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From: Christoph Hellwig <hch@lst.de>
To: iommu@lists.linux-foundation.org
Cc: Robin Murphy <robin.murphy@arm.com>,
	David Rientjes <rientjes@google.com>
Subject: [PATCH 08/11] dma-direct: warn if there is no pool for force unencrypted allocations
Date: Thu, 11 Nov 2021 07:50:24 +0100	[thread overview]
Message-ID: <20211111065028.32761-9-hch@lst.de> (raw)
In-Reply-To: <20211111065028.32761-1-hch@lst.de>

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.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
---
 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 a13017656ecae..84226a764471b 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -159,6 +159,9 @@ 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);
@@ -243,8 +246,7 @@ 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);
 
@@ -354,8 +356,7 @@ 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);
 
-- 
2.30.2

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  parent reply	other threads:[~2021-11-11  6:50 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-11  6:50 dma-direct fixes and cleanups v3 Christoph Hellwig
2021-11-11  6:50 ` [PATCH 01/11] dma-direct: factor out dma_set_{de,en}crypted helpers Christoph Hellwig
2021-11-11  6:50 ` [PATCH 02/11] dma-direct: don't call dma_set_decrypted for remapped allocations Christoph Hellwig
2021-11-11  6:50 ` [PATCH 03/11] dma-direct: always leak memory that can't be re-encrypted Christoph Hellwig
2021-12-06 16:32   ` Robin Murphy
2021-12-07 11:48     ` Christoph Hellwig
2021-11-11  6:50 ` [PATCH 04/11] dma-direct: clean up the remapping checks in dma_direct_alloc Christoph Hellwig
2021-12-06 16:33   ` Robin Murphy
2021-12-07 11:49     ` Christoph Hellwig
2021-12-07 12:43       ` Robin Murphy
2021-11-11  6:50 ` [PATCH 05/11] dma-direct: factor out a helper for DMA_ATTR_NO_KERNEL_MAPPING allocations Christoph Hellwig
2021-11-11  6:50 ` [PATCH 06/11] dma-direct: refactor the !coherent checks in dma_direct_alloc Christoph Hellwig
2021-12-06 16:33   ` Robin Murphy
2021-11-11  6:50 ` [PATCH 07/11] dma-direct: fail allocations that can't be made coherent Christoph Hellwig
2021-12-06 16:33   ` Robin Murphy
2021-11-11  6:50 ` Christoph Hellwig [this message]
2021-11-11  6:50 ` [PATCH 09/11] dma-direct: drop two CONFIG_DMA_RESTRICTED_POOL conditionals Christoph Hellwig
2021-11-11  6:50 ` [PATCH 10/11] dma-direct: factor the swiotlb code out of __dma_direct_alloc_pages Christoph Hellwig
2021-11-11  6:50 ` [PATCH 11/11] dma-direct: add a dma_direct_use_pool helper Christoph Hellwig
2021-12-08 15:44   ` Marek Szyprowski
2021-12-08 15:48     ` Christoph Hellwig
2021-11-16 11:31 ` dma-direct fixes and cleanups v3 Robin Murphy
2021-11-17  5:51   ` Christoph Hellwig

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