2 files changed, 89 insertions, 0 deletions

diff --git a/include/linux/dma-debug.h b/include/linux/dma-debug.h
index 65f73526ba2c..ee9fdb328549 100644
--- a/include/linux/dma-debug.h
+++ b/include/linux/dma-debug.h
@@ -23,6 +23,7 @@
 #include <linux/types.h>
 
 struct device;
+struct scatterlist;
 
 #ifdef CONFIG_DMA_API_DEBUG
 
@@ -36,6 +37,11 @@ extern void debug_dma_map_page(struct device *dev, struct page *page,
 extern void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
                                  size_t size, int direction, bool map_single);
 
+extern void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
+                             int nents, int mapped_ents, int direction);
+
+extern void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
+                               int nelems, int dir);
 
 #else /* CONFIG_DMA_API_DEBUG */
 
@@ -56,6 +62,16 @@ static inline void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
 {
 }
 
+static inline void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
+                                    int nents, int mapped_ents, int direction)
+{
+}
+
+static inline void debug_dma_unmap_sg(struct device *dev,
+                                      struct scatterlist *sglist,
+                                      int nelems, int dir)
+{
+}
 
 #endif /* CONFIG_DMA_API_DEBUG */
 
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index a2ed2b769685..26e40e93e0f2 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -17,6 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
+#include <linux/scatterlist.h>
 #include <linux/dma-mapping.h>
 #include <linux/dma-debug.h>
 #include <linux/spinlock.h>
@@ -619,3 +620,75 @@ void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
 }
 EXPORT_SYMBOL(debug_dma_unmap_page);
 
+void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
+                      int nents, int mapped_ents, int direction)
+{
+        struct dma_debug_entry *entry;
+        struct scatterlist *s;
+        int i;
+
+        if (unlikely(global_disable))
+                return;
+
+        for_each_sg(sg, s, mapped_ents, i) {
+                entry = dma_entry_alloc();
+                if (!entry)
+                        return;
+
+                entry->type           = dma_debug_sg;
+                entry->dev            = dev;
+                entry->paddr          = sg_phys(s);
+                entry->size           = s->length;
+                entry->dev_addr       = s->dma_address;
+                entry->direction      = direction;
+                entry->sg_call_ents   = nents;
+                entry->sg_mapped_ents = mapped_ents;
+
+                check_for_stack(dev, sg_virt(s));
+
+                add_dma_entry(entry);
+        }
+}
+EXPORT_SYMBOL(debug_dma_map_sg);
+
+void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
+                        int nelems, int dir)
+{
+        struct dma_debug_entry *entry;
+        struct scatterlist *s;
+        int mapped_ents = 0, i;
+        unsigned long flags;
+
+        if (unlikely(global_disable))
+                return;
+
+        for_each_sg(sglist, s, nelems, i) {
+
+                struct dma_debug_entry ref = {
+                        .type           = dma_debug_sg,
+                        .dev            = dev,
+                        .paddr          = sg_phys(s),
+                        .dev_addr       = s->dma_address,
+                        .size           = s->length,
+                        .direction      = dir,
+                        .sg_call_ents   = 0,
+                };
+
+                if (mapped_ents && i >= mapped_ents)
+                        break;
+
+                if (mapped_ents == 0) {
+                        struct hash_bucket *bucket;
+                        ref.sg_call_ents = nelems;
+                        bucket = get_hash_bucket(&ref, &flags);
+                        entry = hash_bucket_find(bucket, &ref);
+                        if (entry)
+                                mapped_ents = entry->sg_mapped_ents;
+                        put_hash_bucket(bucket, &flags);
+                }
+
+                check_unmap(&ref);
+        }
+}
+EXPORT_SYMBOL(debug_dma_unmap_sg);
+