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[50.57.142.19]) by mx.google.com with ESMTPS id a110si12553824qge.107.2014.10.25.07.01.11 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Sat, 25 Oct 2014 07:01:11 -0700 (PDT) Received-SPF: none (google.com: xen-devel-bounces@lists.xen.org does not designate permitted sender hosts) client-ip=50.57.142.19; Received: from localhost ([127.0.0.1] helo=lists.xen.org) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Xi1t6-0000GV-UC; Sat, 25 Oct 2014 14:00:12 +0000 Received: from mail6.bemta4.messagelabs.com ([85.158.143.247]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Xi1t0-0000CG-Le for xen-devel@lists.xensource.com; Sat, 25 Oct 2014 14:00:06 +0000 Received: from [85.158.143.35] by server-1.bemta-4.messagelabs.com id A8/7F-02952-6ECAB445; Sat, 25 Oct 2014 14:00:06 +0000 X-Env-Sender: Stefano.Stabellini@citrix.com X-Msg-Ref: server-13.tower-21.messagelabs.com!1414245603!5328063!2 X-Originating-IP: [66.165.176.89] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogNjYuMTY1LjE3Ni44OSA9PiAyMDMwMDc=\n X-StarScan-Received: X-StarScan-Version: 6.12.3; banners=-,-,- X-VirusChecked: Checked Received: (qmail 32389 invoked from network); 25 Oct 2014 14:00:05 -0000 Received: from smtp.citrix.com (HELO SMTP.CITRIX.COM) (66.165.176.89) by server-13.tower-21.messagelabs.com with RC4-SHA encrypted SMTP; 25 Oct 2014 14:00:05 -0000 X-IronPort-AV: E=Sophos;i="5.04,786,1406592000"; d="scan'208";a="184886134" Received: from ukmail1.uk.xensource.com (10.80.16.128) by smtprelay.citrix.com (10.13.107.79) with Microsoft SMTP Server id 14.3.181.6; Sat, 25 Oct 2014 10:00:00 -0400 Received: from kaball.uk.xensource.com ([10.80.2.59]) by ukmail1.uk.xensource.com with esmtp (Exim 4.69) (envelope-from ) id 1Xi1sp-0000C6-Ty; Sat, 25 Oct 2014 14:59:55 +0100 From: Stefano Stabellini To: Date: Sat, 25 Oct 2014 14:57:22 +0100 Message-ID: <1414245442-4306-7-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 X-DLP: MIA2 Cc: Ian.Campbell@citrix.com, Stefano Stabellini , linux-kernel@vger.kernel.org, david.vrabel@citrix.com, linux-arm-kernel@lists.infradead.org Subject: [Xen-devel] [PATCH v6 7/7] xen/arm: introduce GNTTABOP_cache_flush X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: List-Unsubscribe: , List-Post: , List-Help: , List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: stefano.stabellini@eu.citrix.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.217.174 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org X-Google-Group-Id: 836684582541 List-Archive: Introduce support for new hypercall GNTTABOP_cache_flush. Use it to perform cache flashing on pages used for dma when necessary. If GNTTABOP_cache_flush is supported by the hypervisor, we don't need to bounce dma map operations that involve foreign grants and non-coherent devices. Signed-off-by: Stefano Stabellini Acked-by: Ian Campbell --- Changes in v5: - rename hypercall_flush to hypercall_cflush; - remove spurious change. Changes in v4: - add comment; - avoid bouncing dma map operations that involve foreign grants and non-coherent devices if GNTTABOP_cache_flush is provided by Xen. 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/mm.c | 39 ++++++++++++++++++++++++++++++----- include/xen/interface/grant_table.h | 19 +++++++++++++++++ 2 files changed, 53 insertions(+), 5 deletions(-) diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index 5b2c7e3..0bab35b 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -12,6 +12,7 @@ #include #include +#include #include #include @@ -20,6 +21,8 @@ #include #include +static bool hypercall_cflush = false; + #ifdef CONFIG_ARM64 static inline void dmac_map_area(const void *start, size_t size, int dir) @@ -65,17 +68,35 @@ static void dma_cache_maint(dma_addr_t handle, unsigned long offset, do { size_t len = left; void *vaddr; + + /* buffers in highmem or foreign pages cannot cross page + * boundaries */ + 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); @@ -148,7 +169,7 @@ bool xen_arch_need_swiotlb(struct device *dev, unsigned long pfn, unsigned long mfn) { - return ((pfn != mfn) && !is_dma_coherent(dev)); + return (!hypercall_cflush && (pfn != mfn) && !is_dma_coherent(dev)); } int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order, @@ -191,10 +212,18 @@ static struct dma_map_ops xen_swiotlb_dma_ops = { int __init xen_mm_init(void) { + struct gnttab_cache_flush cflush; if (!xen_initial_domain()) return 0; xen_swiotlb_init(1, false); xen_dma_ops = &xen_swiotlb_dma_ops; + + cflush.op = 0; + cflush.a.dev_bus_addr = 0; + cflush.offset = 0; + cflush.length = 0; + if (HYPERVISOR_grant_table_op(GNTTABOP_cache_flush, &cflush, 1) != -ENOSYS) + hypercall_cflush = true; return 0; } arch_initcall(xen_mm_init); 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. */