x86: Add various minor tidy-ups in mrccache codes

Fix some nits, improve some comments and reorder some codes
a little bit.
Signed-off-by: NBin Meng <bmeng.cn@gmail.com>
Acked-by: NSimon Glass <sjg@chromium.org>

arch/x86/include/asm/mrccache.h

 /*
- * Copyright (c) 2014 Google, Inc
+ * Copyright (C) 2014 Google, Inc
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
-#ifndef _ASM_ARCH_MRCCACHE_H
-#define _ASM_ARCH_MRCCACHE_H
+#ifndef _ASM_MRCCACHE_H
+#define _ASM_MRCCACHE_H
 
 #define MRC_DATA_ALIGN		0x1000
-#define MRC_DATA_SIGNATURE	(('M' << 0) | ('R' << 8) | ('C' << 16) | \
-					('D'<<24))
+#define MRC_DATA_SIGNATURE	(('M' << 0) | ('R' << 8) | \
+				 ('C' << 16) | ('D'<<24))
 
-__packed struct mrc_data_container {
+struct __packed mrc_data_container {
 	u32	signature;	/* "MRCD" */
 	u32	data_size;	/* Size of the 'data' field */
 	u32	checksum;	/* IP style checksum */
@@ -28,7 +28,7 @@ struct udevice;
  * This searches the MRC cache region looking for the latest record to use
  * for setting up SDRAM
  *
- * @entry:	Information about the position and size of the MRC cache
+ * @entry:	Position and size of MRC cache in SPI flash
  * @return pointer to latest record, or NULL if none
  */
 struct mrc_data_container *mrccache_find_current(struct fmap_entry *entry);
@@ -36,8 +36,8 @@ struct mrc_data_container *mrccache_find_current(struct fmap_entry *entry);
 /**
  * mrccache_update() - update the MRC cache with a new record
  *
- * This writes a new record to the end of the MRC cache. If the new record is
- * the same as the latest record then the write is skipped
+ * This writes a new record to the end of the MRC cache region. If the new
+ * record is the same as the latest record then the write is skipped
  *
  * @sf:		SPI flash to write to
  * @entry:	Position and size of MRC cache in SPI flash
@@ -48,4 +48,4 @@ struct mrc_data_container *mrccache_find_current(struct fmap_entry *entry);
 int mrccache_update(struct udevice *sf, struct fmap_entry *entry,
 		    struct mrc_data_container *cur);
 
-#endif
+#endif /* _ASM_MRCCACHE_H */

arch/x86/lib/mrccache.c

 /*
- * From Coreboot src/southbridge/intel/bd82x6x/mrccache.c
+ * From coreboot src/southbridge/intel/bd82x6x/mrccache.c
  *
  * Copyright (C) 2014 Google Inc.
  *
@@ -15,17 +15,19 @@
 #include <asm/mrccache.h>
 
 static struct mrc_data_container *next_mrc_block(
-	struct mrc_data_container *mrc_cache)
+	struct mrc_data_container *cache)
 {
 	/* MRC data blocks are aligned within the region */
-	u32 mrc_size = sizeof(*mrc_cache) + mrc_cache->data_size;
+	u32 mrc_size = sizeof(*cache) + cache->data_size;
+	u8 *region_ptr = (u8 *)cache;
+
 	if (mrc_size & (MRC_DATA_ALIGN - 1UL)) {
 		mrc_size &= ~(MRC_DATA_ALIGN - 1UL);
 		mrc_size += MRC_DATA_ALIGN;
 	}
 
-	u8 *region_ptr = (u8 *)mrc_cache;
 	region_ptr += mrc_size;
+
 	return (struct mrc_data_container *)region_ptr;
 }
 
@@ -34,10 +36,6 @@ static int is_mrc_cache(struct mrc_data_container *cache)
 	return cache && (cache->signature == MRC_DATA_SIGNATURE);
 }
 
-/*
- * Find the largest index block in the MRC cache. Return NULL if none is
- * found.
- */
 struct mrc_data_container *mrccache_find_current(struct fmap_entry *entry)
 {
 	struct mrc_data_container *cache, *next;