diff options
| author | Christoph Hellwig <hch@lst.de> | 2023-10-06 15:13:34 +0200 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2023-10-22 16:38:54 +0200 |
| commit | b1da46d70e5427a9ba5eae28bcca29a20e68a442 (patch) | |
| tree | 8c58b5b157df317e8a0eacb734456b49794fd26d /kernel/dma | |
| parent | 2c8ed1b960fb97c82ede5afc974329bfdb457f5f (diff) | |
dma-direct: simplify the use atomic pool logic in dma_direct_alloc
The logic in dma_direct_alloc when to use the atomic pool vs remapping
grew a bit unreadable. Consolidate it into a single check, and clean
up the set_uncached vs remap logic a bit as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.org>
Tested-by: Greg Ungerer <gerg@linux-m68k.org>
Diffstat (limited to 'kernel/dma')
| -rw-r--r-- | kernel/dma/direct.c | 25 |
1 files changed, 10 insertions, 15 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index c078090cd38e..9657ef7c055e 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -234,27 +234,22 @@ void *dma_direct_alloc(struct device *dev, size_t size, dma_handle); /* - * Otherwise remap if the architecture is asking for it. But - * given that remapping memory is a blocking operation we'll - * instead have to dip into the atomic pools. + * Otherwise we require the architecture to either be able to + * mark arbitrary parts of the kernel direct mapping uncached, + * or remapped it uncached. */ + set_uncached = IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED); remap = IS_ENABLED(CONFIG_DMA_DIRECT_REMAP); - if (remap) { - if (dma_direct_use_pool(dev, gfp)) - return dma_direct_alloc_from_pool(dev, size, - dma_handle, gfp); - } else { - if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED)) - return NULL; - set_uncached = true; - } + if (!set_uncached && !remap) + return NULL; } /* - * Decrypting memory may block, so allocate the memory from the atomic - * pools if we can't block. + * Remapping or decrypting memory may block, allocate the memory from + * the atomic pools instead if we aren't allowed block. */ - if (force_dma_unencrypted(dev) && dma_direct_use_pool(dev, gfp)) + if ((remap || force_dma_unencrypted(dev)) && + dma_direct_use_pool(dev, gfp)) return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); /* we always manually zero the memory once we are done */ |