From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751671AbcF0EVd (ORCPT ); Mon, 27 Jun 2016 00:21:33 -0400 Received: from mailout2.samsung.com ([203.254.224.25]:48446 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750772AbcF0EVb (ORCPT ); Mon, 27 Jun 2016 00:21:31 -0400 X-AuditID: cbfee68f-f79476d000001429-b5-5770a9c9913e Date: Mon, 27 Jun 2016 04:20:59 +0000 (GMT) From: Manjeet Pawar Subject: Re: Re: [PATCH] arm:swiotlb:keep disabled in default configuration To: Stefano Stabellini , "konrad@darnok.org" Cc: PANKAJ MISHRA , AJEET YADAV , Rohit Thapliyal , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linux@arm.linux.org.uk" Reply-to: manjeet.p@samsung.com MIME-version: 1.0 X-MTR: 20160627041819600@manjeet.p Msgkey: 20160627041819600@manjeet.p X-EPLocale: en_US.windows-1252 X-Priority: 3 X-EPWebmail-Msg-Type: personal X-EPWebmail-Reply-Demand: 0 X-EPApproval-Locale: X-EPHeader: ML X-MLAttribute: X-RootMTR: 20160624045531022@manjeet.p X-ParentMTR: 20160624045531022@manjeet.p X-ArchiveUser: X-CPGSPASS: N X-ConfirmMail: N,general Content-type: text/plain; charset=windows-1252 MIME-version: 1.0 Message-id: <560602875.24151467001258274.JavaMail.weblogic@epmlwas09d> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprKKsWRmVeSWpSXmKPExsWyRsSkWvfkyoJwg4cnDC0u75rD5sDo8XmT XABjlIhNSmpOZllqkb4dgpUgknHx7mWWgktCFc0z1zE3ME4Q6mLk5BASUJGY0nKEFcSWEDCR ODRvGROELSZx4d56ti5GLqCapYwSc38cZocpWvH9MStEYg6jRPO+i2AJFgFViTVP9gJ1c3Cw CehIPP0CtkBYwFviyq7bbCBhEYEYiTXTDEBamQWOM0lc/niUHeIIeYn+lReZQWxeAUGJkzOf sEDsUpJ4/nY2G0RcWWLD4YtsEHE5iSVTL0Mdyisxo/0pC0x82tc1zBC2tMT5WRsYYZ5Z/P0x VJxf4tjtHVC9AhJTzxxkBLlNQkBd4sA8boiwpkT36WmMMOW7Ti1nhll1f8tcqFYJia0tT8Dh xiygKDGl+yE7hG0gcWTRHFZ0r/AKuEm8PbAVHJ4SAhc4JK6/Xs82gVFpFpK6WUhmzUIyC1nN AkaWVYyiqQXJBcVJ6UXGesWJucWleel6yfm5mxiByeL0v2f9OxjvHrA+xKjOwSglWppXnJyY l5eYlJMan5uYk5ZflJuaosTDe0GmIFyINbGsuDL3EKMpMPImMkuJJucDE1heSbyhsZmRhamJ qbGRuaWZkjjvQqmfwUIC6YklqdmpqQWpRfFFpTmpxYcYmTg4pRoYEzPvvecsfjJ56VTRmitG 29Ku2Mm2Nn4PYv63qvj8mXe3L18tDsn7cfT6jodLX2X2JbjJtflu8ueeGnXZdk2SX8jxZqau W9tsptrExgdv0r0+T5NphdrPoF1rrk4r79/Z+Uk6//qKjV1NofflFm91u57VsVK/qbDq+p9Y juZ+/9pl7xLOX4nQV2Ipzkg01GIuKk4EAL/bgskoAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrEKsWRmVeSWpSXmKPExsVy+t/tPt3VKwvCDSa/M7K4vGsOmwOjx+dN cgGMUQU2Kak5mWWpRfp2NhmpiSmpRQqpecn5KZl56bZK3sHxzvGmZgaGuoaWFuZKCnmJuam2 Si4+AbpumTlA45UUyhJzSoFCAYnFxUpAE4ryS0tSFTLyi0tslaINzY30jAz0TI30DE1jrQwN DIxMgWoSCjIu3r3MUnBJqKJ55jrmBsYJQl2MnBxCAioSU1qOsILYEgImEiu+P4ayxSQu3FvP 