From patchwork Sun May 15 06:26:24 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 9096181 Return-Path: X-Original-To: patchwork-linux-nvdimm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 4ED3E9F1C3 for ; Sun, 15 May 2016 06:27:16 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B0A2B2026C for ; Sun, 15 May 2016 06:27:14 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BB0D720260 for ; Sun, 15 May 2016 06:27:12 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id B7ADC1A1FE8; Sat, 14 May 2016 23:27:15 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by ml01.01.org (Postfix) with ESMTP id 463C81A1FE8 for ; Sat, 14 May 2016 23:27:14 -0700 (PDT) Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga102.jf.intel.com with ESMTP; 14 May 2016 23:27:10 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,621,1455004800"; d="scan'208";a="103563186" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.14]) by fmsmga004.fm.intel.com with ESMTP; 14 May 2016 23:27:10 -0700 Subject: [PATCH v2 1/3] /dev/dax, pmem: direct access to persistent memory From: Dan Williams To: linux-nvdimm@lists.01.org Date: Sat, 14 May 2016 23:26:24 -0700 Message-ID: <146329358394.17948.9595519335631675126.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <146329357870.17948.14240958684074905846.stgit@dwillia2-desk3.amr.corp.intel.com> References: <146329357870.17948.14240958684074905846.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Dave Hansen , linux-kernel@vger.kernel.org, hch@lst.de, linux-block@vger.kernel.org, Andrew Morton Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Spam-Status: No, score=-3.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Device DAX is the device-centric analogue of Filesystem DAX (CONFIG_FS_DAX). It allows memory ranges to be allocated and mapped without need of an intervening file system. Device DAX is strict, precise and predictable. Specifically this interface: 1/ Guarantees fault granularity with respect to a given page size (pte, pmd, or pud) set at configuration time. 2/ Enforces deterministic behavior by being strict about what fault scenarios are supported. For example, by forcing MADV_DONTFORK semantics and omitting MAP_PRIVATE support device-dax guarantees that a mapping always behaves/performs the same once established. It is the "what you see is what you get" access mechanism to differentiated memory vs filesystem DAX which has filesystem specific implementation semantics. Persistent memory is the first target, but the mechanism is also targeted for exclusive allocations of performance differentiated memory ranges. This commit is limited to the base device driver infrastructure to associate a dax device with pmem range. Cc: Jeff Moyer Cc: Christoph Hellwig Cc: Andrew Morton Cc: Dave Hansen Cc: Ross Zwisler Signed-off-by: Dan Williams --- drivers/Kconfig | 2 drivers/Makefile | 1 drivers/dax/Kconfig | 25 +++ drivers/dax/Makefile | 4 + drivers/dax/dax.c | 252 +++++++++++++++++++++++++++++++++++ drivers/dax/dax.h | 24 +++ drivers/dax/pmem.c | 168 +++++++++++++++++++++++ tools/testing/nvdimm/Kbuild | 9 + tools/testing/nvdimm/config_check.c | 2 9 files changed, 487 insertions(+) create mode 100644 drivers/dax/Kconfig create mode 100644 drivers/dax/Makefile create mode 100644 drivers/dax/dax.c create mode 100644 drivers/dax/dax.h create mode 100644 drivers/dax/pmem.c diff --git a/drivers/Kconfig b/drivers/Kconfig index d2ac339de85f..8298eab84a6f 