From patchwork Thu Jul 20 07:14:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13319903 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5DCDBC001DE for ; Thu, 20 Jul 2023 07:14:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230041AbjGTHOf (ORCPT ); Thu, 20 Jul 2023 03:14:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbjGTHOe (ORCPT ); Thu, 20 Jul 2023 03:14:34 -0400 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 765AA1719; Thu, 20 Jul 2023 00:14:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689837272; x=1721373272; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=t5Tx1xjKMmZzJYwXq10A5dhCDPrE7RYDBM8wVBgMdO0=; b=iWgULLWrgDKbq/NCavQ+zSBgg3DHwarvhAaOTtZYkjXCjUKXF2F/vCrJ FHWDxNseD7x+y/BDxYPPlVvMAfdGUR3/pgKO8i02jogzN1y1Y9gufpcgG CAnp0T5/hqIgY3KWwDVx5pfcaUDyUcp27xLrJBrlF1HteyPdraOjRJAMu OoF3xziU7y+/wW9vsYvV/pwlIOpbBRK4VXsJwI/CIAbqEFsR6+IA9nDgC 5zUacEraA66j08Yq8J2XN64Zk9JDOmprlEIpLIDS/SeS1tlNOJpt82kEp 4vGcjnN/w1PZWG+lWjiAolnO2SMhQcNr/7V8+SYtnRqLSL7niz1FYNPbN A==; X-IronPort-AV: E=McAfee;i="6600,9927,10776"; a="430424022" X-IronPort-AV: E=Sophos;i="6.01,218,1684825200"; d="scan'208";a="430424022" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jul 2023 00:14:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10776"; a="794334971" X-IronPort-AV: E=Sophos;i="6.01,218,1684825200"; d="scan'208";a="794334971" Received: from mfgalan-mobl1.amr.corp.intel.com (HELO [192.168.1.200]) ([10.213.172.204]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jul 2023 00:14:30 -0700 From: Vishal Verma Date: Thu, 20 Jul 2023 01:14:24 -0600 Subject: [PATCH v2 3/3] dax/kmem: allow kmem to add memory with memmap_on_memory MIME-Version: 1.0 Message-Id: <20230720-vv-kmem_memmap-v2-3-88bdaab34993@intel.com> References: <20230720-vv-kmem_memmap-v2-0-88bdaab34993@intel.com> In-Reply-To: <20230720-vv-kmem_memmap-v2-0-88bdaab34993@intel.com> To: Andrew Morton , David Hildenbrand , Oscar Salvador , Dan Williams , Dave Jiang Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, Huang Ying , Dave Hansen , "Aneesh Kumar K.V" , Jonathan Cameron , Jeff Moyer , Vishal Verma X-Mailer: b4 0.12.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=4666; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=t5Tx1xjKMmZzJYwXq10A5dhCDPrE7RYDBM8wVBgMdO0=; b=owGbwMvMwCXGf25diOft7jLG02pJDCk77l35ZGnE8/cqw/EfF2OW2vyb9m391imrjrKf35uns 3TSlR0d5zpKWRjEuBhkxRRZ/u75yHhMbns+T2CCI8wcViaQIQxcnAIwkVMJDP/U/uSYVR7RlF/V lsH2ziKjUffFKtY0pZKjzGzthpadntcY/gcnRfPsPtXH5hbMads97c9Ve8UJTBPzXX+mPOJaE5D 5hQEA X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org Large amounts of memory managed by the kmem driver may come in via CXL, and it is often desirable to have the memmap for this memory on the new memory itself. Enroll kmem-managed memory for memmap_on_memory semantics as a default if other requirements for it are met. Add a sysfs override under the dax device to opt out of this behavior. Cc: Andrew Morton Cc: David Hildenbrand Cc: Oscar Salvador Cc: Dan Williams Cc: Dave Jiang Cc: Dave Hansen Cc: Huang Ying Signed-off-by: Vishal Verma --- drivers/dax/dax-private.h | 1 + drivers/dax/bus.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++ drivers/dax/kmem.c | 7 ++++++- 3 files changed, 55 insertions(+), 1 deletion(-) diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index 27cf2daaaa79..446617b73aea 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -70,6 +70,7 @@ struct dev_dax { struct ida ida; struct device dev; struct dev_pagemap *pgmap; + bool memmap_on_memory; int nr_range; struct dev_dax_range { unsigned long pgoff; diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 0ee96e6fc426..c8e3ea7c674d 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -1,6 +1,8 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright(c) 2017-2018 Intel Corporation. All rights reserved. */ +#include #include +#include #include #include #include @@ -1269,6 +1271,43 @@ static ssize_t numa_node_show(struct device *dev, } static DEVICE_ATTR_RO(numa_node); +static ssize_t memmap_on_memory_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + + return sprintf(buf, "%d\n", dev_dax->memmap_on_memory); +} + +static ssize_t memmap_on_memory_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; + ssize_t rc; + bool val; + + rc = kstrtobool(buf, &val); + if (rc) + return rc; + + device_lock(dax_region->dev); + if (!dax_region->dev->driver) { + device_unlock(dax_region->dev); + return -ENXIO; + } + + if (mhp_supports_memmap_on_memory(memory_block_size_bytes())) + dev_dax->memmap_on_memory = val; + else + rc = -ENXIO; + + device_unlock(dax_region->dev); + return rc == 0 ? len : rc; +} +static DEVICE_ATTR_RW(memmap_on_memory); + static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n) { struct device *dev = container_of(kobj, struct device, kobj); @@ -1295,6 +1334,7 @@ static struct attribute *dev_dax_attributes[] = { &dev_attr_align.attr, &dev_attr_resource.attr, &dev_attr_numa_node.attr, + &dev_attr_memmap_on_memory.attr, NULL, }; @@ -1400,6 +1440,14 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) dev_dax->align = dax_region->align; ida_init(&dev_dax->ida); + /* + * If supported by memory_hotplug, allow memmap_on_memory behavior by + * default. This can be overridden via sysfs before handing the memory + * over to kmem if desired. + */ + if (mhp_supports_memmap_on_memory(memory_block_size_bytes())) + dev_dax->memmap_on_memory = true; + inode = dax_inode(dax_dev); dev->devt = inode->i_rdev; dev->bus = &dax_bus_type; diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index 898ca9505754..e6976a79093d 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -56,6 +56,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) unsigned long total_len = 0; struct dax_kmem_data *data; int i, rc, mapped = 0; + mhp_t mhp_flags; int numa_node; /* @@ -136,12 +137,16 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) */ res->flags = IORESOURCE_SYSTEM_RAM; + mhp_flags = MHP_NID_IS_MGID; + if (dev_dax->memmap_on_memory) + mhp_flags |= MHP_MEMMAP_ON_MEMORY; + /* * Ensure that future kexec'd kernels will not treat * this as RAM automatically. */ rc = add_memory_driver_managed(data->mgid, range.start, - range_len(&range), kmem_name, MHP_NID_IS_MGID); + range_len(&range), kmem_name, mhp_flags); if (rc) { dev_warn(dev, "mapping%d: %#llx-%#llx memory add failed\n",