Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932777AbcCRNzd (ORCPT ); Fri, 18 Mar 2016 09:55:33 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:38921 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754971AbcCRNza (ORCPT ); Fri, 18 Mar 2016 09:55:30 -0400 Subject: Re: [PATCH 3/3] dma-mapping: move swiotlb dma-phys functions to common header To: Robin Murphy , linux-arm-kernel@lists.infradead.org, timur@codeaurora.org, cov@codeaurora.org, nwatters@codeaurora.org References: <1458252137-24497-1-git-send-email-okaya@codeaurora.org> <1458252137-24497-3-git-send-email-okaya@codeaurora.org> <56EBE71F.2080203@arm.com> Cc: linux-mips@linux-mips.org, linux-ia64@vger.kernel.org, linux-xtensa@linux-xtensa.org, Catalin Marinas , Will Deacon , Max Filippov , Chris Metcalf , "H. Peter Anvin" , Guan Xuetao , Florian Fainelli , x86@kernel.org, Ingo Molnar , Guenter Roeck , Fenghua Yu , Denys Vlasenko , Arnd Bergmann , Akinobu Mita , Geliang Tang , Zhen Lei , Thomas Gleixner , Valentin Rothberg , Chris Zankel , Tony Luck , linux-kernel@vger.kernel.org, Ralf Baechle , "Suthikulpanit, Suravee" , Joe Perches , Andrew Morton From: Sinan Kaya Message-ID: <56EC08C9.3080809@codeaurora.org> Date: Fri, 18 Mar 2016 09:55:21 -0400 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.7.0 MIME-Version: 1.0 In-Reply-To: <56EBE71F.2080203@arm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2381 Lines: 64 On 3/18/2016 7:31 AM, Robin Murphy wrote: > On 17/03/16 22:02, Sinan Kaya wrote: >> Moving the default implementation of swiotlb_dma_to_phys and >> swiotlb_phys_to_dma functions to dma-mapping.h so that we can get >> rid of the duplicate code in multiple ARCH. >> >> Signed-off-by: Sinan Kaya >> --- >> arch/arm64/include/asm/dma-mapping.h | 14 -------------- >> arch/ia64/include/asm/dma-mapping.h | 14 -------------- >> arch/mips/include/asm/mach-generic/dma-coherence.h | 16 ---------------- >> arch/tile/include/asm/dma-mapping.h | 14 -------------- >> arch/unicore32/include/asm/dma-mapping.h | 14 -------------- >> arch/x86/include/asm/dma-mapping.h | 13 ------------- >> arch/xtensa/include/asm/dma-mapping.h | 14 -------------- >> include/linux/dma-mapping.h | 14 ++++++++++++++ >> 8 files changed, 14 insertions(+), 99 deletions(-) > > [...] > >> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h >> index 728ef07..871d620 100644 >> --- a/include/linux/dma-mapping.h >> +++ b/include/linux/dma-mapping.h >> @@ -683,4 +683,18 @@ static inline int dma_mmap_writecombine(struct device *dev, >> #define dma_unmap_len_set(PTR, LEN_NAME, VAL) do { } while (0) >> #endif >> >> +#ifndef swiotlb_phys_to_dma >> +static inline dma_addr_t swiotlb_phys_to_dma(struct device *dev, phys_addr_t paddr) >> +{ >> + return paddr; >> +} >> +#endif >> + >> +#ifndef swiotlb_dma_to_phys >> +static inline phys_addr_t swiotlb_dma_to_phys(struct device *dev, dma_addr_t daddr) >> +{ >> + return daddr; >> +} >> +#endif >> + >> #endif >> > > Could the default definition not be pushed all the way down into swiotlb.c (or at least swiotlb.h)? I can do that but then we lose the inlining capability of the compiler. This could cost performance penalty on architectures using it. I tried moving it to swiotlb.h. swiotlb.h seems to be only used by swiotlb.c file. I could try including it into dma-mapping.h and then moving the definitions into swiotlb.h file. Let me give this a try. > > Robin. > -- Sinan Kaya Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project