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -190,6 +190,8 @@ source "drivers/android/Kconfig" source "drivers/nvdimm/Kconfig" +source "drivers/dax/Kconfig" + source "drivers/nvmem/Kconfig" source "drivers/hwtracing/stm/Kconfig" diff --git a/drivers/Makefile b/drivers/Makefile index 8f5d076baeb0..0b6f3d60193d 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -66,6 +66,7 @@ obj-$(CONFIG_PARPORT) += parport/ obj-$(CONFIG_NVM) += lightnvm/ obj-y += base/ block/ misc/ mfd/ nfc/ obj-$(CONFIG_LIBNVDIMM) += nvdimm/ +obj-$(CONFIG_DEV_DAX) += dax/ obj-$(CONFIG_DMA_SHARED_BUFFER) += dma-buf/ obj-$(CONFIG_NUBUS) += nubus/ obj-y += macintosh/ diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig new file mode 100644 index 000000000000..86ffbaa891ad --- /dev/null +++ b/drivers/dax/Kconfig @@ -0,0 +1,25 @@ +menuconfig DEV_DAX + tristate "DAX: direct access to differentiated memory" + default m if NVDIMM_DAX + help + Support raw access to differentiated (persistence, bandwidth, + latency...) memory via an mmap(2) capable character + device. Platform firmware or a device driver may identify a + platform memory resource that is differentiated from the + baseline memory pool. Mappings of a /dev/daxX.Y device impose + restrictions that make the mapping behavior deterministic. + +if DEV_DAX + +config DEV_DAX_PMEM + tristate "PMEM DAX: direct access to persistent memory" + depends on NVDIMM_DAX + default DEV_DAX + help + Support raw access to persistent memory. Note that this + driver consumes memory ranges allocated and exported by the + libnvdimm sub-system. + + Say Y if unsure + +endif diff --git a/drivers/dax/Makefile b/drivers/dax/Makefile new file mode 100644 index 000000000000..27c54e38478a --- /dev/null +++ b/drivers/dax/Makefile @@ -0,0 +1,4 @@ +obj-$(CONFIG_DEV_DAX) += dax.o +obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem.o + +dax_pmem-y := pmem.o diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c new file mode 100644 index 000000000000..8207fb33a992 --- /dev/null +++ b/drivers/dax/dax.c @@ -0,0 +1,252 @@ +/* + * Copyright(c) 2016 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ +#include +#include +#include +#include +#include +#include +#include +#include + +static int dax_major; +static struct class *dax_class; +static DEFINE_IDA(dax_minor_ida); + +/** + * struct dax_region - mapping infrastructure for dax devices + * @id: kernel-wide unique region for a memory range + * @base: linear address corresponding to @res + * @kref: to pin while other agents have a need to do lookups + * @dev: parent device backing this region + * @align: allocation and mapping alignment for child dax devices + * @res: physical address range of the region + * @pfn_flags: identify whether the pfns are paged back or not + */ +struct dax_region { + int id; + struct ida ida; + void *base; + struct kref kref; + struct device *dev; + unsigned int align; + struct resource res; + unsigned long pfn_flags; +}; + +/** + * struct dax_dev - subdivision of a dax region + * @region - parent region + * @dev - device backing the character device + * @kref - enable this data to be tracked in filp->private_data + * @id - child id in the region + * @num_resources - number of physical address extents in this device + * @res - array of physical address ranges + */ +struct dax_dev { + struct dax_region *region; + struct device *dev; + struct kref kref; + int id; + int num_resources; + struct resource res[0]; +}; + +static void dax_region_free(struct