From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: [PATCH 1/5] mm: add coherence API for DMA to vmalloc/vmap areas Date: Wed, 09 Sep 2009 03:17:06 +0000 Message-ID: <1252466226.13003.367.camel@mulgrave.site> References: <1252434469.13003.3.camel@mulgrave.site> <20090908190031.GF6538@flint.arm.linux.org.uk> <1252437112.13003.39.camel@mulgrave.site> <20090908201619.GG6538@flint.arm.linux.org.uk> <1252442352.13003.132.camel@mulgrave.site> <20090908213910.GH6538@flint.arm.linux.org.uk> <1252466070.13003.365.camel@mulgrave.site> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1252466070.13003.365.camel@mulgrave.site> Sender: linux-parisc-owner@vger.kernel.org To: Russell King Cc: Parisc List , Linux Filesystem Mailing List , linux-arch@vger.kernel.org, Christoph Hellwig List-Id: linux-arch.vger.kernel.org On Virtually Indexed architectures (which don't do automatic alias resolution in their caches), we have to flush via the correct virtual address to prepare pages for DMA. On some architectures (like arm) we cannot prevent the CPU from doing data movein along the alias (and thus giving stale read data), so we not only have to introduce a flush API to push dirty cache lines out, but also an invalidate API to kill inconsistent cache lines that may have moved in before DMA changed the data Signed-off-by: James Bottomley --- include/linux/highmem.h | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 211ff44..9719952 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -17,6 +17,12 @@ static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page static inline void flush_kernel_dcache_page(struct page *page) { } +static incline void flush_kernel_dcache_addr(void *vaddr) +{ +} +static incline void invalidate_kernel_dcache_addr(void *vaddr) +{ +} #endif #include -- 1.6.3.3 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cantor.suse.de ([195.135.220.2]:33405 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750778AbZIIDRL (ORCPT ); Tue, 8 Sep 2009 23:17:11 -0400 Subject: [PATCH 1/5] mm: add coherence API for DMA to vmalloc/vmap areas From: James Bottomley In-Reply-To: <1252466070.13003.365.camel@mulgrave.site> References: <1252434469.13003.3.camel@mulgrave.site> <20090908190031.GF6538@flint.arm.linux.org.uk> <1252437112.13003.39.camel@mulgrave.site> <20090908201619.GG6538@flint.arm.linux.org.uk> <1252442352.13003.132.camel@mulgrave.site> <20090908213910.GH6538@flint.arm.linux.org.uk> <1252466070.13003.365.camel@mulgrave.site> Content-Type: text/plain Date: Wed, 09 Sep 2009 03:17:06 +0000 Message-ID: <1252466226.13003.367.camel@mulgrave.site> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Russell King Cc: Parisc List , Linux Filesystem Mailing List , linux-arch@vger.kernel.org, Christoph Hellwig Message-ID: <20090909031706.39h-kznw_UnFfvzyrvwvbPVs1A1M0hbDcj5gzo7ISYw@z> On Virtually Indexed architectures (which don't do automatic alias resolution in their caches), we have to flush via the correct virtual address to prepare pages for DMA. On some architectures (like arm) we cannot prevent the CPU from doing data movein along the alias (and thus giving stale read data), so we not only have to introduce a flush API to push dirty cache lines out, but also an invalidate API to kill inconsistent cache lines that may have moved in before DMA changed the data Signed-off-by: James Bottomley --- include/linux/highmem.h | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 211ff44..9719952 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -17,6 +17,12 @@ static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page static inline void flush_kernel_dcache_page(struct page *page) { } +static incline void flush_kernel_dcache_addr(void *vaddr) +{ +} +static incline void invalidate_kernel_dcache_addr(void *vaddr) +{ +} #endif #include -- 1.6.3.3