Re: [PATCH v3] of/fdt: Rework early_init_dt_scan_memory() to call directly

On Wed, Dec 15, 2021 at 4:13 AM Michael Ellerman [off-list ref] wrote:

Rob Herring [off-list ref] writes:

quoted

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 5e216555fe4f..97d7607625ec 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c

@@ -1078,49 +1078,50 @@ u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
 /*
  * early_init_dt_scan_memory - Look for and parse memory nodes
  */
-int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
-                                  int depth, void *data)
+int __init early_init_dt_scan_memory(void)
 {
-     const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
-     const __be32 *reg, *endp;
-     int l;
-     bool hotpluggable;
-
-     /* We are scanning "memory" nodes only */
-     if (type == NULL || strcmp(type, "memory") != 0)
-             return 0;
+     int node;
+     const void *fdt = initial_boot_params;

-     reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
-     if (reg == NULL)
-             reg = of_get_flat_dt_prop(node, "reg", &l);
-     if (reg == NULL)
-             return 0;
+     for (node = fdt_node_offset_by_prop_value(fdt, -1, "device_type", "memory", 6);
+          node != -FDT_ERR_NOTFOUND;
+          node = fdt_node_offset_by_prop_value(fdt, node, "device_type", "memory", 6)) {

The 6 there doesn't work on my machines.

Crap! I meant to keep the original version and just fix the return.

It needs to match the trailing NULL, so 7 or sizeof("memory") works.

That's what I get for trying to look thru libfdt to see what it wants.
Seems to be strlen() on property names and strlen()+1 on values.

Rob