kref *kref) +{ + struct dax_region *dax_region; + + dax_region = container_of(kref, struct dax_region, kref); + kfree(dax_region); +} + +void dax_region_put(struct dax_region *dax_region) +{ + kref_put(&dax_region->kref, dax_region_free); +} +EXPORT_SYMBOL_GPL(dax_region_put); + +static void dax_dev_free(struct kref *kref) +{ + struct dax_dev *dax_dev; + + dax_dev = container_of(kref, struct dax_dev, kref); + dax_region_put(dax_dev->region); + kfree(dax_dev); +} + +static void dax_dev_put(struct dax_dev *dax_dev) +{ + kref_put(&dax_dev->kref, dax_dev_free); +} + +struct dax_region *alloc_dax_region(struct device *parent, int region_id, + struct resource *res, unsigned int align, void *addr, + unsigned long pfn_flags) +{ + struct dax_region *dax_region; + + dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL); + + if (!dax_region) + return NULL; + + memcpy(&dax_region->res, res, sizeof(*res)); + dax_region->pfn_flags = pfn_flags; + kref_init(&dax_region->kref); + dax_region->id = region_id; + ida_init(&dax_region->ida); + dax_region->align = align; + dax_region->dev = parent; + dax_region->base = addr; + + return dax_region; +} +EXPORT_SYMBOL_GPL(alloc_dax_region); + +static ssize_t size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dax_dev *dax_dev = dev_get_drvdata(dev); + unsigned long long size = 0; + int i; + + for (i = 0; i < dax_dev->num_resources; i++) + size += resource_size(&dax_dev->res[i]); + + return sprintf(buf, "%llu\n", size); +} +static DEVICE_ATTR_RO(size); + +static struct attribute *dax_device_attributes[] = { + &dev_attr_size.attr, + NULL, +}; + +static const struct attribute_group dax_device_attribute_group = { + .attrs = dax_device_attributes, +}; + +static const struct attribute_group *dax_attribute_groups[] = { + &dax_device_attribute_group, + NULL, +}; + +static void destroy_dax_dev(void *_dev) +{ + struct device *dev = _dev; + struct dax_dev *dax_dev = dev_get_drvdata(dev); + struct dax_region *dax_region = dax_dev->region; + + dev_dbg(dev, "%s\n", __func__); + + get_device(dev); + device_unregister(dev); + ida_simple_remove(&dax_region->ida, dax_dev->id); + ida_simple_remove(&dax_minor_ida, MINOR(dev->devt)); + put_device(dev); + dax_dev_put(dax_dev); +} + +int devm_create_dax_dev(struct dax_region *dax_region, struct resource *res, + int count) +{ + struct device *parent = dax_region->dev; + struct dax_dev *dax_dev; + struct device *dev; + int rc, minor; + dev_t dev_t; + + dax_dev = kzalloc(sizeof(*dax_dev) + sizeof(*res) * count, GFP_KERNEL); + if (!dax_dev) + return -ENOMEM; + memcpy(dax_dev->res, res, sizeof(*res) * count); + dax_dev->num_resources = count; + kref_init(&dax_dev->kref); + dax_dev->region = dax_region; + kref_get(&dax_region->kref); + + dax_dev->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL); + if (dax_dev->id < 0) { + rc = dax_dev->id; + goto err_id; + } + + minor = ida_simple_get(&dax_minor_ida, 0, 0, GFP_KERNEL); + if (minor < 0) { + rc = minor; + goto err_minor; + } + + dev_t = MKDEV(dax_major, minor); + dev = device_create_with_groups(dax_class, parent, dev_t, dax_dev, + dax_attribute_groups, "dax%d.