diff options
Diffstat (limited to 'kernel/dma/direct.c')
| -rw-r--r-- | kernel/dma/direct.c | 24 |
1 files changed, 11 insertions, 13 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 6af7ae83c4ad..32ec69cdba54 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -472,28 +472,26 @@ int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma, } #endif /* CONFIG_MMU */ -/* - * Because 32-bit DMA masks are so common we expect every architecture to be - * able to satisfy them - either by not supporting more physical memory, or by - * providing a ZONE_DMA32. If neither is the case, the architecture needs to - * use an IOMMU instead of the direct mapping. - */ int dma_direct_supported(struct device *dev, u64 mask) { - u64 min_mask; - - if (IS_ENABLED(CONFIG_ZONE_DMA)) - min_mask = DMA_BIT_MASK(zone_dma_bits); - else - min_mask = DMA_BIT_MASK(32); + u64 min_mask = (max_pfn - 1) << PAGE_SHIFT; - min_mask = min_t(u64, min_mask, (max_pfn - 1) << PAGE_SHIFT); + /* + * Because 32-bit DMA masks are so common we expect every architecture + * to be able to satisfy them - either by not supporting more physical + * memory, or by providing a ZONE_DMA32. If neither is the case, the + * architecture needs to use an IOMMU instead of the direct mapping. + */ + if (mask >= DMA_BIT_MASK(32)) + return 1; /* * This check needs to be against the actual bit mask value, so * use __phys_to_dma() here so that the SME encryption mask isn't * part of the check. */ + if (IS_ENABLED(CONFIG_ZONE_DMA)) + min_mask = min_t(u64, min_mask, DMA_BIT_MASK(zone_dma_bits)); return mask >= __phys_to_dma(dev, min_mask); } |