lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 16 Oct 2012 11:04:29 +0100 From: Catalin Marinas <catalin.marinas@....com> To: Russell King - ARM Linux <linux@....linux.org.uk> Cc: Hiroshi Doyu <hdoyu@...dia.com>, Marek Szyprowski <m.szyprowski@...sung.com>, Inki Dae <inki.dae@...sung.com>, Arnd Bergmann <arnd@...db.de>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, "linaro-mm-sig@...ts.linaro.org" <linaro-mm-sig@...ts.linaro.org>, "linux-mm@...ck.org" <linux-mm@...ck.org>, Kyungmin Park <kyungmin.park@...sung.com>, "linux-arm-kernel@...ts.infradead.org" <linux-arm-kernel@...ts.infradead.org>, linux-tegra@...r.kernel.org Subject: Re: [Linaro-mm-sig] [RFC 0/2] DMA-mapping & IOMMU - physically contiguous allocations On 16 October 2012 09:59, Russell King - ARM Linux <linux@....linux.org.uk> wrote: > On Tue, Oct 16, 2012 at 09:04:34AM +0300, Hiroshi Doyu wrote: >> In addition to those contiguous/discontiguous page allocation, is >> there any way to _import_ anonymous pages allocated by a process to be >> used in dma-mapping API later? >> >> I'm considering the following scenario, an user process allocates a >> buffer by malloc() in advance, and then it asks some driver to convert >> that buffer into IOMMU'able/DMA'able ones later. In this case, pages >> are discouguous and even they may not be yet allocated at >> malloc()/mmap(). > > That situation is covered. It's the streaming API you're wanting for that. > dma_map_sg() - but you may need additional cache handling via > flush_dcache_page() to ensure that your code is safe for all CPU cache > architectures. For user-allocated pages you first need get_user_pages() to make sure they are in memory (and will stay there). This function also calls flush_dcache_page(). Then you can build the sg list for dma_map_sg(). -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists