From patchwork Fri Sep 25 19:13:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 11800699 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1FAAA112C for ; Fri, 25 Sep 2020 19:31:39 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F24722076D for ; Fri, 25 Sep 2020 19:31:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F24722076D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id B1C1D15508B2A; Fri, 25 Sep 2020 12:31:38 -0700 (PDT) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=134.134.136.20; helo=mga02.intel.com; envelope-from=dan.j.williams@intel.com; receiver= Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 7BE8415508B21 for ; Fri, 25 Sep 2020 12:31:36 -0700 (PDT) IronPort-SDR: FvZ2yehQt0CfDxeBUA3XuThzmgf5hHinAkeQ2+eT+RrbGSj8Msk7kRwO/4U+OiyqN8MHSY/OZ1 wBc3I9BqOAcQ== X-IronPort-AV: E=McAfee;i="6000,8403,9755"; a="149272236" X-IronPort-AV: E=Sophos;i="5.77,303,1596524400"; d="scan'208";a="149272236" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2020 12:31:36 -0700 IronPort-SDR: VMbc7ZmBQB/F8HKZReuENs4o+rZepmL6hLQ53EkUQItqX8nx6NIeOUZnodDC+yf9ejTO0Iw0Rz xkvwopeQ9iCQ== X-IronPort-AV: E=Sophos;i="5.77,303,1596524400"; d="scan'208";a="349880741" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2020 12:31:36 -0700 Subject: [PATCH v5 17/17] device-dax: add a range mapping allocation attribute From: Dan Williams To: akpm@linux-foundation.org Date: Fri, 25 Sep 2020 12:13:15 -0700 Message-ID: <160106119570.30709.4548889722645210610.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <160106109960.30709.7379926726669669398.stgit@dwillia2-desk3.amr.corp.intel.com> References: <160106109960.30709.7379926726669669398.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Message-ID-Hash: BA3276KPPE3LYHGNTJWHLAZIXMIVAEGG X-Message-ID-Hash: BA3276KPPE3LYHGNTJWHLAZIXMIVAEGG X-MailFrom: dan.j.williams@intel.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header CC: Joao Martins , dave.hansen@linux.intel.com, linux-mm@kvack.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: From: Joao Martins Add a sysfs attribute which denotes a range from the dax region to be allocated. It's an write only @mapping sysfs attribute in the format of '-' to allocate a range. @start and @end use hexadecimal values and the @pgoff is implicitly ordered wrt to previous writes to @mapping sysfs e.g. a write of a range of length 1G the pgoff is 0..1G(-4K), a second write will use @pgoff for 1G+4K... This range mapping interface is useful for: 1) Application which want to implement its own allocation logic, and thus pick the desired ranges from dax_region. 2) For use cases like VMM fast restart[0] where after kexec we want to the same gpa<->phys mappings (as originally created before kexec). [0] https://static.sched.com/hosted_files/kvmforum2019/66/VMM-fast-restart_kvmforum2019.pdf Link: https://lkml.kernel.org/r/159643106970.4062302.10402616567780784722.stgit@dwillia2-desk3.amr.corp.intel.com Link: https://lore.kernel.org/r/20200716172913.19658-5-joao.m.martins@oracle.com Signed-off-by: Joao Martins Signed-off-by: Dan Williams --- drivers/dax/bus.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 0ac4a9c0fd18..27513d311242 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -1043,6 +1043,67 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RW(size); +static ssize_t range_parse(const char *opt, size_t len, struct range *range) +{ + unsigned long long addr = 0; + char *start, *end, *str; + ssize_t rc = EINVAL; + + str = kstrdup(opt, GFP_KERNEL); + if (!str) + return rc; + + end = str; + start = strsep(&end, "-"); + if (!start || !end) + goto err; + + rc = kstrtoull(start, 16, &addr); + if (rc) + goto err; + range->start = addr; + + rc = kstrtoull(end, 16, &addr); + if (rc) + goto err; + range->end = addr; + +err: + kfree(str); + return rc; +} + +static ssize_t mapping_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + struct dax_region *dax_region = dev_dax->region; + size_t to_alloc; + struct range r; + ssize_t rc; + + rc = range_parse(buf, len, &r); + if (rc) + return rc; + + rc = -ENXIO; + device_lock(dax_region->dev); + if (!dax_region->dev->driver) { + device_unlock(dax_region->dev); + return rc; + } + device_lock(dev); + + to_alloc = range_len(&r); + if (alloc_is_aligned(dev_dax, to_alloc)) + rc = alloc_dev_dax_range(dev_dax, r.start, to_alloc); + device_unlock(dev); + device_unlock(dax_region->dev); + + return rc == 0 ? len : rc; +} +static DEVICE_ATTR_WO(mapping); + static ssize_t align_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -1175,6 +1236,8 @@ static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n) return 0; if (a == &dev_attr_numa_node.attr && !IS_ENABLED(CONFIG_NUMA)) return 0; + if (a == &dev_attr_mapping.attr && is_static(dax_region)) + return 0; if ((a == &dev_attr_align.attr || a == &dev_attr_size.attr) && is_static(dax_region)) return 0444; @@ -1184,6 +1247,7 @@ static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n) static struct attribute *dev_dax_attributes[] = { &dev_attr_modalias.attr, &dev_attr_size.attr, + &dev_attr_mapping.attr, &dev_attr_target_node.attr, &dev_attr_align.attr, &dev_attr_resource.attr,