dma-debug: Make leak-like behaviour apparent

When the code disables itself at runtime this is most likely because it ran

out of dma_debug_entries and was unable to allocate more on-demand. 65536

entries are preallocated at boot - if this is too low for you boot with

'dma_debug_entries=<your_desired_number>' to overwrite the default.

'dma_debug_entries=<your_desired_number>' to overwrite the default. The

code will print to the kernel log each time it has dynamically allocated

as many entries as were initially preallocated. This is to indicate that a

larger preallocation size may be appropriate, or if it happens continually

that a driver may be leaking mappings.

::

	return entry;

}

void __dma_entry_alloc_check_leak(void)

{

	u32 tmp = nr_total_entries % nr_prealloc_entries;

	/* Shout each time we tick over some multiple of the initial pool */

	if (tmp < DMA_DEBUG_DYNAMIC_ENTRIES) {

		pr_info("dma_debug_entry pool grown to %u (%u00%%)\n",

			nr_total_entries,

			(nr_total_entries / nr_prealloc_entries));

	}

}

/* struct dma_entry allocator

 *

 * The next two functions implement the allocator for

			pr_err("debugging out of memory - disabling\n");

			return NULL;

		}

		__dma_entry_alloc_check_leak();

	}

	entry = __dma_entry_alloc();