dma-debug: fix debug_dma_sync_sg_for_cpu and debug_dma_sync_sg_for_device

DMA-mapping.txt says that debug_dma_sync_sg family must be called with
the _same_ one you passed into the dma_map_sg call, it should _NOT_ be
the 'count' value _returned_ from the dma_map_sg call.

debug_dma_sync_sg_for_cpu and debug_dma_sync_sg_for_device can't
handle this properly; they need to use the sg_mapped_ents in struct
dma_debug_entry as debug_dma_unmap_sg() does.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 37 insertions, 11 deletions

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 51f95e5b6265..1abed176d35a 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -855,13 +855,32 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
 }
 EXPORT_SYMBOL(debug_dma_map_sg);
 
+static int get_nr_mapped_entries(struct device *dev, struct scatterlist *s)
+{
+        struct dma_debug_entry *entry;
+        struct hash_bucket *bucket;
+        unsigned long flags;
+        int mapped_ents = 0;
+        struct dma_debug_entry ref;
+
+        ref.dev = dev;
+        ref.dev_addr = sg_dma_address(s);
+        ref.size = sg_dma_len(s),
+
+        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);
+
+        return mapped_ents;
+}
+
 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;
@@ -881,14 +900,9 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
                 if (mapped_ents && i >= mapped_ents)
                         break;
 
-                if (mapped_ents == 0) {
-                        struct hash_bucket *bucket;
+                if (!i) {
                         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);
+                        mapped_ents = get_nr_mapped_entries(dev, s);
                 }
 
                 check_unmap(&ref);
@@ -990,12 +1004,18 @@ void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
                                int nelems, int direction)
 {
         struct scatterlist *s;
-        int i;
+        int mapped_ents = 0, i;
 
         if (unlikely(global_disable))
                 return;
 
         for_each_sg(sg, s, nelems, i) {
+                if (!i)
+                        mapped_ents = get_nr_mapped_entries(dev, s);
+
+                if (i >= mapped_ents)
+                        break;
+
                 check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0,
                            direction, true);
         }
@@ -1006,12 +1026,18 @@ void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
                                   int nelems, int direction)
 {
         struct scatterlist *s;
-        int i;
+        int mapped_ents = 0, i;
 
         if (unlikely(global_disable))
                 return;
 
         for_each_sg(sg, s, nelems, i) {
+                if (!i)
+                        mapped_ents = get_nr_mapped_entries(dev, s);
+
+                if (i >= mapped_ents)
+                        break;
+
                 check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0,
                            direction, false);
         }