From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <stable-owner@vger.kernel.org>
Received: from eddie.linux-mips.org ([148.251.95.138]:38606 "EHLO
        cvs.linux-mips.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1751322AbdGRLov (ORCPT
        <rfc822;stable@vger.kernel.org>); Tue, 18 Jul 2017 07:44:51 -0400
Received: from localhost.localdomain ([127.0.0.1]:56764 "EHLO
        localhost.localdomain" rhost-flags-OK-OK-OK-OK)
        by eddie.linux-mips.org with ESMTP id S23990924AbdGRLot4nJPZ (ORCPT
        <rfc822;stable@vger.kernel.org>); Tue, 18 Jul 2017 13:44:49 +0200
Date: Tue, 18 Jul 2017 12:44:49 +0100 (BST)
From: "Maciej W. Rozycki" <macro@linux-mips.org>
To: Ralf Baechle <ralf@linux-mips.org>
cc: linux-mips@linux-mips.org, stable@vger.kernel.org
Subject: Re: [PATCH] MIPS: DEC: Fix an int-handler.S CPU_DADDI_WORKAROUNDS
 regression
In-Reply-To: <alpine.LFD.2.20.1707090226390.5208@eddie.linux-mips.org>
Message-ID: <alpine.LFD.2.20.1707181236230.26637@eddie.linux-mips.org>
References: <alpine.LFD.2.20.1707090226390.5208@eddie.linux-mips.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Sender: stable-owner@vger.kernel.org
List-ID: <stable.vger.kernel.org>

On Sun, 9 Jul 2017, Maciej W. Rozycki wrote:

> Fix a commit 3021773c7c3e ("MIPS: DEC: Avoid la pseudo-instruction in 
> delay slots") regression and remove assembly errors:
> 
> arch/mips/dec/int-handler.S: Assembler messages:
> arch/mips/dec/int-handler.S:162: Error: Macro used $at after ".set noat"
> arch/mips/dec/int-handler.S:163: Error: Macro used $at after ".set noat"
> arch/mips/dec/int-handler.S:229: Error: Macro used $at after ".set noat"
> arch/mips/dec/int-handler.S:230: Error: Macro used $at after ".set noat"
> 
> triggering with with the CPU_DADDI_WORKAROUNDS option set and the DADDIU 
> instruction.  This is because with that option in place the instruction 
> becomes a macro, which expands to an LI/DADDU (or actually ADDIU/DADDU) 
> sequence that uses $at as a temporary register.  Use ADDIU instead then, 
> which is equivalent when used with LUI to compose the intermediate 
> 32-bit values.

 64-bit DEC configurations unconditionally select CPU_DADDI_WORKAROUNDS, 
which in turn requires KBUILD_SYM32 or a build error is triggered in our 
top-level arch Makefile.  Therefore this issue can be handled better, by 
checking for KBUILD_64BIT_SYM32 and then the problematic 64-bit leg of 
the #ifdef can be reduced to #error, as not supposed to be ever enabled.

 Withdrawing this patch then, I'll send a different one soon.

  Maciej