dma-debug: re-add dma memory leak detection
Joerg Roedel [Fri, 22 May 2009 15:16:04 +0000 (17:16 +0200)]
This is basically a revert of commit 314eeac9 but now in a
fixed version.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

lib/dma-debug.c

index cdd205d..e47e1a0 100644 (file)
@@ -105,6 +105,11 @@ static const char *type2name[4] = { "single", "page",
 static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
                                   "DMA_FROM_DEVICE", "DMA_NONE" };
 
+/* little merge helper - remove it after the merge window */
+#ifndef BUS_NOTIFY_UNBOUND_DRIVER
+#define BUS_NOTIFY_UNBOUND_DRIVER 0x0005
+#endif
+
 /*
  * The access to some variables in this macro is racy. We can't use atomic_t
  * here because all these variables are exported to debugfs. Some of them even
@@ -458,9 +463,60 @@ out_err:
        return -ENOMEM;
 }
 
+static int device_dma_allocations(struct device *dev)
+{
+       struct dma_debug_entry *entry;
+       unsigned long flags;
+       int count = 0, i;
+
+       for (i = 0; i < HASH_SIZE; ++i) {
+               spin_lock_irqsave(&dma_entry_hash[i].lock, flags);
+               list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
+                       if (entry->dev == dev)
+                               count += 1;
+               }
+               spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags);
+       }
+
+       return count;
+}
+
+static int dma_debug_device_change(struct notifier_block *nb,
+                                   unsigned long action, void *data)
+{
+       struct device *dev = data;
+       int count;
+
+
+       switch (action) {
+       case BUS_NOTIFY_UNBOUND_DRIVER:
+               count = device_dma_allocations(dev);
+               if (count == 0)
+                       break;
+               err_printk(dev, NULL, "DMA-API: device driver has pending "
+                               "DMA allocations while released from device "
+                               "[count=%d]\n", count);
+               break;
+       default:
+               break;
+       }
+
+       return 0;
+}
+
 void dma_debug_add_bus(struct bus_type *bus)
 {
-       /* FIXME: register notifier */
+       struct notifier_block *nb;
+
+       nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
+       if (nb == NULL) {
+               printk(KERN_ERR "dma_debug_add_bus: out of memory\n");
+               return;
+       }
+
+       nb->notifier_call = dma_debug_device_change;
+
+       bus_register_notifier(bus, nb);
 }
 
 /*