From mboxrd@z Thu Jan 1 00:00:00 1970 From: skannan@codeaurora.org (Saravana Kannan) Date: Fri, 17 Dec 2010 15:14:35 -0800 (PST) Subject: [PATCH] arm: dma-mapping: move consistent_init to early_initcall In-Reply-To: References: <4CF94DDD.8000409@codeaurora.org> <20101203203653.GB10245@n2100.arm.linux.org.uk> <4CFDD297.4020600@codeaurora.org> <15d23d63900e4545a40555961c49c421.squirrel@codeaurora.org> <20101209103835.GA31465@n2100.arm.linux.org.uk> <4D017B45.4000805@codeaurora.org> <4D045692.4050607@codeaurora.org> <8c67e174d807416f0c6c190cc72d3f5a.squirrel@www.codeaurora.org> <20101217094818.GA9937@n2100.arm.linux.org.uk> <99eb693af85e07b01d81d45f1bc77f64.squirrel@www.codeaurora.org> Message-ID: <7276921204ba82a2065faa61548f1699.squirrel@www.codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Catalin Marinas wrote: >> Russell, >> >> I agree with your point about using an API for purpose and not property. >> But I read Catalin's proposal as, let's treat secure domain as another >> DMA >> "device". If we make a conscious agreement to do that, then using the >> DMA >> API for secure domain would be "using it for its purpose" and we will >> make >> an effort to not break it with future updates. Of course, if we don't >> agree on that proposal, then we can't use the DMA API for secure domain >> stuff. > > If there is no better proposal, I'm for such extension to the DMA API. > From the kernel perspecitve, the secure side is just another entity > that accesses the RAM directly. It's not a physically separate device > indeed but from a direct memory access perspective it can be treated > as any other device. > > In the DMA API we can fall back to the non-coherent ops when a NULL > struct device is passed. I assume in your code you already pass a NULL > device to dma_alloc_coherent(). Russell, Would the extension of the DMA API as described above be acceptable to you? If not, can you please suggest an alternative that's acceptable to you? -Saravana -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.