Date: Mon, 1 Jun 2009 18:16:56 +0900
To: rmk+lkml@arm.linux.org.uk
Cc: fujita.tomonori@lab.ntt.co.jp, arnd@arndb.de, linux-kernel@vger.kernel.org,
       linux-arch@vger.kernel.org
Subject: Re: [PATCH] asm-generic: add dma-mapping-linear.h
From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
In-Reply-To: <20090601082943.GA5550@flint.arm.linux.org.uk>
References: <20090601075114.GA29107@flint.arm.linux.org.uk>
	<20090601170847V.fujita.tomonori@lab.ntt.co.jp>
	<20090601082943.GA5550@flint.arm.linux.org.uk>
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Message-Id: <20090601181723U.fujita.tomonori@lab.ntt.co.jp>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1099
Lines: 22

On Mon, 1 Jun 2009 09:29:43 +0100
Russell King <rmk+lkml@arm.linux.org.uk> wrote:

> On Mon, Jun 01, 2009 at 05:08:09PM +0900, FUJITA Tomonori wrote:
> > This adds a version of the dma-mapping API to asm-generic that can be
> > used by most architectures that only need a linear mapping.
> 
> It depends what is meant by "linear mapping".
> 
> If that's just a way of saying "all that needs to be done for the
> DMA streaming APIs is to flush the cache" then the vast majority of
> ARMs fall into that category.

I guess that his definition is 'no dynamic remapping'.


> The DMA bounce code is a broken design concept that really needs to
> be put to death.

You are talking about arch/arm/common/dmabounce.c? If so, it sounds
more interesting (to me at least). It's kinda swiotlb per device,
right? What you want to do for arch/arm/common/dmabounce.c?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/