Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754405Ab3IEQJ4 (ORCPT ); Thu, 5 Sep 2013 12:09:56 -0400 Received: from fw-tnat.cambridge.arm.com ([217.140.96.21]:51641 "EHLO cam-smtp0.cambridge.arm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752927Ab3IEQJy (ORCPT ); Thu, 5 Sep 2013 12:09:54 -0400 Date: Thu, 5 Sep 2013 17:09:05 +0100 From: Catalin Marinas To: Stefano Stabellini Cc: "xen-devel@lists.xensource.com" , "Ian.Campbell@citrix.com" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "konrad.wilk@oracle.com" Subject: Re: [PATCH v5 11/13] xen: introduce xen_alloc/free_coherent_pages Message-ID: <20130905160905.GI11887@arm.com> References: <1377801154-29215-11-git-send-email-stefano.stabellini@eu.citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1377801154-29215-11-git-send-email-stefano.stabellini@eu.citrix.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 710 Lines: 16 On Thu, Aug 29, 2013 at 07:32:32PM +0100, Stefano Stabellini wrote: > xen_swiotlb_alloc_coherent needs to allocate a coherent buffer for cpu > and devices. On native x86 and ARMv8 is sufficient to call > __get_free_pages in order to get a coherent buffer, while on ARM we need > to call arm_dma_ops.alloc. Don't bet on this for ARMv8. It's not mandated for the architecture, so at some point some SoC will require non-cacheable buffers for coherency. -- Catalin -- 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/