dma-debug: add initialization code
Impact: add code to initialize dma-debug core data structures
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index b609146..5b50bb3 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -21,6 +21,7 @@
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/list.h>
+#include <linux/slab.h>
#define HASH_SIZE 1024ULL
#define HASH_FN_SHIFT 13
@@ -198,3 +199,68 @@
spin_unlock_irqrestore(&free_entries_lock, flags);
}
+/*
+ * DMA-API debugging init code
+ *
+ * The init code does two things:
+ * 1. Initialize core data structures
+ * 2. Preallocate a given number of dma_debug_entry structs
+ */
+
+static int prealloc_memory(u32 num_entries)
+{
+ struct dma_debug_entry *entry, *next_entry;
+ int i;
+
+ for (i = 0; i < num_entries; ++i) {
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ goto out_err;
+
+ list_add_tail(&entry->list, &free_entries);
+ }
+
+ num_free_entries = num_entries;
+ min_free_entries = num_entries;
+
+ printk(KERN_INFO "DMA-API: preallocated %d debug entries\n",
+ num_entries);
+
+ return 0;
+
+out_err:
+
+ list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
+ list_del(&entry->list);
+ kfree(entry);
+ }
+
+ return -ENOMEM;
+}
+
+/*
+ * Let the architectures decide how many entries should be preallocated.
+ */
+void dma_debug_init(u32 num_entries)
+{
+ int i;
+
+ if (global_disable)
+ return;
+
+ for (i = 0; i < HASH_SIZE; ++i) {
+ INIT_LIST_HEAD(&dma_entry_hash[i].list);
+ dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED;
+ }
+
+ if (prealloc_memory(num_entries) != 0) {
+ printk(KERN_ERR "DMA-API: debugging out of memory error "
+ "- disabled\n");
+ global_disable = true;
+
+ return;
+ }
+
+ printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n");
+}
+