From mboxrd@z Thu Jan 1 00:00:00 1970 From: lauraa@codeaurora.org (Laura Abbott) Date: Wed, 12 Mar 2014 11:20:35 -0700 Subject: Query on patch to be upstream ? In-Reply-To: <20140311182600.GB50212@MacBook-Pro.local> References: <20140311121500.GH31104@arm.com> <1394561059-29307-1-git-send-email-lauraa@codeaurora.org> <20140311182600.GB50212@MacBook-Pro.local> Message-ID: <5320A573.9080501@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 3/11/2014 11:26 AM, Catalin Marinas wrote: > On Tue, Mar 11, 2014 at 06:04:19PM +0000, Laura Abbott wrote: >> With one caveat below, you can add >> >> Tested-by: Laura Abbott > > Thanks. > >> From: Laura Abbott >> Date: Thu, 6 Mar 2014 21:05:41 -0800 >> Subject: [PATCH] arm64: Use custom mmap function for noncoherent dma ops >> >> The non-coherent dma ops remap memory with appropriate attributes. >> This remapped address cannot be used with virt_to_page which >> dma_common_mmap uses. Implement a custom (but very similar) function >> which correctly calculates the physical address and remaps to userspace. > > Looking at the coherent implementation, I think we also have a > (performance) problem with dma_common_mmap(). It uses pgprot_noncached() > by default and if the DMA is coherent we don't really need strongly > ordered memory. > > Would you mind writing a __dma_common_mmap() for arm64 with separate > coherent/non-coherent dma mmap functions that set the vm_page_prot > accordingly? > > Thanks. > Yes, I will add that to my TODO list. Thanks, Laura -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation