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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham 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 C4940C10F0E for ; Thu, 4 Apr 2019 19:21:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7EEF821741 for ; Thu, 4 Apr 2019 19:21:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730337AbfDDTVg (ORCPT ); Thu, 4 Apr 2019 15:21:36 -0400 Received: from mga18.intel.com ([134.134.136.126]:14071 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730243AbfDDTVf (ORCPT ); Thu, 4 Apr 2019 15:21:35 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Apr 2019 12:21:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,309,1549958400"; d="scan'208";a="335059446" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by fmsmga005.fm.intel.com with ESMTP; 04 Apr 2019 12:21:34 -0700 Subject: [RFC PATCH 5/5] device-dax: Add a driver for "hmem" devices From: Dan Williams To: linux-kernel@vger.kernel.org Cc: Vishal Verma , Keith Busch , Dave Jiang , x86@kernel.org, linux-mm@kvack.org, keith.busch@intel.com, vishal.l.verma@intel.com, linux-nvdimm@lists.01.org Date: Thu, 04 Apr 2019 12:08:55 -0700 Message-ID: <155440493544.3190322.10165040361847405101.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <155440490809.3190322.15060922240602775809.stgit@dwillia2-desk3.amr.corp.intel.com> References: <155440490809.3190322.15060922240602775809.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-2-gc94f MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Platform firmware like EFI/ACPI may publish "hmem" platform devices. Such a device is a performance differentiated memory range likely reserved for an application specific use case. The driver gives access to 100% of the capacity via a device-dax mmap instance by default. However, if over-subscription and other kernel memory management is desired the resulting dax device can be assigned to the core-mm via the kmem driver. Cc: Vishal Verma Cc: Keith Busch Cc: Dave Jiang Signed-off-by: Dan Williams --- drivers/dax/Kconfig | 26 ++++++++++++++++++---- drivers/dax/Makefile | 2 ++ drivers/dax/hmem.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+), 5 deletions(-) create mode 100644 drivers/dax/hmem.c diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig index 5ef624fe3934..b3886f43dd77 100644 --- a/drivers/dax/Kconfig +++ b/drivers/dax/Kconfig @@ -38,16 +38,32 @@ config DEV_DAX_KMEM depends on DEV_DAX depends on MEMORY_HOTPLUG # for add_memory() and friends help - Support access to persistent memory as if it were RAM. This - allows easier use of persistent memory by unmodified - applications. + Support access to persistent, or other performance + differentiated memory as if it were System RAM. This allows + easier use of persistent memory by unmodified applications, or + adds core kernel memory services to heterogeneous memory types + (HMEM) marked "reserved" by platform firmware. To use this feature, a DAX device must be unbound from the - device_dax driver (PMEM DAX) and bound to this kmem driver - on each boot. + device_dax driver and bound to this kmem driver on each boot. Say N if unsure. +config DEV_DAX_HMEM + tristate "HMEM DAX: generic support for 'special purpose' memory" + default DEV_DAX + help + EFI 2.8 platforms, and others, may advertise 'special purpose' + memory. For example, a high bandwidth memory pool. The + indication from platform firmware is meant to reserve the + memory from typical usage by default. This driver creates + device-dax instances for these memory ranges, and that also + enables the possibility to assign them to the DEV_DAX_KMEM + driver to override the reservation and add them to kernel + "System RAM" pool. + + Say Y if unsure. + config DEV_DAX_PMEM_COMPAT tristate "PMEM DAX: support the deprecated /sys/class/dax interface" depends on DEV_DAX_PMEM diff --git a/drivers/dax/Makefile b/drivers/dax/Makefile index 81f7d54dadfb..80065b38b3c4 100644 --- a/drivers/dax/Makefile +++ b/drivers/dax/Makefile @@ -2,9 +2,11 @@ obj-$(CONFIG_DAX) += dax.o obj-$(CONFIG_DEV_DAX) += device_dax.o obj-$(CONFIG_DEV_DAX_KMEM) += kmem.o +obj-$(CONFIG_DEV_DAX_HMEM) += dax_hmem.o dax-y := super.o dax-y += bus.o device_dax-y := device.o +dax_hmem-y := hmem.o obj-y += pmem/ diff --git a/drivers/dax/hmem.c b/drivers/dax/hmem.c new file mode 100644 index 000000000000..b01cf9c65329 --- /dev/null +++ b/drivers/dax/hmem.c @@ -0,0 +1,58 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include "bus.h" + +static int dax_hmem_probe(struct platform_device *pdev) +{ + struct dev_pagemap pgmap = { 0 }; + struct device *dev = &pdev->dev; + struct dax_region *dax_region; + struct memregion_info *mri; + struct dev_dax *dev_dax; + struct resource *res; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENOMEM; + + mri = dev->platform_data; + pgmap.dev = dev; + memcpy(&pgmap.res, res, sizeof(*res)); + + dax_region = alloc_dax_region(dev, pdev->id, res, mri->target_node, + PMD_SIZE, PFN_DEV|PFN_MAP); + if (!dax_region) + return -ENOMEM; + + dev_dax = devm_create_dev_dax(dax_region, 0, &pgmap); + if (IS_ERR(dev_dax)) + return PTR_ERR(dev_dax); + + /* child dev_dax instances now own the lifetime of the dax_region */ + dax_region_put(dax_region); + return 0; +} + +static int dax_hmem_remove(struct platform_device *pdev) +{ + /* devm handles teardown */ + return 0; +} + +static struct platform_driver dax_hmem_driver = { + .probe = dax_hmem_probe, + .remove = dax_hmem_remove, + .driver = { + .name = "hmem", + }, +}; + +module_platform_driver(dax_hmem_driver); + +MODULE_ALIAS("platform:hmem*"); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Intel Corporation");