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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 0AB59C43603 for ; Wed, 11 Dec 2019 16:09:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CA8BB20836 for ; Wed, 11 Dec 2019 16:09:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388969AbfLKQJj (ORCPT ); Wed, 11 Dec 2019 11:09:39 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:65366 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388797AbfLKQJh (ORCPT ); Wed, 11 Dec 2019 11:09:37 -0500 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xBBG8K96139346 for ; Wed, 11 Dec 2019 11:09:36 -0500 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2wt2kupfjd-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 11 Dec 2019 11:09:35 -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) Wed, 11 Dec 2019 16:09:29 -0000 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xBBG9SPG56098860 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 11 Dec 2019 16:09:28 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3B867A405B; Wed, 11 Dec 2019 16:09:28 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E8293A405C; Wed, 11 Dec 2019 16:09:25 +0000 (GMT) Received: from localhost.localdomain.com (unknown [9.85.74.172]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 11 Dec 2019 16:09:25 +0000 (GMT) From: Sourabh Jain To: mpe@ellerman.id.au Cc: mahesh@linux.vnet.ibm.com, hbathini@linux.ibm.com, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, corbet@lwn.net, linux-doc@vger.kernel.org, gregkh@linuxfoundation.org, Sourabh Jain Subject: [PATCH v6 3/6] powerpc/fadump: reorganize /sys/kernel/fadump_* sysfs files Date: Wed, 11 Dec 2019 21:39:07 +0530 X-Mailer: git-send-email 2.17.2 In-Reply-To: <20191211160910.21656-1-sourabhjain@linux.ibm.com> References: <20191211160910.21656-1-sourabhjain@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19121116-0028-0000-0000-000003C7992F X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19121116-0029-0000-0000-0000248ACF15 Message-Id: <20191211160910.21656-4-sourabhjain@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-12-11_04:2019-12-11,2019-12-11 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=1 spamscore=0 mlxscore=0 adultscore=0 mlxlogscore=999 priorityscore=1501 malwarescore=0 lowpriorityscore=0 clxscore=1015 phishscore=0 bulkscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1912110136 Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org As the number of FADump sysfs files increases it is hard to manage all of them inside /sys/kernel directory. It's better to have all the FADump related sysfs files in a dedicated directory /sys/kernel/fadump. But in order to maintain backward compatibility a symlink has been added for every sysfs that has moved to new location. As the FADump sysfs files are now part of a dedicated directory there is no need to prefix their name with fadump_, hence sysfs file names are also updated. For example fadump_enabled sysfs file is now referred as enabled. Also consolidate ABI documentation for all the FADump sysfs files in a single file Documentation/ABI/testing/sysfs-kernel-fadump. Signed-off-by: Sourabh Jain --- Documentation/ABI/testing/sysfs-kernel-fadump | 33 +++++ arch/powerpc/kernel/fadump.c | 118 +++++++++++++----- 2 files changed, 117 insertions(+), 34 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-kernel-fadump diff --git a/Documentation/ABI/testing/sysfs-kernel-fadump b/Documentation/ABI/testing/sysfs-kernel-fadump new file mode 100644 index 000000000000..5d988b919e81 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-kernel-fadump @@ -0,0 +1,33 @@ +What: /sys/kernel/fadump/* +Date: Dec 2019 +Contact: linuxppc-dev@lists.ozlabs.org +Description: + The /sys/kernel/fadump/* is a collection of FADump sysfs + file provide information about the configuration status + of Firmware Assisted Dump (FADump). + +What: /sys/kernel/fadump/enabled +Date: Dec 2019 +Contact: linuxppc-dev@lists.ozlabs.org +Description: read only + Primarily used to identify whether the FADump is enabled in + the kernel or not. +User: Kdump service + +What: /sys/kernel/fadump/registered +Date: Dec 2019 +Contact: linuxppc-dev@lists.ozlabs.org +Description: read/write + Helps to control the dump collect feature from userspace. + Setting 1 to this file enables the system to collect the + dump and 0 to disable it. +User: Kdump service + +What: /sys/kernel/fadump/release_mem +Date: Dec 2019 +Contact: linuxppc-dev@lists.ozlabs.org +Description: write only + This is a special sysfs file and only available when + the system is booted to capture the vmcore using FADump. + It is used to release the memory reserved by FADump to + save the crash dump. diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c index ed59855430b9..23f15bfea512 