From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id A2152900137 for ; Mon, 8 Aug 2011 11:21:48 -0400 (EDT) Received: by mail-vw0-f48.google.com with SMTP id 7so4239026vws.7 for ; Mon, 08 Aug 2011 08:21:46 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <000301cc4dc4$31b53630$951fa290$%szyprowski@samsung.com> <20110729093555.GA13522@8bytes.org> <001901cc4dd8$4afb4e40$e0f1eac0$%szyprowski@samsung.com> <20110729105422.GB13522@8bytes.org> <004201cc4dfb$47ee4770$d7cad650$%szyprowski@samsung.com> Date: Mon, 8 Aug 2011 10:21:46 -0500 Message-ID: Subject: Re: [RFC] ARM: dma_map|unmap_sg plus iommu From: "Ramirez Luna, Omar" Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: KyongHo Cho Cc: Marek Szyprowski , Joerg Roedel , linux-arm-kernel@lists.infradead.org, linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org, Kyungmin Park , Russell King - ARM Linux , Arnd Bergmann , Ohad Ben-Cohen Hi, On Sun, Jul 31, 2011 at 7:57 PM, KyongHo Cho wrote: > On Fri, Jul 29, 2011 at 11:24 PM, Marek Szyprowski ... >> Right now I have no idea how to handle this better. Perhaps with should be >> possible >> to specify somehow the target dma_address when doing memory allocation, but I'm >> not >> really convinced yet if this is really required. >> > What about using 'dma_handle' argument of alloc_coherent callback of > dma_map_ops? > Although it is an output argument, I think we can convey a hint or > start address to map > to the IO memory manager that resides behind dma API. I also thought on this one, even dma_map_single receives a void *ptr which could be casted into a struct with both physical and virtual addresses to be mapped, but IMHO, this starts to add twists into the dma map parameters which might create confusion. > DMA API is so abstract that it cannot cover all requirements by > various device drivers;; Agree. Regards, Omar -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org