Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755071Ab2HXLN5 (ORCPT ); Fri, 24 Aug 2012 07:13:57 -0400 Received: from acsinet15.oracle.com ([141.146.126.227]:33217 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752884Ab2HXLNz (ORCPT ); Fri, 24 Aug 2012 07:13:55 -0400 Date: Fri, 24 Aug 2012 07:13:23 -0400 From: Konrad Rzeszutek Wilk To: Hiroshi Doyu Cc: m.szyprowski@samsung.com, linux-arm-kernel@lists.infradead.org, linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kyungmin.park@samsung.com, arnd@arndb.de, linux@arm.linux.org.uk, chunsang.jeong@linaro.org, vdumpa@nvidia.com, subashrp@gmail.com, minchan@kernel.org, pullip.cho@samsung.com Subject: Re: [v3 1/4] ARM: dma-mapping: atomic_pool with struct page **pages Message-ID: <20120824111323.GB11007@konrad-lan.dumpdata.com> References: <1345796945-21115-1-git-send-email-hdoyu@nvidia.com> <1345796945-21115-2-git-send-email-hdoyu@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1345796945-21115-2-git-send-email-hdoyu@nvidia.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2759 Lines: 79 On Fri, Aug 24, 2012 at 11:29:02AM +0300, Hiroshi Doyu wrote: > struct page **pages is necessary to align with non atomic path in > __iommu_get_pages(). atomic_pool() has the intialized **pages instead > of just *page. > > Signed-off-by: Hiroshi Doyu > --- > arch/arm/mm/dma-mapping.c | 17 +++++++++++++---- > 1 files changed, 13 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index 601da7a..b14ee64 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -296,7 +296,7 @@ struct dma_pool { > unsigned long *bitmap; > unsigned long nr_pages; > void *vaddr; > - struct page *page; > + struct page **pages; > }; > > static struct dma_pool atomic_pool = { > @@ -335,12 +335,16 @@ static int __init atomic_pool_init(void) > unsigned long nr_pages = pool->size >> PAGE_SHIFT; > unsigned long *bitmap; > struct page *page; > + struct page **pages; > void *ptr; > int bitmap_size = BITS_TO_LONGS(nr_pages) * sizeof(long); > + size_t size = nr_pages * sizeof(struct page *); > > - bitmap = kzalloc(bitmap_size, GFP_KERNEL); > + size += bitmap_size; > + bitmap = kzalloc(size, GFP_KERNEL); > if (!bitmap) > goto no_bitmap; > + pages = (void *)bitmap + bitmap_size; So you stuck a bitmap field in front of the array then? Why not just define a structure where this is clearly defined instead of doing the casting. > > if (IS_ENABLED(CONFIG_CMA)) > ptr = __alloc_from_contiguous(NULL, pool->size, prot, &page); > @@ -348,9 +352,14 @@ static int __init atomic_pool_init(void) > ptr = __alloc_remap_buffer(NULL, pool->size, GFP_KERNEL, prot, > &page, NULL); > if (ptr) { > + int i; > + > + for (i = 0; i < nr_pages; i++) > + pages[i] = page + i; > + > spin_lock_init(&pool->lock); > pool->vaddr = ptr; > - pool->page = page; > + pool->pages = pages; > pool->bitmap = bitmap; > pool->nr_pages = nr_pages; > pr_info("DMA: preallocated %u KiB pool for atomic coherent allocations\n", > @@ -481,7 +490,7 @@ static void *__alloc_from_pool(size_t size, struct page **ret_page) > if (pageno < pool->nr_pages) { > bitmap_set(pool->bitmap, pageno, count); > ptr = pool->vaddr + PAGE_SIZE * pageno; > - *ret_page = pool->page + pageno; > + *ret_page = pool->pages[pageno]; > } else { > pr_err_once("ERROR: %u KiB atomic DMA coherent pool is too small!\n" > "Please increase it with coherent_pool= kernel parameter!\n", > -- > 1.7.5.4 > -- 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/