Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752066AbaJBKlL (ORCPT ); Thu, 2 Oct 2014 06:41:11 -0400 Received: from smtp.citrix.com ([66.165.176.89]:30096 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751927AbaJBKlJ (ORCPT ); Thu, 2 Oct 2014 06:41:09 -0400 X-IronPort-AV: E=Sophos;i="5.04,638,1406592000"; d="scan'208";a="177419782" Message-ID: <542D2BC2.2040505@citrix.com> Date: Thu, 2 Oct 2014 11:41:06 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Icedove/24.5.0 MIME-Version: 1.0 To: Stefano Stabellini , CC: , , , Subject: Re: [PATCH 2/2] xen/arm: introduce XENMEM_cache_flush References: <1412244417-12251-2-git-send-email-stefano.stabellini@eu.citrix.com> In-Reply-To: <1412244417-12251-2-git-send-email-stefano.stabellini@eu.citrix.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/10/14 11:06, Stefano Stabellini wrote: > Introduce support for new hypercall XENMEM_cache_flush. > Use it to perform cache flashing on pages used for dma when necessary. [...] > --- a/arch/arm/xen/mm32.c > +++ b/arch/arm/xen/mm32.c [...] > @@ -24,7 +27,21 @@ static void dma_cache_maint(dma_addr_t handle, unsigned long offset, > > if (!pfn_valid(pfn)) > { > - /* TODO: cache flush */ > + struct xen_cache_flush cflush; > + > + cflush.op = 0; > + cflush.addr = handle + offset; > + cflush.size = size; > + > + if (op == dmac_unmap_area && dir != DMA_TO_DEVICE) > + cflush.op = XENMEM_CACHE_INVAL; > + if (op == dmac_map_area) { > + cflush.op = XENMEM_CACHE_CLEAN; > + if (dir == DMA_FROM_DEVICE) > + cflush.op |= XENMEM_CACHE_INVAL; > + } > + if (cflush.op) > + HYPERVISOR_memory_op(XENMEM_cache_flush, &cflush); > } else { > struct page *page = pfn_to_page(pfn); > [...] > --- a/include/xen/interface/memory.h > +++ b/include/xen/interface/memory.h > @@ -263,4 +263,20 @@ struct xen_remove_from_physmap { > }; > DEFINE_GUEST_HANDLE_STRUCT(xen_remove_from_physmap); > > +/* > + * Issue one or more cache maintenance operations on a memory range > + * owned by the calling domain or granted to the calling domain by a > + * foreign domain. > + */ > +#define XENMEM_cache_flush 27 > +struct xen_cache_flush { > +/* addr is the machine address at the start of the memory range */ You say machine address here but call it with a bus address. With no IOMMU these are equivalent but what's correct if an IOMMU is used? David > +uint64_t addr; > +uint64_t size; > +#define XENMEM_CACHE_CLEAN (1<<0) > +#define XENMEM_CACHE_INVAL (1<<1) > +uint32_t op; > +}; > +DEFINE_GUEST_HANDLE_STRUCT(xen_cache_flush); > + > #endif /* __XEN_PUBLIC_MEMORY_H__ */ > -- 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/