%d", dax_region->id, + dax_dev->id); + if (IS_ERR(dev)) { + rc = PTR_ERR(dev); + goto err_create; + } + dax_dev->dev = dev; + + rc = devm_add_action(dax_region->dev, destroy_dax_dev, dev); + if (rc) { + destroy_dax_dev(dev); + return rc; + } + + return 0; + + err_create: + ida_simple_remove(&dax_minor_ida, minor); + err_minor: + ida_simple_remove(&dax_region->ida, dax_dev->id); + err_id: + dax_dev_put(dax_dev); + + return rc; +} +EXPORT_SYMBOL_GPL(devm_create_dax_dev); + +static const struct file_operations dax_fops = { + .llseek = noop_llseek, + .owner = THIS_MODULE, +}; + +static int __init dax_init(void) +{ + int rc; + + rc = register_chrdev(0, "dax", &dax_fops); + if (rc < 0) + return rc; + dax_major = rc; + + dax_class = class_create(THIS_MODULE, "dax"); + if (IS_ERR(dax_class)) { + unregister_chrdev(dax_major, "dax"); + return PTR_ERR(dax_class); + } + + return 0; +} + +static void __exit dax_exit(void) +{ + class_destroy(dax_class); + unregister_chrdev(dax_major, "dax"); +} + +MODULE_AUTHOR("Intel Corporation"); +MODULE_LICENSE("GPL v2"); +subsys_initcall(dax_init); +module_exit(dax_exit); diff --git a/drivers/dax/dax.h b/drivers/dax/dax.h new file mode 100644 index 000000000000..d8b8f1f25054 --- /dev/null +++ b/drivers/dax/dax.h @@ -0,0 +1,24 @@ +/* + * Copyright(c) 2016 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ +#ifndef __DAX_H__ +#define __DAX_H__ +struct device; +struct resource; +struct dax_region; +void dax_region_put(struct dax_region *dax_region); +struct dax_region *alloc_dax_region(struct device *parent, + int region_id, struct resource *res, unsigned int align, + void *addr, unsigned long flags); +int devm_create_dax_dev(struct dax_region *dax_region, struct resource *res, + int count); +#endif /* __DAX_H__ */ diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c new file mode 100644 index 000000000000..4e97555e1cab --- /dev/null +++ b/drivers/dax/pmem.c @@ -0,0 +1,168 @@ +/* + * Copyright(c) 2016 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ +#include +#include +#include +#include +#include "../nvdimm/pfn.h" +#include "../nvdimm/nd.h" +#include "dax.h" + +struct dax_pmem { + struct device *dev; + struct percpu_ref ref; + struct completion cmp; +}; + +struct dax_pmem *to_dax_pmem(struct percpu_ref *ref) +{ + return container_of(ref, struct dax_pmem, ref); +} + +static void dax_pmem_percpu_release(struct percpu_ref *ref) +{ + struct dax_pmem *dax_pmem = to_dax_pmem(ref); + + dev_dbg(dax_pmem->dev, "%s\n", __func__); + complete(&dax_pmem->cmp); +} + +static void dax_pmem_percpu_exit(void *data) +{ + struct percpu_ref *ref = data; + struct dax_pmem *dax_pmem = to_dax_pmem(ref); + + dev_dbg(dax_pmem->dev, "%s\n", __func__); + percpu_ref_exit(ref); + wait_for_completion(&dax_pmem->cmp); +} + +static void dax_pmem_percpu_kill(void *data) +{ + struct percpu_ref *ref = data; + struct dax_pmem *dax_pmem = to_dax_pmem(ref); + + dev_dbg(dax_pmem->dev, "%s\n", __func__); + percpu_ref_kill(ref); +} + +static int dax_pmem_probe(struct device *dev) +{ + int rc; + void *addr; + struct resource res; + struct nd_pfn_sb *pfn_sb; + struct dax_pmem *dax_pmem; + struct nd_region *nd_region; + struct nd_namespace_io *nsio; + struct dax_region *dax_region; + struct nd_namespace_common *ndns; + struct nd_dax *nd_dax = to_nd_dax(dev); + struct nd_pfn *nd_pfn = &nd_dax->nd_pfn; + struct vmem_altmap __altmap, *altmap = NULL; + + ndns = nvdimm_namespace_common_probe(dev); + if (IS_ERR(ndns)) + return PTR_ERR(ndns); + nsio = to_nd_namespace_io(&ndns->dev); + + /* parse the 'pfn' info block via ->rw_bytes */ + devm_nsio_enable(dev, nsio); + altmap = nvdimm_setup_pfn(nd_pfn, &res, &__altmap); + if (IS_ERR(altmap)) + return PTR_ERR(altmap); + devm_nsio_disable(dev, nsio); + + pfn_sb = nd_pfn->pfn_sb; + + if (!devm_request_mem_region(dev, nsio->res.start, + resource_size(&nsio->res), dev_name(dev))) { + dev_warn(dev, "could not reserve region %pR\n", &nsio->res); + return -EBUSY; + } + + dax_pmem = devm_kzalloc(dev, sizeof(*dax_pmem), GFP_KERNEL); + if (!dax_pmem) + return -ENOMEM; + + dax_pmem->dev = dev; + init_completion(&dax_pmem->cmp); + rc = percpu_ref_init(&dax_pmem->ref, dax_pmem_percpu_release, 0, + GFP_KERNEL); + if (rc) + return rc; + + rc = devm_add_action(dev, dax_pmem_percpu_exit, &dax_pmem->ref); + if (rc) { + dax_pmem_percpu_exit(&dax_pmem->ref); + return rc; + } + + addr = devm_memremap_pages(dev, &res, &dax_pmem->ref, altmap); + if (IS_ERR(addr)) + return PTR_ERR(addr); + + rc = devm_add_action(dev, dax_pmem_percpu_kill, &dax_pmem->ref); + if (rc) { + dax_pmem_percpu_kill(&dax_pmem->ref); + return rc; + } + + nd_region = to_nd_region(dev->parent); + dax_region = alloc_dax_region(dev, nd_region->id, &res, + le32_to_cpu(pfn_sb->align), addr, PFN_DEV|PFN_MAP); + if (!dax_region) + return -ENOMEM; + + /* TODO: support for subdividing a dax region... */ + rc = devm_create_dax_dev(dax_region, &res, 1); + + /* child dax_dev instances now own the lifetime of the dax_region */ + dax_region_put(dax_region); + + return rc; +} + +static int dax_pmem_remove(struct device *dev) +{ + /* + * The init path is fully devm-enabled, or child devices + * otherwise hold references on parent resources. + */ + return 0; +} + +static struct nd_device_driver dax_pmem_driver = { + .probe = dax_pmem_probe, + .remove = dax_pmem_remove, + .drv = { + .name = "dax_pmem", + }, + .type = ND_DRIVER_DAX_PMEM, +}; + +static int __init dax_pmem_init(void) +{ + return nd_driver_register(&dax_pmem_driver); +} +module_init(dax_pmem_init); + +static void __exit dax_pmem_exit(void) +{ + driver_unregister(&dax_pmem_driver.drv); +} +module_exit(dax_pmem_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Intel Corporation"); +MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM); diff --git a/tools/testing/nvdimm/Kbuild b/tools/testing/nvdimm/Kbuild index 5ff6d3c126a9..785985677159 100644 --- a/tools/testing/nvdimm/Kbuild +++ b/tools/testing/nvdimm/Kbuild @@ -16,6 +16,7 @@ ldflags-y += --wrap=phys_to_pfn_t DRIVERS := ../../../drivers NVDIMM_SRC := $(DRIVERS)/nvdimm ACPI_SRC := $(DRIVERS)/acpi +DAX_SRC := $(DRIVERS)/dax obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o @@ -23,6 +24,8 @@ obj-$(CONFIG_ND_BTT) += nd_btt.o obj-$(CONFIG_ND_BLK) += nd_blk.o obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o obj-$(CONFIG_ACPI_NFIT) += nfit.o +obj-$(CONFIG_DEV_DAX) += dax.o +obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem.o nfit-y := $(ACPI_SRC)/nfit.o nfit-y += config_check.o @@ -39,6 +42,12 @@ nd_blk-y += config_check.o nd_e820-y := $(NVDIMM_SRC)/e820.o nd_e820-y += config_check.o +dax-y := $(DAX_SRC)/dax.o +dax-y += config_check.o + +dax_pmem-y := $(DAX_SRC)/pmem.o +dax_pmem-y += config_check.o + libnvdimm-y := $(NVDIMM_SRC)/core.o libnvdimm-y += $(NVDIMM_SRC)/bus.o libnvdimm-y += $(NVDIMM_SRC)/dimm_devs.o diff --git a/tools/testing/nvdimm/config_check.c b/tools/testing/nvdimm/config_check.c index f2c7615554eb..adf18bfeca00 100644 --- a/tools/testing/nvdimm/config_check.c +++ b/tools/testing/nvdimm/config_check.c @@ -12,4 +12,6 @@ void check(void) BUILD_BUG_ON(!IS_MODULE(CONFIG_ND_BTT)); BUILD_BUG_ON(!IS_MODULE(CONFIG_ND_BLK)); BUILD_BUG_ON(!IS_MODULE(CONFIG_ACPI_NFIT)); + BUILD_BUG_ON(!IS_MODULE(CONFIG_DEV_DAX)); + BUILD_BUG_ON(!IS_MODULE(CONFIG_DEV_DAX_PMEM)); }