Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932539AbaJHNHc (ORCPT ); Wed, 8 Oct 2014 09:07:32 -0400 Received: from smtp.citrix.com ([66.165.176.89]:43631 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932397AbaJHNHa (ORCPT ); Wed, 8 Oct 2014 09:07:30 -0400 X-IronPort-AV: E=Sophos;i="5.04,677,1406592000"; d="scan'208";a="179348840" From: Stefano Stabellini To: CC: , , , , , , Stefano Stabellini Subject: [PATCH v3 2/2] xen/arm: introduce GNTTABOP_cache_flush Date: Wed, 8 Oct 2014 14:04:56 +0100 Message-ID: <1412773496-15364-2-git-send-email-stefano.stabellini@eu.citrix.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Introduce support for new hypercall GNTTABOP_cache_flush. Use it to perform cache flashing on pages used for dma when necessary. Signed-off-by: Stefano Stabellini --- Changes in v3: - fix the cache maintenance op call to match what Linux does natively; - update the hypercall interface to match Xen. Changes in v2: - update the hypercall interface to match Xen; - call the interface on a single page at a time. --- arch/arm/xen/mm32.c | 27 +++++++++++++++++++++++---- include/xen/interface/grant_table.h | 19 +++++++++++++++++++ 2 files changed, 42 insertions(+), 4 deletions(-) diff --git a/arch/arm/xen/mm32.c b/arch/arm/xen/mm32.c index a5a93fc..ec2eb02 100644 --- a/arch/arm/xen/mm32.c +++ b/arch/arm/xen/mm32.c @@ -4,6 +4,9 @@ #include #include +#include + +#include /* functions called by SWIOTLB */ @@ -22,16 +25,32 @@ static void dma_cache_maint(dma_addr_t handle, unsigned long offset, size_t len = left; void *vaddr; + if (len + offset > PAGE_SIZE) + len = PAGE_SIZE - offset; + if (!pfn_valid(pfn)) { - /* TODO: cache flush */ + struct gnttab_cache_flush cflush; + + cflush.op = 0; + cflush.a.dev_bus_addr = pfn << PAGE_SHIFT; + cflush.offset = offset; + cflush.length = len; + + if (op == dmac_unmap_area && dir != DMA_TO_DEVICE) + cflush.op = GNTTAB_CACHE_INVAL; + if (op == dmac_map_area) { + if (dir == DMA_FROM_DEVICE) + cflush.op = GNTTAB_CACHE_INVAL; + else + cflush.op = GNTTAB_CACHE_CLEAN; + } + if (cflush.op) + HYPERVISOR_grant_table_op(GNTTABOP_cache_flush, &cflush, 1); } else { struct page *page = pfn_to_page(pfn); if (PageHighMem(page)) { - if (len + offset > PAGE_SIZE) - len = PAGE_SIZE - offset; - if (cache_is_vipt_nonaliasing()) { vaddr = kmap_atomic(page); op(vaddr + offset, len, dir); diff --git a/include/xen/interface/grant_table.h b/include/xen/interface/grant_table.h index e40fae9..bcce564 100644 --- a/include/xen/interface/grant_table.h +++ b/include/xen/interface/grant_table.h @@ -479,6 +479,25 @@ struct gnttab_get_version { DEFINE_GUEST_HANDLE_STRUCT(gnttab_get_version); /* + * Issue one or more cache maintenance operations on a portion of a + * page granted to the calling domain by a foreign domain. + */ +#define GNTTABOP_cache_flush 12 +struct gnttab_cache_flush { + union { + uint64_t dev_bus_addr; + grant_ref_t ref; + } a; + uint16_t offset; /* offset from start of grant */ + uint16_t length; /* size within the grant */ +#define GNTTAB_CACHE_CLEAN (1<<0) +#define GNTTAB_CACHE_INVAL (1<<1) +#define GNTTAB_CACHE_SOURCE_GREF (1<<31) + uint32_t op; +}; +DEFINE_GUEST_HANDLE_STRUCT(gnttab_cache_flush); + +/* * Bitfield values for update_pin_status.flags. */ /* Map the grant entry for access by I/O devices. */ -- 1.7.10.4 -- 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/