From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753565AbcEYIT5 (ORCPT ); Wed, 25 May 2016 04:19:57 -0400 Received: from science.sciencehorizons.net ([71.41.210.147]:51482 "HELO ns.sciencehorizons.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with SMTP id S1752561AbcEYITv (ORCPT ); Wed, 25 May 2016 04:19:51 -0400 Date: 25 May 2016 04:19:49 -0400 Message-ID: <20160525081949.7160.qmail@ns.sciencehorizons.net> From: "George Spelvin" To: geert@linux-m68k.org, linux@sciencehorizons.net Subject: Re: [PATCH 08/10] m68k: Add Cc: gerg@linux-m68k.org, linux-kernel@vger.kernel.org, linux-m68k@vger.kernel.org, tglx@linutronix.de, torvalds@linux-foundation.org In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > With my comment above, you wouldn't need this, but I'm gonna comment anyway. > > We don't use special GCCs to target specific CPU variants. Hence inside the > kernel, you should check the config symbols, to see if support for 68000 or > 68010 (which isn't supported by the kernel yet) is enabled. Do you remember some earlier discussion about the m68k Makefile and old GCC versions? In particular, lines like: cpuflags-$(CONFIG_M525x) := $(call cc-option,-mcpu=5253,-m5200) cpuflags-$(CONFIG_M5249) := $(call cc-option,-mcpu=5249,-m5200) cpuflags-$(CONFIG_M520x) := $(call cc-option,-mcpu=5208,-m5200) cpuflags-$(CONFIG_M5206e) := $(call cc-option,-mcpu=5206e,-m5200) cpuflags-$(CONFIG_M5206) := $(call cc-option,-mcpu=5206,-m5200) The problem is that whether MULU.L exists depends on the targeted architecture, and *that* depends on this Makefile trickery, not just CONFIG symbols... Oh, f*** me. I misremembered. That problem exists, but only for DIVU.L. As I said in the comments (which I wrote *after* deciding I needed this approach), all ColdFire have MULU.L. It's DIVU.L that's missing from some early ones. You're absolutely right. MULU.L support can be done perfectly from CONFIG_ options. Improved patch coming in a few minutes. My sincere apologies.