From 21b9e979501fdb5f6797193d70428a2b00bd5247 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 19 Jul 2017 14:55:26 -0700 Subject: device-dax: Kill dax_region ida Commit bbb3be170ac2 "device-dax: fix sysfs duplicate warnings" arranged for passing a dax instance-id to devm_create_dax_dev(), rather than generating one internally. Remove the dax_region ida and related code. Signed-off-by: Dan Williams --- drivers/dax/dax-private.h | 3 --- drivers/dax/device.c | 24 +++--------------------- 2 files changed, 3 insertions(+), 24 deletions(-) (limited to 'drivers/dax') diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index b6fc4f04636d..d1b36a42132f 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -28,7 +28,6 @@ */ struct dax_region { int id; - struct ida ida; void *base; struct kref kref; struct device *dev; @@ -42,7 +41,6 @@ struct dax_region { * @region - parent region * @dax_dev - core dax functionality * @dev - device core - * @id - child id in the region * @num_resources - number of physical address extents in this device * @res - array of physical address ranges */ @@ -50,7 +48,6 @@ struct dev_dax { struct dax_region *region; struct dax_device *dax_dev; struct device dev; - int id; int num_resources; struct resource res[0]; }; diff --git a/drivers/dax/device.c b/drivers/dax/device.c index 948806e57cee..a5a670c1cd58 100644 --- a/drivers/dax/device.c +++ b/drivers/dax/device.c @@ -128,7 +128,6 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id, 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; @@ -582,8 +581,6 @@ static void dev_dax_release(struct device *dev) struct dax_region *dax_region = dev_dax->region; struct dax_device *dax_dev = dev_dax->dax_dev; - if (dev_dax->id >= 0) - ida_simple_remove(&dax_region->ida, dev_dax->id); dax_region_put(dax_region); put_dax(dax_dev); kfree(dev_dax); @@ -642,19 +639,7 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, } if (i < count) - goto err_id; - - if (id < 0) { - id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL); - dev_dax->id = id; - if (id < 0) { - rc = id; - goto err_id; - } - } else { - /* region provider owns @id lifetime */ - dev_dax->id = -1; - } + goto err; /* * No 'host' or dax_operations since there is no access to this @@ -663,7 +648,7 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, dax_dev = alloc_dax(dev_dax, NULL, NULL); if (!dax_dev) { rc = -ENOMEM; - goto err_dax; + goto err; } /* from here on we're committed to teardown via dax_dev_release() */ @@ -700,10 +685,7 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, return dev_dax; - err_dax: - if (dev_dax->id >= 0) - ida_simple_remove(&dax_region->ida, dev_dax->id); - err_id: + err: kfree(dev_dax); return ERR_PTR(rc); -- cgit v1.2.3 From 93694f9630b0ed29cda61df58e480dcb34ef52fd Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 19 Jul 2017 15:57:44 -0700 Subject: device-dax: Kill dax_region base Nothing consumes this attribute of a region and devres otherwise remembers the value for de-allocation purposes. Signed-off-by: Dan Williams --- drivers/dax/dax-private.h | 2 -- drivers/dax/device-dax.h | 5 ++--- drivers/dax/device.c | 3 +-- drivers/dax/pmem.c | 2 +- 4 files changed, 4 insertions(+), 8 deletions(-) (limited to 'drivers/dax') diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index d1b36a42132f..9b393c218fe4 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -19,7 +19,6 @@ /** * 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 @@ -28,7 +27,6 @@ */ struct dax_region { int id; - void *base; struct kref kref; struct device *dev; unsigned int align; diff --git a/drivers/dax/device-dax.h b/drivers/dax/device-dax.h index 688b051750bd..4f1c69e1b3a2 100644 --- a/drivers/dax/device-dax.h +++ b/drivers/dax/device-dax.h @@ -17,9 +17,8 @@ struct dev_dax; 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); +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 resource *res, int count); #endif /* __DEVICE_DAX_H__ */ diff --git a/drivers/dax/device.c b/drivers/dax/device.c index a5a670c1cd58..811c1015194c 100644 --- a/drivers/dax/device.c +++ b/drivers/dax/device.c @@ -100,7 +100,7 @@ static void dax_region_unregister(void *region) } struct dax_region *alloc_dax_region(struct device *parent, int region_id, - struct resource *res, unsigned int align, void *addr, + struct resource *res, unsigned int align, unsigned long pfn_flags) { struct dax_region *dax_region; @@ -130,7 +130,6 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id, dax_region->id = region_id; dax_region->align = align; dax_region->dev = parent; - dax_region->base = addr; if (sysfs_create_groups(&parent->kobj, dax_region_attribute_groups)) { kfree(dax_region); return NULL; diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c index 2c1f459c0c63..72a76105eb02 100644 --- a/drivers/dax/pmem.c +++ b/drivers/dax/pmem.c @@ -125,7 +125,7 @@ static int dax_pmem_probe(struct device *dev) return -EINVAL; dax_region = alloc_dax_region(dev, region_id, &res, - le32_to_cpu(pfn_sb->align), addr, PFN_DEV|PFN_MAP); + le32_to_cpu(pfn_sb->align), PFN_DEV|PFN_MAP); if (!dax_region) return -ENOMEM; -- cgit v1.2.3 From 753a0850e707e9a8c5861356222f9b9e4eba7945 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 14 Jul 2017 13:54:50 -0700 Subject: device-dax: Remove multi-resource infrastructure The multi-resource implementation anticipated discontiguous sub-division support. That has not yet materialized, delete the infrastructure and related code. Signed-off-by: Dan Williams --- drivers/dax/dax-private.h | 4 ---- drivers/dax/device-dax.h | 3 +-- drivers/dax/device.c | 49 ++++++++--------------------------------------- drivers/dax/pmem.c | 3 +-- 4 files changed, 10 insertions(+), 49 deletions(-) (limited to 'drivers/dax') diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index 9b393c218fe4..dbd077653b5c 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -39,14 +39,10 @@ struct dax_region { * @region - parent region * @dax_dev - core dax functionality * @dev - device core - * @num_resources - number of physical address extents in this device - * @res - array of physical address ranges */ struct dev_dax { struct dax_region *region; struct dax_device *dax_dev; struct device dev; - int num_resources; - struct resource res[0]; }; #endif diff --git a/drivers/dax/device-dax.h b/drivers/dax/device-dax.h index 4f1c69e1b3a2..e9be99584b92 100644 --- a/drivers/dax/device-dax.h +++ b/drivers/dax/device-dax.h @@ -19,6 +19,5 @@ 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 resource *res, int count); +struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id); #endif /* __DEVICE_DAX_H__ */ diff --git a/drivers/dax/device.c b/drivers/dax/device.c index 811c1015194c..db12e24b8005 100644 --- a/drivers/dax/device.c +++ b/drivers/dax/device.c @@ -151,11 +151,7 @@ static ssize_t size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct dev_dax *dev_dax = to_dev_dax(dev); - unsigned long long size = 0; - int i; - - for (i = 0; i < dev_dax->num_resources; i++) - size += resource_size(&dev_dax->res[i]); + unsigned long long size = resource_size(&dev_dax->region->res); return sprintf(buf, "%llu\n", size); } @@ -224,21 +220,11 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma, __weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff, unsigned long size) { - struct resource *res; - /* gcc-4.6.3-nolibc for i386 complains that this is uninitialized */ - phys_addr_t uninitialized_var(phys); - int i; - - for (i = 0; i < dev_dax->num_resources; i++) { - res = &dev_dax->res[i]; - phys = pgoff * PAGE_SIZE + res->start; - if (phys >= res->start && phys <= res->end) - break; - pgoff -= PHYS_PFN(resource_size(res)); - } + struct resource *res = &dev_dax->region->res; + phys_addr_t phys; - if (i < dev_dax->num_resources) { - res = &dev_dax->res[i]; + phys = pgoff * PAGE_SIZE + res->start; + if (phys >= res->start && phys <= res->end) { if (phys + size - 1 <= res->end) return phys; } @@ -608,8 +594,7 @@ 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 resource *res, int count) +struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id) { struct device *parent = dax_region->dev; struct dax_device *dax_dev; @@ -617,29 +602,12 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, struct inode *inode; struct device *dev; struct cdev *cdev; - int rc, i; + int rc; - if (!count) - return ERR_PTR(-EINVAL); - - dev_dax = kzalloc(struct_size(dev_dax, res, count), GFP_KERNEL); + dev_dax = kzalloc(sizeof(*dev_dax), GFP_KERNEL); if (!dev_dax) return ERR_PTR(-ENOMEM); - for (i = 0; i < count; i++) { - if (!IS_ALIGNED(res[i].start, dax_region->align) - || !IS_ALIGNED(resource_size(&res[i]), - dax_region->align)) { - rc = -EINVAL; - break; - } - dev_dax->res[i].start = res[i].start; - dev_dax->res[i].end = res[i].end; - } - - if (i < count) - goto err; - /* * No 'host' or dax_operations since there is no access to this * device outside of mmap of the resulting character device. @@ -659,7 +627,6 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, cdev_init(cdev, &dax_fops); cdev->owner = parent->driver->owner; - dev_dax->num_resources = count; dev_dax->dax_dev = dax_dev; dev_dax->region = dax_region; kref_get(&dax_region->kref); diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c index 72a76105eb02..6c61a019f997 100644 --- a/drivers/dax/pmem.c +++ b/drivers/dax/pmem.c @@ -129,8 +129,7 @@ static int dax_pmem_probe(struct device *dev) if (!dax_region) return -ENOMEM; - /* TODO: support for subdividing a dax region... */ - dev_dax = devm_create_dev_dax(dax_region, id, &res, 1); + dev_dax = devm_create_dev_dax(dax_region, id); /* child dev_dax instances now own the lifetime of the dax_region */ dax_region_put(dax_region); -- cgit v1.2.3 From 51cf784c42d07fbd62cb604836a9270cf3361509 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 12 Jul 2017 17:58:21 -0700 Subject: device-dax: Start defining a dax bus model Towards eliminating the dax_class, move the dax-device-attribute enabling to a new bus.c file in the core. The amount of code thrash of sub-sequent patches is reduced as no logic changes are made, just pure code movement. A temporary export of unregister_dex_dax() and dax_attribute_groups is needed to preserve compilation, but those symbols become static again in a follow-on patch. Signed-off-by: Dan Williams --- drivers/dax/Makefile | 1 + drivers/dax/bus.c | 174 +++++++++++++++++++++++++++++++++++++++++++ drivers/dax/bus.h | 15 ++++ drivers/dax/dax-private.h | 14 ++++ drivers/dax/dax.h | 18 ----- drivers/dax/device-dax.h | 23 ------ drivers/dax/device.c | 185 +--------------------------------------------- drivers/dax/pmem.c | 2 +- drivers/dax/super.c | 1 + 9 files changed, 209 insertions(+), 224 deletions(-) create mode 100644 drivers/dax/bus.c create mode 100644 drivers/dax/bus.h delete mode 100644 drivers/dax/dax.h delete mode 100644 drivers/dax/device-dax.h (limited to 'drivers/dax') diff --git a/drivers/dax/Makefile b/drivers/dax/Makefile index 574286fac87c..658e6b9b1d74 100644 --- a/drivers/dax/Makefile +++ b/drivers/dax/Makefile @@ -4,5 +4,6 @@ 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 diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c new file mode 100644 index 000000000000..8a398e8e1956 --- /dev/null +++ b/drivers/dax/bus.c @@ -0,0 +1,174 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2017-2018 Intel Corporation. All rights reserved. */ +#include +#include +#include +#include "dax-private.h" +#include "bus.h" + +/* + * Rely on the fact that drvdata is set before the attributes are + * registered, and that the attributes are unregistered before drvdata + * is cleared to assume that drvdata is always valid. + */ +static ssize_t id_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dax_region *dax_region = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", dax_region->id); +} +static DEVICE_ATTR_RO(id); + +static ssize_t region_size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dax_region *dax_region = dev_get_drvdata(dev); + + return sprintf(buf, "%llu\n", (unsigned long long) + resource_size(&dax_region->res)); +} +static struct device_attribute dev_attr_region_size = __ATTR(size, 0444, + region_size_show, NULL); + +static ssize_t align_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dax_region *dax_region = dev_get_drvdata(dev); + + return sprintf(buf, "%u\n", dax_region->align); +} +static DEVICE_ATTR_RO(align); + +static struct attribute *dax_region_attributes[] = { + &dev_attr_region_size.attr, + &dev_attr_align.attr, + &dev_attr_id.attr, + NULL, +}; + +static const struct attribute_group dax_region_attribute_group = { + .name = "dax_region", + .attrs = dax_region_attributes, +}; + +static const struct attribute_group *dax_region_attribute_groups[] = { + &dax_region_attribute_group, + NULL, +}; + +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_region_unregister(void *region) +{ + struct dax_region *dax_region = region; + + sysfs_remove_groups(&dax_region->dev->kobj, + dax_region_attribute_groups); + dax_region_put(dax_region); +} + +struct dax_region *alloc_dax_region(struct device *parent, int region_id, + struct resource *res, unsigned int align, + unsigned long pfn_flags) +{ + struct dax_region *dax_region; + + /* + * The DAX core assumes that it can store its private data in + * parent->driver_data. This WARN is a reminder / safeguard for + * developers of device-dax drivers. + */ + if (dev_get_drvdata(parent)) { + dev_WARN(parent, "dax core failed to setup private data\n"); + return NULL; + } + + if (!IS_ALIGNED(res->start, align) + || !IS_ALIGNED(resource_size(res), align)) + return NULL; + + dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL); + if (!dax_region) + return NULL; + + dev_set_drvdata(parent, dax_region); + memcpy(&dax_region->res, res, sizeof(*res)); + dax_region->pfn_flags = pfn_flags; + kref_init(&dax_region->kref); + dax_region->id = region_id; + dax_region->align = align; + dax_region->dev = parent; + if (sysfs_create_groups(&parent->kobj, dax_region_attribute_groups)) { + kfree(dax_region); + return NULL; + } + + kref_get(&dax_region->kref); + if (devm_add_action_or_reset(parent, dax_region_unregister, dax_region)) + return NULL; + return dax_region; +} +EXPORT_SYMBOL_GPL(alloc_dax_region); + +static ssize_t size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + unsigned long long size = resource_size(&dev_dax->region->res); + + return sprintf(buf, "%llu\n", size); +} +static DEVICE_ATTR_RO(size); + +static struct attribute *dev_dax_attributes[] = { + &dev_attr_size.attr, + NULL, +}; + +static const struct attribute_group dev_dax_attribute_group = { + .attrs = dev_dax_attributes, +}; + +const struct attribute_group *dax_attribute_groups[] = { + &dev_dax_attribute_group, + NULL, +}; +EXPORT_SYMBOL_GPL(dax_attribute_groups); + +void kill_dev_dax(struct dev_dax *dev_dax) +{ + struct dax_device *dax_dev = dev_dax->dax_dev; + struct inode *inode = dax_inode(dax_dev); + + kill_dax(dax_dev); + unmap_mapping_range(inode->i_mapping, 0, 0, 1); +} +EXPORT_SYMBOL_GPL(kill_dev_dax); + +void unregister_dev_dax(void *dev) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + struct dax_device *dax_dev = dev_dax->dax_dev; + struct inode *inode = dax_inode(dax_dev); + struct cdev *cdev = inode->i_cdev; + + dev_dbg(dev, "trace\n"); + + kill_dev_dax(dev_dax); + cdev_device_del(cdev, dev); + put_device(dev); +} +EXPORT_SYMBOL_GPL(unregister_dev_dax); diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h new file mode 100644 index 000000000000..840865aa69e8 --- /dev/null +++ b/drivers/dax/bus.h @@ -0,0 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */ +#ifndef __DAX_BUS_H__ +#define __DAX_BUS_H__ +struct device; +struct dev_dax; +struct resource; +struct dax_device; +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); +void kill_dev_dax(struct dev_dax *dev_dax); +#endif /* __DAX_BUS_H__ */ diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index dbd077653b5c..620c3f4eefe7 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -16,6 +16,15 @@ #include #include +/* private routines between core files */ +struct dax_device; +struct dax_device *inode_dax(struct inode *inode); +struct inode *dax_inode(struct dax_device *dax_dev); + +/* temporary until devm_create_dax_dev moves to bus.c */ +extern const struct attribute_group *dax_attribute_groups[]; +void unregister_dev_dax(void *dev); + /** * struct dax_region - mapping infrastructure for dax devices * @id: kernel-wide unique region for a memory range @@ -45,4 +54,9 @@ struct dev_dax { struct dax_device *dax_dev; struct device dev; }; + +static inline struct dev_dax *to_dev_dax(struct device *dev) +{ + return container_of(dev, struct dev_dax, dev); +} #endif diff --git a/drivers/dax/dax.h b/drivers/dax/dax.h deleted file mode 100644 index f9e5feea742c..000000000000 --- a/drivers/dax/dax.h +++ /dev/null @@ -1,18 +0,0 @@ -/* - * Copyright(c) 2016 - 2017 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 dax_device; -struct dax_device *inode_dax(struct inode *inode); -struct inode *dax_inode(struct dax_device *dax_dev); -#endif /* __DAX_H__ */ diff --git a/drivers/dax/device-dax.h b/drivers/dax/device-dax.h deleted file mode 100644 index e9be99584b92..000000000000 --- a/drivers/dax/device-dax.h +++ /dev/null @@ -1,23 +0,0 @@ -/* - * 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 __DEVICE_DAX_H__ -#define __DEVICE_DAX_H__ -struct device; -struct dev_dax; -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, unsigned long flags); -struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id); -#endif /* __DEVICE_DAX_H__ */ diff --git a/drivers/dax/device.c b/drivers/dax/device.c index db12e24b8005..1fc375783e0b 100644 --- a/drivers/dax/device.c +++ b/drivers/dax/device.c @@ -1,15 +1,5 @@ -/* - * Copyright(c) 2016 - 2017 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. - */ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2016-2018 Intel Corporation. All rights reserved. */ #include #include #include @@ -21,156 +11,10 @@ #include #include #include "dax-private.h" -#include "dax.h" +#include "bus.h" static struct class *dax_class; -/* - * Rely on the fact that drvdata is set before the attributes are - * registered, and that the attributes are unregistered before drvdata - * is cleared to assume that drvdata is always valid. - */ -static ssize_t id_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct dax_region *dax_region = dev_get_drvdata(dev); - - return sprintf(buf, "%d\n", dax_region->id); -} -static DEVICE_ATTR_RO(id); - -static ssize_t region_size_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct dax_region *dax_region = dev_get_drvdata(dev); - - return sprintf(buf, "%llu\n", (unsigned long