common: add blkcache init

On m68k, block_cache list is relocated, but next and prev list
pointers are not adjusted to the relocated struct list_head address,
so the first iteration over the block_cache list hangs.

This patch initializes the block_cache list after relocation.

Signed-off-by: Angelo Durgehello <angelo.dureghello@timesys.com>
Reviewed-by: Eric Nelson <eric@nelint.com>

common/board_r.c

@@ -864,6 +864,9 @@ static init_fnc_t init_sequence_r[] = {
 #endif
 #if defined(CONFIG_PRAM)
 	initr_mem,
+#endif
+#ifdef CONFIG_BLOCK_CACHE
+	blkcache_init,
 #endif
 	run_main_loop,
 };

drivers/block/blkcache.c

@@ -21,13 +21,20 @@ struct block_cache_node {
 	char *cache;
 };
 
-static LIST_HEAD(block_cache);
+static struct list_head block_cache;
 
 static struct block_cache_stats _stats = {
 	.max_blocks_per_entry = 8,
 	.max_entries = 32
 };
 
+int blkcache_init(void)
+{
+	INIT_LIST_HEAD(&block_cache);
+
+	return 0;
+}
+
 static struct block_cache_node *cache_find(int iftype, int devnum,
 					   lbaint_t start, lbaint_t blkcnt,
 					   unsigned long blksz)

include/blk.h

@@ -113,6 +113,12 @@ struct blk_desc {
 	(PAD_SIZE(size, blk_desc->blksz))
 
 #if CONFIG_IS_ENABLED(BLOCK_CACHE)
+
+/**
+ * blkcache_init() - initialize the block cache list pointers
+ */
+int blkcache_init(void);
+
 /**
  * blkcache_read() - attempt to read a set of blocks from cache
  *