From: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
To: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Cc: geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org,
iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Subject: Re: [PATCH] iommu/io-pgtable-armv7s: Fix kmem_cache_alloc() flags
Date: Tue, 1 Mar 2016 18:53:13 +0000 [thread overview]
Message-ID: <20160301185312.GC14022@arm.com> (raw)
In-Reply-To: <cbd13a3db3924a67f8aa8a352f04c883c47d8815.1456856051.git.robin.murphy-5wv7dgnIgG8@public.gmane.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 <geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org>
> Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
> ---
> 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.deacon-5wv7dgnIgG8@public.gmane.org>
Will
WARNING: multiple messages have this Message-ID (diff)
From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] iommu/io-pgtable-armv7s: Fix kmem_cache_alloc() flags
Date: Tue, 1 Mar 2016 18:53:13 +0000 [thread overview]
Message-ID: <20160301185312.GC14022@arm.com> (raw)
In-Reply-To: <cbd13a3db3924a67f8aa8a352f04c883c47d8815.1456856051.git.robin.murphy@arm.com>
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 <geert@linux-m68k.org>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
> 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.deacon@arm.com>
Will
next prev parent reply other threads:[~2016-03-01 18:53 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-01 18:17 [PATCH] iommu/io-pgtable-armv7s: Fix kmem_cache_alloc() flags Robin Murphy
2016-03-01 18:17 ` Robin Murphy
[not found] ` <cbd13a3db3924a67f8aa8a352f04c883c47d8815.1456856051.git.robin.murphy-5wv7dgnIgG8@public.gmane.org>
2016-03-01 18:53 ` Will Deacon [this message]
2016-03-01 18:53 ` Will Deacon
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