From: Paul Murphy <paul.j.murphy@linux.intel.com>
To: Florian Fainelli <f.fainelli@gmail.com>,
Daniele Alessandrelli <daniele.alessandrelli@linux.intel.com>,
Sudeep Holla <sudeep.holla@arm.com>,
linux-arm-kernel@lists.infradead.org
Cc: Peng Fan <peng.fan@nxp.com>,
"Paul J. Murphy" <paul.j.murphy@intel.com>,
linux-kernel@vger.kernel.org,
Daniele Alessandrelli <daniele.alessandrelli@intel.com>
Subject: Re: [PATCH] firmware: arm_scmi: Pass shmem address to SMCCC call
Date: Fri, 17 Jul 2020 15:00:16 +0100 [thread overview]
Message-ID: <1117fc3b-3c35-c66c-bf73-cb879a08bde5@linux.intel.com> (raw)
In-Reply-To: <faa53c11-3c72-9b9b-85ad-9d234f373b4d@gmail.com>
Hi Florian
On 7/16/20 20:57, Florian Fainelli wrote:
>>>
>>> Given that the kernel must somehow reserve this memory as a shared
>>> memory area for obvious reasons, and the trusted firmware must also
>>> ensure it treats this memory region with specific permissions in its
>>> translation regime, does it really make sense to give that much
>>> flexibility?
>>
>> Well, the trusted firmware might reserve a bigger region to be used for
>> other service as well. In other words, the MMU of TF-A is not necessary
>> specifically set up for this region, but, possibly, for a bigger
>> general shared region.
>
> But presumably the Linux shared memory area should be mapped in a
> slightly different way than
>
Sorry - could you clarify what you mean by that?
Just checking if we are doing everything correctly.
I didn't understand that there is a connection between the TF-A MMU
tables for this region and the normal world MMU tables?
For example:
TF-A may map physical address range: 0x0 -> 0x400_000 as 'normal' memory
for various purposes.
Linux SCMI driver could map physical address range, eg: 0x300_000 ->
0x301_000 as IO memory for mailbox purpose only.
Is there any issue here?
Regards,
Paul
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-07-17 14:01 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-15 16:55 [PATCH] firmware: arm_scmi: Pass shmem address to SMCCC call Daniele Alessandrelli
2020-07-15 22:43 ` Florian Fainelli
2020-07-16 14:13 ` Daniele Alessandrelli
2020-07-16 19:57 ` Florian Fainelli
2020-07-17 10:31 ` Sudeep Holla
2020-07-17 14:59 ` Daniele Alessandrelli
2020-07-17 14:00 ` Paul Murphy [this message]
2020-07-17 14:42 ` Daniele Alessandrelli
2020-07-17 10:08 ` Sudeep Holla
2020-07-17 9:45 ` Sudeep Holla
2020-07-17 18:01 ` Florian Fainelli
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=1117fc3b-3c35-c66c-bf73-cb879a08bde5@linux.intel.com \
--to=paul.j.murphy@linux.intel.com \
--cc=daniele.alessandrelli@intel.com \
--cc=daniele.alessandrelli@linux.intel.com \
--cc=f.fainelli@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=paul.j.murphy@intel.com \
--cc=peng.fan@nxp.com \
--cc=sudeep.holla@arm.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).