11/01/17 à 17:36, David Daney a écrit : >>> From: Carlos Munoz >>> >>> From the hardware user manual: "The FPA is a unit that maintains >>> pools of pointers to free L2/DRAM memory. To provide QoS, the pools >>> are referenced indirectly through 1024 auras. Both core software >>> and hardware units allocate and free pointers." >> >> This looks like a possibly similar implement to what >> drivers/net/ethernet/marvell/mvneta_bm.c, can you see if you can make >> any use of genpool_* and include/net/hwbm.h here as well? > > Yikes! Is it permitted to put function definitions that are not "static > inline" in header files? Meh well, this is not even ressembling what we initially discussed, so I was hoping we could build more interesting features on top of this. > > The driver currently doesn't use page fragments, so I don't think that > the hwbm thing can be used. > > Also the FPA unit is used to control RED and back pressure in the PKI > (packet input processor), which are features that are features not > considered in hwbm. > > The OCTEON-III hardware also uses the FPA for non-packet-buffer memory > allocations. So for those, it seems that hwbm is also not a good fit. OK, let me see if I understand how FPA works, can we say that this is more or less a buffer tokenizer in that, you give it a buffer physical address and it returns an unique identifier that the FPA uses for actual packet passing, transmission and other manipulations? There were a few funky things in the network driver, I will comment there. -- Florian -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html