Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755352AbaJWRfI (ORCPT ); Thu, 23 Oct 2014 13:35:08 -0400 Received: from smtp.citrix.com ([66.165.176.89]:28822 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752690AbaJWRfC (ORCPT ); Thu, 23 Oct 2014 13:35:02 -0400 X-IronPort-AV: E=Sophos;i="5.04,776,1406592000"; d="scan'208";a="184362046" From: Stefano Stabellini To: CC: , , , , , , , Stefano Stabellini Subject: [PATCH v5 3/6] xen/arm: introduce xen_is_dma_coherent Date: Thu, 23 Oct 2014 18:27:23 +0100 Message-ID: <1414085246-16160-3-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 a utility function to check whether a device is dma coherent. The current implementation is suboptimal. Let's rework it later in common arch/arm code. Use it to figure out whether we need to issue cache maintenance operations instead of checking on the existence of a particular dma_ops function for the device. Signed-off-by: Stefano Stabellini --- Changes in v5: - introduce xen_is_dma_coherent as a xen specific function; - call xen_is_dma_coherent instead of is_dma_coherent. --- arch/arm/include/asm/xen/page-coherent.h | 5 +++++ arch/arm/xen/mm32.c | 6 +++--- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/arch/arm/include/asm/xen/page-coherent.h b/arch/arm/include/asm/xen/page-coherent.h index e8275ea..6f0f882 100644 --- a/arch/arm/include/asm/xen/page-coherent.h +++ b/arch/arm/include/asm/xen/page-coherent.h @@ -5,6 +5,11 @@ #include #include +static inline bool xen_is_dma_coherent(struct device *dev) +{ + return (__generic_dma_ops(dev) == &arm_coherent_dma_ops); +} + static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t flags, struct dma_attrs *attrs) diff --git a/arch/arm/xen/mm32.c b/arch/arm/xen/mm32.c index 6153d61..6c0224e 100644 --- a/arch/arm/xen/mm32.c +++ b/arch/arm/xen/mm32.c @@ -76,7 +76,7 @@ void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, struct dma_attrs *attrs) { - if (!__generic_dma_ops(hwdev)->unmap_page) + if (xen_is_dma_coherent(hwdev)) return; if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) return; @@ -87,7 +87,7 @@ void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, void xen_dma_sync_single_for_cpu(struct device *hwdev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - if (!__generic_dma_ops(hwdev)->sync_single_for_cpu) + if (xen_is_dma_coherent(hwdev)) return; __xen_dma_page_dev_to_cpu(hwdev, handle, size, dir); } @@ -95,7 +95,7 @@ void xen_dma_sync_single_for_cpu(struct device *hwdev, void xen_dma_sync_single_for_device(struct device *hwdev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - if (!__generic_dma_ops(hwdev)->sync_single_for_device) + if (xen_is_dma_coherent(hwdev)) return; __xen_dma_page_cpu_to_dev(hwdev, handle, size, dir); } -- 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/