From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: [PATCH/RFC 1/6] dma-mapping: Convert NO_DMA get_dma_ops() into a real dummy Date: Tue, 6 Feb 2018 11:14:47 +0100 Message-ID: <1517912092-15470-2-git-send-email-geert@linux-m68k.org> References: <1517912092-15470-1-git-send-email-geert@linux-m68k.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1517912092-15470-1-git-send-email-geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Christoph Hellwig , Marek Szyprowski , Robin Murphy , Arnd Bergmann , Mark Brown , Richard Weinberger Cc: linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Felipe Balbi , "James E . J . Bottomley" , linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Martin K . Petersen" , Greg Kroah-Hartman , linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Geert Uytterhoeven List-Id: linux-arch.vger.kernel.org If NO_DMA=y, get_dma_ops() returns a reference to the non-existing symbol bad_dma_ops, thus causing a link failure if it is ever used. Make get_dma_ops() return NULL instead, to avoid the link failure. This allows to improve compile-testing, and limits the need to keep on sprinkling dependencies on HAS_DMA all over the place. Signed-off-by: Geert Uytterhoeven --- include/linux/dma-mapping.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 34fe8463d10ea3be..d78d7541f784875b 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -212,14 +212,14 @@ static inline void set_dma_ops(struct device *dev, } #else /* - * Define the dma api to allow compilation but not linking of - * dma dependent code. Code that depends on the dma-mapping - * API needs to set 'depends on HAS_DMA' in its Kconfig + * Define the dma api to allow compilation of dma dependent code. + * Code that depends on the dma-mapping API needs to set 'depends on HAS_DMA' + * in its Kconfig, unless it already depends on || COMPILE_TEST, + * where guarantuees the availability of the dma-mapping API. */ -extern const struct dma_map_ops bad_dma_ops; static inline const struct dma_map_ops *get_dma_ops(struct device *dev) { - return &bad_dma_ops; + return NULL; } #endif -- 2.7.4 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from baptiste.telenet-ops.be ([195.130.132.51]:46858 "EHLO baptiste.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752625AbeBFKPD (ORCPT ); Tue, 6 Feb 2018 05:15:03 -0500 From: Geert Uytterhoeven Subject: [PATCH/RFC 1/6] dma-mapping: Convert NO_DMA get_dma_ops() into a real dummy Date: Tue, 6 Feb 2018 11:14:47 +0100 Message-ID: <1517912092-15470-2-git-send-email-geert@linux-m68k.org> In-Reply-To: <1517912092-15470-1-git-send-email-geert@linux-m68k.org> References: <1517912092-15470-1-git-send-email-geert@linux-m68k.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Christoph Hellwig , Marek Szyprowski , Robin Murphy , Arnd Bergmann , Mark Brown , Richard Weinberger Cc: Felipe Balbi , Greg Kroah-Hartman , "James E . J . Bottomley" , "Martin K . Petersen" , iommu@lists.linux-foundation.org, linux-usb@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Geert Uytterhoeven Message-ID: <20180206101447.ZlYu51337x_7Kl0uvgUf1ZWNNZjmSaJB4ZS2H9_MGSE@z> If NO_DMA=y, get_dma_ops() returns a reference to the non-existing symbol bad_dma_ops, thus causing a link failure if it is ever used. Make get_dma_ops() return NULL instead, to avoid the link failure. This allows to improve compile-testing, and limits the need to keep on sprinkling dependencies on HAS_DMA all over the place. Signed-off-by: Geert Uytterhoeven --- include/linux/dma-mapping.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 34fe8463d10ea3be..d78d7541f784875b 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -212,14 +212,14 @@ static inline void set_dma_ops(struct device *dev, } #else /* - * Define the dma api to allow compilation but not linking of - * dma dependent code. Code that depends on the dma-mapping - * API needs to set 'depends on HAS_DMA' in its Kconfig + * Define the dma api to allow compilation of dma dependent code. + * Code that depends on the dma-mapping API needs to set 'depends on HAS_DMA' + * in its Kconfig, unless it already depends on || COMPILE_TEST, + * where guarantuees the availability of the dma-mapping API. */ -extern const struct dma_map_ops bad_dma_ops; static inline const struct dma_map_ops *get_dma_ops(struct device *dev) { - return &bad_dma_ops; + return NULL; } #endif -- 2.7.4