long) - resource_size(&dax_region->res)); -} -static struct device_attribute dev_attr_region_size = __ATTR(size, 0444, - region_size_show, NULL); - -static ssize_t align_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct dax_region *dax_region = dev_get_drvdata(dev); - - return sprintf(buf, "%u\n", dax_region->align); -} -static DEVICE_ATTR_RO(align); - -static struct attribute *dax_region_attributes[] = { - &dev_attr_region_size.attr, - &dev_attr_align.attr, - &dev_attr_id.attr, - NULL, -}; - -static const struct attribute_group dax_region_attribute_group = { - .name = "dax_region", - .attrs = dax_region_attributes, -}; - -static const struct attribute_group *dax_region_attribute_groups[] = { - &dax_region_attribute_group, - NULL, -}; - -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_region_unregister(void *region) -{ - struct dax_region *dax_region = region; - - sysfs_remove_groups(&dax_region->dev->kobj, - dax_region_attribute_groups); - dax_region_put(dax_region); -} - -struct dax_region *alloc_dax_region(struct device *parent, int region_id, - struct resource *res, unsigned int align, - unsigned long pfn_flags) -{ - struct dax_region *dax_region; - - /* - * The DAX core assumes that it can store its private data in - * parent->driver_data. This WARN is a reminder / safeguard for - * developers of device-dax drivers. - */ - if (dev_get_drvdata(parent)) { - dev_WARN(parent, "dax core failed to setup private data\n"); - return NULL; - } - - if (!IS_ALIGNED(res->start, align) - || !IS_ALIGNED(resource_size(res), align)) - return NULL; - - dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL); - if (!dax_region) - return NULL; - - dev_set_drvdata(parent, dax_region); - memcpy(&dax_region->res, res, sizeof(*res)); - dax_region->pfn_flags = pfn_flags; - kref_init(&dax_region->kref); - dax_region->id = region_id; - dax_region->align = align; - dax_region->dev = parent; - if (sysfs_create_groups(&parent->kobj, dax_region_attribute_groups)) { - kfree(dax_region); - return NULL; - } - - kref_get(&dax_region->kref); - if (devm_add_action_or_reset(parent, dax_region_unregister, dax_region)) - return NULL; - return dax_region; -} -EXPORT_SYMBOL_GPL(alloc_dax_region); - -static struct dev_dax *to_dev_dax(struct device *dev) -{ - return container_of(dev, struct dev_dax, dev); -} - -static ssize_t size_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct dev_dax *dev_dax = to_dev_dax(dev); - unsigned long long size = resource_size(&dev_dax->region->res); - - return sprintf(buf, "%llu\n", size); -} -static DEVICE_ATTR_RO(size); - -static struct attribute *dev_dax_attributes[] = { - &dev_attr_size.attr, - NULL, -}; - -static const struct attribute_group dev_dax_attribute_group = { - .attrs = dev_dax_attributes, -}; - -static const struct attribute_group *dax_attribute_groups[] = { - &dev_dax_attribute_group, - NULL, -}; - static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma, const char *func) { @@ -571,29 +415,6 @@ static void dev_dax_release(struct device *dev) kfree(dev_dax); } -static void kill_dev_dax(struct dev_dax *dev_dax) -{ - struct dax_device *dax_dev = dev_dax->dax_dev; - struct inode *inode = dax_inode(dax_dev); - - kill_dax(dax_dev); - unmap_mapping_range(inode->i_mapping, 0, 0, 1); -} - -static void unregister_dev_dax(void *dev) -{ - struct dev_dax *dev_dax = to_dev_dax(dev); - struct dax_device *dax_dev = dev_dax->dax_dev; - struct inode *inode = dax_inode(dax_dev); - struct cdev *cdev = inode->i_cdev; - - dev_dbg(dev, "trace\n"); - - kill_dev_dax(dev_dax); - cdev_device_del(cdev, dev); - put_device(dev); -} - struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id) { struct device *parent = dax_region->dev; diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c index 6c61a019f997..e1b50d8fd1f8 100644 --- a/drivers/dax/pmem.c +++ b/drivers/dax/pmem.c @@ -16,7 +16,7 @@ #include #include "../nvdimm/pfn.h" #include "../nvdimm/nd.h" -#include "device-dax.h" +#include "bus.h" struct dax_pmem { struct device *dev; diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 6e928f37d084..0ecc1a2cf1cc 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -22,6 +22,7 @@ #include #include #include +#include "dax-private.h" static dev_t dax_devt; DEFINE_STATIC_SRCU(dax_srcu); -- cgit v1.2.3 From 9567da0b408a2553d32ca83cba4f1fc5a8aad459 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 12 Jul 2017 17:58:21 -0700 Subject: device-dax: Introduce bus + driver model In support of multiple device-dax instances per device-dax-region and allowing the 'kmem' driver to attach to dax-instances instead of the current device-node access, convert the dax sub-system from a class to a bus. Recall that the kmem driver takes reserved / special purpose memories and assigns them to be managed by the core-mm. Aside from the fact the device-dax instances are registered and probed on a bus, two other lifetime-management changes are made: 1/ Delay attaching a cdev until driver probe time 2/ A new run_dax() helper is introduced to allow restoring dax-operation after a kill_dax() event. So, at driver ->probe() time we run_dax() and at ->remove() time we kill_dax() and invalidate all mappings. Signed-off-by: Dan Williams --- drivers/dax/bus.c | 133 +++++++++++++++++++++++++++++++++++++++++++--- drivers/dax/bus.h | 16 ++++++ drivers/dax/dax-private.h | 6 +-- drivers/dax/device.c | 95 +++++++++++---------------------- drivers/dax/super.c | 40 +++++++++----- 5 files changed, 203 insertions(+), 87 deletions(-) (limited to 'drivers/dax') diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 8a398e8e1956..0cff32102c4c 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -6,6 +6,33 @@ #include "dax-private.h" #include "bus.h" +static int dax_bus_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + /* + * We only ever expect to handle device-dax instances, i.e. the + * @type argument to MODULE_ALIAS_DAX_DEVICE() is always zero + */ + return add_uevent_var(env, "MODALIAS=" DAX_DEVICE_MODALIAS_FMT, 0); +} + +static int dax_bus_match(struct device *dev, struct device_driver *drv); + +static struct bus_type dax_bus_type = { + .name = "dax", + .uevent = dax_bus_uevent, + .match = dax_bus_match, +}; + +static int dax_bus_match(struct device *dev, struct device_driver *drv) +{ + /* + * The drivers that can register on the 'dax' bus are private to + * drivers/dax/ so any device and driver on the bus always + * match. + */ + return 1; +} + /* * Rely on the fact that drvdata is set before the attributes are * registered, and that the attributes are unregistered before drvdata @@ -142,11 +169,10 @@ static const struct attribute_group dev_dax_attribute_group = { .attrs = dev_dax_attributes, }; -const struct attribute_group *dax_attribute_groups[] = { +static const struct attribute_group *dax_attribute_groups[] = { &dev_dax_attribute_group, NULL, }; -EXPORT_SYMBOL_GPL(dax_attribute_groups); void kill_dev_dax(struct dev_dax *dev_dax) { @@ -158,17 +184,108 @@ void kill_dev_dax(struct dev_dax *dev_dax) } EXPORT_SYMBOL_GPL(kill_dev_dax); -void unregister_dev_dax(void *dev) +static void dev_dax_release(struct device *dev) { struct dev_dax *dev_dax = to_dev_dax(dev); + struct dax_region *dax_region = dev_dax->region; struct dax_device *dax_dev = dev_dax->dax_dev; - struct inode *inode = dax_inode(dax_dev); - struct cdev *cdev = inode->i_cdev; - dev_dbg(dev, "trace\n"); + dax_region_put(dax_region); + put_dax(dax_dev); + kfree(dev_dax); +} + +static void unregister_dev_dax(void *dev) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + + dev_dbg(dev, "%s\n", __func__); kill_dev_dax(dev_dax); - cdev_device_del(cdev, dev); + device_del(dev); put_device(dev); } -EXPORT_SYMBOL_GPL(unregister_dev_dax); + +struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id) +{ + struct device *parent = dax_region->dev; + struct dax_device *dax_dev; + struct dev_dax *dev_dax; + struct inode *inode; + struct device *dev; + int rc = -ENOMEM; + + if (id < 0) + return ERR_PTR(-EINVAL); + + dev_dax = kzalloc(sizeof(*dev_dax), GFP_KERNEL); + if (!dev_dax) + return ERR_PTR(-ENOMEM); + + /* + * No 'host' or dax_operations since there is no access to this + * device outside of mmap of the resulting character device. + */ + dax_dev = alloc_dax(dev_dax, NULL, NULL); + if (!dax_dev) + goto err; + + /* a device_dax instance is dead while the driver is not attached */ + kill_dax(dax_dev); + + /* from here on we're committed to teardown via dax_dev_release() */ + dev = &dev_dax->dev; + device_initialize(dev); + + dev_dax->dax_dev = dax_dev; + dev_dax->region = dax_region; + kref_get(&dax_region->kref); + + inode = dax_inode(dax_dev); + dev->devt = inode->i_rdev; + dev->bus = &dax_bus_type; + dev->parent = parent; + dev->groups = dax_attribute_groups; + dev->release = dev_dax_release; + dev_set_name(dev, "dax%d.