Re: [PATCH 01/20] mips: octeon: convert to use unflatten_and_copy_device_tree

[Andreas Herrmann <herrmann.der.user@xxxxxxxxxxxxxx>]

On Thu, Apr 03, 2014 at 05:16:44PM -0500, Rob Herring wrote:
> From: Rob Herring <robh@xxxxxxxxxx>
> 
> The octeon FDT code can be simplified by using
> unflatten_and_copy_device_tree function. This removes all accesses to
> FDT header data by the arch code.

Hi Rob,

I think (in general) this modification is ok. But I suggest to use
following (slightly modified) version.


Thanks,

Andreas

-- 8< --
Subject: MIPS: Octeon: Convert to use unflatten_and_copy_device_tree

From: Rob Herring <robh@xxxxxxxxxx>

The octeon FDT code can be simplified by using
unflatten_and_copy_device_tree function. This removes all accesses to
FDT header data by the arch code.

[andreas.herrmann: * Fixed compile problem:
 arch/mips/cavium-octeon/setup.c: In function 'device_tree_init':
 arch/mips/cavium-octeon/setup.c:1070:7: error: assignment discards 'const' qualifier from pointer target type [-Werror]
 arch/mips/cavium-octeon/setup.c:1073:7: error: assignment discards 'const' qualifier from pointer target type [-Werror]
                   * Removed (now) obsolete extern declarations (for __dtb_octeon_3xxx_end,
                     __dtb_octeon_68xx_end)]

Tested-by: Andreas Herrmann <andreas.herrmann@xxxxxxxxxxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
---
 arch/mips/cavium-octeon/setup.c |   20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c
index 331b837..72ae938 100644
--- a/arch/mips/cavium-octeon/setup.c
+++ b/arch/mips/cavium-octeon/setup.c
@@ -1053,36 +1053,26 @@ void prom_free_prom_memory(void)
 int octeon_prune_device_tree(void);
 
 extern const char __dtb_octeon_3xxx_begin;
-extern const char __dtb_octeon_3xxx_end;
 extern const char __dtb_octeon_68xx_begin;
-extern const char __dtb_octeon_68xx_end;
 void __init device_tree_init(void)
 {
-	int dt_size;
-	struct boot_param_header *fdt;
+	const void *fdt;
 	bool do_prune;
 
 	if (octeon_bootinfo->minor_version >= 3 && octeon_bootinfo->fdt_addr) {
 		fdt = phys_to_virt(octeon_bootinfo->fdt_addr);
 		if (fdt_check_header(fdt))
 			panic("Corrupt Device Tree passed to kernel.");
-		dt_size = be32_to_cpu(fdt->totalsize);
 		do_prune = false;
 	} else if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
-		fdt = (struct boot_param_header *)&__dtb_octeon_68xx_begin;
-		dt_size = &__dtb_octeon_68xx_end - &__dtb_octeon_68xx_begin;
+		fdt = &__dtb_octeon_68xx_begin;
 		do_prune = true;
 	} else {
-		fdt = (struct boot_param_header *)&__dtb_octeon_3xxx_begin;
-		dt_size = &__dtb_octeon_3xxx_end - &__dtb_octeon_3xxx_begin;
+		fdt = &__dtb_octeon_3xxx_begin;
 		do_prune = true;
 	}
 
-	/* Copy the default tree from init memory. */
-	initial_boot_params = early_init_dt_alloc_memory_arch(dt_size, 8);
-	if (initial_boot_params == NULL)
-		panic("Could not allocate initial_boot_params");
-	memcpy(initial_boot_params, fdt, dt_size);
+	initial_boot_params = (void *)fdt;
 
 	if (do_prune) {
 		octeon_prune_device_tree();
@@ -1090,7 +1080,7 @@ void __init device_tree_init(void)
 	} else {
 		pr_info("Using passed Device Tree.\n");
 	}
-	unflatten_device_tree();
+	unflatten_and_copy_device_tree();
 }
 
 static int __initdata disable_octeon_edac_p;
-- 
1.7.9.5