region_file_update_data_arr: Modify region_file with array of buffers

Add region_file_update_data_arr, which has the same functionality as
region_file_update_data, but accepts mutliple data buffers.  This is
useful for when we have the mrc_metadata and data in non-contiguous
addresses, which is the case when we bypass the storing of mrc_cache
data into the cbmem.

BUG=b:150502246
BRANCH=None
TEST=reboot from ec console.  Make sure memory training happens.
     reboot from ec console.  Make sure that we don't do training again.

Change-Id: Ia530f7d428b9b07ce3a73e348016038d9daf4c15
Signed-off-by: Shelley Chen <shchen@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45407
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/include/region_file.h

@@ -31,9 +31,22 @@ int region_file_init(struct region_file *f, const struct region_device *p);
  */
 int region_file_data(const struct region_file *f, struct region_device *rdev);
 
+/*
+ * Create region file entry struct to insert multiple data buffers
+ * into the same region_file.
+ */
+struct update_region_file_entry {
+	/* size of this entry */
+	size_t size;
+	/* data pointer */
+	const void *data;
+};
+
 /* Update region file with latest data. Returns < 0 on error, 0 on success. */
-int region_file_update_data(struct region_file *f, const void *buf,
+int region_file_update_data_arr(struct region_file *f,
-				size_t size);
+				  const struct update_region_file_entry *entries,
+				  size_t num_entries);
+int region_file_update_data(struct region_file *f, const void *buf, size_t size);
 
 /* Declared here for easy object allocation. */
 struct region_file {

src/lib/region_file.c

@@ -365,12 +365,16 @@ static int commit_data_allocation(struct region_file *f, size_t data_blks)
 	return 0;
 }
 
-static int commit_data(const struct region_file *f, const void *buf,
+static int commit_data(const struct region_file *f,
-			size_t size)
+		       const struct update_region_file_entry *entries,
+		       size_t num_entries)
 {
 	size_t offset = block_to_bytes(region_file_data_begin(f));
-	if (rdev_writeat(&f->rdev, buf, offset, size) < 0)
+	for (int i = 0; i < num_entries; i++) {
-		return -1;
+		if (rdev_writeat(&f->rdev, entries[i].data, offset, entries[i].size) < 0)
+			return -1;
+		offset += entries[i].size;
+	}
 	return 0;
 }
 
@@ -399,8 +403,9 @@ static int handle_need_to_empty(struct region_file *f)
 	return 0;
 }
 
-static int handle_update(struct region_file *f, size_t blocks, const void *buf,
+static int handle_update(struct region_file *f, size_t blocks,
-				size_t size)
+			 const struct update_region_file_entry *entries,
+			 size_t num_entries)
 {
 	if (!update_can_fit(f, blocks)) {
 		printk(BIOS_INFO, "REGF update can't fit. Will empty.\n");
@@ -413,7 +418,7 @@ static int handle_update(struct region_file *f, size_t blocks, const void *buf,
 		return -1;
 	}
 
-	if (commit_data(f, buf, size)) {
+	if (commit_data(f, entries, num_entries)) {
 		printk(BIOS_ERR, "REGF failed to commit data.\n");
 		return -1;
 	}
@@ -421,11 +426,16 @@ static int handle_update(struct region_file *f, size_t blocks, const void *buf,
 	return 0;
 }
 
-int region_file_update_data(struct region_file *f, const void *buf, size_t size)
+int region_file_update_data_arr(struct region_file *f,
+				const struct update_region_file_entry *entries,
+				size_t num_entries)
 {
 	int ret;
 	size_t blocks;
+	size_t size = 0;
 
+	for (int i = 0; i < num_entries; i++)
+		size += entries[i].size;
 	blocks = bytes_to_block(ALIGN_UP(size, REGF_BLOCK_GRANULARITY));
 
 	while (1) {
@@ -442,7 +452,7 @@ int region_file_update_data(struct region_file *f, const void *buf, size_t size)
 			ret = -1;
 			break;
 		default:
-			ret = handle_update(f, blocks, buf, size);
+			ret = handle_update(f, blocks, entries, num_entries);
 			break;
 		}
 
@@ -459,3 +469,12 @@ int region_file_update_data(struct region_file *f, const void *buf, size_t size)
 
 	return ret;
 }
+
+int region_file_update_data(struct region_file *f, const void *buf, size_t size)
+{
+	struct update_region_file_entry entry = {
+		.size = size,
+		.data = buf,
+	};
+	return region_file_update_data_arr(f, &entry, 1);
+}