[PATCHv2 1/2] of: fdt: Aggregate the processing of "linux,usable-memory-range"

[Pingfan Liu <kernelfans@xxxxxxxxx>]

From: Zhen Lei <thunder.leizhen@xxxxxxxxxx>

Currently, we parse the "linux,usable-memory-range" property in
early_init_dt_scan_chosen(), to obtain the specified memory range of the
crash kernel. We then reserve the required memory after
early_init_dt_scan_memory() has identified all available physical memory.
Because the two pieces of code are separated far, the readability and
maintainability are reduced. So bring them together.

Suggested-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
(change the prototype of early_init_dt_check_for_usable_mem_range(), in
order to use it outside)
Signed-off-by: Pingfan Liu <kernelfans@xxxxxxxxx>
Tested-by: Dave Kleikamp <dave.kleikamp@xxxxxxxxxx>
Acked-by: John Donnelly <john.p.donnelly@xxxxxxxxxx>
Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
To: devicetree@xxxxxxxxxxxxxxx
To: linux-efi@xxxxxxxxxxxxxxx
---
I keep the Signed-off-by, Tested-by, Acked-by and Reviewed-by, since I
think that the prototype change is not significant.
early_init_dt_check_for_usable_mem_range() only handle chosen node, and
it is fine to isolate this info inside the function itself so later
easier to be used outside.

Sorry if you disagree, please let me know.

 drivers/of/fdt.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index bdca35284ceb..18a2df431bfd 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -965,18 +965,23 @@ static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
 		 elfcorehdr_addr, elfcorehdr_size);
 }
 
-static phys_addr_t cap_mem_addr;
-static phys_addr_t cap_mem_size;
+static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
 
 /**
  * early_init_dt_check_for_usable_mem_range - Decode usable memory range
  * location from flat tree
  * @node: reference to node containing usable memory range location ('chosen')
  */
-static void __init early_init_dt_check_for_usable_mem_range(unsigned long node)
+static void __init early_init_dt_check_for_usable_mem_range(void)
 {
 	const __be32 *prop;
 	int len;
+	phys_addr_t cap_mem_addr;
+	phys_addr_t cap_mem_size;
+	unsigned long node = chosen_node_offset;
+
+	if ((long)node < 0)
+		return;
 
 	pr_debug("Looking for usable-memory-range property... ");
 
@@ -989,6 +994,8 @@ static void __init early_init_dt_check_for_usable_mem_range(unsigned long node)
 
 	pr_debug("cap_mem_start=%pa cap_mem_size=%pa\n", &cap_mem_addr,
 		 &cap_mem_size);
+
+	memblock_cap_memory_range(cap_mem_addr, cap_mem_size);
 }
 
 #ifdef CONFIG_SERIAL_EARLYCON
@@ -1137,9 +1144,10 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
 	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
 		return 0;
 
+	chosen_node_offset = node;
+
 	early_init_dt_check_for_initrd(node);
 	early_init_dt_check_for_elfcorehdr(node);
-	early_init_dt_check_for_usable_mem_range(node);
 
 	/* Retrieve command line */
 	p = of_get_flat_dt_prop(node, "bootargs", &l);
@@ -1275,7 +1283,7 @@ void __init early_init_dt_scan_nodes(void)
 	of_scan_flat_dt(early_init_dt_scan_memory, NULL);
 
 	/* Handle linux,usable-memory-range property */
-	memblock_cap_memory_range(cap_mem_addr, cap_mem_size);
+	early_init_dt_check_for_usable_mem_range();
 }
 
 bool __init early_init_dt_scan(void *params)
-- 
2.31.1