dma-debug: teach add_dma_entry() about DMA_ATTR_SKIP_CPU_SYNC

Mapping something twice should be possible as long as,
DMA_ATTR_SKIP_CPU_SYNC is passed to the strictly speaking second relevant
mapping operation (that attempts to map the same thing). So, don't issue a
warning if the specified condition is met in add_dma_entry().

Signed-off-by: Hamza Mahfooz <someguy@effective-light.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 14 insertions, 10 deletions

diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index 35da4c3a6486..7a14ca29c377 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -552,7 +552,7 @@ static void active_cacheline_remove(struct dma_debug_entry *entry)
  * Wrapper function for adding an entry to the hash.
  * This function takes care of locking itself.
  */
-static void add_dma_entry(struct dma_debug_entry *entry)
+static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs)
 {
 	struct hash_bucket *bucket;
 	unsigned long flags;
@@ -566,7 +566,7 @@ static void add_dma_entry(struct dma_debug_entry *entry)
 	if (rc == -ENOMEM) {
 		pr_err("cacheline tracking ENOMEM, dma-debug disabled\n");
 		global_disable = true;
-	} else if (rc == -EEXIST) {
+	} else if (rc == -EEXIST && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
 		err_printk(entry->dev, entry,
 			"cacheline tracking EEXIST, overlapping mappings aren't supported\n");
 	}
@@ -1191,7 +1191,8 @@ void debug_dma_map_single(struct device *dev, const void *addr,
 EXPORT_SYMBOL(debug_dma_map_single);
 
 void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
-			size_t size, int direction, dma_addr_t dma_addr)
+			size_t size, int direction, dma_addr_t dma_addr,
+			unsigned long attrs)
 {
 	struct dma_debug_entry *entry;
 
@@ -1222,7 +1223,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
 		check_for_illegal_area(dev, addr, size);
 	}
 
-	add_dma_entry(entry);
+	add_dma_entry(entry, attrs);
 }
 
 void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
@@ -1280,7 +1281,8 @@ void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
 }
 
 void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
-		      int nents, int mapped_ents, int direction)
+		      int nents, int mapped_ents, int direction,
+		      unsigned long attrs)
 {
 	struct dma_debug_entry *entry;
 	struct scatterlist *s;
@@ -1312,7 +1314,7 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
 
 		check_sg_segment(dev, s);
 
-		add_dma_entry(entry);
+		add_dma_entry(entry, attrs);
 	}
 }
 
@@ -1368,7 +1370,8 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 }
 
 void debug_dma_alloc_coherent(struct device *dev, size_t size,
-			      dma_addr_t dma_addr, void *virt)
+			      dma_addr_t dma_addr, void *virt,
+			      unsigned long attrs)
 {
 	struct dma_debug_entry *entry;
 
@@ -1398,7 +1401,7 @@ void debug_dma_alloc_coherent(struct device *dev, size_t size,
 	else
 		entry->pfn = page_to_pfn(virt_to_page(virt));
 
-	add_dma_entry(entry);
+	add_dma_entry(entry, attrs);
 }
 
 void debug_dma_free_coherent(struct device *dev, size_t size,
@@ -1429,7 +1432,8 @@ void debug_dma_free_coherent(struct device *dev, size_t size,
 }
 
 void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size,
-			    int direction, dma_addr_t dma_addr)
+			    int direction, dma_addr_t dma_addr,
+			    unsigned long attrs)
 {
 	struct dma_debug_entry *entry;
 
@@ -1449,7 +1453,7 @@ void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size,
 	entry->direction	= direction;
 	entry->map_err_type	= MAP_ERR_NOT_CHECKED;
 
-	add_dma_entry(entry);
+	add_dma_entry(entry, attrs);
 }
 
 void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,