From: Dan Williams Date: Sun, 16 Jul 2017 20:51:53 +0000 (-0700) Subject: device-dax: Add /sys/class/dax backwards compatibility X-Git-Tag: v5.15~6747^2~9 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=730926c3b0998943654019f00296cf8e3b02277e;p=platform%2Fkernel%2Flinux-starfive.git device-dax: Add /sys/class/dax backwards compatibility On the expectation that some environments may not upgrade libdaxctl (userspace component that depends on the /sys/class/dax hierarchy), provide a default / legacy dax_pmem_compat driver. The dax_pmem_compat driver implements the original /sys/class/dax sysfs layout rather than /sys/bus/dax. When userspace is upgraded it can blacklist this module and switch to the dax_pmem driver going forward. CONFIG_DEV_DAX_PMEM_COMPAT and supporting code will be deleted according to the dax_pmem entry in Documentation/ABI/obsolete/. Signed-off-by: Dan Williams --- diff --git a/Documentation/ABI/obsolete/sysfs-class-dax b/Documentation/ABI/obsolete/sysfs-class-dax new file mode 100644 index 0000000..2cb9fc5 --- /dev/null +++ b/Documentation/ABI/obsolete/sysfs-class-dax @@ -0,0 +1,22 @@ +What: /sys/class/dax/ +Date: May, 2016 +KernelVersion: v4.7 +Contact: linux-nvdimm@lists.01.org +Description: 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. + + The /sys/class/dax/ interface enumerates all the + device-dax instances in the system. The ABI is + deprecated and will be removed after 2020. It is + replaced with the DAX bus interface /sys/bus/dax/ where + device-dax instances can be found under + /sys/bus/dax/devices/ diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig index e0700bf..6fc96f0 100644 --- a/drivers/dax/Kconfig +++ b/drivers/dax/Kconfig @@ -23,12 +23,22 @@ config DEV_DAX config DEV_DAX_PMEM tristate "PMEM DAX: direct access to persistent memory" depends on LIBNVDIMM && NVDIMM_DAX && DEV_DAX + depends on m # until we can kill DEV_DAX_PMEM_COMPAT 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 + Say M if unsure + +config DEV_DAX_PMEM_COMPAT + tristate "PMEM DAX: support the deprecated /sys/class/dax interface" + depends on DEV_DAX_PMEM + default DEV_DAX_PMEM + help + Older versions of the libdaxctl library expect to find all + device-dax instances under /sys/class/dax. If libdaxctl in + your distribution is older than v58 say M, otherwise say N. endif diff --git a/drivers/dax/Makefile b/drivers/dax/Makefile index 658e6b9..233bbff 100644 --- a/drivers/dax/Makefile +++ b/drivers/dax/Makefile @@ -1,9 +1,9 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_DAX) += dax.o obj-$(CONFIG_DEV_DAX) += device_dax.o -obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem.o dax-y := super.o dax-y += bus.o -dax_pmem-y := pmem.o device_dax-y := device.o + +obj-y += pmem/ diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 17af6fb..5681685 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -9,6 +9,8 @@ #include "dax-private.h" #include "bus.h" +static struct class *dax_class; + static DEFINE_MUTEX(dax_bus_lock); #define DAX_NAME_LEN 30 @@ -310,8 +312,8 @@ static void unregister_dev_dax(void *dev) put_device(dev); } -struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id, - struct dev_pagemap *pgmap) +struct dev_dax *__devm_create_dev_dax(struct dax_region *dax_region, int id, + struct dev_pagemap *pgmap, enum dev_dax_subsys subsys) { struct device *parent = dax_region->dev; struct dax_device *dax_dev; @@ -350,7 +352,10 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id, inode = dax_inode(dax_dev); dev->devt = inode->i_rdev; - dev->bus = &dax_bus_type; + if (subsys == DEV_DAX_BUS) + dev->bus = &dax_bus_type; + else + dev->class = dax_class; dev->parent = parent; dev->groups = dax_attribute_groups; dev->release = dev_dax_release; @@ -374,7 +379,7 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id, return ERR_PTR(rc); } -EXPORT_SYMBOL_GPL(devm_create_dev_dax); +EXPORT_SYMBOL_GPL(__devm_create_dev_dax); static int match_always_count; @@ -407,6 +412,7 @@ EXPORT_SYMBOL_GPL(__dax_driver_register); void dax_driver_unregister(struct dax_device_driver *dax_drv) { + struct device_driver *drv = &dax_drv->drv; struct dax_id *dax_id, *_id; mutex_lock(&dax_bus_lock); @@ -416,15 +422,28 @@ void dax_driver_unregister(struct dax_device_driver *dax_drv) kfree(dax_id); } mutex_unlock(&dax_bus_lock); + driver_unregister(drv); } EXPORT_SYMBOL_GPL(dax_driver_unregister); int __init dax_bus_init(void) { - return bus_register(&dax_bus_type); + int rc; + + if (IS_ENABLED(CONFIG_DEV_DAX_PMEM_COMPAT)) { + dax_class = class_create(THIS_MODULE, "dax"); + if (IS_ERR(dax_class)) + return PTR_ERR(dax_class); + } + + rc = bus_register(&dax_bus_type); + if (rc) + class_destroy(dax_class); + return rc; } void __exit dax_bus_exit(void) { bus_unregister(&dax_bus_type); + class_destroy(dax_class); } diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h index 395ab812..ce97755 100644 --- a/drivers/dax/bus.h +++ b/drivers/dax/bus.h @@ -2,7 +2,8 @@ /* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */ #ifndef __DAX_BUS_H__ #define __DAX_BUS_H__ -struct device; +#include + struct dev_dax; struct resource; struct dax_device; @@ -10,8 +11,23 @@ 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, unsigned long flags); -struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id, - struct dev_pagemap *pgmap); + +enum dev_dax_subsys { + DEV_DAX_BUS, + DEV_DAX_CLASS, +}; + +struct dev_dax *__devm_create_dev_dax(struct dax_region *dax_region, int id, + struct dev_pagemap *pgmap, enum dev_dax_subsys subsys); + +static inline struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, + int id, struct dev_pagemap *pgmap) +{ + return __devm_create_dev_dax(dax_region, id, pgmap, DEV_DAX_BUS); +} + +/* to be deleted when DEV_DAX_CLASS is removed */ +struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys); struct dax_device_driver { struct device_driver drv; @@ -26,6 +42,10 @@ int __dax_driver_register(struct dax_device_driver *dax_drv, void dax_driver_unregister(struct dax_device_driver *dax_drv); void kill_dev_dax(struct dev_dax *dev_dax); +#if IS_ENABLED(CONFIG_DEV_DAX_PMEM_COMPAT) +int dev_dax_probe(struct device *dev); +#endif + /* * While run_dax() is potentially a generic operation that could be * defined in include/linux/dax.h we don't want to grow any users diff --git a/drivers/dax/device.c b/drivers/dax/device.c index ad31203..e428468 100644 --- a/drivers/dax/device.c +++ b/drivers/dax/device.c @@ -445,7 +445,7 @@ static void dev_dax_kill(void *dev_dax) kill_dev_dax(dev_dax); } -static int dev_dax_probe(struct device *dev) +int dev_dax_probe(struct device *dev) { struct dev_dax *dev_dax = to_dev_dax(dev); struct dax_device *dax_dev = dev_dax->dax_dev; @@ -484,7 +484,11 @@ static int dev_dax_probe(struct device *dev) inode = dax_inode(dax_dev); cdev = inode->i_cdev; cdev_init(cdev, &dax_fops); - cdev->owner = dev->driver->owner; + if (dev->class) { + /* for the CONFIG_DEV_DAX_PMEM_COMPAT case */ + cdev->owner = dev->parent->driver->owner; + } else + cdev->owner = dev->driver->owner; cdev_set_parent(cdev, &dev->kobj); rc = cdev_add(cdev, dev->devt, 1); if (rc) @@ -497,6 +501,7 @@ static int dev_dax_probe(struct device *dev) run_dax(dax_dev); return devm_add_action_or_reset(dev, dev_dax_kill, dev_dax); } +EXPORT_SYMBOL_GPL(dev_dax_probe); static int dev_dax_remove(struct device *dev) { diff --git a/drivers/dax/pmem/Makefile b/drivers/dax/pmem/Makefile new file mode 100644 index 0000000..e2e79bd --- /dev/null +++ b/drivers/dax/pmem/Makefile @@ -0,0 +1,7 @@ +obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem.o +obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem_core.o +obj-$(CONFIG_DEV_DAX_PMEM_COMPAT) += dax_pmem_compat.o + +dax_pmem-y := pmem.o +dax_pmem_core-y := core.o +dax_pmem_compat-y := compat.o diff --git a/drivers/dax/pmem/compat.c b/drivers/dax/pmem/compat.c new file mode 100644 index 0000000..d7b15e6 --- /dev/null +++ b/drivers/dax/pmem/compat.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */ +#include +#include +#include +#include +#include +#include "../bus.h" + +/* we need the private definitions to implement compat suport */ +#include "../dax-private.h" + +static int dax_pmem_compat_probe(struct device *dev) +{ + struct dev_dax *dev_dax = __dax_pmem_probe(dev, DEV_DAX_CLASS); + int rc; + + if (IS_ERR(dev_dax)) + return PTR_ERR(dev_dax); + + if (!devres_open_group(&dev_dax->dev, dev_dax, GFP_KERNEL)) + return -ENOMEM; + + device_lock(&dev_dax->dev); + rc = dev_dax_probe(&dev_dax->dev); + device_unlock(&dev_dax->dev); + + devres_close_group(&dev_dax->dev, dev_dax); + if (rc) + devres_release_group(&dev_dax->dev, dev_dax); + + return rc; +} + +static int dax_pmem_compat_release(struct device *dev, void *data) +{ + device_lock(dev); + devres_release_group(dev, to_dev_dax(dev)); + device_unlock(dev); + + return 0; +} + +static int dax_pmem_compat_remove(struct device *dev) +{ + device_for_each_child(dev, NULL, dax_pmem_compat_release); + return 0; +} + +static struct nd_device_driver dax_pmem_compat_driver = { + .probe = dax_pmem_compat_probe, + .remove = dax_pmem_compat_remove, + .drv = { + .name = "dax_pmem_compat", + }, + .type = ND_DRIVER_DAX_PMEM, +}; + +static int __init dax_pmem_compat_init(void) +{ + return nd_driver_register(&dax_pmem_compat_driver); +} +module_init(dax_pmem_compat_init); + +static void __exit dax_pmem_compat_exit(void) +{ + driver_unregister(&dax_pmem_compat_driver.drv); +} +module_exit(dax_pmem_compat_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Intel Corporation"); +MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM); diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem/core.c similarity index 57% rename from drivers/dax/pmem.c rename to drivers/dax/pmem/core.c index d3cefa7..bdcff1b 100644 --- a/drivers/dax/pmem.c +++ b/drivers/dax/pmem/core.c @@ -1,24 +1,13 @@ -/* - * 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 +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */ #include #include #include -#include "../nvdimm/pfn.h" -#include "../nvdimm/nd.h" -#include "bus.h" +#include "../../nvdimm/pfn.h" +#include "../../nvdimm/nd.h" +#include "../bus.h" -static int dax_pmem_probe(struct device *dev) +struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys) { struct resource