From: hli@broadcom.com (Henry Li)
To: linux-arm-kernel@lists.infradead.org
Subject: Alignment Requirement for MT_MEMORY type
Date: Thu, 18 Feb 2010 10:08:36 -0800 [thread overview]
Message-ID: <B125D8217ABC4B43826503DE00A2D44910F4639C3F@SJEXCHCCR01.corp.ad.broadcom.com> (raw)
In-Reply-To: <20100218085125.GA848@n2100.arm.linux.org.uk>
On Wed, Feb 17, 2010 at 04:33:00PM -0800, Henry Li wrote:
> Can someone tell me why there is a requirement for the virtual and
> physical addresses and size using MT_MEMORY memtype (where prot_l1=0)
> to be aligned to section boundary (1MB) in
> linux-2.6.32/arch/arm/mm/mmu.c/create_mapping
> during IO table init?
Because today SDRAM is always a whole number of MB, so its pointless defining it in terms of 4K pages. MT_MEMORY is not for general purpose use, but only for setting up the initial kernel SDRAM mapping.
>> I see. The platform I am working with has 160kB of SRAM that I need to map as cacheable and shareable but its physical address is not 1MB aligned. Is there suitable memtype that I could use to map this?
next prev parent reply other threads:[~2010-02-18 18:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-18 0:33 Alignment Requirement for MT_MEMORY type Henry Li
2010-02-18 8:51 ` Russell King - ARM Linux
2010-02-18 18:08 ` Henry Li [this message]
2010-02-19 8:44 ` Linus Walleij
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=B125D8217ABC4B43826503DE00A2D44910F4639C3F@SJEXCHCCR01.corp.ad.broadcom.com \
--to=hli@broadcom.com \
--cc=linux-arm-kernel@lists.infradead.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.