dma-debug: add function to dump dma mappings
This adds a function to dump the DMA mappings that the debugging code is
aware of -- either for a single device, or for _all_ devices.
This can be useful for debugging -- sticking a call to it in the DMA
page fault handler, for example, to see if the faulting address _should_
be mapped or not, and hence work out whether it's IOMMU bugs we're
seeing, or driver bugs.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 9d11e89..91ed1df 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -194,6 +194,36 @@
}
/*
+ * Dump mapping entries for debugging purposes
+ */
+void debug_dma_dump_mappings(struct device *dev)
+{
+ int idx;
+
+ for (idx = 0; idx < HASH_SIZE; idx++) {
+ struct hash_bucket *bucket = &dma_entry_hash[idx];
+ struct dma_debug_entry *entry;
+ unsigned long flags;
+
+ spin_lock_irqsave(&bucket->lock, flags);
+
+ list_for_each_entry(entry, &bucket->list, list) {
+ if (!dev || dev == entry->dev) {
+ dev_info(entry->dev,
+ "%s idx %d P=%Lx D=%Lx L=%Lx %s\n",
+ type2name[entry->type], idx,
+ (unsigned long long)entry->paddr,
+ entry->dev_addr, entry->size,
+ dir2name[entry->direction]);
+ }
+ }
+
+ spin_unlock_irqrestore(&bucket->lock, flags);
+ }
+}
+EXPORT_SYMBOL(debug_dma_dump_mappings);
+
+/*
* Wrapper function for adding an entry to the hash.
* This function takes care of locking itself.
*/