Merge tag 'dma-mapping-6.7-2023-11-10' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - don't leave pages decrypted for DMA in encrypted memory setups linger
   around on failure (Petr Tesarik)

 - fix an out of bounds access in the new dynamic swiotlb code (Petr
   Tesarik)

 - fix dma_addressing_limited for systems with weird physical memory
   layouts (Jia He)

* tag 'dma-mapping-6.7-2023-11-10' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: fix out-of-bounds TLB allocations with CONFIG_SWIOTLB_DYNAMIC
  dma-mapping: fix dma_addressing_limited() if dma_range_map can't cover all system RAM
  dma-mapping: move dma_addressing_limited() out of line
  swiotlb: do not free decrypted pages if dynamic

1 files changed, 22 insertions, 0 deletions

diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index e323ca48f7f2..58db8fd70471 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -793,6 +793,28 @@ int dma_set_coherent_mask(struct device *dev, u64 mask)
 }
 EXPORT_SYMBOL(dma_set_coherent_mask);
 
+/**
+ * dma_addressing_limited - return if the device is addressing limited
+ * @dev:	device to check
+ *
+ * Return %true if the devices DMA mask is too small to address all memory in
+ * the system, else %false.  Lack of addressing bits is the prime reason for
+ * bounce buffering, but might not be the only one.
+ */
+bool dma_addressing_limited(struct device *dev)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	if (min_not_zero(dma_get_mask(dev), dev->bus_dma_limit) <
+			 dma_get_required_mask(dev))
+		return true;
+
+	if (unlikely(ops))
+		return false;
+	return !dma_direct_all_ram_mapped(dev);
+}
+EXPORT_SYMBOL_GPL(dma_addressing_limited);
+
 size_t dma_max_mapping_size(struct device *dev)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);