From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gdb-patches-return-103152-listarch-gdb-patches=sources.redhat.com@sourceware.org>
Received: (qmail 28791 invoked by alias); 2 Jul 2013 20:03:42 -0000
Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm
Precedence: bulk
List-Id: <gdb-patches.sourceware.org>
List-Subscribe: <mailto:gdb-patches-subscribe@sourceware.org>
List-Archive: <http://sourceware.org/ml/gdb-patches/>
List-Post: <mailto:gdb-patches@sourceware.org>
List-Help: <mailto:gdb-patches-help@sourceware.org>, <http://sourceware.org/ml/#faqs>
Sender: gdb-patches-owner@sourceware.org
Received: (qmail 28756 invoked by uid 89); 2 Jul 2013 20:03:37 -0000
X-Spam-SWARE-Status: No, score=-4.2 required=5.0 tests=AWL,BAYES_00,KHOP_THREADED,RCVD_IN_DNSWL_NONE,RCVD_IN_HOSTKARMA_NO,SPF_SOFTFAIL autolearn=no version=3.3.1
Received: from mtaout22.012.net.il (HELO mtaout22.012.net.il) (80.179.55.172)    by sourceware.org (qpsmtpd/0.84/v0.84-167-ge50287c) with ESMTP; Tue, 02 Jul 2013 20:03:36 +0000
Received: from conversion-daemon.a-mtaout22.012.net.il by a-mtaout22.012.net.il (HyperSendmail v2007.08) id <0MPB00K00RKKIN00@a-mtaout22.012.net.il> for gdb-patches@sourceware.org; Tue, 02 Jul 2013 23:03:11 +0300 (IDT)
Received: from HOME-C4E4A596F7 ([87.69.4.28]) by a-mtaout22.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0MPB00K7WRPB9780@a-mtaout22.012.net.il>; Tue, 02 Jul 2013 23:03:11 +0300 (IDT)
Date: Tue, 02 Jul 2013 20:03:00 -0000
From: Eli Zaretskii <eliz@gnu.org>
Subject: Re: [PATCH] Enable hw watchpoint with longer ranges using DAWR on Power
In-reply-to: <1372786761-29726-1-git-send-email-emachado@linux.vnet.ibm.com>
To: Edjunior Barbosa Machado <emachado@linux.vnet.ibm.com>
Cc: gdb-patches@sourceware.org, emachado@linux.vnet.ibm.com, Ulrich.Weigand@de.ibm.com
Reply-to: Eli Zaretskii <eliz@gnu.org>
Message-id: <83ip0sbuh7.fsf@gnu.org>
References: <1372786761-29726-1-git-send-email-emachado@linux.vnet.ibm.com>
X-SW-Source: 2013-07/txt/msg00092.txt.bz2

> From: Edjunior Barbosa Machado <emachado@linux.vnet.ibm.com>
> Cc: Edjunior Barbosa Machado <emachado@linux.vnet.ibm.com>,        Ulrich Weigand <Ulrich.Weigand@de.ibm.com>
> Date: Tue,  2 Jul 2013 14:39:21 -0300
> 
> The new DAWR interface provided by the next generation of Power processors
> (Power ISA Version 2.07) included in the kernel this year allows gdb to use
> hardware watchpoint with longer ranges (up to 512 bytes wide), which can't cross
> a 512 byte boundary [1]. The patch below enables the usage of this new feature,
> currently exported to the userspace as PPC_DEBUG_FEATURE_DATA_BP_DAWR via struct
> ppc_debug_info [2]. Ok?

Is only one watchpoint of this kind possible at any given time?  If
more than one such watchpoint can be used at the same time, I don't
see why we should expose the 512-byte limitation to users.  Just use
more than one such watchpoint to cover the range of addresses
requested by the user command.