%d", dax_region->id, id); + + rc = device_add(dev); + if (rc) { + kill_dev_dax(dev_dax); + put_device(dev); + return ERR_PTR(rc); + } + + rc = devm_add_action_or_reset(dax_region->dev, unregister_dev_dax, dev); + if (rc) + return ERR_PTR(rc); + + return dev_dax; + + err: + kfree(dev_dax); + + return ERR_PTR(rc); +} +EXPORT_SYMBOL_GPL(devm_create_dev_dax); + +int __dax_driver_register(struct device_driver *drv, + struct module *module, const char *mod_name) +{ + drv->owner = module; + drv->name = mod_name; + drv->mod_name = mod_name; + drv->bus = &dax_bus_type; + return driver_register(drv); +} +EXPORT_SYMBOL_GPL(__dax_driver_register); + +int __init dax_bus_init(void) +{ + return bus_register(&dax_bus_type); +} + +void __exit dax_bus_exit(void) +{ + bus_unregister(&dax_bus_type); +} diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h index 840865aa69e8..ea509504df3a 100644 --- a/drivers/dax/bus.h +++ b/drivers/dax/bus.h @@ -11,5 +11,21 @@ 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); +int __dax_driver_register(struct device_driver *drv, + struct module *module, const char *mod_name); +#define dax_driver_register(driver) \ + __dax_driver_register(driver, THIS_MODULE, KBUILD_MODNAME) void kill_dev_dax(struct dev_dax *dev_dax); + +/* + * 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 + * outside of drivers/dax/ + */ +void run_dax(struct dax_device *dax_dev); + +#define MODULE_ALIAS_DAX_DEVICE(type) \ + MODULE_ALIAS("dax:t" __stringify(type) "*") +#define DAX_DEVICE_MODALIAS_FMT "dax:t%d" + #endif /* __DAX_BUS_H__ */ diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index 620c3f4eefe7..c3a121700837 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -20,10 +20,8 @@ struct dax_device; struct dax_device *inode_dax(struct inode *inode); struct inode *dax_inode(struct dax_device *dax_dev); - -/* temporary until devm_create_dax_dev moves to bus.c */ -extern const struct attribute_group *dax_attribute_groups[]; -void unregister_dev_dax(void *dev); +int dax_bus_init(void); +void dax_bus_exit(void); /** * struct dax_region - mapping infrastructure for dax devices diff --git a/drivers/dax/device.c b/drivers/dax/device.c index 1fc375783e0b..f55829404a24 100644 --- a/drivers/dax/device.c +++ b/drivers/dax/device.c @@ -13,8 +13,6 @@ #include "dax-private.h" #include "bus.h" -static struct class *dax_class; - static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma, const char *func) { @@ -404,93 +402,64 @@ static const struct file_operations dax_fops = { .mmap_supported_flags = MAP_SYNC, }; -static void dev_dax_release(struct device *dev) +static void dev_dax_cdev_del(void *cdev) { - struct dev_dax *dev_dax = to_dev_dax(dev); - struct dax_region *dax_region = dev_dax->region; - struct dax_device *dax_dev = dev_dax->dax_dev; + cdev_del(cdev); +} - dax_region_put(dax_region); - put_dax(dax_dev); - kfree(dev_dax); +static void dev_dax_kill(void *dev_dax) +{ + kill_dev_dax(dev_dax); } -struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id) +static int dev_dax_probe(struct device *dev) { - struct device *parent = dax_region->dev; - struct dax_device *dax_dev; - struct dev_dax *dev_dax; + struct dev_dax *dev_dax = to_dev_dax(dev); + struct dax_device *dax_dev = dev_dax->dax_dev; struct inode *inode; - struct device *dev; struct cdev *cdev; int rc; - dev_dax = kzalloc(sizeof(*dev_dax), GFP_KERNEL); - if (!dev_dax) - return ERR_PTR(-ENOMEM); - - /* - * No 'host' or dax_operations since there is no access to this - * device outside of mmap of the resulting character device. - */ - dax_dev = alloc_dax(dev_dax, NULL, NULL); - if (!dax_dev) { - rc = -ENOMEM; - goto err; - } - - /* from here on we're committed to teardown via dax_dev_release() */ - dev = &dev_dax->dev; - device_initialize(dev); - inode = dax_inode(dax_dev); cdev = inode->i_cdev; cdev_init(cdev, &dax_fops); - cdev->owner = parent->driver->owner; - - dev_dax->dax_dev = dax_dev; - dev_dax->region = dax_region; - kref_get(&dax_region->kref); - - dev->devt = inode->i_rdev; - dev->class = dax_class; - dev->parent = parent; - dev->groups = dax_attribute_groups; - dev->release = dev_dax_release; - dev_set_name(dev, "dax%d.%d", dax_region->id, id); - - rc = cdev_device_add(cdev, dev); - if (rc) { - kill_dev_dax(dev_dax); - put_device(dev); - return ERR_PTR(rc); - } - - rc = devm_add_action_or_reset(dax_region->dev, unregister_dev_dax, dev); + cdev->owner = dev->driver->owner; + cdev_set_parent(cdev, &dev->kobj); + rc = cdev_add(cdev, dev->devt, 1); if (rc) - return ERR_PTR(rc); + return rc; - return dev_dax; + rc = devm_add_action_or_reset(dev, dev_dax_cdev_del, cdev); + if (rc) + return rc; - err: - kfree(dev_dax); + run_dax(dax_dev); + return devm_add_action_or_reset(dev, dev_dax_kill, dev_dax); +} - return ERR_PTR(rc); +static int dev_dax_remove(struct device *dev) +{ + /* all probe actions are unwound by devm */ + return 0; } -EXPORT_SYMBOL_GPL(devm_create_dev_dax); + +static struct device_driver device_dax_driver = { + .probe = dev_dax_probe, + .remove = dev_dax_remove, +}; static int __init dax_init(void) { - dax_class = class_create(THIS_MODULE, "dax"); - return PTR_ERR_OR_ZERO(dax_class); + return dax_driver_register(&device_dax_driver); } static void __exit dax_exit(void) { - class_destroy(dax_class); + driver_unregister(&device_dax_driver); } MODULE_AUTHOR("Intel Corporation"); MODULE_LICENSE("GPL v2"); -subsys_initcall(dax_init); +module_init(dax_init); module_exit(dax_exit); +MODULE_ALIAS_DAX_DEVICE(0); diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 0ecc1a2cf1cc..ccb22d8db3a2 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -366,11 +366,15 @@ void kill_dax(struct dax_device *dax_dev) spin_lock(&dax_host_lock); hlist_del_init(&dax_dev->list); spin_unlock(&dax_host_lock); - - dax_dev->private = NULL; } EXPORT_SYMBOL_GPL(kill_dax); +void run_dax(struct dax_device *dax_dev) +{ + set_bit(DAXDEV_ALIVE, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(run_dax); + static struct inode *dax_alloc_inode(struct super_block *sb) { struct dax_device *dax_dev; @@ -585,6 +589,8 @@ EXPORT_SYMBOL_GPL(dax_inode); void *dax_get_private(struct dax_device *dax_dev) { + if (!test_bit(DAXDEV_ALIVE, &dax_dev->flags)) + return NULL; return dax_dev->private; } EXPORT_SYMBOL_GPL(dax_get_private); @@ -598,7 +604,7 @@ static void init_once(void *_dax_dev) inode_init_once(inode); } -static int __dax_fs_init(void) +static int dax_fs_init(void) { int rc; @@ -630,35 +636,45 @@ static int __dax_fs_init(void) return rc; } -static void __dax_fs_exit(void) +static void dax_fs_exit(void) { kern_unmount(dax_mnt); unregister_filesystem(&dax_fs_type); kmem_cache_destroy(dax_cache); } -static int __init dax_fs_init(void) +static int __init dax_core_init(void) { int rc; - rc = __dax_fs_init(); + rc = dax_fs_init(); if (rc) return rc; rc = alloc_chrdev_region(&dax_devt, 0, MINORMASK+1, "dax"); if (rc) - __dax_fs_exit(); - return rc; + goto err_chrdev; + + rc = dax_bus_init(); + if (rc) + goto err_bus; + return 0; + +err_bus: + unregister_chrdev_region(dax_devt, MINORMASK+1); +err_chrdev: + dax_fs_exit(); + return 0; } -static void __exit dax_fs_exit(void) +static void __exit dax_core_exit(void) { unregister_chrdev_region(dax_devt, MINORMASK+1); ida_destroy(&dax_minor_ida); - __dax_fs_exit(); + dax_fs_exit(); } MODULE_AUTHOR("Intel Corporation"); MODULE_LICENSE("GPL v2"); -subsys_initcall(dax_fs_init); -module_exit(dax_fs_exit); +subsys_initcall(dax_core_init); +module_exit(dax_core_exit); -- cgit v1.2.3 From 89ec9f2cfa36cc5fca2fb445ed221bb9add7b536 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 29 Oct 2018 15:52:42 -0700 Subject: device-dax: Move resource pinning+mapping into the common driver Move the responsibility of calling devm_request_resource() and devm_memremap_pages() into the common device-dax driver. This is another preparatory step to allowing an alternate personality driver for a device-dax range. Signed-off-by: Dan Williams --- drivers/dax/bus.c | 6 +++- drivers/dax/bus.h | 3 +- drivers/dax/dax-private.h | 9 ++++- drivers/dax/device.c | 61 ++++++++++++++++++++++++++++++++ drivers/dax/pmem.c | 90 ++++++++--------------------------------------- 5 files changed, 90 insertions(+), 79 deletions(-) (limited to 'drivers/dax') diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 0cff32102c4c..69aae2cbd45f 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright(c) 2017-2018 Intel Corporation. All rights reserved. */ +#include #include #include #include @@ -206,7 +207,8 @@ 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_dax *devm_create_dev_dax(struct dax_region *dax_region, int id, + struct dev_pagemap *pgmap) { struct device *parent = dax_region->dev; struct dax_device *dax_dev; @@ -222,6 +224,8 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id) if (!dev_dax) return ERR_PTR(-ENOMEM); + memcpy(&dev_dax->pgmap, pgmap, sizeof(*pgmap)); + /* * No 'host' or dax_operations since there is no access to this * device outside of mmap of the resulting character device. diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h index ea509504df3a..e08e0c394983 100644 --- a/drivers/dax/bus.h +++ b/drivers/dax/bus.h @@ -10,7 +10,8 @@ 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_dax *devm_create_dev_dax(struct dax_region *dax_region, int id, + struct dev_pagemap *pgmap); int __dax_driver_register(struct device_driver *drv, struct module *module, const char *mod_name); #define dax_driver_register(driver) \ diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index c3a121700837..a82ce48f5884 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -42,15 +42,22 @@ struct dax_region { }; /** - * struct dev_dax - instance data for a subdivision of a dax region + * struct dev_dax - instance data for a subdivision of a dax region, and + * data while the device is activated in the driver. * @region - parent region * @dax_dev - core dax functionality * @dev - device core + * @pgmap - pgmap for memmap setup / lifetime (driver owned) + * @ref: pgmap reference count (driver owned) + * @cmp: @ref final put completion (driver owned) */ struct dev_dax { struct dax_region *region; struct dax_device *dax_dev; struct device dev; + struct dev_pagemap pgmap; + struct percpu_ref ref; + struct completion cmp; }; static inline struct dev_dax *to_dev_dax(struct device *dev) diff --git a/drivers/dax/device.c b/drivers/dax/device.c index f55829404a24..6ad964d7b077 100644 --- a/drivers/dax/device.c +++ b/drivers/dax/device.