dma-debug: move initialization to common code

Most mainstream architectures are using 65536 entries, so lets stick to
that.  If someone is really desperate to override it that can still be
done through <asm/dma-mapping.h>, but I'd rather see a really good
rationale for that.

dma_debug_init is now called as a core_initcall, which for many
architectures means much earlier, and provides dma-debug functionality
earlier in the boot process.  This should be safe as it only relies
on the memory allocator already being available.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>

1 files changed, 14 insertions, 7 deletions

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 7f5cdc1e6b29..712a897174e4 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -41,6 +41,11 @@
 #define HASH_FN_SHIFT   13
 #define HASH_FN_MASK    (HASH_SIZE - 1)
 
+/* allow architectures to override this if absolutely required */
+#ifndef PREALLOC_DMA_DEBUG_ENTRIES
+#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
+#endif
+
 enum {
 	dma_debug_single,
 	dma_debug_page,
@@ -1004,18 +1009,16 @@ void dma_debug_add_bus(struct bus_type *bus)
 	bus_register_notifier(bus, nb);
 }
 
-/*
- * Let the architectures decide how many entries should be preallocated.
- */
-void dma_debug_init(u32 num_entries)
+static int dma_debug_init(void)
 {
+	u32 num_entries;
 	int i;
 
 	/* Do not use dma_debug_initialized here, since we really want to be
 	 * called to set dma_debug_initialized
 	 */
 	if (global_disable)
-		return;
+		return 0;
 
 	for (i = 0; i < HASH_SIZE; ++i) {
 		INIT_LIST_HEAD(&dma_entry_hash[i].list);
@@ -1026,17 +1029,19 @@ void dma_debug_init(u32 num_entries)
 		pr_err("DMA-API: error creating debugfs entries - disabling\n");
 		global_disable = true;
 
-		return;
+		return 0;
 	}
 
 	if (req_entries)
 		num_entries = req_entries;
+	else
+		num_entries = PREALLOC_DMA_DEBUG_ENTRIES;
 
 	if (prealloc_memory(num_entries) != 0) {
 		pr_err("DMA-API: debugging out of memory error - disabled\n");
 		global_disable = true;
 
-		return;
+		return 0;
 	}
 
 	nr_total_entries = num_free_entries;
@@ -1044,7 +1049,9 @@ void dma_debug_init(u32 num_entries)
 	dma_debug_initialized = true;
 
 	pr_info("DMA-API: debugging enabled by kernel config\n");
+	return 0;
 }
+core_initcall(dma_debug_init);
 
 static __init int dma_debug_cmdline(char *str)
 {