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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 AA6EDC43331 for ; Mon, 11 Nov 2019 21:55:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8128021872 for ; Mon, 11 Nov 2019 21:55:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727028AbfKKVzo (ORCPT ); Mon, 11 Nov 2019 16:55:44 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:59544 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726896AbfKKVzo (ORCPT ); Mon, 11 Nov 2019 16:55:44 -0500 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id xABLsJMt073254 for ; Mon, 11 Nov 2019 16:55:43 -0500 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2w7c3sg7u0-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 11 Nov 2019 16:55:42 -0500 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 11 Nov 2019 21:55:35 -0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xABLtYBY59572406 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 11 Nov 2019 21:55:34 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9B92611C052; Mon, 11 Nov 2019 21:55:34 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B682C11C04C; Mon, 11 Nov 2019 21:55:31 +0000 (GMT) Received: from linux.ibm.com (unknown [9.148.207.107]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Mon, 11 Nov 2019 21:55:31 +0000 (GMT) Date: Mon, 11 Nov 2019 22:55:28 +0100 From: Mike Rapoport To: Logan Gunthorpe Cc: Yash Shah , "Paul Walmsley ( Sifive)" , "linux-riscv@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "palmer@dabbelt.com" , "aou@eecs.berkeley.edu" , "Anup.Patel@wdc.com" , "ren_guo@c-sky.com" , "bmeng.cn@gmail.com" , "tglx@linutronix.de" , Sachin Ghadi Subject: Re: [PATCH] RISC-V: Add address map dumper References: <1573450015-16475-1-git-send-email-yash.shah@sifive.com> <91f35033-ffc8-cd2e-36f7-c6f4f25be36b@deltatee.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <91f35033-ffc8-cd2e-36f7-c6f4f25be36b@deltatee.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-TM-AS-GCONF: 00 x-cbid: 19111121-0028-0000-0000-000003B60582 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19111121-0029-0000-0000-0000247905BA Message-Id: <20191111215527.GA10647@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-11-11_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=963 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1910280000 definitions=main-1911110188 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 11, 2019 at 11:14:30AM -0700, Logan Gunthorpe wrote: > > > On 2019-11-10 10:27 p.m., Yash Shah wrote: > > Add support for dumping the kernel address space layout to the console. > > User can enable CONFIG_DEBUG_VM_LAYOUT to dump the virtual memory region > > into dmesg buffer during boot-up. > > Cool, I'd find this useful. Though, is there any reason we don't do this > more generally for all architectures? Some architectures do this, some don't. I don't think there's a particular reason we don't do this generally, it just evolved that way :) > > Signed-off-by: Yash Shah > > --- > > This patch is based on Linux 5.4-rc6 and tested on SiFive HiFive Unleashed > > board. > > --- > > arch/riscv/Kconfig.debug | 9 +++++++++ > > arch/riscv/mm/init.c | 30 ++++++++++++++++++++++++++++++ > > 2 files changed, 39 insertions(+) > > > > diff --git a/arch/riscv/Kconfig.debug b/arch/riscv/Kconfig.debug > > index e69de29..cdedfd3 100644 > > --- a/arch/riscv/Kconfig.debug > > +++ b/arch/riscv/Kconfig.debug > > @@ -0,0 +1,9 @@ > > +config DEBUG_VM_LAYOUT > > + bool "Print virtual memory layout on boot up" > > + depends on DEBUG_KERNEL > > + help > > + Say Y here if you want to dump the kernel virtual memory layout to > > + dmesg log on boot up. This information is only useful for kernel > > + developers who are working in architecture specific areas of the > > + kernel. It is probably not a good idea to enable this feature in a > > + production kernel. > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > > index 79cfb35..fcb8144 100644 > > --- a/arch/riscv/mm/init.c > > +++ b/arch/riscv/mm/init.c > > @@ -55,6 +55,36 @@ void __init mem_init(void) > > memblock_free_all(); > > > > mem_init_print_info(NULL); > > +#ifdef CONFIG_DEBUG_VM_LAYOUT > > Generally, it's best to avoid #ifdefs inside functions, it's even > counter-indicated in the style guide[1]. > > > +#define MLK(b, t) b, t, (((t) - (b)) >> 10) > > +#define MLM(b, t) b, t, (((t) - (b)) >> 20) > > +#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K) > > I personally find these inline defines rather ugly. Maybe it would be > better to have a helper function that prints a single line. Also seems > like MLK and MLK_ROUNDUP could be the same assuming the entries in MLK > are aligned... > > > + > > + pr_notice("Virtual kernel memory layout:\n" > > + " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" > > + " vmemmap : 0x%08lx - 0x%08lx (%4ld MB)\n" > > + " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" > > + " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" > > + " .init : 0x%px - 0x%px (%4td kB)\n" > > + " .text : 0x%px - 0x%px (%4td kB)\n" > > + " .data : 0x%px - 0x%px (%4td kB)\n" > > + " .bss : 0x%px - 0x%px (%4td kB)\n", > > + > > + MLK(FIXADDR_START, FIXADDR_TOP), > > + MLM(VMEMMAP_START, VMEMMAP_END), > > + MLM(VMALLOC_START, VMALLOC_END), > > + MLM(PAGE_OFFSET, (unsigned long)high_memory), > > + > > + MLK_ROUNDUP(__init_begin, __init_end), > > + MLK_ROUNDUP(_text, _etext), > > + MLK_ROUNDUP(_sdata, _edata), > > + MLK_ROUNDUP(__bss_start, __bss_stop)); > > + > > +#undef MLK > > +#undef MLM > > +#undef MLK_ROUNDUP > > +#endif > > } > > > > #ifdef CONFIG_BLK_DEV_INITRD > > Thanks, > > Logan > > [1] > https://www.kernel.org/doc/html/latest/process/coding-style.html#conditional-compilation -- Sincerely yours, Mike.