From patchwork Mon Jun 13 20:40:43 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thiago Jung Bauermann X-Patchwork-Id: 634854 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3rT4T20CRQz9sD5 for ; Tue, 14 Jun 2016 06:41:58 +1000 (AEST) Received: from ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3rT4T16ZrCzDqhh for ; Tue, 14 Jun 2016 06:41:57 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rT4Rp2K3nzDqcg for ; Tue, 14 Jun 2016 06:40:53 +1000 (AEST) Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u5DKdIhv077652 for ; Mon, 13 Jun 2016 16:40:51 -0400 Received: from e24smtp04.br.ibm.com (e24smtp04.br.ibm.com [32.104.18.25]) by mx0a-001b2d01.pphosted.com with ESMTP id 23geqncpbj-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 13 Jun 2016 16:40:51 -0400 Received: from localhost by e24smtp04.br.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 13 Jun 2016 17:40:47 -0300 X-IBM-Helo: d24dlp02.br.ibm.com X-IBM-MailFrom: bauerman@linux.vnet.ibm.com X-IBM-RcptTo: linuxppc-dev@lists.ozlabs.org Received: from d24relay03.br.ibm.com (d24relay03.br.ibm.com [9.13.184.25]) by d24dlp02.br.ibm.com (Postfix) with ESMTP id 5E0CB1DC0070 for ; Mon, 13 Jun 2016 16:40:39 -0400 (EDT) Received: from d24av03.br.ibm.com (d24av03.br.ibm.com [9.8.31.95]) by d24relay03.br.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u5DKekQr10092926 for ; Mon, 13 Jun 2016 17:40:46 -0300 Received: from d24av03.br.ibm.com (localhost [127.0.0.1]) by d24av03.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u5DKejp0003414 for ; Mon, 13 Jun 2016 17:40:46 -0300 Received: from hactar.localnet (sergioc.br.ibm.com [9.18.201.47] (may be forged)) by d24av03.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u5DKejvm003383; Mon, 13 Jun 2016 17:40:45 -0300 From: Thiago Jung Bauermann To: linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 2/8] kexec_file: Generalize kexec_add_buffer. Date: Mon, 13 Jun 2016 17:40:43 -0300 User-Agent: KMail/4.14.3 (Linux/3.13.0-87-generic; KDE/4.14.13; x86_64; ; ) In-Reply-To: <11831785.bAnhpkoBlL@hactar> References: <1465701022-11601-1-git-send-email-bauerman@linux.vnet.ibm.com> <20160613072939.GD4974@dhcp-128-65.nay.redhat.com> <11831785.bAnhpkoBlL@hactar> MIME-Version: 1.0 X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16061320-0028-0000-0000-000001158BDA X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16061320-0029-0000-0000-000013B33989 Message-Id: <1524764.qHvH6Mt1uV@hactar> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-06-13_10:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=13 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1606130227 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kexec@lists.infradead.org, Dave Young , linux-kernel@vger.kernel.org, Eric Biederman Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Hi Dave, Am Montag, 13 Juni 2016, 16:08:19 schrieb Thiago Jung Bauermann: > Am Montag, 13 Juni 2016, 15:29:39 schrieb Dave Young: > > On 06/12/16 at 12:10am, Thiago Jung Bauermann wrote: > > > Allow architectures to specify different memory walking functions for > > > kexec_add_buffer. Intel uses iomem to track reserved memory ranges, > > > but PowerPC uses the memblock subsystem. > > > > Can the crashk_res be inserted to iomem_resource so that only one > > weak function for system ram is needed? > > Sorry, it's not clear to me what you mean by inserting crashk_res into > iomem_resource, but I can add a bool for_crashkernel to > arch_walk_system_ram so that it can decide which kind of memory to > traverse. This is the patch implementing that idea. What do you think? diff --git a/include/linux/kexec.h b/include/linux/kexec.h index e8acb2b43dd9..be18cb80c14e 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -315,6 +315,9 @@ int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, unsigned int relsec); int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, unsigned int relsec); +int __weak arch_walk_system_ram(bool for_crashkernel, unsigned long start, + unsigned long end, bool top_down, void *data, + int (*func)(u64, u64, void *)); void arch_kexec_protect_crashkres(void); void arch_kexec_unprotect_crashkres(void); diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index b6eec7527e9f..5d0a6a20b12b 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -428,6 +428,38 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg) return locate_mem_hole_bottom_up(start, end, kbuf); } +/** + * arch_walk_system_ram - call func(data) on free memory regions + * @for_crashkernel: Is this for the crash kernel? + * @start: Don't visit memory regions below this address. + * @end: Don't visit memory regions above this address. + * @top_down: Starts from the highest address? + * @data: Argument to pass to @func. + * @func: Function to call for each memory region. + * + * Return: 0 on success, negative errno on error. + */ +int __weak arch_walk_system_ram(bool for_crashkernel, unsigned long start, + unsigned long end, bool top_down, void *data, + int (*func)(u64, u64, void *)) +{ + int ret; + + if (for_crashkernel) + ret = walk_iomem_res_desc(crashk_res.desc, + IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY, + start, end, data, func); + else + ret = walk_system_ram_res(start, end, data, func); + + if (ret != 1) { + /* A suitable memory range could not be found for buffer */ + return -EADDRNOTAVAIL; + } + + return 0; +} + /* * Helper function for placing a buffer in a kexec segment. This assumes * that kexec_mutex is held. @@ -473,17 +505,14 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz, /* Walk the RAM ranges and allocate a suitable range for the buffer */ if (image->type == KEXEC_TYPE_CRASH) - ret = walk_iomem_res_desc(crashk_res.desc, - IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY, - crashk_res.start, crashk_res.end, kbuf, - locate_mem_hole_callback); + ret = arch_walk_system_ram(true, crashk_res.start, + crashk_res.end, top_down, kbuf, + locate_mem_hole_callback); else - ret = walk_system_ram_res(0, -1, kbuf, - locate_mem_hole_callback); - if (ret != 1) { - /* A suitable memory range could not be found for buffer */ - return -EADDRNOTAVAIL; - } + ret = arch_walk_system_ram(false, 0, -1, top_down, kbuf, + locate_mem_hole_callback); + if (ret) + return ret; /* Found a suitable memory range */ ksegment = &image->segment[image->nr_segments];