[PATCH v3 4/6] bloblist: add API for applying blobs with specified tag

[Raymond Mao]

Add an API to search for the blobs with specified tag and use the
hook function to apply the blob data.
Add a helper function to return the inline header size as according
to recent spec[1] updates, the actual data can be following an inline
header instead of following the TE header immediately.

[1] Firmware Handoff spec:
https://github.com/FirmwareHandoff/firmware_handoff

Signed-off-by: Raymond Mao <raymond.mao at linaro.org>
---
Changes in v2:
- Add inline header into the blob payload.
- Add arg 'size' to 'bloblist_apply_blobs()' for more general purpose.
Changes in v3:
- Add including errno.h.

 common/bloblist.c  | 51 ++++++++++++++++++++++++++++++++++++++++++++++
 include/bloblist.h | 21 +++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/common/bloblist.c b/common/bloblist.c
index 550c0c78ffc..2b5026e00da 100644
--- a/common/bloblist.c
+++ b/common/bloblist.c
@@ -235,6 +235,19 @@ static int bloblist_ensurerec(uint tag, struct bloblist_rec **recp, int size,
 	return 0;
 }
 
+static int bloblist_get_blob_data_offset(uint tag)
+{
+	switch (tag) {
+	case BLOBLISTT_FDT_OVERLAY:
+		return sizeof(struct dto_blob_hdr);
+	/*
+	 * return the data offset if it is not following the blob
+	 * header immediately.
+	 */
+	}
+	return 0;
+}
+
 void *bloblist_find(uint tag, int size)
 {
 	void *blob = NULL;
@@ -261,6 +274,44 @@ void *bloblist_get_blob(uint tag, int *sizep)
 	return (void *)rec + rec_hdr_size(rec);
 }
 
+int bloblist_apply_blobs(uint tag, int (*func)(void **data, int size))
+{
+	struct bloblist_hdr *hdr = gd->bloblist;
+	struct bloblist_rec *rec;
+
+	if (!func || !hdr)
+		return -ENOENT;
+
+	foreach_rec(rec, hdr) {
+		/* Apply all blobs with the specified tag */
+		if (rec_tag(rec) == tag) {
+			int ret;
+			int tag = rec_tag(rec);
+			void *blob = (void *)rec + rec_hdr_size(rec);
+			int dat_off = bloblist_get_blob_data_offset(tag);
+
+			blob += dat_off;
+			ret = func(&blob, rec->size - dat_off);
+			if (ret) {
+				log_err("Failed to apply blob with tag %d\n",
+					tag);
+				return ret;
+			}
+
+			rec = rec_from_blob(blob - dat_off);
+			if (rec <= 0) {
+				log_err("Blob corrupted\n");
+				return -ENOENT;
+			}
+
+			/* Mark applied blob record as void */
+			void_blob(rec);
+		}
+	}
+
+	return 0;
+}
+
 void *bloblist_add(uint tag, int size, int align_log2)
 {
 	struct bloblist_rec *rec;
diff --git a/include/bloblist.h b/include/bloblist.h
index c2d3065a43c..e67b2a76358 100644
--- a/include/bloblist.h
+++ b/include/bloblist.h
@@ -73,6 +73,7 @@
 #define __BLOBLIST_H
 
 #include <mapmem.h>
+#include <linux/errno.h>
 
 enum {
 	BLOBLIST_VERSION	= 1,
@@ -279,6 +280,26 @@ static inline void *bloblist_get_blob(uint tag, int *sizep)
 }
 #endif
 
+#if CONFIG_IS_ENABLED(BLOBLIST)
+/**
+ * bloblist_apply_blobs() - Apply the data of blobs by tag
+ *
+ * Scan the bloblist, find the blobs with the matching tag and apply the data
+ * of blobs
+ *
+ * @tag:	Tag to search for (enum bloblist_tag_t)
+ * @func:	Function to apply the data of blobs
+ * Return: 0 if OK, otherwise error.
+ */
+int bloblist_apply_blobs(uint tag, int (*func)(void **data, int size));
+#else
+static inline int bloblist_apply_blobs(uint tag,
+				       int (*func)(void **data, int size))
+{
+	return -EPERM;
+}
+#endif
+
 /**
  * bloblist_find() - Find a blob
  *
-- 
2.25.1