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright(c) 2016-2018 Intel Corporation. All rights reserved. */ +#include #include #include #include @@ -13,6 +14,38 @@ #include "dax-private.h" #include "bus.h" +static struct dev_dax *ref_to_dev_dax(struct percpu_ref *ref) +{ + return container_of(ref, struct dev_dax, ref); +} + +static void dev_dax_percpu_release(struct percpu_ref *ref) +{ + struct dev_dax *dev_dax = ref_to_dev_dax(ref); + + dev_dbg(&dev_dax->dev, "%s\n", __func__); + complete(&dev_dax->cmp); +} + +static void dev_dax_percpu_exit(void *data) +{ + struct percpu_ref *ref = data; + struct dev_dax *dev_dax = ref_to_dev_dax(ref); + + dev_dbg(&dev_dax->dev, "%s\n", __func__); + wait_for_completion(&dev_dax->cmp); + percpu_ref_exit(ref); +} + +static void dev_dax_percpu_kill(struct percpu_ref *data) +{ + struct percpu_ref *ref = data; + struct dev_dax *dev_dax = ref_to_dev_dax(ref); + + dev_dbg(&dev_dax->dev, "%s\n", __func__); + percpu_ref_kill(ref); +} + static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma, const char *func) { @@ -416,10 +449,38 @@ static 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; + struct resource *res = &dev_dax->region->res; struct inode *inode; struct cdev *cdev; + void *addr; int rc; + /* 1:1 map region resource range to device-dax instance range */ + if (!devm_request_mem_region(dev, res->start, resource_size(res), + dev_name(dev))) { + dev_warn(dev, "could not reserve region %pR\n", res); + return -EBUSY; + } + + init_completion(&dev_dax->cmp); + rc = percpu_ref_init(&dev_dax->ref, dev_dax_percpu_release, 0, + GFP_KERNEL); + if (rc) + return rc; + + rc = devm_add_action_or_reset(dev, dev_dax_percpu_exit, &dev_dax->ref); + if (rc) + return rc; + + dev_dax->pgmap.ref = &dev_dax->ref; + dev_dax->pgmap.kill = dev_dax_percpu_kill; + addr = devm_memremap_pages(dev, &dev_dax->pgmap); + if (IS_ERR(addr)) { + devm_remove_action(dev, dev_dax_percpu_exit, &dev_dax->ref); + percpu_ref_exit(&dev_dax->ref); + return PTR_ERR(addr); + } + inode = dax_inode(dax_dev); cdev = inode->i_cdev; cdev_init(cdev, &dax_fops); diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c index e1b50d8fd1f8..d3cefa7868ac 100644 --- a/drivers/dax/pmem.c +++ b/drivers/dax/pmem.c @@ -18,54 +18,16 @@ #include "../nvdimm/nd.h" #include "bus.h" -struct dax_pmem { - struct device *dev; - struct percpu_ref ref; - struct dev_pagemap pgmap; - struct completion cmp; -}; - -static 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, "trace\n"); - 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, "trace\n"); - wait_for_completion(&dax_pmem->cmp); - percpu_ref_exit(ref); -} - -static void dax_pmem_percpu_kill(struct percpu_ref *ref) -{ - struct dax_pmem *dax_pmem = to_dax_pmem(ref); - - dev_dbg(dax_pmem->dev, "trace\n"); - percpu_ref_kill(ref); -} - static int dax_pmem_probe(struct device *dev) { - void *addr; struct resource res; int rc, id, region_id; + resource_size_t offset; struct nd_pfn_sb *pfn_sb; struct dev_dax *dev_dax; - struct dax_pmem *dax_pmem; struct nd_namespace_io *nsio; struct dax_region *dax_region; + struct dev_pagemap pgmap = { 0 }; struct nd_namespace_common *ndns; struct nd_dax *nd_dax = to_nd_dax(dev); struct nd_pfn *nd_pfn = &nd_dax->nd_pfn; @@ -75,61 +37,37 @@ static int dax_pmem_probe(struct device *dev) return PTR_ERR(ndns); nsio = to_nd_namespace_io(&ndns->dev); - dax_pmem = devm_kzalloc(dev, sizeof(*dax_pmem), GFP_KERNEL); - if (!dax_pmem) - return -ENOMEM; - /* parse the 'pfn' info block via ->rw_bytes */ rc = devm_nsio_enable(dev, nsio); if (rc) return rc; - rc = nvdimm_setup_pfn(nd_pfn, &dax_pmem->pgmap); + rc = nvdimm_setup_pfn(nd_pfn, &pgmap); if (rc) return rc; devm_nsio_disable(dev, nsio); - pfn_sb = nd_pfn->pfn_sb; - - if (!devm_request_mem_region(dev, nsio->res.start, - resource_size(&nsio->res), + /* reserve the metadata area, device-dax will reserve the data */ + pfn_sb = nd_pfn->pfn_sb; + offset = le64_to_cpu(pfn_sb->dataoff); + if (!devm_request_mem_region(dev, nsio->res.start, offset, dev_name(&ndns->dev))) { - dev_warn(dev, "could not reserve region %pR\n", &nsio->res); - return -EBUSY; - } - - 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) { - percpu_ref_exit(&dax_pmem->ref); - return rc; - } - - dax_pmem->pgmap.ref = &dax_pmem->ref; - dax_pmem->pgmap.kill = dax_pmem_percpu_kill; - addr = devm_memremap_pages(dev, &dax_pmem->pgmap); - if (IS_ERR(addr)) - return PTR_ERR(addr); - - /* adjust the dax_region resource to the start of data */ - memcpy(&res, &dax_pmem->pgmap.res, sizeof(res)); - res.start += le64_to_cpu(pfn_sb->dataoff); + dev_warn(dev, "could not reserve metadata\n"); + return -EBUSY; + } rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", ®ion_id, &id); if (rc != 2) return -EINVAL; + /* adjust the dax_region resource to the start of data */ + memcpy(&res, &pgmap.res, sizeof(res)); + res.start += offset; dax_region = alloc_dax_region(dev, region_id, &res, le32_to_cpu(pfn_sb->align), PFN_DEV|PFN_MAP); if (!dax_region) return -ENOMEM; - dev_dax = devm_create_dev_dax(dax_region, id); + dev_dax = devm_create_dev_dax(dax_region, id, &pgmap); /* child dev_dax instances now own the lifetime of the dax_region */ dax_region_put(dax_region); -- cgit v1.2.3 From d200781ef237a354d918ceff5cee350d88a93d42 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 7 Nov 2018 15:31:23 -0800 Subject: device-dax: Add support for a dax override driver Introduce the 'new_id' concept for enabling a custom device-driver attach policy for dax-bus drivers. The intended use is to have a mechanism for hot-plugging device-dax ranges into the page allocator on-demand. With this in place the default policy of using device-dax for performance differentiated memory can be overridden by user-space policy that can arrange for the memory range to be managed as 'System RAM' with user-defined NUMA and other performance attributes. Signed-off-by: Dan Williams --- drivers/dax/bus.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++++-- drivers/dax/bus.h | 10 +++- drivers/dax/device.c | 11 ++-- 3 files changed, 156 insertions(+), 10 deletions(-) (limited to 'drivers/dax') diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 69aae2cbd45f..17af6fbc3be5 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -2,11 +2,21 @@ /* Copyright(c) 2017-2018 Intel Corporation. All rights reserved. */ #include #include +#include +#include #include #include #include "dax-private.h" #include "bus.h" +static DEFINE_MUTEX(dax_bus_lock); + +#define DAX_NAME_LEN 30 +struct dax_id { + struct list_head list; + char dev_name[DAX_NAME_LEN]; +}; + static int dax_bus_uevent(struct device *dev, struct kobj_uevent_env *env) { /* @@ -16,22 +26,115 @@ static int dax_bus_uevent(struct device *dev, struct kobj_uevent_env *env) return add_uevent_var(env, "MODALIAS=" DAX_DEVICE_MODALIAS_FMT, 0); } +static struct dax_device_driver *to_dax_drv(struct device_driver *drv) +{ + return container_of(drv, struct dax_device_driver, drv); +} + +static struct dax_id *__dax_match_id(struct dax_device_driver *dax_drv, + const char *dev_name) +{ + struct dax_id *dax_id; + + lockdep_assert_held(&dax_bus_lock); + + list_for_each_entry(dax_id, &dax_drv->ids, list) + if (sysfs_streq(dax_id->dev_name, dev_name)) + return dax_id; + return NULL; +} + +static int dax_match_id(struct dax_device_driver *dax_drv, struct device *dev) +{ + int match; + + mutex_lock(&dax_bus_lock); + match = !!__dax_match_id(dax_drv, dev_name(dev)); + mutex_unlock(&dax_bus_lock); + + return match; +} + +static ssize_t do_id_store(struct device_driver *drv, const char *buf, + size_t count, bool add) +{ + struct dax_device_driver *dax_drv = to_dax_drv(drv); + unsigned int region_id, id; + char devname[DAX_NAME_LEN]; + struct dax_id *dax_id; + ssize_t rc = count; + int fields; + + fields = sscanf(buf, "dax%d.%d", ®ion_id, &id); + if (fields != 2) + return -EINVAL; + sprintf(devname, "dax%d.%d", region_id, id); + if (!sysfs_streq(buf, devname)) + return -EINVAL; + + mutex_lock(&dax_bus_lock); + dax_id = __dax_match_id(dax_drv, buf); + if (!dax_id) { + if (add) { + dax_id = kzalloc(sizeof(*dax_id), GFP_KERNEL); + if (dax_id) { + strncpy(dax_id->dev_name, buf, DAX_NAME_LEN); + list_add(&dax_id->list, &dax_drv->ids); + } else + rc = -ENOMEM; + } else + /* nothing to remove */; + } else if (!add) { + list_del(&dax_id->list); + kfree(dax_id); + } else + /* dax_id already added */; + mutex_unlock(&dax_bus_lock); + return rc; +} + +static ssize_t new_id_store(struct device_driver *drv, const char *buf, + size_t count) +{ + return do_id_store(drv, buf, count, true); +} +static DRIVER_ATTR_WO(new_id); + +static ssize_t remove_id_store(struct device_driver *drv, const char *buf, + size_t count) +{ + return do_id_store(drv, buf, count, false); +} +static DRIVER_ATTR_WO(remove_id); + +static struct attribute *dax_drv_attrs[] = { + &driver_attr_new_id.attr, + &driver_attr_remove_id.attr, + NULL, +}; +ATTRIBUTE_GROUPS(dax_drv); + static int dax_bus_match(struct device *dev, struct device_driver *drv); static struct bus_type dax_bus_type = { .name = "dax", .uevent = dax_bus_uevent, .match = dax_bus_match, + .drv_groups = dax_drv_groups, }; static int dax_bus_match(struct device *dev, struct device_driver *drv) { + struct dax_device_driver *dax_drv = to_dax_drv(drv); + /* - * The drivers that can register on the 'dax' bus are private to - * drivers/dax/ so any device and driver on the bus always - * match. + * All but the 'device-dax' driver, which has 'match_always' + * set, requires an exact id match. */ - return 1; + if (dax_drv->match_always) + return 1; + + return dax_match_id(dax_drv, dev); } /* @@ -273,17 +376,49 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id, } EXPORT_SYMBOL_GPL(devm_create_dev_dax); -int __dax_driver_register(struct device_driver *drv, +static int match_always_count; + +int __dax_driver_register(struct dax_device_driver *dax_drv, struct module *module, const char *mod_name) { + struct device_driver *drv = &dax_drv->drv; + int rc = 0; + + INIT_LIST_HEAD(&dax_drv->ids); drv->owner = module; drv->name = mod_name; drv->mod_name = mod_name; drv->bus = &dax_bus_type; + + /* there can only be one default driver */ + mutex_lock(&dax_bus_lock); + match_always_count += dax_drv->match_always; + if (match_always_count > 1) { + match_always_count--; + WARN_ON(1); + rc = -EINVAL; + } + mutex_unlock(&dax_bus_lock); + if (rc) + return rc; return driver_register(drv); } EXPORT_SYMBOL_GPL(__dax_driver_register); +void dax_driver_unregister(struct dax_device_driver *dax_drv) +{ + struct dax_id *dax_id, *_id; + + mutex_lock(&dax_bus_lock); + match_always_count -= dax_drv->match_always; + list_for_each_entry_safe(dax_id, _id, &dax_drv->ids, list) { + list_del(&dax_id->list); + kfree(dax_id); + } + mutex_unlock(&dax_bus_lock); +} +EXPORT_SYMBOL_GPL(dax_driver_unregister); + int __init dax_bus_init(void) { return bus_register(&dax_bus_type); diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h index e08e0c394983..395ab812367c 100644 --- a/drivers/dax/bus.h +++ b/drivers/dax/bus.h @@ -12,10 +12,18 @@ 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); -int __dax_driver_register(struct device_driver *drv, + +struct dax_device_driver { + struct device_driver drv; + struct list_head ids; + int match_always; +}; + +int __dax_driver_register(struct dax_device_driver *dax_drv, struct module *module, const char *mod_name); #define dax_driver_register(driver) \ __dax_driver_register(driver, THIS_MODULE, KBUILD_MODNAME) +void dax_driver_unregister(struct dax_device_driver *dax_drv); void kill_dev_dax(struct dev_dax *dev_dax); /* diff --git a/drivers/dax/device.c b/drivers/dax/device.c index 6ad964d7b077..ad3120395f7a 100644 --- a/drivers/dax/device.c +++ b/drivers/dax/device.c @@ -504,9 +504,12 @@ static int dev_dax_remove(struct device *dev) return 0; } -static struct device_driver device_dax_driver = { - .probe = dev_dax_probe, - .remove = dev_dax_remove, +static struct dax_device_driver device_dax_driver = { + .drv = { + .probe = dev_dax_probe, + .remove = dev_dax_remove, + }, + .match_always = 1, }; static int __init dax_init(void) @@ -516,7 +519,7 @@ static int __init dax_init(void) static void __exit dax_exit(void) { - driver_unregister(&device_dax_driver); + dax_driver_unregister(&device_dax_driver); } MODULE_AUTHOR("Intel Corporation"); -- cgit v1.2.3 From 730926c3b0998943654019f00296cf8e3b02277e Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sun, 16 Jul 2017 13:51:53 -0700 Subject: 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 --- drivers/dax/Kconfig | 12 ++++++- drivers/dax/Makefile | 4 +-- drivers/dax/bus.c | 29 ++++++++++++--- drivers/dax/bus.h | 26 ++++++++++++-- drivers/dax/device.c | 9 +++-- drivers/dax/pmem.c | 90 ----------------------------------------------- drivers/dax/pmem/Makefile | 7 ++++ drivers/dax/pmem/compat.c | 73 ++++++++++++++++++++++++++++++++++++++ drivers/dax/pmem/core.c | 69 ++++++++++++++++++++++++++++++++++++ drivers/dax/pmem/pmem.c | 40 +++++++++++++++++++++ 10 files changed, 256 insertions(+), 103 deletions(-) delete mode 100644 drivers/dax/pmem.c create mode 100644 drivers/dax/pmem/Makefile create mode 100644 drivers/dax/pmem/compat.c create mode 100644 drivers/dax/pmem/core.c create mode 100644 drivers/dax/pmem/pmem.c (limited to 'drivers/dax') diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig index e0700bf4893a..6fc96f03920e 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 658e6b9b1d74..233bbffccbe6 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 17af6fbc3be5..568168500217 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 395ab812367c..ce977552ffb5 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 ad3120395f7a..e428468ab661 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.c b/drivers/dax/pmem.c deleted file mode 100644 index d3cefa7868ac..000000000000 --- a/drivers/dax/pmem.c +++ /dev/null @@ -1,90 +0,0 @@ -/* - * 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 "bus.h" - -static int dax_pmem_probe(struct device *dev) -{ - struct resource res; - int rc, id, region_id; - resource_size_t offset; - struct nd_pfn_sb *pfn_sb; - struct dev_dax *dev_dax; - struct nd_namespace_io *nsio; - struct dax_region *dax_region; - struct dev_pagemap pgmap = { 0 }; - struct nd_namespace_common *ndns; - struct nd_dax *nd_dax = to_nd_dax(dev); - struct nd_pfn *nd_pfn = &nd_dax->nd_pfn; - - 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 */ - rc = devm_nsio_enable(dev, nsio); - if (rc) - return rc; - rc = nvdimm_setup_pfn(nd_pfn, &pgmap); - if (rc) - return rc; - devm_nsio_disable(dev, nsio); - - /* reserve the metadata area, device-dax will reserve the data */ - pfn_sb = nd_pfn->pfn_sb; - offset = le64_to_cpu(pfn_sb->dataoff); - if (!devm_request_mem_region(dev, nsio->res.start, offset, - dev_name(&ndns->dev))) { - dev_warn(dev, "could not reserve metadata\n"); - return -EBUSY; - } - - rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", ®ion_id, &id); - if (rc != 2) - return -EINVAL; - - /* adjust the dax_region resource to the start of data */ - memcpy(&res, &pgmap.res, sizeof(res)); - res.start += offset; - dax_region = alloc_dax_region(dev, region_id, &res, - le32_to_cpu(pfn_sb->align), PFN_DEV|PFN_MAP); - if (!dax_region) - return -ENOMEM; - - dev_dax = devm_create_dev_dax(dax_region, id, &pgmap); - - /* child dev_dax instances now own the lifetime of the dax_region */ - dax_region_put(dax_region); - - return PTR_ERR_OR_ZERO(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); - -MODULE_LICENSE("GPL v2"); -MODULE_AUTHOR("Intel Corporation"); -MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM); diff --git a/drivers/dax/pmem/Makefile b/drivers/dax/pmem/Makefile new file mode 100644 index 000000000000..e2e79bd3fdcf --- /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 000000000000..d7b15e6f30c5 --- /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/core.c b/drivers/dax/pmem/core.c new file mode 100644 index 000000000000..bdcff1b14e95 --- /dev/null +++ b/drivers/dax/pmem/core.c @@ -0,0 +1,69 @@ +// 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" + +struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys) +{ + struct resource res; + int rc, id, region_id; + resource_size_t offset; + struct nd_pfn_sb *pfn_sb; + struct dev_dax *dev_dax; + struct nd_namespace_io *nsio; + struct dax_region *dax_region; + struct dev_pagemap pgmap = { 0 }; + struct nd_namespace_common *ndns; + struct nd_dax *nd_dax = to_nd_dax(dev); + struct nd_pfn *nd_pfn = &nd_dax->nd_pfn; + + ndns = nvdimm_namespace_common_probe(dev); + if (IS_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 ERR_PTR(rc); + rc = nvdimm_setup_pfn(nd_pfn, &pgmap); + if (rc) + return ERR_PTR(rc); + devm_nsio_disable(dev, nsio); + + /* reserve the metadata area, device-dax will reserve the data */ + pfn_sb = nd_pfn->pfn_sb; + offset = le64_to_cpu(pfn_sb->dataoff); + if (!devm_request_mem_region(dev, nsio->res.start, offset, + dev_name(&ndns->dev))) { + dev_warn(dev, "could not reserve metadata\n"); + return ERR_PTR(-EBUSY); + } + + rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", ®ion_id, &id); + if (rc != 2) + return ERR_PTR(-EINVAL); + + /* adjust the dax_region resource to the start of data */ + memcpy(&res, &pgmap.res, sizeof(res)); + res.start += offset; + dax_region = alloc_dax_region(dev, region_id, &res, + le32_to_cpu(pfn_sb->align), PFN_DEV|PFN_MAP); + if (!dax_region) + return ERR_PTR(-ENOMEM); + + 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 dev_dax; +} +EXPORT_SYMBOL_GPL(__dax_pmem_probe); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Intel Corporation"); diff --git a/drivers/dax/pmem/pmem.c b/drivers/dax/pmem/pmem.c new file mode 100644 index 000000000000..0ae4238a0ef8 --- /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 -- cgit v1.2.3 From 8fc5c73554db0ac18c0c6ac5b2099ab917f83bdf Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 9 Nov 2018 12:43:07 -0800 Subject: acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Persistent memory, as described by the ACPI NFIT (NVDIMM Firmware Interface Table), is the first known instance of a memory range described by a unique "target" proximity domain. Where "initiator" and "target" proximity domains is an approach that the ACPI HMAT (Heterogeneous Memory Attributes Table) uses to described the unique performance properties of a memory range relative to a given initiator (e.g. CPU or DMA device). Currently the numa-node for a /dev/pmemX block-device or /dev/daxX.Y char-device follows the traditional notion of 'numa-node' where the attribute conveys the closest online numa-node. That numa-node attribute is useful for cpu-binding and memory-binding processes *near* the device. However, when the memory range backing a 'pmem', or 'dax' device is onlined (memory hot-add) the memory-only-numa-node representing that address needs to be differentiated from the set of online nodes. In other words, the numa-node association of the device depends on whether you can bind processes *near* the cpu-numa-node in the offline device-case, or bind process *on* the memory-range directly after the backing address range is onlined. Allow for the case that platform firmware describes persistent memory with a unique proximity domain, i.e. when it is distinct from the proximity of DRAM and CPUs that are on the same socket. Plumb the Linux numa-node translation of that proximity through the libnvdimm region device to namespaces that are in device-dax mode. With this in place the proposed kmem driver [1] can optionally discover a unique numa-node number for the address range as it transitions the memory from an offline state managed by a device-driver to an online memory range managed by the core-mm. [1]: https://lore.kernel.org/lkml/20181022201317.8558C1D8@viggo.jf.intel.com Reported-by: Fan Du Cc: Michael Ellerman Cc: "Oliver O'Halloran" Cc: Dave Hansen Cc: Jérôme Glisse Reviewed-by: Yang Shi Signed-off-by: Dan Williams --- drivers/dax/bus.c | 4 +++- drivers/dax/bus.h | 3 ++- drivers/dax/dax-private.h | 4 ++++ drivers/dax/pmem/core.c | 4 +++- 4 files changed, 12 insertions(+), 3 deletions(-) (limited to 'drivers/dax') diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 568168500217..c620ad52d7e5 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -214,7 +214,7 @@ static void dax_region_unregister(void *region) } struct dax_region *alloc_dax_region(struct device *parent, int region_id, - struct resource *res, unsigned int align, + struct resource *res, int target_node, unsigned int align, unsigned long pfn_flags) { struct dax_region *dax_region; @@ -244,6 +244,7 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id, dax_region->id = region_id; dax_region->align = align; dax_region->dev = parent; + dax_region->target_node = target_node; if (sysfs_create_groups(&parent->kobj, dax_region_attribute_groups)) { kfree(dax_region); return NULL; @@ -348,6 +349,7 @@ struct dev_dax *__devm_create_dev_dax(struct dax_region *dax_region, int id, dev_dax->dax_dev = dax_dev; dev_dax->region = dax_region; + dev_dax->target_node = dax_region->target_node; kref_get(&dax_region->kref); inode = dax_inode(dax_dev); diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h index ce977552ffb5..8619e3299943 100644 --- a/drivers/dax/bus.h +++ b/drivers/dax/bus.h @@ -10,7 +10,8 @@ struct dax_device; 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 resource *res, int target_node, unsigned int align, + unsigned long flags); enum dev_dax_subsys { DEV_DAX_BUS, diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index a82ce48f5884..a45612148ca0 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -26,6 +26,7 @@ void dax_bus_exit(void); /** * struct dax_region - mapping infrastructure for dax devices * @id: kernel-wide unique region for a memory range + * @target_node: effective numa node if this memory range is onlined * @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 @@ -34,6 +35,7 @@ void dax_bus_exit(void); */ struct dax_region { int id; + int target_node; struct kref kref; struct device *dev; unsigned int align; @@ -46,6 +48,7 @@ struct dax_region { * data while the device is activated in the driver. * @region - parent region * @dax_dev - core dax functionality + * @target_node: effective numa node if dev_dax memory range is onlined * @dev - device core * @pgmap - pgmap for memmap setup / lifetime (driver owned) * @ref: pgmap reference count (driver owned) @@ -54,6 +57,7 @@ struct dax_region { struct dev_dax { struct dax_region *region; struct dax_device *dax_dev; + int target_node; struct device dev; struct dev_pagemap pgmap; struct percpu_ref ref; diff --git a/drivers/dax/pmem/core.c b/drivers/dax/pmem/core.c index bdcff1b14e95..f71019ce0647 100644 --- a/drivers/dax/pmem/core.c +++ b/drivers/dax/pmem/core.c @@ -20,6 +20,7 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys) struct nd_namespace_common *ndns; struct nd_dax *nd_dax = to_nd_dax(dev); struct nd_pfn *nd_pfn = &nd_dax->nd_pfn; + struct nd_region *nd_region = to_nd_region(dev->parent); ndns = nvdimm_namespace_common_probe(dev); if (IS_ERR(ndns)) @@ -52,7 +53,8 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys) memcpy(&res, &pgmap.res, sizeof(res)); res.start += offset; dax_region = alloc_dax_region(dev, region_id, &res, - le32_to_cpu(pfn_sb->align), PFN_DEV|PFN_MAP); + nd_region->target_node, le32_to_cpu(pfn_sb->align), + PFN_DEV|PFN_MAP); if (!dax_region) return ERR_PTR(-ENOMEM); -- cgit v1.2.3 From 664525b2d84abca1074c9546654ae9689de8a818 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 24 Jan 2019 13:12:04 -0800 Subject: device-dax: Auto-bind device after successful new_id The typical 'new_id' attribute behavior is to immediately attach a device to its driver after a new device-id is added. Implement this behavior for the dax bus. Reported-by: Alexander Duyck Reported-by: Brice Goglin Cc: Dave Hansen Signed-off-by: Dan Williams --- drivers/dax/bus.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) (limited to 'drivers/dax') diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index c620ad52d7e5..a410154d75fb 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -57,8 +57,13 @@ static int dax_match_id(struct dax_device_driver *dax_drv, struct device *dev) return match; } +enum id_action { + ID_REMOVE, + ID_ADD, +}; + static ssize_t do_id_store(struct device_driver *drv, const char *buf, - size_t count, bool add) + size_t count, enum id_action action) { struct dax_device_driver *dax_drv = to_dax_drv(drv); unsigned int region_id, id; @@ -77,7 +82,7 @@ static ssize_t do_id_store(struct device_driver *drv, const char *buf, mutex_lock(&dax_bus_lock); dax_id = __dax_match_id(dax_drv, buf); if (!dax_id) { - if (add) { + if (action == ID_ADD) { dax_id = kzalloc(sizeof(*dax_id), GFP_KERNEL); if (dax_id) { strncpy(dax_id->dev_name, buf, DAX_NAME_LEN); @@ -86,26 +91,33 @@ static ssize_t do_id_store(struct device_driver *drv, const char *buf, rc = -ENOMEM; } else /* nothing to remove */; - } else if (!add) { + } else if (action == ID_REMOVE) { list_del(&dax_id->list); kfree(dax_id); } else /* dax_id already added */; mutex_unlock(&dax_bus_lock); - return rc; + + if (rc < 0) + return rc; + if (action == ID_ADD) + rc = driver_attach(drv); + if (rc) + return rc; + return count; } static ssize_t new_id_store(struct device_driver *drv, const char *buf, size_t count) { - return do_id_store(drv, buf, count, true); + return do_id_store(drv, buf, count, ID_ADD); } static DRIVER_ATTR_WO(new_id); static ssize_t remove_id_store(struct device_driver *drv, const char *buf, size_t count) { - return do_id_store(drv, buf, count, false); + return do_id_store(drv, buf, count, ID_REMOVE); } static DRIVER_ATTR_WO(remove_id); -- cgit v1.2.3 From 21c75763a3ae18679e5c4e2260aa9379b073566b Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 20 Feb 2019 11:39:36 -0800 Subject: device-dax: Add a 'target_node' attribute The target-node attribute is the Linux numa-node that a device-dax instance may create when it is online. Prior to being online the device's 'numa_node' property reflects the closest online cpu node which is the typical expectation of a device 'numa_node'. Once it is online it becomes its own distinct numa node, i.e. 'target_node'. Export the 'target_node' property to give userspace tooling the ability to predict the effective numa-node from a device-dax instance configured to provide 'System RAM' capacity. Cc: Vishal Verma Reported-by: Dave Hansen Signed-off-by: Dan Williams --- drivers/dax/bus.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'drivers/dax') diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index a410154d75fb..28c3324271ac 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -279,13 +279,41 @@ static ssize_t size_show(struct device *dev, } static DEVICE_ATTR_RO(size); +static int dev_dax_target_node(struct dev_dax *dev_dax) +{ + struct dax_region *dax_region = dev_dax->region; + + return dax_region->target_node; +} + +static ssize_t target_node_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_target_node(dev_dax)); +} +static DEVICE_ATTR_RO(target_node); + +static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct dev_dax *dev_dax = to_dev_dax(dev); + + if (a == &dev_attr_target_node.attr && dev_dax_target_node(dev_dax) < 0) + return 0; + return a->mode; +} + static struct attribute *dev_dax_attributes[] = { &dev_attr_size.attr, + &dev_attr_target_node.attr, NULL, }; static const struct attribute_group dev_dax_attribute_group = { .attrs = dev_dax_attributes, + .is_visible = dev_dax_visible, }; static const struct attribute_group *dax_attribute_groups[] = { -- cgit v1.2.3 From c347bd71dcdb2d0ac8b3a771486584dca8c8dd80 Mon Sep 17 00:00:00 2001 From: Vishal Verma Date: Fri, 22 Feb 2019 16:58:54 -0700 Subject: device-dax: Add a 'modalias' attribute to DAX 'bus' devices Add a 'modalias' attribute to devices under the DAX bus so that userspace is able to dynamically load modules as needed. Normally, udev can get the modalias from 'uevent', and that is correctly set up by the DAX bus. However other tooling such as 'libndctl' for interacting with drivers/nvdimm/, and 'libdaxctl' for drivers/dax/ can also use the modalias to dynamically load modules via libkmod lookups. The 'nd' bus set up by the libnvdimm subsystem exports a modalias attribute. Imitate this to export the same for the 'dax' bus. Cc: Dave Hansen Signed-off-by: Vishal Verma Signed-off-by: Dan Williams --- drivers/dax/bus.