linux-kernel - Re: [RFC PATCH 4/4] ARM: Xilinx: Adding Xilinx board support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <201105030958.14698.arnd@arndb.de>
Date:	Tue, 3 May 2011 09:58:14 +0200
From:	Arnd Bergmann <arnd@...db.de>
To:	linux-arm-kernel@...ts.infradead.org
Cc:	"Russell King - ARM Linux" <linux@....linux.org.uk>,
	johnlinn@...cast.net, nicolas pitre <nicolas.pitre@...aro.org>,
	devicetree-discuss@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
	grant likely <grant.likely@...retlab.ca>,
	john linn <john.linn@...inx.com>
Subject: Re: [RFC PATCH 4/4] ARM: Xilinx: Adding Xilinx board support

On Tuesday 03 May 2011 01:01:18 Russell King - ARM Linux wrote:
> It is preferable to use the same mapping, as it ensures that you're not
> going to create incompatible aliases.

Is aliasing a problem for MMIO mappings? I would think that you can
ioremap registers anywhere and as often as you want because they are
never cacheable.

> But, before we get too bogged down with this, please realise that it is
> possible to setup early mappings from the device tree for things like the
> SCU.  Maybe not using ioremap(), but I'm sure we can find some way to use
> the iotable_init() stuff to setup some early mappings from DT for this
> stuff.

Good point. It doesn't really matter how the entries get into the page
table, whether you call it ioremap, iotable_init, create_mapping or
ioremap_early. What matters is that we don't hardcode the physical
address in the board code, because that limits the possible reuse
on other device tree enabled targets.

	Arnd
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/