Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752945AbaKLLlf (ORCPT ); Wed, 12 Nov 2014 06:41:35 -0500 Received: from smtp.citrix.com ([66.165.176.89]:15000 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752893AbaKLLlc (ORCPT ); Wed, 12 Nov 2014 06:41:32 -0500 X-IronPort-AV: E=Sophos;i="5.07,368,1413244800"; d="scan'208";a="190474975" From: Stefano Stabellini To: CC: , , , , , , , Stefano Stabellini Subject: [PATCH v9 08/13] xen/arm: use hypercall to flush caches in map_page Date: Wed, 12 Nov 2014 11:40:49 +0000 Message-ID: <1415792454-23161-8-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: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In xen_dma_map_page, if the page is a local page, call the native map_page dma_ops. If the page is foreign, call __xen_dma_map_page that issues any required cache maintenane operations via hypercall. The reason for doing this is that the native dma_ops map_page could allocate buffers than need to be freed. If the page is foreign we don't call the native unmap_page dma_ops function, resulting in a memory leak. Suggested-by: Catalin Marinas Signed-off-by: Stefano Stabellini Reviewed-by: Catalin Marinas --- Changes in v9: - map_page is always present; - use bool local for clarity; - add a comment. --- arch/arm/include/asm/xen/page-coherent.h | 13 ++++++++++++- arch/arm/xen/mm32.c | 12 ++++++++++++ 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/arch/arm/include/asm/xen/page-coherent.h b/arch/arm/include/asm/xen/page-coherent.h index a309f42..efd5624 100644 --- a/arch/arm/include/asm/xen/page-coherent.h +++ b/arch/arm/include/asm/xen/page-coherent.h @@ -5,6 +5,9 @@ #include #include +void __xen_dma_map_page(struct device *hwdev, struct page *page, + dma_addr_t dev_addr, unsigned long offset, size_t size, + enum dma_data_direction dir, struct dma_attrs *attrs); void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, size_t size, enum dma_data_direction dir, struct dma_attrs *attrs); @@ -32,7 +35,15 @@ static inline void xen_dma_map_page(struct device *hwdev, struct page *page, dma_addr_t dev_addr, unsigned long offset, size_t size, enum dma_data_direction dir, struct dma_attrs *attrs) { - __generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs); + bool local = PFN_DOWN(dev_addr) == page_to_pfn(page); + /* Dom0 is mapped 1:1, so if pfn == mfn the page is local otherwise + * is a foreign page grant-mapped in dom0. If the page is local we + * can safely call the native dma_ops function, otherwise we call + * the xen specific function. */ + if (local) + __generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs); + else + __xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs); } static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, diff --git a/arch/arm/xen/mm32.c b/arch/arm/xen/mm32.c index 3ce9dc1..c86919b 100644 --- a/arch/arm/xen/mm32.c +++ b/arch/arm/xen/mm32.c @@ -43,6 +43,18 @@ static void __xen_dma_page_cpu_to_dev(struct device *hwdev, dma_addr_t handle, dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, DMA_MAP); } +void __xen_dma_map_page(struct device *hwdev, struct page *page, + dma_addr_t dev_addr, unsigned long offset, size_t size, + enum dma_data_direction dir, struct dma_attrs *attrs) +{ + if (is_device_dma_coherent(hwdev)) + return; + if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) + return; + + __xen_dma_page_cpu_to_dev(hwdev, dev_addr, size, dir); +} + void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, size_t size, enum dma_data_direction dir, struct dma_attrs *attrs) -- 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/