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From: Robin Murphy <robin.murphy@arm.com>
To: Christoph Hellwig <hch@lst.de>, iommu@lists.linux-foundation.org
Cc: David Rientjes <rientjes@google.com>
Subject: Re: [PATCH 07/10] dma-direct: warn if there is no pool for force unencrypted allocations
Date: Thu, 4 Nov 2021 12:36:45 +0000	[thread overview]
Message-ID: <afd0a660-4b4f-23e4-ceaa-78ea2873ca8b@arm.com> (raw)
In-Reply-To: <20211021090611.488281-8-hch@lst.de>

On 2021-10-21 10:06, Christoph Hellwig wrote:
> Instead of blindly running into a blocking operation for a non-blocking gfp,
> return NULL and spew an error.  Note that Kconfig prevents this for all
> currently relevant platforms, and this is just a debug check.

Reviewed-by: Robin Murphy <robin.murphy@arm.com>

> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   kernel/dma/direct.c | 9 +++++----
>   1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
> index d66f37f34ba71..680fe10410645 100644
> --- a/kernel/dma/direct.c
> +++ b/kernel/dma/direct.c
> @@ -154,6 +154,9 @@ static void *dma_direct_alloc_from_pool(struct device *dev, size_t size,
>   	u64 phys_mask;
>   	void *ret;
>   
> +	if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_DMA_COHERENT_POOL)))
> +		return NULL;
> +
>   	gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
>   					   &phys_mask);
>   	page = dma_alloc_from_pool(dev, size, &ret, gfp, dma_coherent_ok);
> @@ -234,8 +237,7 @@ void *dma_direct_alloc(struct device *dev, size_t size,
>   	 * Decrypting memory may block, so allocate the memory from the atomic
>   	 * pools if we can't block.
>   	 */
> -	if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
> -	    force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&
> +	if (force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&
>   	    !is_swiotlb_for_alloc(dev))
>   		return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
>   
> @@ -353,8 +355,7 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size,
>   	struct page *page;
>   	void *ret;
>   
> -	if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
> -	    force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&
> +	if (force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&
>   	    !is_swiotlb_for_alloc(dev))
>   		return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
>   
> 
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  reply	other threads:[~2021-11-04 12:37 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-21  9:06 dma-direct fixes and cleanups v2 Christoph Hellwig
2021-10-21  9:06 ` [PATCH 01/10] dma-direct: factor out dma_set_{de,en}crypted helpers Christoph Hellwig
2021-11-04 12:35   ` Robin Murphy
2021-10-21  9:06 ` [PATCH 02/10] dma-direct: unmapped remapped pages when dma_set_decrypted Christoph Hellwig
2021-11-04 12:35   ` Robin Murphy
2021-11-09 14:10     ` Christoph Hellwig
2021-11-09 14:27       ` Robin Murphy
2021-10-21  9:06 ` [PATCH 03/10] dma-direct: leak memory that can't be re-encrypted Christoph Hellwig
2021-11-04 12:35   ` Robin Murphy
2021-11-09 14:19     ` Christoph Hellwig
2021-10-21  9:06 ` [PATCH 04/10] dma-direct: clean up the remapping checks in dma_direct_alloc Christoph Hellwig
2021-11-04 12:35   ` Robin Murphy
2021-11-09 14:23     ` Christoph Hellwig
2021-10-21  9:06 ` [PATCH 05/10] dma-direct: factor out a helper for DMA_ATTR_NO_KERNEL_MAPPING allocations Christoph Hellwig
2021-11-04 12:36   ` Robin Murphy
2021-11-09 14:25     ` Christoph Hellwig
2021-11-09 14:39       ` Robin Murphy
2021-10-21  9:06 ` [PATCH 06/10] dma-direct: refactor the !coherent checks in dma_direct_alloc Christoph Hellwig
2021-11-04 12:36   ` Robin Murphy
2021-11-09 14:27     ` Christoph Hellwig
2021-10-21  9:06 ` [PATCH 07/10] dma-direct: warn if there is no pool for force unencrypted allocations Christoph Hellwig
2021-11-04 12:36   ` Robin Murphy [this message]
2021-10-21  9:06 ` [PATCH 08/10] dma-direct: drop two CONFIG_DMA_RESTRICTED_POOL conditionals Christoph Hellwig
2021-11-04 12:37   ` Robin Murphy
2021-10-21  9:06 ` [PATCH 09/10] dma-direct: factor the swiotlb code out of __dma_direct_alloc_pages Christoph Hellwig
2021-11-04 12:37   ` Robin Murphy
2021-10-21  9:06 ` [PATCH 10/10] dma-direct: add a dma_direct_use_pool helper Christoph Hellwig
2021-11-04 12:37   ` Robin Murphy
2021-11-04  8:54 ` dma-direct fixes and cleanups v2 Christoph Hellwig

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