[PATCH v2] pstore: Support already existing reserved-memory node

[Detlev Casanova]

The pstore command tries to create a reserved-memory node but fails if
it is already present with:

    Add 'reserved-memory' node failed: FDT_ERR_EXISTS

This patch creates the node only if it does not exist and adapts the reg
values sizes depending on already present #address-cells and #size-cells
values.

Signed-off-by: Detlev Casanova <detlev.casanova at collabora.com>
---

Changes in v2:
 - Move declarations at beginning of function
 - Use if instead of switch
 - Reword Subject

 cmd/pstore.c | 39 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/cmd/pstore.c b/cmd/pstore.c
index 9fac8c7218..cd6f6feb2f 100644
--- a/cmd/pstore.c
+++ b/cmd/pstore.c
@@ -11,6 +11,7 @@
 #include <mapmem.h>
 #include <memalign.h>
 #include <part.h>
+#include <fdt_support.h>
 
 struct persistent_ram_buffer {
 	u32    sig;
@@ -485,6 +486,8 @@ void fdt_fixup_pstore(void *blob)
 {
 	char node[32];
 	int  nodeoffset;	/* node offset from libfdt */
+	u32 addr_cells;
+	u32 size_cells;
 
 	nodeoffset = fdt_path_offset(blob, "/");
 	if (nodeoffset < 0) {
@@ -493,14 +496,18 @@ void fdt_fixup_pstore(void *blob)
 		return;
 	}
 
-	nodeoffset = fdt_add_subnode(blob, nodeoffset, "reserved-memory");
+	nodeoffset = fdt_find_or_add_subnode(blob, nodeoffset, "reserved-memory");
 	if (nodeoffset < 0) {
 		log_err("Add 'reserved-memory' node failed: %s\n",
 				fdt_strerror(nodeoffset));
 		return;
 	}
-	fdt_setprop_u32(blob, nodeoffset, "#address-cells", 2);
-	fdt_setprop_u32(blob, nodeoffset, "#size-cells", 2);
+
+	addr_cells = fdt_getprop_u32_default_node(blob, nodeoffset, 0, "#address-cells", 2);
+	size_cells = fdt_getprop_u32_default_node(blob, nodeoffset, 0, "#size-cells", 2);
+	fdt_setprop_u32(blob, nodeoffset, "#address-cells", addr_cells);
+	fdt_setprop_u32(blob, nodeoffset, "#size-cells", size_cells);
+
 	fdt_setprop_empty(blob, nodeoffset, "ranges");
 
 	sprintf(node, "ramoops@%llx", (unsigned long long)pstore_addr);
@@ -509,14 +516,36 @@ void fdt_fixup_pstore(void *blob)
 		log_err("Add '%s' node failed: %s\n", node, fdt_strerror(nodeoffset));
 		return;
 	}
+
 	fdt_setprop_string(blob, nodeoffset, "compatible", "ramoops");
-	fdt_setprop_u64(blob, nodeoffset, "reg", pstore_addr);
-	fdt_appendprop_u64(blob, nodeoffset, "reg", pstore_length);
+
+	if (addr_cells == 1) {
+		fdt_setprop_u32(blob, nodeoffset, "reg", pstore_addr);
+	} else if (addr_cells == 2) {
+		fdt_setprop_u64(blob, nodeoffset, "reg", pstore_addr);
+	} else {
+		log_err("Unsupported #address-cells: %u\n", addr_cells);
+		goto clean_ramoops;
+	}
+
+	if (size_cells == 1) {
+		// Let's consider that the pstore_length fits in a 32 bits value
+		fdt_appendprop_u32(blob, nodeoffset, "reg", pstore_length);
+	} else if (size_cells == 2) {
+		fdt_appendprop_u64(blob, nodeoffset, "reg", pstore_length);
+	} else {
+		log_err("Unsupported #size-cells: %u\n", addr_cells);
+		goto clean_ramoops;
+	}
+
 	fdt_setprop_u32(blob, nodeoffset, "record-size", pstore_record_size);
 	fdt_setprop_u32(blob, nodeoffset, "console-size", pstore_console_size);
 	fdt_setprop_u32(blob, nodeoffset, "ftrace-size", pstore_ftrace_size);
 	fdt_setprop_u32(blob, nodeoffset, "pmsg-size", pstore_pmsg_size);
 	fdt_setprop_u32(blob, nodeoffset, "ecc-size", pstore_ecc_size);
+
+clean_ramoops:
+	fdt_del_node_and_alias(blob, node);
 }
 
 U_BOOT_CMD(pstore, 10, 0, do_pstore,
-- 
2.35.1