Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759431AbZDGRXQ (ORCPT ); Tue, 7 Apr 2009 13:23:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752786AbZDGRXA (ORCPT ); Tue, 7 Apr 2009 13:23:00 -0400 Received: from sh.osrg.net ([192.16.179.4]:58675 "EHLO sh.osrg.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751964AbZDGRW7 (ORCPT ); Tue, 7 Apr 2009 13:22:59 -0400 Date: Wed, 8 Apr 2009 02:22:29 +0900 To: galak@kernel.crashing.org Cc: fujita.tomonori@lab.ntt.co.jp, beckyb@kernel.crashing.org, linux-kernel@vger.kernel.org, mingo@elte.hu, jeremy@goop.org, ian.campbell@citrix.com Subject: Re: [PATCH 5/7] swiotlb: (re)Create swiotlb_unmap_single From: FUJITA Tomonori In-Reply-To: <77EA4458-602F-4DA9-B7E7-E48B5B0DCF91@kernel.crashing.org> References: <9C76D5F2-5D3C-4499-B358-129428FA6F33@kernel.crashing.org> <20090408013700L.fujita.tomonori@lab.ntt.co.jp> <77EA4458-602F-4DA9-B7E7-E48B5B0DCF91@kernel.crashing.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <20090408022241U.fujita.tomonori@lab.ntt.co.jp> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (sh.osrg.net [192.16.179.4]); Wed, 08 Apr 2009 02:22:30 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5875 Lines: 156 On Tue, 7 Apr 2009 11:50:56 -0500 Kumar Gala wrote: > > On Apr 7, 2009, at 11:37 AM, FUJITA Tomonori wrote: > > > On Tue, 7 Apr 2009 10:32:20 -0500 > > Kumar Gala wrote: > > > >> > >> On Apr 7, 2009, at 4:09 AM, FUJITA Tomonori wrote: > >> > >>> On Tue, 7 Apr 2009 01:34:44 -0500 > >>> Kumar Gala wrote: > >>> > >>>> > >>>> On Apr 6, 2009, at 9:24 PM, FUJITA Tomonori wrote: > >>>> > >>>>> On Fri, 3 Apr 2009 20:56:47 -0500 > >>>>> Becky Bruce wrote: > >>>>> > >>>>>> This mirrors the current swiotlb_sync_single() setup > >>>>>> where the swiotlb_unmap_single() function is static to this > >>>>>> file and contains the logic required to determine if we need > >>>>>> to call actual sync_single. Previously, swiotlb_unmap_page > >>>>>> and swiotlb_unmap_sg were duplicating very similar code. > >>>>>> The duplicated code has also been reformatted for > >>>>>> readability. > >>>>>> > >>>>>> Note that the swiotlb_unmap_sg code was previously doing > >>>>>> a complicated comparison to determine if an addresses needed > >>>>>> to be unmapped where a simple is_swiotlb_buffer() call > >>>>>> would have sufficed. > >>>>>> > >>>>>> Signed-off-by: Becky Bruce > >>>>>> --- > >>>>>> lib/swiotlb.c | 36 +++++++++++++++++++++++------------- > >>>>>> 1 files changed, 23 insertions(+), 13 deletions(-) > >>>>>> > >>>>>> diff --git a/lib/swiotlb.c b/lib/swiotlb.c > >>>>>> index af2ec25..602315b 100644 > >>>>>> --- a/lib/swiotlb.c > >>>>>> +++ b/lib/swiotlb.c > >>>>> > >>>>> I don't think 'swiotlb_unmap_single' name is appropriate. > >>>>> > >>>>> swiotlb_unmap_single sounds like an exported function that IOMMUs > >>>>> can > >>>>> use (and it was) however it should not be. > >>>> > >>>> What do you suggest we call it? __swiotlb_unmap_single. > >>> > >>> I think that __swiotlb_unmap_single is better because the name > >>> implies > >>> that it's an internal function. It's fine by me. > >>> > >>> If it is odd that __swiotlb_unmap_single() is just a wrapper > >>> function > >>> of unmap_single(), which does the real job to unmap a dma mapping, > >>> it > >>> might be another possible option to rename unmap_single to > >>> do_unamp_single and use unmap_single. > >> > >> I think you lost me here. I'd prefer to just use > >> __swiotlb_unmap_single at this point and get this code into the tree > >> and work on such renaming after the fact (if that's ok). > > > > If you are rushing to merge this right now, the original patchset is > > fine by me (I thought that you missed this merge window). I'll rename > > it later. > > We probably did, but one can never tell with these things. It seemed > like Ingo merged and pushed some swiotlb changes late in the game for . > 29 Well, merging patches that have not been tested linux-next late is what we should not do, I guess. I like to see Becky's patch in 2.6.30 because I have some swiotlb changes for 2.6.31 though. > I'm still not clear on what you are suggesting... "rename unmap_single > to do_unamp_single and use unmap_single". This can be applied after Becky's patchset. diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 1c86553..bffe6d7 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -482,7 +482,7 @@ found: * dma_addr is the kernel virtual address of the bounce buffer to unmap. */ static void -unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir) +do_unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir) { unsigned long flags; int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; @@ -591,7 +591,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, (unsigned long long)dev_addr); /* DMA_TO_DEVICE to avoid memcpy in unmap_single */ - unmap_single(hwdev, ret, size, DMA_TO_DEVICE); + do_unmap_single(hwdev, ret, size, DMA_TO_DEVICE); return NULL; } *dma_handle = dev_addr; @@ -608,7 +608,7 @@ swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, free_pages((unsigned long) vaddr, get_order(size)); else /* DMA_TO_DEVICE to avoid memcpy in unmap_single */ - unmap_single(hwdev, vaddr, size, DMA_TO_DEVICE); + do_unmap_single(hwdev, vaddr, size, DMA_TO_DEVICE); } EXPORT_SYMBOL(swiotlb_free_coherent); @@ -688,16 +688,15 @@ EXPORT_SYMBOL_GPL(swiotlb_map_page); * After this call, reads by the cpu to the buffer are guaranteed to see * whatever the device wrote there. */ -static void -swiotlb_unmap_single(struct device *hwdev, dma_addr_t dev_addr, - size_t size, int dir) +static void unmap_single(struct device *hwdev, dma_addr_t dev_addr, + size_t size, int dir) { char *dma_addr = swiotlb_bus_to_virt(hwdev, dev_addr); BUG_ON(dir == DMA_NONE); if (is_swiotlb_buffer(dma_addr)) { - unmap_single(hwdev, dma_addr, size, dir); + do_unmap_single(hwdev, dma_addr, size, dir); return; } @@ -711,7 +710,7 @@ void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, size_t size, enum dma_data_direction dir, struct dma_attrs *attrs) { - swiotlb_unmap_single(hwdev, dev_addr, size, dir); + unmap_single(hwdev, dev_addr, size, dir); } EXPORT_SYMBOL_GPL(swiotlb_unmap_page); @@ -864,8 +863,7 @@ swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, BUG_ON(dir == DMA_NONE); for_each_sg(sgl, sg, nelems, i) - swiotlb_unmap_single(hwdev, sg->dma_address, sg->dma_length, - dir); + unmap_single(hwdev, sg->dma_address, sg->dma_length, dir); } EXPORT_SYMBOL(swiotlb_unmap_sg_attrs); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/