From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Thu, 5 Sep 2013 17:09:05 +0100 Subject: [PATCH v5 11/13] xen: introduce xen_alloc/free_coherent_pages In-Reply-To: <1377801154-29215-11-git-send-email-stefano.stabellini@eu.citrix.com> References: <1377801154-29215-11-git-send-email-stefano.stabellini@eu.citrix.com> Message-ID: <20130905160905.GI11887@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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