summaryrefslogtreecommitdiffstats
path: root/kernel/dma/direct.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/dma/direct.c')
-rw-r--r--kernel/dma/direct.c24
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);
}