From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423264AbcFMUky (ORCPT ); Mon, 13 Jun 2016 16:40:54 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:37568 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1423214AbcFMUkw (ORCPT ); Mon, 13 Jun 2016 16:40:52 -0400 X-IBM-Helo: d24dlp02.br.ibm.com X-IBM-MailFrom: bauerman@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org From: Thiago Jung Bauermann To: linuxppc-dev@lists.ozlabs.org Cc: Dave Young , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Eric Biederman 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 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16061320-0032-0000-0000-000002579776 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16061320-0033-0000-0000-00000E849014 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 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? -- []'s Thiago Jung Bauermann IBM Linux Technology Center kexec_file: Generalize kexec_add_buffer. 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. Signed-off-by: Thiago Jung Bauermann Cc: Eric Biederman Cc: kexec@lists.infradead.org Cc: linux-kernel@vger.kernel.org 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];