1sXIBVQzh1Gied9FdpAEi4CqxJone5m6GDk42AR0JJ5+AZsjLOAtcWXXbTaQsIhAjMSaaQYg rcwCx5kkLn88yg6xS16if+VFZhCbV0BQ4uTMJywQu5Qknr+dzQYRV5bYcPgiG0RcTmLJ1MtM EDavxIz2pyww8Wlf1zBD2NIS52dtYIS5efH3x1Bxfoljt3dA9QpITD1zkBHkNgkBdYkD87gh wpoS3aenMcKU7zq1nBlm1f0tc6FaJSS2tjwBBwmzgKLElO6H7BC2gcSRRXNY0b3CK+Am8fbA VrYJjLKzkKRmIWmfhaQdWc0CRpZVjKKpBckFxUnpFUZ6xYm5xaV56XrJ+bmbGMGJ6dmiHYz/ zlsfYlTnYJQSLc0rTk7My0tMykmNz03MScsvyk1NUeLhvZFXEC7EmlhWXJl7iFEFaNWjDasv MEqx5OXnpSqJ8KYvB0rzpiRWVqUW5ccXleakFh9iNAVG60RmKdHkfGDqzSuJNzQ2MTc1NrUw MDQ3N1MS5w34uy5MSCA9sSQ1OzW1ILUIpo+Jg1OqgVFmVUpK4TYZVlGv1YUbtqUZP+CzNP/X tNHdytfmUhzQqHVvAmdvvMy75vTkOaee7rlX2nA2uq1i6aqQHPct1SfLFxqbJFlFnrtRWLZk wSz7vYGH5pSKZJ94ZBJt07NfTEyY63SEk534B9sZzZ7NdtWiC2oW/Zn2uuRajMFxUQ/P6Oqz HizrlViKMxINtZiLihMBKtFllYUDAAA= DLP-Filter: Pass X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id u5R4Lb5K002432 >> > >> > From: Rohit Thapliyal >> > >> > swiotlb implementation not required to be enabled in arm and >> > disabling it reduces uImage size by 16KB. >> > >> >> How so? There are no DMA operations on ARM? >Xen actively uses the swiotlb on ARM, see >arch/arm64/include/asm/dma-mapping.h:get_dma_ops >arch/arm/xen/mm.c:xen_swiotlb_dma_ops Sorry, my last reply didn't go through so sending it again. If XEN is enabled, it shall eventually enable SWIOTLB through SWIOTLB_XEN. So, there is no need to keep it enabled otherwise. ------- Original Message ------- Sender : Stefano Stabellini Date : Jun 24, 2016 01:00 (GMT+09:00) Title : Re: [PATCH] arm:swiotlb:keep disabled in default configuration On Thu, 23 Jun 2016, Stefano Stabellini wrote: > On Jun 23, 2016 8:27 AM, "Manjeet Pawar" wrote: > > > > From: Rohit Thapliyal > > > > swiotlb implementation not required to be enabled in arm and > > disabling it reduces uImage size by 16KB. > > > > How so? There are no DMA operations on ARM? Xen actively uses the swiotlb on ARM, see arch/arm64/include/asm/dma-mapping.h:get_dma_ops arch/arm/xen/mm.c:xen_swiotlb_dma_ops > > Signed-off-by: Rohit Thapliyal > > Signed-off-by: Ajeet Kumar Yadav > > --- > > arch/arm/Kconfig | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > > index 90542db..ae65f29 100644 > > --- a/arch/arm/Kconfig > > +++ b/arch/arm/Kconfig > > @@ -1754,7 +1754,7 @@ config SECCOMP > > defined by each seccomp mode. > > > > config SWIOTLB > > - def_bool y > > + def_bool n > > > > config IOMMU_HELPER > > def_bool SWIOTLB > > -- > > 1.7.9.5 > > >