ALSA: hda - Move generic array helpers to core lib

This will be used by the regmap support.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/hda/array.c

@@ -0,0 +1,49 @@
+/*
+ * generic arrays
+ */
+
+#include <linux/slab.h>
+#include <sound/core.h>
+#include <sound/hdaudio.h>
+
+/**
+ * snd_array_new - get a new element from the given array
+ * @array: the array object
+ *
+ * Get a new element from the given array.  If it exceeds the
+ * pre-allocated array size, re-allocate the array.
+ *
+ * Returns NULL if allocation failed.
+ */
+void *snd_array_new(struct snd_array *array)
+{
+	if (snd_BUG_ON(!array->elem_size))
+		return NULL;
+	if (array->used >= array->alloced) {
+		int num = array->alloced + array->alloc_align;
+		int size = (num + 1) * array->elem_size;
+		void *nlist;
+		if (snd_BUG_ON(num >= 4096))
+			return NULL;
+		nlist = krealloc(array->list, size, GFP_KERNEL | __GFP_ZERO);
+		if (!nlist)
+			return NULL;
+		array->list = nlist;
+		array->alloced = num;
+	}
+	return snd_array_elem(array, array->used++);
+}
+EXPORT_SYMBOL_GPL(snd_array_new);
+
+/**
+ * snd_array_free - free the given array elements
+ * @array: the array object
+ */
+void snd_array_free(struct snd_array *array)
+{
+	kfree(array->list);
+	array->used = 0;
+	array->alloced = 0;
+	array->list = NULL;
+}
+EXPORT_SYMBOL_GPL(snd_array_free);