From: Benjamin GAIGNARD <benjamin.gaignard@st.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: "broonie@kernel.org" <broonie@kernel.org>,
"robh@kernel.org" <robh@kernel.org>,
"arnd@arndb.de" <arnd@arndb.de>,
"shawnguo@kernel.org" <shawnguo@kernel.org>,
"s.hauer@pengutronix.de" <s.hauer@pengutronix.de>,
"fabio.estevam@nxp.com" <fabio.estevam@nxp.com>,
"sudeep.holla@arm.com" <sudeep.holla@arm.com>,
"lkml@metux.net" <lkml@metux.net>,
Loic PALLARDY <loic.pallardy@st.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-imx@nxp.com" <linux-imx@nxp.com>,
"kernel@pengutronix.de" <kernel@pengutronix.de>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"system-dt@lists.openampproject.org"
<system-dt@lists.openampproject.org>,
"stefano.stabellini@xilinx.com" <stefano.stabellini@xilinx.com>
Subject: Re: [PATCH v2 2/7] bus: Introduce firewall controller framework
Date: Tue, 28 Jan 2020 20:29:45 +0000 [thread overview]
Message-ID: <62b38576-0e1a-e30e-a954-a8b6a7d8d897@st.com> (raw)
In-Reply-To: <20200128165712.GA3667596@kroah.com>
On 1/28/20 5:57 PM, Greg KH wrote:
> On Tue, Jan 28, 2020 at 04:41:29PM +0000, Benjamin GAIGNARD wrote:
>> On 1/28/20 4:52 PM, Greg KH wrote:
>>> On Tue, Jan 28, 2020 at 04:38:01PM +0100, Benjamin Gaignard wrote:
>>>> The goal of this framework is to offer an interface for the
>>>> hardware blocks controlling bus accesses rights.
>>>>
>>>> Bus firewall controllers are typically used to control if a
>>>> hardware block can perform read or write operations on bus.
>>> So put this in the bus-specific code that controls the bus that these
>>> devices live on. Why put it in the driver core when this is only on one
>>> "bus" (i.e. the catch-all-and-a-bag-of-chips platform bus)?
>> It is really similar to what pin controller does, configuring an
>> hardware block given DT information.
> Great, then use that instead :)
I think that Linus W. will complain if I do that :)
>
>> I could argue that firewalls are not bus themselves they only interact
>> with it.
> They live on a bus, and do so in bus-specific ways, right?
>
>> Bus firewalls exist on other SoC, I hope some others could be added in
>> this framework. ETZPC is only the first.
> Then put it on the bus it lives on, and the bus that the drivers for
> that device are being controlled with. That sounds like the sane place
> to do so, right?
If that means that all drivers have to be modified it will be
problematic because not all
are specifics to the SoC.
>
>>> And really, this should just be a totally new bus type, right? And any
>>> devices on this bus should be changed to be on this new bus, and the
>>> drivers changed to support them, instead of trying to overload the
>>> platform bus with more stuff.
>> I have tried to use the bus notifier to avoid to add this code at probe
>> time but without success:
>>
>> https://lkml.org/lkml/2018/2/27/300
> Almost 2 years ago? I can't remember something written 1 week ago...
>
> Yes, don't abuse the notifier chain. I hate that thing as it is.
>
>> I have also tried to disable the nodes at runtime and Mark Rutland
>> explain me why it was wrong.
> The bus controller should do this, right? Why not just do it there?
The bus controller is a different hardware block.
>
> thanks,
>
> greg k-h
next prev parent reply other threads:[~2020-01-28 20:30 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-28 15:37 [PATCH v2 0/7] Introduce bus firewall controller framework Benjamin Gaignard
2020-01-28 15:38 ` [PATCH v2 1/7] dt-bindings: bus: Add firewall bindings Benjamin Gaignard
2020-01-28 15:38 ` [PATCH v2 2/7] bus: Introduce firewall controller framework Benjamin Gaignard
2020-01-28 15:52 ` Greg KH
2020-01-28 16:41 ` Benjamin GAIGNARD
2020-01-28 16:57 ` Greg KH
2020-01-28 20:29 ` Benjamin GAIGNARD [this message]
2020-01-29 5:49 ` Greg KH
2020-01-29 9:42 ` Linus Walleij
2020-01-29 9:52 ` Greg KH
2020-01-29 11:17 ` Mark Brown
2020-01-31 8:37 ` Benjamin GAIGNARD
2020-01-31 9:06 ` Greg KH
2020-02-14 16:05 ` Linus Walleij
2020-02-14 21:40 ` Greg KH
2020-02-15 12:41 ` Benjamin GAIGNARD
2020-02-16 7:21 ` Greg KH
2020-01-28 15:38 ` [PATCH v2 3/7] base: Add calls to firewall controller Benjamin Gaignard
2020-01-28 15:38 ` [PATCH v2 4/7] dt-bindings: bus: Add STM32 ETZPC " Benjamin Gaignard
2020-01-28 15:38 ` [PATCH v2 5/7] bus: firewall: Add driver for STM32 ETZPC controller Benjamin Gaignard
2020-01-28 15:38 ` [PATCH v2 6/7] ARM: dts: stm32: Add firewall node for stm32mp157 SoC Benjamin Gaignard
2020-01-28 15:38 ` [PATCH v2 7/7] ARM: dts: stm32: enable firewall controller node on stm32mp157c-ed1 Benjamin Gaignard
2020-01-28 16:36 ` [PATCH v2 0/7] Introduce bus firewall controller framework Sudeep Holla
2020-01-28 16:46 ` Benjamin GAIGNARD
2020-01-28 17:17 ` Sudeep Holla
2020-01-28 20:06 ` Benjamin GAIGNARD
2020-01-28 22:06 ` Robin Murphy
2020-01-29 13:40 ` Benjamin GAIGNARD
2020-01-31 18:25 ` Robin Murphy
2020-02-03 13:16 ` Benjamin GAIGNARD
2020-01-31 20:51 ` Florian Fainelli
2020-02-03 13:41 ` Benjamin GAIGNARD
2020-01-31 20:48 ` Florian Fainelli
2020-02-02 12:23 ` Mark Brown
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=62b38576-0e1a-e30e-a954-a8b6a7d8d897@st.com \
--to=benjamin.gaignard@st.com \
--cc=arnd@arndb.de \
--cc=broonie@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=fabio.estevam@nxp.com \
--cc=gregkh@linuxfoundation.org \
--cc=kernel@pengutronix.de \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-imx@nxp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lkml@metux.net \
--cc=loic.pallardy@st.com \
--cc=robh@kernel.org \
--cc=s.hauer@pengutronix.de \
--cc=shawnguo@kernel.org \
--cc=stefano.stabellini@xilinx.com \
--cc=sudeep.holla@arm.com \
--cc=system-dt@lists.openampproject.org \
/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).