Merge tag 'dma-mapping-6.8-2024-01-08' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping updates from Christoph Hellwig:

 - reduce area lock contention for non-primary IO TLB pools (Petr
   Tesarik)

 - don't store redundant offsets in the dma_ranges stuctures (Robin
   Murphy)

 - clear dev->dma_mem when freeing per-device pools (Joakim Zhang)

* tag 'dma-mapping-6.8-2024-01-08' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: clear dev->dma_mem to NULL after freeing it
  swiotlb: reduce area lock contention for non-primary IO TLB pools
  dma-mapping: don't store redundant offsets

1 files changed, 12 insertions, 7 deletions

diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
index 18aade195884..3eb3589ff43e 100644
--- a/include/linux/dma-direct.h
+++ b/include/linux/dma-direct.h
@@ -21,7 +21,6 @@ struct bus_dma_region {
 	phys_addr_t	cpu_start;
 	dma_addr_t	dma_start;
 	u64		size;
-	u64		offset;
 };
 
 static inline dma_addr_t translate_phys_to_dma(struct device *dev,
@@ -29,9 +28,12 @@ static inline dma_addr_t translate_phys_to_dma(struct device *dev,
 {
 	const struct bus_dma_region *m;
 
-	for (m = dev->dma_range_map; m->size; m++)
-		if (paddr >= m->cpu_start && paddr - m->cpu_start < m->size)
-			return (dma_addr_t)paddr - m->offset;
+	for (m = dev->dma_range_map; m->size; m++) {
+		u64 offset = paddr - m->cpu_start;
+
+		if (paddr >= m->cpu_start && offset < m->size)
+			return m->dma_start + offset;
+	}
 
 	/* make sure dma_capable fails when no translation is available */
 	return DMA_MAPPING_ERROR;
@@ -42,9 +44,12 @@ static inline phys_addr_t translate_dma_to_phys(struct device *dev,
 {
 	const struct bus_dma_region *m;
 
-	for (m = dev->dma_range_map; m->size; m++)
-		if (dma_addr >= m->dma_start && dma_addr - m->dma_start < m->size)
-			return (phys_addr_t)dma_addr + m->offset;
+	for (m = dev->dma_range_map; m->size; m++) {
+		u64 offset = dma_addr - m->dma_start;
+
+		if (dma_addr >= m->dma_start && offset < m->size)
+			return m->cpu_start + offset;
+	}
 
 	return (phys_addr_t)-1;
 }