Merge tag 'for-v3.12' of git://git.infradead.org/battery-2.6

[karo-tx-linux.git] / lib / dma-debug.c

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 5e396accd3d02a8dce6d06cc2d6020e311b308b0..d87a17a819d07a58bc8f1dd40f2d41ae499935c8 100644 (file)
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -862,17 +862,21 @@ static void check_unmap(struct dma_debug_entry *ref)
        entry = bucket_find_exact(bucket, ref);
 
        if (!entry) {
+               /* must drop lock before calling dma_mapping_error */
+               put_hash_bucket(bucket, &flags);
+
                if (dma_mapping_error(ref->dev, ref->dev_addr)) {
                        err_printk(ref->dev, NULL,
-                                  "DMA-API: device driver tries "
-                                  "to free an invalid DMA memory address\n");
-                       return;
+                                  "DMA-API: device driver tries to free an "
+                                  "invalid DMA memory address\n");
+               } else {
+                       err_printk(ref->dev, NULL,
+                                  "DMA-API: device driver tries to free DMA "
+                                  "memory it has not allocated [device "
+                                  "address=0x%016llx] [size=%llu bytes]\n",
+                                  ref->dev_addr, ref->size);
                }
-               err_printk(ref->dev, NULL, "DMA-API: device driver tries "
-                          "to free DMA memory it has not allocated "
-                          "[device address=0x%016llx] [size=%llu bytes]\n",
-                          ref->dev_addr, ref->size);
-               goto out;
+               return;
        }
 
        if (ref->size != entry->size) {
@@ -936,7 +940,6 @@ static void check_unmap(struct dma_debug_entry *ref)
        hash_bucket_del(entry);
        dma_entry_free(entry);
 
-out:
        put_hash_bucket(bucket, &flags);
 }
 
@@ -1082,13 +1085,27 @@ void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
        ref.dev = dev;
        ref.dev_addr = dma_addr;
        bucket = get_hash_bucket(&ref, &flags);
-       entry = bucket_find_exact(bucket, &ref);
 
-       if (!entry)
-               goto out;
+       list_for_each_entry(entry, &bucket->list, list) {
+               if (!exact_match(&ref, entry))
+                       continue;
+
+               /*
+                * The same physical address can be mapped multiple
+                * times. Without a hardware IOMMU this results in the
+                * same device addresses being put into the dma-debug
+                * hash multiple times too. This can result in false
+                * positives being reported. Therefore we implement a
+                * best-fit algorithm here which updates the first entry
+                * from the hash which fits the reference value and is
+                * not currently listed as being checked.
+                */
+               if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
+                       entry->map_err_type = MAP_ERR_CHECKED;
+                       break;
+               }
+       }
 
-       entry->map_err_type = MAP_ERR_CHECKED;
-out:
        put_hash_bucket(bucket, &flags);
 }
 EXPORT_SYMBOL(debug_dma_mapping_error);