1 files changed, 62 insertions, 7 deletions

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index db07bfd9298e..74c6c7fce749 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -24,6 +24,7 @@
 #include <linux/spinlock.h>
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
+#include <linux/export.h>
 #include <linux/device.h>
 #include <linux/types.h>
 #include <linux/sched.h>
@@ -62,6 +63,8 @@ struct dma_debug_entry {
 #endif
 };
 
+typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
+
 struct hash_bucket {
         struct list_head list;
         spinlock_t lock;
@@ -240,18 +243,37 @@ static void put_hash_bucket(struct hash_bucket *bucket,
         spin_unlock_irqrestore(&bucket->lock, __flags);
 }
 
+static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
+{
+        return ((a->dev_addr == a->dev_addr) &&
+                (a->dev == b->dev)) ? true : false;
+}
+
+static bool containing_match(struct dma_debug_entry *a,
+                             struct dma_debug_entry *b)
+{
+        if (a->dev != b->dev)
+                return false;
+
+        if ((b->dev_addr <= a->dev_addr) &&
+            ((b->dev_addr + b->size) >= (a->dev_addr + a->size)))
+                return true;
+
+        return false;
+}
+
 /*
  * Search a given entry in the hash bucket list
  */
-static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket,
-                                                struct dma_debug_entry *ref)
+static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket,
+                                                  struct dma_debug_entry *ref,
+                                                  match_fn match)
 {
         struct dma_debug_entry *entry, *ret = NULL;
         int matches = 0, match_lvl, last_lvl = 0;
 
         list_for_each_entry(entry, &bucket->list, list) {
-                if ((entry->dev_addr != ref->dev_addr) ||
-                    (entry->dev != ref->dev))
+                if (!match(ref, entry))
                         continue;
 
                 /*
@@ -293,6 +315,39 @@ static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket,
         return ret;
 }
 
+static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket,
+                                                 struct dma_debug_entry *ref)
+{
+        return __hash_bucket_find(bucket, ref, exact_match);
+}
+
+static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket,
+                                                   struct dma_debug_entry *ref,
+                                                   unsigned long *flags)
+{
+
+        unsigned int max_range = dma_get_max_seg_size(ref->dev);
+        struct dma_debug_entry *entry, index = *ref;
+        unsigned int range = 0;
+
+        while (range <= max_range) {
+                entry = __hash_bucket_find(*bucket, &index, containing_match);
+
+                if (entry)
+                        return entry;
+
+                /*
+                 * Nothing found, go back a hash bucket
+                 */
+                put_hash_bucket(*bucket, flags);
+                range          += (1 << HASH_FN_SHIFT);
+                index.dev_addr -= (1 << HASH_FN_SHIFT);
+                *bucket = get_hash_bucket(&index, flags);
+        }
+
+        return NULL;
+}
+
 /*
  * Add an entry to a hash bucket
  */
@@ -802,7 +857,7 @@ static void check_unmap(struct dma_debug_entry *ref)
         }
 
         bucket = get_hash_bucket(ref, &flags);
-        entry = hash_bucket_find(bucket, ref);
+        entry = bucket_find_exact(bucket, ref);
 
         if (!entry) {
                 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
@@ -902,7 +957,7 @@ static void check_sync(struct device *dev,
 
         bucket = get_hash_bucket(ref, &flags);
 
-        entry = hash_bucket_find(bucket, ref);
+        entry = bucket_find_contain(&bucket, ref, &flags);
 
         if (!entry) {
                 err_printk(dev, NULL, "DMA-API: device driver tries "
@@ -1060,7 +1115,7 @@ static int get_nr_mapped_entries(struct device *dev,
         int mapped_ents;
 
         bucket       = get_hash_bucket(ref, &flags);
-        entry        = hash_bucket_find(bucket, ref);
+        entry        = bucket_find_exact(bucket, ref);
         mapped_ents  = 0;
 
         if (entry)