[PATCH v2 19/21] x86: use FDT accessors for FDT blob header data

[Rob Herring <robherring2@gmail.com>]

From: Rob Herring <robh@kernel.org>

Remove the direct accesses to FDT header data using accessor
function instead. This makes the code more readable and makes the FDT
blob structure more opaque to the arch code. This also prepares for
removing struct boot_param_header completely.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
---
v2: reworked to use of_get_flat_dt_size helper function

 arch/x86/kernel/devicetree.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index d35078e..7db54b5 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -206,23 +206,21 @@ static void __init dtb_apic_setup(void)
 static void __init x86_flattree_get_config(void)
 {
 	u32 size, map_len;
-	struct boot_param_header *dt;
+	void *dt;
 
 	if (!initial_dtb)
 		return;
 
-	map_len = max(PAGE_SIZE - (initial_dtb & ~PAGE_MASK),
-			(u64)sizeof(struct boot_param_header));
+	map_len = max(PAGE_SIZE - (initial_dtb & ~PAGE_MASK), (u64)128);
 
-	dt = early_memremap(initial_dtb, map_len);
-	size = be32_to_cpu(dt->totalsize);
+	initial_boot_params = dt = early_memremap(initial_dtb, map_len);
+	size = of_get_flat_dt_size();
 	if (map_len < size) {
 		early_iounmap(dt, map_len);
-		dt = early_memremap(initial_dtb, size);
+		initial_boot_params = dt = early_memremap(initial_dtb, size);
 		map_len = size;
 	}
 
-	initial_boot_params = dt;
 	unflatten_and_copy_device_tree();
 	early_iounmap(dt, map_len);
 }
-- 
1.9.1