From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21174C43331 for ; Wed, 1 Apr 2020 06:50:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E68F9206F6 for ; Wed, 1 Apr 2020 06:50:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="uDJQlg1Y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731903AbgDAGuI (ORCPT ); Wed, 1 Apr 2020 02:50:08 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:29668 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731741AbgDAGuH (ORCPT ); Wed, 1 Apr 2020 02:50:07 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 48scJX6ylSz9tyZJ; Wed, 1 Apr 2020 08:50:04 +0200 (CEST) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=uDJQlg1Y; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id rp9wn7S42rj0; Wed, 1 Apr 2020 08:50:04 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 48scJX5ksnz9tyYt; Wed, 1 Apr 2020 08:50:04 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1585723804; bh=/v/yFC5Me+oB029ChIvZOH8gGHQt7UZV4uLwljZmJUo=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=uDJQlg1YWF7fudqZaNEW0MQCyx90f8sHgEQit+ZOzHZziOpdB2TsC9GVJWQDF+5bV 7TCsvLELllCQxpE0W7Up3xJDdymf1seXxNtaDrVDTr/29ZuStzu/n7plj50z2U44DR huqR6cocjHjZtuQKrioAxyMsih7fdse9I6DdPJCw= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 870568B7B3; Wed, 1 Apr 2020 08:50:05 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id wCkTTMMTen22; Wed, 1 Apr 2020 08:50:05 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id A894D8B778; Wed, 1 Apr 2020 08:50:02 +0200 (CEST) Subject: Re: [PATCH v2 13/16] powerpc/watchpoint: Prepare handler to handle more than one watcnhpoint To: Ravi Bangoria , mpe@ellerman.id.au, mikey@neuling.org Cc: apopple@linux.ibm.com, paulus@samba.org, npiggin@gmail.com, naveen.n.rao@linux.vnet.ibm.com, peterz@infradead.org, jolsa@kernel.org, oleg@redhat.com, fweisbec@gmail.com, mingo@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org References: <20200401061309.92442-1-ravi.bangoria@linux.ibm.com> <20200401061309.92442-14-ravi.bangoria@linux.ibm.com> From: Christophe Leroy Message-ID: <6b89991b-481a-8cbd-b5b7-559e5e16cf92@c-s.fr> Date: Wed, 1 Apr 2020 08:50:01 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200401061309.92442-14-ravi.bangoria@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 01/04/2020 à 08:13, Ravi Bangoria a écrit : > Currently we assume that we have only one watchpoint supported by hw. > Get rid of that assumption and use dynamic loop instead. This should > make supporting more watchpoints very easy. > > With more than one watchpoint, exception handler need to know which > DAWR caused the exception, and hw currently does not provide it. So > we need sw logic for the same. To figure out which DAWR caused the > exception, check all different combinations of user specified range, > dawr address range, actual access range and dawrx constrains. For ex, > if user specified range and actual access range overlaps but dawrx is > configured for readonly watchpoint and the instruction is store, this > DAWR must not have caused exception. > > Signed-off-by: Ravi Bangoria > --- > arch/powerpc/include/asm/processor.h | 2 +- > arch/powerpc/include/asm/sstep.h | 2 + > arch/powerpc/kernel/hw_breakpoint.c | 396 +++++++++++++++++++++------ > arch/powerpc/kernel/process.c | 3 - > 4 files changed, 313 insertions(+), 90 deletions(-) > [...] > -static bool > -dar_range_overlaps(unsigned long dar, int size, struct arch_hw_breakpoint *info) > +static bool dar_user_range_overlaps(unsigned long dar, int size, > + struct arch_hw_breakpoint *info) > { > return ((dar <= info->address + info->len - 1) && > (dar + size - 1 >= info->address)); > } Here and several other places, I think it would be more clear if you could avoid the - 1 : return ((dar < info->address + info->len) && (dar + size > info->address)); > > +static bool dar_in_hw_range(unsigned long dar, struct arch_hw_breakpoint *info) > +{ > + unsigned long hw_start_addr, hw_end_addr; > + > + hw_start_addr = ALIGN_DOWN(info->address, HW_BREAKPOINT_SIZE); > + hw_end_addr = ALIGN(info->address + info->len, HW_BREAKPOINT_SIZE) - 1; > + > + return ((hw_start_addr <= dar) && (hw_end_addr >= dar)); > +} hw_end_addr = ALIGN(info->address + info->len, HW_BREAKPOINT_SIZE); return ((hw_start_addr <= dar) && (hw_end_addr > dar)); Christophe > + > +static bool dar_hw_range_overlaps(unsigned long dar, int size, > + struct arch_hw_breakpoint *info) > +{ > + unsigned long hw_start_addr, hw_end_addr; > + > + hw_start_addr = ALIGN_DOWN(info->address, HW_BREAKPOINT_SIZE); > + hw_end_addr = ALIGN(info->address + info->len, HW_BREAKPOINT_SIZE) - 1; > + > + return ((dar <= hw_end_addr) && (dar + size - 1 >= hw_start_addr)); > +} Same Christophe