res; int rc, id, region_id; @@ -34,16 +23,16 @@ static int dax_pmem_probe(struct device *dev) ndns = nvdimm_namespace_common_probe(dev); if (IS_ERR(ndns)) - return PTR_ERR(ndns); + return ERR_CAST(ndns); nsio = to_nd_namespace_io(&ndns->dev); /* parse the 'pfn' info block via ->rw_bytes */ rc = devm_nsio_enable(dev, nsio); if (rc) - return rc; + return ERR_PTR(rc); rc = nvdimm_setup_pfn(nd_pfn, &pgmap); if (rc) - return rc; + return ERR_PTR(rc); devm_nsio_disable(dev, nsio); /* reserve the metadata area, device-dax will reserve the data */ @@ -52,12 +41,12 @@ static int dax_pmem_probe(struct device *dev) if (!devm_request_mem_region(dev, nsio->res.start, offset, dev_name(&ndns->dev))) { dev_warn(dev, "could not reserve metadata\n"); - return -EBUSY; + return ERR_PTR(-EBUSY); } rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", ®ion_id, &id); if (rc != 2) - return -EINVAL; + return ERR_PTR(-EINVAL); /* adjust the dax_region resource to the start of data */ memcpy(&res, &pgmap.res, sizeof(res)); @@ -65,26 +54,16 @@ static int dax_pmem_probe(struct device *dev) dax_region = alloc_dax_region(dev, region_id, &res, le32_to_cpu(pfn_sb->align), PFN_DEV|PFN_MAP); if (!dax_region) - return -ENOMEM; + return ERR_PTR(-ENOMEM); - dev_dax = devm_create_dev_dax(dax_region, id, &pgmap); + dev_dax = __devm_create_dev_dax(dax_region, id, &pgmap, subsys); /* child dev_dax instances now own the lifetime of the dax_region */ dax_region_put(dax_region); - return PTR_ERR_OR_ZERO(dev_dax); + return dev_dax; } - -static struct nd_device_driver dax_pmem_driver = { - .probe = dax_pmem_probe, - .drv = { - .name = "dax_pmem", - }, - .type = ND_DRIVER_DAX_PMEM, -}; - -module_nd_driver(dax_pmem_driver); +EXPORT_SYMBOL_GPL(__dax_pmem_probe); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Intel Corporation"); -MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM); diff --git a/drivers/dax/pmem/pmem.c b/drivers/dax/pmem/pmem.c new file mode 100644 index 0000000..0ae4238 --- /dev/null +++ b/drivers/dax/pmem/pmem.c @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */ +#include +#include +#include +#include +#include +#include "../bus.h" + +static int dax_pmem_probe(struct device *dev) +{ + return PTR_ERR_OR_ZERO(__dax_pmem_probe(dev, DEV_DAX_BUS)); +} + +static struct nd_device_driver dax_pmem_driver = { + .probe = dax_pmem_probe, + .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"); +#if !IS_ENABLED(CONFIG_DEV_DAX_PMEM_COMPAT) +/* For compat builds, don't load this module by default */ +MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM); +#endif diff --git a/tools/testing/nvdimm/Kbuild b/tools/testing/nvdimm/Kbuild index c9b500a..e1286d2 100644 --- a/tools/testing/nvdimm/Kbuild +++ b/tools/testing/nvdimm/Kbuild @@ -35,6 +35,8 @@ obj-$(CONFIG_DAX) += dax.o endif obj-$(CONFIG_DEV_DAX) += device_dax.o obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem.o +obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem_core.o +obj-$(CONFIG_DEV_DAX_PMEM_COMPAT) += dax_pmem_compat.o nfit-y := $(ACPI_SRC)/core.o nfit-y += $(ACPI_SRC)/intel.o @@ -65,7 +67,9 @@ device_dax-y += dax-dev.o device_dax-y += device_dax_test.o device_dax-y += config_check.o -dax_pmem-y := $(DAX_SRC)/pmem.o +dax_pmem-y := $(DAX_SRC)/pmem/pmem.o +dax_pmem_core-y := $(DAX_SRC)/pmem/core.o +dax_pmem_compat-y := $(DAX_SRC)/pmem/compat.o dax_pmem-y += config_check.o libnvdimm-y := $(NVDIMM_SRC)/core.o