[PATCH v4 7/9] bloblist: Load the bloblist from the previous loader

[Raymond Mao]

During bloblist initialization, when OF_BOARD is defined, load the
bloblist via boot arguments from the previous loader.
If a valid bloblist exists in boot arguments, relocate it into the
fixed bloblist memory region.
If not, fallback to support BLOBLIST_ADDR or BLOBLIST_ALLOC.

Signed-off-by: Raymond Mao <raymond.mao at linaro.org>
---
Changes in v4
- Add weak default function.
- Add comments for BLOBLIST_ALLOC.
- Add local debug macro.
- Refine the commit message.

 common/bloblist.c  | 66 +++++++++++++++++++++++++++++++++-------------
 include/bloblist.h | 10 +++++++
 2 files changed, 58 insertions(+), 18 deletions(-)

diff --git a/common/bloblist.c b/common/bloblist.c
index 4e76975627..65c3c031d0 100644
--- a/common/bloblist.c
+++ b/common/bloblist.c
@@ -17,6 +17,9 @@
 #include <asm/global_data.h>
 #include <u-boot/crc.h>
 
+/* local debug macro */
+#undef BLOBLIST_DEBUG
+
 /*
  * A bloblist is a single contiguous chunk of memory with a header
  * (struct bloblist_hdr) and a number of blobs in it.
@@ -487,37 +490,58 @@ int bloblist_reloc(void *to, uint to_size)
 	return 0;
 }
 
+/*
+ * Weak default function for getting bloblist from boot args.
+ */
+int __weak xferlist_from_boot_arg(ulong __always_unused addr,
+				  ulong __always_unused size)
+{
+	return -ENOENT;
+}
+
 int bloblist_init(void)
 {
 	bool fixed = IS_ENABLED(CONFIG_BLOBLIST_FIXED);
 	int ret = -ENOENT;
 	ulong addr, size;
-	bool expected;
-
-	/**
-	 * We don't expect to find an existing bloblist in the first phase of
-	 * U-Boot that runs. Also we have no way to receive the address of an
-	 * allocated bloblist from a previous stage, so it must be at a fixed
+	/*
+	 * If U-Boot is not in the first phase, an existing bloblist must be
+	 * at a fixed address.
+	 */
+	bool from_addr = fixed && !u_boot_first_phase();
+	/*
+	 * If U-Boot is in the first phase that a board specific routine should
+	 * install the bloblist passed from previous loader to this fixed
 	 * address.
 	 */
-	expected = fixed && !u_boot_first_phase();
+	bool from_board = fixed && IS_ENABLED(CONFIG_OF_BOARD) &&
+			  u_boot_first_phase();
+
 	if (spl_prev_phase() == PHASE_TPL && !IS_ENABLED(CONFIG_TPL_BLOBLIST))
-		expected = false;
+		from_addr = false;
 	if (fixed)
 		addr = IF_ENABLED_INT(CONFIG_BLOBLIST_FIXED,
 				      CONFIG_BLOBLIST_ADDR);
 	size = CONFIG_BLOBLIST_SIZE;
-	if (expected) {
+
+	if (from_board)
+		ret = xferlist_from_boot_arg(addr, size);
+	else if (from_addr)
 		ret = bloblist_check(addr, size);
-		if (ret) {
-			log_warning("Expected bloblist at %lx not found (err=%d)\n",
-				    addr, ret);
-		} else {
-			/* Get the real size, if it is not what we expected */
-			size = gd->bloblist->total_size;
-		}
-	}
+
+	if (ret)
+		log_warning("Bloblist at %lx not found (err=%d)\n",
+			    addr, ret);
+	else
+		/* Get the real size */
+		size = gd->bloblist->total_size;
+
 	if (ret) {
+		/*
+		 * If we don't have a bloblist from a fixed address, or the one
+		 * in the fixed address is not valid. we must allocate the
+		 * memory for it now.
+		 */
 		if (CONFIG_IS_ENABLED(BLOBLIST_ALLOC)) {
 			void *ptr = memalign(BLOBLIST_ALIGN, size);
 
@@ -525,7 +549,8 @@ int bloblist_init(void)
 				return log_msg_ret("alloc", -ENOMEM);
 			addr = map_to_sysmem(ptr);
 		} else if (!fixed) {
-			return log_msg_ret("!fixed", ret);
+			return log_msg_ret("BLOBLIST_FIXED is not enabled",
+					   ret);
 		}
 		log_debug("Creating new bloblist size %lx at %lx\n", size,
 			  addr);
@@ -538,6 +563,11 @@ int bloblist_init(void)
 		return log_msg_ret("ini", ret);
 	gd->flags |= GD_FLG_BLOBLIST_READY;
 
+#ifdef BLOBLIST_DEBUG
+	bloblist_show_stats();
+	bloblist_show_list();
+#endif
+
 	return 0;
 }
 
diff --git a/include/bloblist.h b/include/bloblist.h
index 81f1dfa027..af215932bc 100644
--- a/include/bloblist.h
+++ b/include/bloblist.h
@@ -482,4 +482,14 @@ static inline int bloblist_maybe_init(void)
  */
 int bloblist_check_reg_conv(ulong rfdt, ulong rzero, ulong rsig);
 
+/**
+ * xferlist_from_boot_arg() - Get bloblist from the boot args and relocate it
+ *			      to the specified address.
+ *
+ * @addr: Address for the bloblist
+ * @size: Size of space reserved for the bloblist
+ * Return: 0 if OK, else on error
+ */
+int xferlist_from_boot_arg(ulong addr, ulong size);
+
 #endif /* __BLOBLIST_H */
-- 
2.25.1