From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Szyprowski Subject: Re: [PATCH v2 2/2] arm/dma-mapping: Respect NO_KERNEL_MAPPING when we don't have an IOMMU Date: Fri, 06 Feb 2015 13:16:57 +0100 Message-ID: <54D4B0B9.6090300@samsung.com> References: <1423041800-27859-1-git-send-email-carlo@caione.org> <1423041800-27859-3-git-send-email-carlo@caione.org> <54D1F2AE.4070003@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mailout2.w1.samsung.com ([210.118.77.12]:47940 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755768AbbBFMRB (ORCPT ); Fri, 6 Feb 2015 07:17:01 -0500 Received: from eucpsbgm2.samsung.com (unknown [203.254.199.245]) by mailout2.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NJC00AGXNN11X10@mailout2.w1.samsung.com> for linux-samsung-soc@vger.kernel.org; Fri, 06 Feb 2015 12:21:01 +0000 (GMT) In-reply-to: Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Carlo Caione Cc: linux-arm-kernel , "Jasper St. Pierre" , Daniel Drake , Russell King - ARM Linux , Rob Clark , inki.dae@samsung.com, linux-samsung-soc@vger.kernel.org, sw0312.kim@samsung.com, kgene@kernel.org, jy0922.shim@samsung.com, Laura Abbott Hello, On 2015-02-05 11:13, Carlo Caione wrote: > On Wed, Feb 4, 2015 at 11:21 AM, Marek Szyprowski > wrote: >> On 2015-02-04 10:23, Carlo Caione wrote: >>> From: "Jasper St. Pierre" >>> >>> Even without an iommu, NO_KERNEL_MAPPING is still convenient to save on >>> kernel address space in places where we don't need a kernel mapping. >>> Implement support for it in the two places where we're creating an >>> expensive mapping. >>> >>> __alloc_from_pool uses an internal pool from which we already have >>> virtual addresses, so it's not relevant, and __alloc_simple_buffer uses >>> alloc_pages, which will always return a lowmem page, which is already >>> mapped into kernel space, so we can't prevent a mapping for it in that >>> case. >>> >>> Signed-off-by: Jasper St. Pierre >>> Signed-off-by: Carlo Caione >>> Reviewed-by: Rob Clark >>> Reviewed-by: Daniel Drake >> >> Acked-by: Marek Szyprowski > Thanks. Who is supposed to take this patch? Russel? I think this will be the best way to get it merged. Please upload it to http://www.arm.linux.org.uk/developer/patches/ Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland From mboxrd@z Thu Jan 1 00:00:00 1970 From: m.szyprowski@samsung.com (Marek Szyprowski) Date: Fri, 06 Feb 2015 13:16:57 +0100 Subject: [PATCH v2 2/2] arm/dma-mapping: Respect NO_KERNEL_MAPPING when we don't have an IOMMU In-Reply-To: References: <1423041800-27859-1-git-send-email-carlo@caione.org> <1423041800-27859-3-git-send-email-carlo@caione.org> <54D1F2AE.4070003@samsung.com> Message-ID: <54D4B0B9.6090300@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello, On 2015-02-05 11:13, Carlo Caione wrote: > On Wed, Feb 4, 2015 at 11:21 AM, Marek Szyprowski > wrote: >> On 2015-02-04 10:23, Carlo Caione wrote: >>> From: "Jasper St. Pierre" >>> >>> Even without an iommu, NO_KERNEL_MAPPING is still convenient to save on >>> kernel address space in places where we don't need a kernel mapping. >>> Implement support for it in the two places where we're creating an >>> expensive mapping. >>> >>> __alloc_from_pool uses an internal pool from which we already have >>> virtual addresses, so it's not relevant, and __alloc_simple_buffer uses >>> alloc_pages, which will always return a lowmem page, which is already >>> mapped into kernel space, so we can't prevent a mapping for it in that >>> case. >>> >>> Signed-off-by: Jasper St. Pierre >>> Signed-off-by: Carlo Caione >>> Reviewed-by: Rob Clark >>> Reviewed-by: Daniel Drake >> >> Acked-by: Marek Szyprowski > Thanks. Who is supposed to take this patch? Russel? I think this will be the best way to get it merged. Please upload it to http://www.arm.linux.org.uk/developer/patches/ Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland