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authorJoerg Roedel <joerg.roedel@amd.com>2009-03-16 12:32:14 -0400
committerJoerg Roedel <joerg.roedel@amd.com>2009-03-17 07:56:49 -0400
commit41531c8f5f05aba5ec645d9770557eedbf75b422 (patch)
tree7635e68efbee5ea7b5208e5d4b332f6ef2113dd3 /lib
parent2e34bde18576a02c897ae6b699ea26301d92be1b (diff)
dma-debug: add a check dma memory leaks
Impact: allow architectures to monitor busses for dma mem leakage This patch adds checking code to detect if a device has pending DMA operations when it is about to be unbound from its device driver. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Diffstat (limited to 'lib')
-rw-r--r--lib/dma-debug.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 6022eb4a0cd0..9a350b414a50 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -400,6 +400,61 @@ out_err:
400 return -ENOMEM; 400 return -ENOMEM;
401} 401}
402 402
403static int device_dma_allocations(struct device *dev)
404{
405 struct dma_debug_entry *entry;
406 unsigned long flags;
407 int count = 0, i;
408
409 for (i = 0; i < HASH_SIZE; ++i) {
410 spin_lock_irqsave(&dma_entry_hash[i].lock, flags);
411 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
412 if (entry->dev == dev)
413 count += 1;
414 }
415 spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags);
416 }
417
418 return count;
419}
420
421static int dma_debug_device_change(struct notifier_block *nb,
422 unsigned long action, void *data)
423{
424 struct device *dev = data;
425 int count;
426
427
428 switch (action) {
429 case BUS_NOTIFY_UNBIND_DRIVER:
430 count = device_dma_allocations(dev);
431 if (count == 0)
432 break;
433 err_printk(dev, NULL, "DMA-API: device driver has pending "
434 "DMA allocations while released from device "
435 "[count=%d]\n", count);
436 break;
437 default:
438 break;
439 }
440
441 return 0;
442}
443
444void dma_debug_add_bus(struct bus_type *bus)
445{
446 struct notifier_block *nb;
447
448 nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
449 if (nb == NULL) {
450 printk(KERN_ERR "dma_debug_add_bus: out of memory\n");
451 return;
452 }
453
454 nb->notifier_call = dma_debug_device_change;
455
456 bus_register_notifier(bus, nb);
457}
403 458
404/* 459/*
405 * Let the architectures decide how many entries should be preallocated. 460 * Let the architectures decide how many entries should be preallocated.