From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH] iommu/io-pgtable-armv7s: Fix kmem_cache_alloc() flags Date: Tue, 1 Mar 2016 18:53:13 +0000 Message-ID: <20160301185312.GC14022@arm.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Robin Murphy Cc: geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Tue, Mar 01, 2016 at 06:17:38PM +0000, Robin Murphy wrote: > Whilst the default SLUB allocator happily just merges the original > allocation flags from kmem_cache_create() with those passed through > kmem_cache_alloc(), there is a code path in the SLAB allocator which > will aggressively BUG_ON() if the cache was created with SLAB_CACHE_DMA > but GFP_DMA is not specified for an allocation. It would be nice to include the backtrace here. > Keep the peace by adding GFP_DMA when allocating a table. > > Reported-by: Geert Uytterhoeven > Signed-off-by: Robin Murphy > --- > drivers/iommu/io-pgtable-arm-v7s.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c > index 9fcceb1..9488e3c 100644 > --- a/drivers/iommu/io-pgtable-arm-v7s.c > +++ b/drivers/iommu/io-pgtable-arm-v7s.c > @@ -192,7 +192,7 @@ static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp, > if (lvl == 1) > table = (void *)__get_dma_pages(__GFP_ZERO, get_order(size)); > else if (lvl == 2) > - table = kmem_cache_zalloc(data->l2_tables, gfp); > + table = kmem_cache_zalloc(data->l2_tables, gfp | GFP_DMA); > if (table && !selftest_running) { > dma = dma_map_single(dev, table, size, DMA_TO_DEVICE); > if (dma_mapping_error(dev, dma)) Acked-by: Will Deacon Will