100644 --- a/arch/powerpc/kernel/fadump.c +++ b/arch/powerpc/kernel/fadump.c @@ -36,6 +36,8 @@ static struct fw_dump fw_dump; static void __init fadump_reserve_crash_area(u64 base); +struct kobject *fadump_kobj; + #ifndef CONFIG_PRESERVE_FA_DUMP static DEFINE_MUTEX(fadump_mutex); struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0 }; @@ -1323,9 +1325,9 @@ static void fadump_invalidate_release_mem(void) fw_dump.ops->fadump_init_mem_struct(&fw_dump); } -static ssize_t fadump_release_memory_store(struct kobject *kobj, - struct kobj_attribute *attr, - const char *buf, size_t count) +static ssize_t release_mem_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) { int input = -1; @@ -1350,23 +1352,33 @@ static ssize_t fadump_release_memory_store(struct kobject *kobj, return count; } -static ssize_t fadump_enabled_show(struct kobject *kobj, - struct kobj_attribute *attr, - char *buf) +/* Release the reserved memory and disable the FADump */ +static void unregister_fadump(void) +{ + fadump_cleanup(); + fadump_release_memory(fw_dump.reserve_dump_area_start, + fw_dump.reserve_dump_area_size); + fw_dump.fadump_enabled = 0; + kobject_put(fadump_kobj); +} + +static ssize_t enabled_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) { return sprintf(buf, "%d\n", fw_dump.fadump_enabled); } -static ssize_t fadump_register_show(struct kobject *kobj, - struct kobj_attribute *attr, - char *buf) +static ssize_t registered_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) { return sprintf(buf, "%d\n", fw_dump.dump_registered); } -static ssize_t fadump_register_store(struct kobject *kobj, - struct kobj_attribute *attr, - const char *buf, size_t count) +static ssize_t registered_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) { int ret = 0; int input = -1; @@ -1418,15 +1430,17 @@ static int fadump_region_show(struct seq_file *m, void *private) return 0; } -static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem, - 0200, NULL, - fadump_release_memory_store); -static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled, - 0444, fadump_enabled_show, - NULL); -static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered, - 0644, fadump_register_show, - fadump_register_store); +static struct kobj_attribute release_attr = __ATTR_WO(release_mem); +static struct kobj_attribute enable_attr = __ATTR_RO(enabled); +static struct kobj_attribute register_attr = __ATTR_RW(registered); + +static struct attribute *fadump_attrs[] = { + &enable_attr.attr, + ®ister_attr.attr, + NULL, +}; + +ATTRIBUTE_GROUPS(fadump); DEFINE_SHOW_ATTRIBUTE(fadump_region); @@ -1435,16 +1449,11 @@ static void fadump_init_files(void) struct dentry *debugfs_file; int rc = 0; - rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); - if (rc) - printk(KERN_ERR "fadump: unable to create sysfs file" - " fadump_enabled (%d)\n", rc); - - rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr); - if (rc) - printk(KERN_ERR "fadump: unable to create sysfs file" - " fadump_registered (%d)\n", rc); - + fadump_kobj = kobject_create_and_add("fadump", kernel_kobj); + if (!fadump_kobj) { + pr_err("failed to create fadump kobject\n"); + return; + } debugfs_file = debugfs_create_file("fadump_region", 0444, powerpc_debugfs_root, NULL, &fadump_region_fops); @@ -1453,10 +1462,51 @@ static void fadump_init_files(void) " fadump_region\n"); if (fw_dump.dump_active) { - rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr); + rc = sysfs_create_file(fadump_kobj, &release_attr.attr); + if (rc) + pr_err("unable to create release_mem sysfs file (%d)\n", + rc); + } + + rc = sysfs_create_groups(fadump_kobj, fadump_groups); + if (rc) { + pr_err("sysfs group creation failed (%d), unregistering FADump", + rc); + unregister_fadump(); + return; + } + + /* The FADump sysfs are moved from kernel_kobj to fadump_kobj need to + * create symlink at old location to maintain backward compatibility. + * + * - fadump_enabled -> fadump/enabled + * - fadump_registered -> fadump/registered + * - fadump_release_mem -> fadump/release_mem + */ + rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj, + "enabled", "fadump_enabled"); + if (rc) { + pr_err("unable to create fadump_enabled symlink (%d)", rc); + return; + } + + rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj, + "registered", + "fadump_registered"); + if (rc) { + pr_err("unable to create fadump_registered symlink (%d)", rc); + sysfs_remove_link(kernel_kobj, "fadump_enabled"); + return; + } + + if (fw_dump.dump_active) { + rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, + fadump_kobj, + "release_mem", + "fadump_release_mem"); if (rc) - printk(KERN_ERR "fadump: unable to create sysfs file" - " fadump_release_mem (%d)\n", rc); + pr_err("unable to create fadump_release_mem symlink (%d)", + rc); } return; } -- 2.17.2