From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932454Ab3KMPve (ORCPT ); Wed, 13 Nov 2013 10:51:34 -0500 Received: from mail-oa0-f48.google.com ([209.85.219.48]:62992 "EHLO mail-oa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932390Ab3KMPva (ORCPT ); Wed, 13 Nov 2013 10:51:30 -0500 Message-ID: <5283A000.8090007@gmail.com> Date: Wed, 13 Nov 2013 09:51:28 -0600 From: Rob Herring User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Geert Uytterhoeven CC: Andrew Morton , "linux-arch@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Vineet Gupta , James Hogan , Ralf Baechle , Jonas Bonn , Chris Zankel , Rob Herring , "devicetree@vger.kernel.org" Subject: Re: [PATCH 14/17] dt: Consolidate __dtb_start declarations in References: <1384285347-13506-1-git-send-email-geert@linux-m68k.org> <1384285347-13506-15-git-send-email-geert@linux-m68k.org> In-Reply-To: <1384285347-13506-15-git-send-email-geert@linux-m68k.org> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 12, 2013 at 1:42 PM, Geert Uytterhoeven wrote: > The different architectures used their own (and different) declarations: > > extern struct boot_param_header __dtb_start; > extern u32 __dtb_start[]; > extern char __dtb_start[]; > > Consolidate them using the first variant in . > This requires adding a few "address of" operators on architectures where > __dtb_start was an array before. > > Signed-off-by: Geert Uytterhoeven > Cc: Vineet Gupta > Cc: James Hogan > Cc: Ralf Baechle > Cc: Jonas Bonn > CC: Chris Zankel > Cc: Rob Herring > Cc: devicetree@vger.kernel.org > --- > arch/arc/include/asm/sections.h | 1 - > arch/arc/kernel/setup.c | 2 +- > arch/metag/kernel/setup.c | 6 +----- > arch/mips/include/asm/mips-boards/generic.h | 4 ---- > arch/mips/lantiq/prom.h | 2 -- > arch/mips/netlogic/xlp/dt.c | 4 ++-- > arch/mips/ralink/of.c | 2 -- > arch/openrisc/kernel/setup.c | 2 +- > arch/openrisc/kernel/vmlinux.h | 2 -- > arch/xtensa/kernel/setup.c | 3 +-- > include/linux/of_fdt.h | 3 +++ > 11 files changed, 9 insertions(+), 22 deletions(-) This is great, but I would like to see this taken one step further and move the selection logic into the core code. We can try to use the built-in dtb if early_init_dt_scan is passed a NULL or invalid dtb. This should work for most arches I think and still allows an arch to do a different selection algorithm if desired. Are the DT related patches dependent on the rest of the series? Something like this is what I have in mind: diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 5c47910..723f854d 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -869,14 +869,16 @@ void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align) bool __init early_init_dt_scan(void *params) { - if (!params) - return false; - /* Setup flat device-tree pointer */ initial_boot_params = params; + if (!initial_boot_params || + (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER)) + initial_boot_params = &__dtb_start; + /* check device tree validity */ - if (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER) { + if (!initial_boot_params || + (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER)) { initial_boot_params = NULL; return false; }