ARM: DMA: add support for DMA debugging

Add ARM support for the DMA debug infrastructure, which allows the
DMA API usage to be debugged.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 21 insertions, 3 deletions

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 44e72108d7a7..85f9361f3e02 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -554,17 +554,20 @@ int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
         struct scatterlist *s;
         int i, j;
 
+        BUG_ON(!valid_dma_direction(dir));
+
         for_each_sg(sg, s, nents, i) {
-                s->dma_address = dma_map_page(dev, sg_page(s), s->offset,
+                s->dma_address = __dma_map_page(dev, sg_page(s), s->offset,
                                                 s->length, dir);
                 if (dma_mapping_error(dev, s->dma_address))
                         goto bad_mapping;
         }
+        debug_dma_map_sg(dev, sg, nents, nents, dir);
         return nents;
 
  bad_mapping:
         for_each_sg(sg, s, i, j)
-                dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
+                __dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
         return 0;
 }
 EXPORT_SYMBOL(dma_map_sg);
@@ -585,8 +588,10 @@ void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
         struct scatterlist *s;
         int i;
 
+        debug_dma_unmap_sg(dev, sg, nents, dir);
+
         for_each_sg(sg, s, nents, i)
-                dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
+                __dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
 }
 EXPORT_SYMBOL(dma_unmap_sg);
 
@@ -611,6 +616,8 @@ void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
                 __dma_page_dev_to_cpu(sg_page(s), s->offset,
                                       s->length, dir);
         }
+
+        debug_dma_sync_sg_for_cpu(dev, sg, nents, dir);
 }
 EXPORT_SYMBOL(dma_sync_sg_for_cpu);
 
@@ -635,5 +642,16 @@ void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
                 __dma_page_cpu_to_dev(sg_page(s), s->offset,
                                       s->length, dir);
         }
+
+        debug_dma_sync_sg_for_device(dev, sg, nents, dir);
 }
 EXPORT_SYMBOL(dma_sync_sg_for_device);
+
+#define PREALLOC_DMA_DEBUG_ENTRIES      4096
+
+static int __init dma_debug_do_init(void)
+{
+        dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
+        return 0;
+}
+fs_initcall(dma_debug_do_init);