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/dax') diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 28c3324271ac..2109cfe80219 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -295,6 +295,17 @@ static ssize_t target_node_show(struct device *dev, } static DEVICE_ATTR_RO(target_node); +static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + /* + * We only ever expect to handle device-dax instances, i.e. the + * @type argument to MODULE_ALIAS_DAX_DEVICE() is always zero + */ + return sprintf(buf, DAX_DEVICE_MODALIAS_FMT "\n", 0); +} +static DEVICE_ATTR_RO(modalias); + static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n) { struct device *dev = container_of(kobj, struct device, kobj); @@ -306,6 +317,7 @@ 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_target_node.attr, NULL, -- cgit v1.2.3 From c221c0b0308fd01d9fb33a16f64d2fd95f8830a4 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Mon, 25 Feb 2019 10:57:40 -0800 Subject: device-dax: "Hotplug" persistent memory for use like normal RAM This is intended for use with NVDIMMs that are physically persistent (physically like flash) so that they can be used as a cost-effective RAM replacement. Intel Optane DC persistent memory is one implementation of this kind of NVDIMM. Currently, a persistent memory region is "owned" by a device driver, either the "Direct DAX" or "Filesystem DAX" drivers. These drivers allow applications to explicitly use persistent memory, generally by being modified to use special, new libraries. (DIMM-based persistent memory hardware/software is described in great detail here: Documentation/nvdimm/nvdimm.txt). However, this limits persistent memory use to applications which *have* been modified. To make it more broadly usable, this driver "hotplugs" memory into the kernel, to be managed and used just like normal RAM would be. To make this work, management software must remove the device from being controlled by the "Device DAX" infrastructure: echo dax0.0 > /sys/bus/dax/drivers/device_dax/unbind and then tell the new driver that it can bind to the device: echo dax0.0 > /sys/bus/dax/drivers/kmem/new_id After this, there will be a number of new memory sections visible in sysfs that can be onlined, or that may get onlined by existing udev-initiated memory hotplug rules. This rebinding procedure is currently a one-way trip. Once memory is bound to "kmem", it's there permanently and can not be unbound and assigned back to device_dax. The kmem driver will never bind to a dax device unless the device is *explicitly* bound to the driver. There are two reasons for this: One, since it is a one-way trip, it can not be undone if bound incorrectly. Two, the kmem driver destroys data on the device. Think of if you had good data on a pmem device. It would be catastrophic if you compile-in "kmem", but leave out the "device_dax" driver. kmem would take over the device and write volatile data all over your good data. This inherits any existing NUMA information for the newly-added memory from the persistent memory device that came from the firmware. On Intel platforms, the firmware has guarantees that require each socket's persistent memory to be in a separate memory-only NUMA node. That means that this patch is not expected to create NUMA nodes, but will simply hotplug memory into existing nodes. Because NUMA nodes are created, the existing NUMA APIs and tools are sufficient to create policies for applications or memory areas to have affinity for or an aversion to using this memory. There is currently some metadata at the beginning of pmem regions. The section-size memory hotplug restrictions, plus this small reserved area can cause the "loss" of a section or two of capacity. This should be fixable in follow-on patches. But, as a first step, losing 256MB of memory (worst case) out of hundreds of gigabytes is a good tradeoff vs. the required code to fix this up precisely. This calculation is also the reason we export memory_block_size_bytes(). Signed-off-by: Dave Hansen Reviewed-by: Dan Williams Reviewed-by: Keith Busch Cc: Dave Jiang Cc: Ross Zwisler Cc: Vishal Verma Cc: Tom Lendacky Cc: Andrew Morton Cc: Michal Hocko Cc: linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Huang Ying Cc: Fengguang Wu Cc: Borislav Petkov Cc: Bjorn Helgaas Cc: Yaowei Bai Cc: Takashi Iwai Cc: Jerome Glisse Reviewed-by: Vishal Verma Signed-off-by: Dan Williams --- drivers/dax/Kconfig | 16 ++++++++ drivers/dax/Makefile | 1 + drivers/dax/kmem.c | 108 +++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 125 insertions(+) create mode 100644 drivers/dax/kmem.c (limited to 'drivers/dax') diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig index 6fc96f03920e..5ef624fe3934 100644 --- a/drivers/dax/Kconfig +++ b/drivers/dax/Kconfig @@ -32,6 +32,22 @@ config DEV_DAX_PMEM Say M if unsure +config DEV_DAX_KMEM + tristate "KMEM DAX: volatile-use of persistent memory" + default DEV_DAX + 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. + + 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. + + Say N 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 233bbffccbe6..81f7d54dadfb 100644 --- a/drivers/dax/Makefile +++ b/drivers/dax/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_DAX) += dax.o obj-$(CONFIG_DEV_DAX) += device_dax.o +obj-$(CONFIG_DEV_DAX_KMEM) += kmem.o dax-y := super.o dax-y += bus.o diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c new file mode 100644 index 000000000000..a02318c6d28a --- /dev/null +++ b/drivers/dax/kmem.c @@ -0,0 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2016-2019 Intel Corporation. All rights reserved. */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "dax-private.h" +#include "bus.h" + +int dev_dax_kmem_probe(struct device *dev) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + struct resource *res = &dev_dax->region->res; + resource_size_t kmem_start; + resource_size_t kmem_size; + resource_size_t kmem_end; + struct resource *new_res; + int numa_node; + int rc; + + /* + * Ensure good NUMA information for the persistent memory. + * Without this check, there is a risk that slow memory + * could be mixed in a node with faster memory, causing + * unavoidable performance issues. + */ + numa_node = dev_dax->target_node; + if (numa_node < 0) { + dev_warn(dev, "rejecting DAX region %pR with invalid node: %d\n", + res, numa_node); + return -EINVAL; + } + + /* Hotplug starting at the beginning of the next block: */ + kmem_start = ALIGN(res->start, memory_block_size_bytes()); + + kmem_size = resource_size(res); + /* Adjust the size down to compensate for moving up kmem_start: */ + kmem_size -= kmem_start - res->start; + /* Align the size down to cover only complete blocks: */ + kmem_size &= ~(memory_block_size_bytes() - 1); + kmem_end = kmem_start + kmem_size; + + /* Region is permanently reserved. Hot-remove not yet implemented. */ + new_res = request_mem_region(kmem_start, kmem_size, dev_name(dev)); + if (!new_res) { + dev_warn(dev, "could not reserve region [%pa-%pa]\n", + &kmem_start, &kmem_end); + return -EBUSY; + } + + /* + * Set flags appropriate for System RAM. Leave ..._BUSY clear + * so that add_memory() can add a child resource. Do not + * inherit flags from the parent since it may set new flags + * unknown to us that will break add_memory() below. + */ + new_res->flags = IORESOURCE_SYSTEM_RAM; + new_res->name = dev_name(dev); + + rc = add_memory(numa_node, new_res->start, resource_size(new_res)); + if (rc) + return rc; + + return 0; +} + +static int dev_dax_kmem_remove(struct device *dev) +{ + /* + * Purposely leak the request_mem_region() for the device-dax + * range and return '0' to ->remove() attempts. The removal of + * the device from the driver always succeeds, but the region + * is permanently pinned as reserved by the unreleased + * request_mem_region(). + */ + return 0; +} + +static struct dax_device_driver device_dax_kmem_driver = { + .drv = { + .probe = dev_dax_kmem_probe, + .remove = dev_dax_kmem_remove, + }, +}; + +static int __init dax_kmem_init(void) +{ + return dax_driver_register(&device_dax_kmem_driver); +} + +static void __exit dax_kmem_exit(void) +{ + dax_driver_unregister(&device_dax_kmem_driver); +} + +MODULE_AUTHOR("Intel Corporation"); +MODULE_LICENSE("GPL v2"); +module_init(dax_kmem_init); +module_exit(dax_kmem_exit); +MODULE_ALIAS_DAX_DEVICE(0); -- cgit v1.2.3