Merge tag 'dma-mapping-6.12-2024-09-19' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping updates from Christoph Hellwig:

 - support DMA zones for arm64 systems where memory starts at > 4GB
   (Baruch Siach, Catalin Marinas)

 - support direct calls into dma-iommu and thus obsolete dma_map_ops for
   many common configurations (Leon Romanovsky)

 - add DMA-API tracing (Sean Anderson)

 - remove the not very useful return value from various dma_set_* APIs
   (Christoph Hellwig)

 - misc cleanups and minor optimizations (Chen Y, Yosry Ahmed, Christoph
   Hellwig)

* tag 'dma-mapping-6.12-2024-09-19' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: reflow dma_supported
  dma-mapping: reliably inform about DMA support for IOMMU
  dma-mapping: add tracing for dma-mapping API calls
  dma-mapping: use IOMMU DMA calls for common alloc/free page calls
  dma-direct: optimize page freeing when it is not addressable
  dma-mapping: clearly mark DMA ops as an architecture feature
  vdpa_sim: don't select DMA_OPS
  arm64: mm: keep low RAM dma zone
  dma-mapping: don't return errors from dma_set_max_seg_size
  dma-mapping: don't return errors from dma_set_seg_boundary
  dma-mapping: don't return errors from dma_set_min_align_mask
  scsi: check that busses support the DMA API before setting dma parameters
  arm64: mm: fix DMA zone when dma-ranges is missing
  dma-mapping: direct calls for dma-iommu
  dma-mapping: call ->unmap_page and ->unmap_sg unconditionally
  arm64: support DMA zone above 4GB
  dma-mapping: replace zone_dma_bits by zone_dma_limit
  dma-mapping: use bit masking to check VM_DMA_COHERENT

1 files changed, 10 insertions, 15 deletions

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index f693aafe221f..1524da363734 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -524,13 +524,11 @@ static inline unsigned int dma_get_max_seg_size(struct device *dev)
 	return SZ_64K;
 }
 
-static inline int dma_set_max_seg_size(struct device *dev, unsigned int size)
+static inline void dma_set_max_seg_size(struct device *dev, unsigned int size)
 {
-	if (dev->dma_parms) {
-		dev->dma_parms->max_segment_size = size;
-		return 0;
-	}
-	return -EIO;
+	if (WARN_ON_ONCE(!dev->dma_parms))
+		return;
+	dev->dma_parms->max_segment_size = size;
 }
 
 static inline unsigned long dma_get_seg_boundary(struct device *dev)
@@ -559,13 +557,11 @@ static inline unsigned long dma_get_seg_boundary_nr_pages(struct device *dev,
 	return (dma_get_seg_boundary(dev) >> page_shift) + 1;
 }
 
-static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask)
+static inline void dma_set_seg_boundary(struct device *dev, unsigned long mask)
 {
-	if (dev->dma_parms) {
-		dev->dma_parms->segment_boundary_mask = mask;
-		return 0;
-	}
-	return -EIO;
+	if (WARN_ON_ONCE(!dev->dma_parms))
+		return;
+	dev->dma_parms->segment_boundary_mask = mask;
 }
 
 static inline unsigned int dma_get_min_align_mask(struct device *dev)
@@ -575,13 +571,12 @@ static inline unsigned int dma_get_min_align_mask(struct device *dev)
 	return 0;
 }
 
-static inline int dma_set_min_align_mask(struct device *dev,
+static inline void dma_set_min_align_mask(struct device *dev,
 		unsigned int min_align_mask)
 {
 	if (WARN_ON_ONCE(!dev->dma_parms))
-		return -EIO;
+		return;
 	dev->dma_parms->min_align_mask = min_align_mask;
-	return 0;
 }
 
 #ifndef dma_get_cache_alignment