From: Thomas Bogendoerfer <tbogendoerfer@suse.de>
To: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Jonathan Corbet <corbet@lwn.net>,
Ralf Baechle <ralf@linux-mips.org>,
Paul Burton <paul.burton@mips.com>,
James Hogan <jhogan@kernel.org>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Lee Jones <lee.jones@linaro.org>,
"David S. Miller" <davem@davemloft.net>,
Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
Alessandro Zummo <a.zummo@towertech.it>,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>, Evgeniy Polyakov <zbr@ioremap.net>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mips@vger.kernel.org, linux-input@vger.kernel.org,
netdev@vger.kernel.org, linux-rtc@vger.kernel.org,
linux-serial@vger.kernel.org
Subject: Re: [PATCH v5 10/17] net: sgi: ioc3-eth: rework skb rx handling
Date: Wed, 21 Aug 2019 16:28:47 +0200 [thread overview]
Message-ID: <20190821162847.479c9967d4dc8026fe65fa0e@suse.de> (raw)
In-Reply-To: <20190819165522.451f2ea2@cakuba.netronome.com>
On Mon, 19 Aug 2019 16:55:22 -0700
Jakub Kicinski <jakub.kicinski@netronome.com> wrote:
> On Mon, 19 Aug 2019 18:31:33 +0200, Thomas Bogendoerfer wrote:
> > Buffers alloacted by alloc_skb() are already cache aligned so there
> > is no need for an extra align done by ioc3_alloc_skb. And instead
> > of skb_put/skb_trim simply use one skb_put after frame size is known
> > during receive.
> [...]
> > -/* We use this to acquire receive skb's that we can DMA directly into. */
> > -
> > -#define IOC3_CACHELINE 128UL
>
> Is the cache line on the platform this driver works on 128B?
right now yes, in theory IOC3 CAD DUO cards might work in SGI O2 systems,
but the current Linux PCI implementation for O2 will not detect that card.
On X86 usually the BIOS will choke up on that cards.
> This looks like a DMA engine alignment requirement, more than an
> optimization.
that true, there are two constraints for the rx buffers, start must be aligned
to 128 bytes and a buffer must not cross a 16kbyte boundary. I was already
thinking of allocating pages and chop them up. Is there a Linux API available,
which could help for implementing this ?
I'll probably drop this patch or only change the skb_put stuff plus RX_BUF_SIZE
define.
Thomas.
--
SUSE Linux GmbH
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)
next prev parent reply other threads:[~2019-08-21 14:28 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-19 16:31 [PATCH v5 00/17] Use MFD framework for SGI IOC3 drivers Thomas Bogendoerfer
2019-08-19 16:31 ` [PATCH v5 01/17] w1: add 1-wire master driver for IP block found in SGI ASICs Thomas Bogendoerfer
2019-08-19 16:31 ` [PATCH v5 02/17] w1: add DS2501, DS2502, DS2505 EPROM device driver Thomas Bogendoerfer
2019-08-19 16:31 ` [PATCH v5 03/17] nvmem: core: add nvmem_device_find Thomas Bogendoerfer
2019-08-19 16:31 ` [PATCH v5 04/17] MIPS: PCI: refactor ioc3 special handling Thomas Bogendoerfer
2019-09-03 9:10 ` Paul Burton
2019-08-19 16:31 ` [PATCH v5 05/17] MIPS: PCI: use information from 1-wire PROM for IOC3 detection Thomas Bogendoerfer
2019-08-19 16:31 ` [PATCH v5 06/17] MIPS: SGI-IP27: remove ioc3 ethernet init Thomas Bogendoerfer
2019-08-19 16:31 ` [PATCH v5 07/17] MIPS: SGI-IP27: restructure ioc3 register access Thomas Bogendoerfer
2019-08-19 16:31 ` [PATCH v5 08/17] net: sgi: ioc3-eth: remove checkpatch errors/warning Thomas Bogendoerfer
2019-08-19 16:31 ` [PATCH v5 09/17] net: sgi: ioc3-eth: use defines for constants dealing with desc rings Thomas Bogendoerfer
2019-08-19 23:53 ` Jakub Kicinski
2019-08-19 16:31 ` [PATCH v5 10/17] net: sgi: ioc3-eth: rework skb rx handling Thomas Bogendoerfer
2019-08-19 23:55 ` Jakub Kicinski
2019-08-21 14:28 ` Thomas Bogendoerfer [this message]
2019-08-21 20:37 ` Jakub Kicinski
2019-08-19 16:31 ` [PATCH v5 11/17] net: sgi: ioc3-eth: no need to stop queue set_multicast_list Thomas Bogendoerfer
2019-08-20 0:04 ` Jakub Kicinski
2019-08-21 12:40 ` Thomas Bogendoerfer
2019-08-19 16:31 ` [PATCH v5 12/17] net: sgi: ioc3-eth: use dma-direct for dma allocations Thomas Bogendoerfer
2019-08-20 0:07 ` Jakub Kicinski
2019-08-19 16:31 ` [PATCH v5 13/17] net: sgi: ioc3-eth: use csum_fold Thomas Bogendoerfer
2019-08-19 16:31 ` [PATCH v5 14/17] net: sgi: ioc3-eth: Fix IPG settings Thomas Bogendoerfer
2019-08-19 16:31 ` [PATCH v5 15/17] mfd: ioc3: Add driver for SGI IOC3 chip Thomas Bogendoerfer
2019-08-20 6:23 ` Alexandre Belloni
2019-08-20 8:17 ` Thomas Bogendoerfer
2019-08-19 16:31 ` [PATCH v5 16/17] MIPS: SGI-IP27: fix readb/writeb addressing Thomas Bogendoerfer
2019-08-19 16:31 ` [PATCH v5 17/17] Input: add IOC3 serio driver Thomas Bogendoerfer
2019-08-19 23:51 ` [PATCH v5 00/17] Use MFD framework for SGI IOC3 drivers Jakub Kicinski
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