From owner-freebsd-mips@FreeBSD.ORG  Tue Jan 13 19:06:35 2015
Return-Path: <owner-freebsd-mips@FreeBSD.ORG>
Delivered-To: freebsd-mips@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115])
 (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id E7DF5141
 for <freebsd-mips@freebsd.org>; Tue, 13 Jan 2015 19:06:35 +0000 (UTC)
Received: from mwork.nabble.com (mwork.nabble.com [162.253.133.43])
 by mx1.freebsd.org (Postfix) with ESMTP id D2CCCC75
 for <freebsd-mips@freebsd.org>; Tue, 13 Jan 2015 19:06:35 +0000 (UTC)
Received: from msam.nabble.com (unknown [162.253.133.85])
 by mwork.nabble.com (Postfix) with ESMTP id A60F710682C3
 for <freebsd-mips@freebsd.org>; Tue, 13 Jan 2015 11:06:36 -0800 (PST)
Date: Tue, 13 Jan 2015 12:06:34 -0700 (MST)
From: sson <sson@FreeBSD.org>
To: freebsd-mips@freebsd.org
Message-ID: <1421175994697-5980362.post@n5.nabble.com>
Subject: [RFC] Cache control from user land (patch)
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-BeenThere: freebsd-mips@freebsd.org
X-Mailman-Version: 2.1.18-1
Precedence: list
List-Id: Porting FreeBSD to MIPS <freebsd-mips.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-mips>,
 <mailto:freebsd-mips-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-mips/>
List-Post: <mailto:freebsd-mips@freebsd.org>
List-Help: <mailto:freebsd-mips-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-mips>,
 <mailto:freebsd-mips-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 13 Jan 2015 19:06:36 -0000

Hi all:

Below is a link to a patch that provides a sysarch() so that cache lines may
be invalidated from userspace (via the sysarch() system call).   For
convenience mips_cacheflush() is provided in the machine/cachectl.h header
file:

   int mips_cacheflush(void *addr, size_t nbytes, int whichcache);

mips_cacheflush() flushes the content of the selected cache for the user
addresses in the range from addr to (addr+nbytes-1).  whichcache may be:

MIPS_CF_ICACHE:   Flush the instruction cache lines for a given user address
range.
MIPS_CF_DCACHE:  Write back to memory and invalidate the cache lines for a
given user address range.
MIPS_CF_BCACHE:  Write back and invalidate both types of caches for a given
user address range.
MIPS_CF_ICACHE_ALL, MIPS_CF_DCACHE, or MIPS_CF_BCACHE: Full the entire given
cache(s).

mips_cacheflush() may return the errno EFAULT or EINVAL (whichcache is not
valid).  In short, it is similar to the cacheflush() that netbsd provides
for mips.

The diff: 
https://people.freebsd.org/~sson/mips/cacheflush/mips_cacheflush.diff

Comments, concerns, questions, suggestions, etc. are welcome.

Regards,

-stacey.





--
View this message in context: http://freebsd.1045724.n5.nabble.com/RFC-Cache-control-from-user-land-patch-tp5980362.html
Sent from the freebsd-mips mailing list archive at Nabble.com.