![Linus Torvalds](/assets/img/avatar_default.png)
* A rework of the filesytem-dax implementation provides for detection of
unmap operations (truncate / hole punch) colliding with in-progress
device-DMA. A fix for these collisions remains a work-in-progress
pending resolution of truncate latency and starvation regressions.
* The of_pmem driver expands the users of libnvdimm outside of x86 and
ACPI to describe an implementation of persistent memory on PowerPC with
Open Firmware / Device tree.
* Address Range Scrub (ARS) handling is completely rewritten to account for
the fact that ARS may run for 100s of seconds and there is no platform
defined way to cancel it. ARS will now no longer block namespace
initialization.
* The NVDIMM Namespace Label implementation is updated to handle label
areas as small as 1K, down from 128K.
* Miscellaneous cleanups and updates to unit test infrastructure.
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Merge tag 'libnvdimm-for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm updates from Dan Williams:
"This cycle was was not something I ever want to repeat as there were
several late changes that have only now just settled.
Half of the branch up to commit d2c997c0f1
("fs, dax: use
page->mapping to warn...") have been in -next for several releases.
The of_pmem driver and the address range scrub rework were late
arrivals, and the dax work was scaled back at the last moment.
The of_pmem driver missed a previous merge window due to an oversight.
A sense of obligation to rectify that miss is why it is included for
4.17. It has acks from PowerPC folks. Stephen reported a build failure
that only occurs when merging it with your latest tree, for now I have
fixed that up by disabling modular builds of of_pmem. A test merge
with your tree has received a build success report from the 0day robot
over 156 configs.
An initial version of the ARS rework was submitted before the merge
window. It is self contained to libnvdimm, a net code reduction, and
passing all unit tests.
The filesystem-dax changes are based on the wait_var_event()
functionality from tip/sched/core. However, late review feedback
showed that those changes regressed truncate performance to a large
degree. The branch was rewound to drop the truncate behavior change
and now only includes preparation patches and cleanups (with full acks
and reviews). The finalization of this dax-dma-vs-trnucate work will
need to wait for 4.18.
Summary:
- A rework of the filesytem-dax implementation provides for detection
of unmap operations (truncate / hole punch) colliding with
in-progress device-DMA. A fix for these collisions remains a
work-in-progress pending resolution of truncate latency and
starvation regressions.
- The of_pmem driver expands the users of libnvdimm outside of x86
and ACPI to describe an implementation of persistent memory on
PowerPC with Open Firmware / Device tree.
- Address Range Scrub (ARS) handling is completely rewritten to
account for the fact that ARS may run for 100s of seconds and there
is no platform defined way to cancel it. ARS will now no longer
block namespace initialization.
- The NVDIMM Namespace Label implementation is updated to handle
label areas as small as 1K, down from 128K.
- Miscellaneous cleanups and updates to unit test infrastructure"
* tag 'libnvdimm-for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (39 commits)
libnvdimm, of_pmem: workaround OF_NUMA=n build error
nfit, address-range-scrub: add module option to skip initial ars
nfit, address-range-scrub: rework and simplify ARS state machine
nfit, address-range-scrub: determine one platform max_ars value
powerpc/powernv: Create platform devs for nvdimm buses
doc/devicetree: Persistent memory region bindings
libnvdimm: Add device-tree based driver
libnvdimm: Add of_node to region and bus descriptors
libnvdimm, region: quiet region probe
libnvdimm, namespace: use a safe lookup for dimm device name
libnvdimm, dimm: fix dpa reservation vs uninitialized label area
libnvdimm, testing: update the default smart ctrl_temperature
libnvdimm, testing: Add emulation for smart injection commands
nfit, address-range-scrub: introduce nfit_spa->ars_state
libnvdimm: add an api to cast a 'struct nd_region' to its 'struct device'
nfit, address-range-scrub: fix scrub in-progress reporting
dax, dm: allow device-mapper to operate without dax support
dax: introduce CONFIG_DAX_DRIVER
fs, dax: use page->mapping to warn if truncate collides with a busy page
ext2, dax: introduce ext2_dax_aops
...
694 lines
17 KiB
C
694 lines
17 KiB
C
/*
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* Copyright(c) 2016 - 2017 Intel Corporation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#include <linux/pagemap.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/pfn_t.h>
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#include <linux/cdev.h>
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#include <linux/slab.h>
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#include <linux/dax.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include "dax-private.h"
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#include "dax.h"
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static struct class *dax_class;
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/*
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* Rely on the fact that drvdata is set before the attributes are
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* registered, and that the attributes are unregistered before drvdata
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* is cleared to assume that drvdata is always valid.
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*/
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static ssize_t id_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct dax_region *dax_region = dev_get_drvdata(dev);
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return sprintf(buf, "%d\n", dax_region->id);
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}
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static DEVICE_ATTR_RO(id);
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static ssize_t region_size_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct dax_region *dax_region = dev_get_drvdata(dev);
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return sprintf(buf, "%llu\n", (unsigned long long)
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resource_size(&dax_region->res));
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}
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static struct device_attribute dev_attr_region_size = __ATTR(size, 0444,
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region_size_show, NULL);
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static ssize_t align_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct dax_region *dax_region = dev_get_drvdata(dev);
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return sprintf(buf, "%u\n", dax_region->align);
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}
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static DEVICE_ATTR_RO(align);
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static struct attribute *dax_region_attributes[] = {
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&dev_attr_region_size.attr,
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&dev_attr_align.attr,
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&dev_attr_id.attr,
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NULL,
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};
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static const struct attribute_group dax_region_attribute_group = {
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.name = "dax_region",
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.attrs = dax_region_attributes,
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};
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static const struct attribute_group *dax_region_attribute_groups[] = {
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&dax_region_attribute_group,
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NULL,
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};
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static void dax_region_free(struct kref *kref)
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{
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struct dax_region *dax_region;
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dax_region = container_of(kref, struct dax_region, kref);
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kfree(dax_region);
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}
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void dax_region_put(struct dax_region *dax_region)
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{
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kref_put(&dax_region->kref, dax_region_free);
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}
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EXPORT_SYMBOL_GPL(dax_region_put);
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static void dax_region_unregister(void *region)
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{
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struct dax_region *dax_region = region;
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sysfs_remove_groups(&dax_region->dev->kobj,
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dax_region_attribute_groups);
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dax_region_put(dax_region);
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}
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struct dax_region *alloc_dax_region(struct device *parent, int region_id,
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struct resource *res, unsigned int align, void *addr,
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unsigned long pfn_flags)
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{
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struct dax_region *dax_region;
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/*
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* The DAX core assumes that it can store its private data in
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* parent->driver_data. This WARN is a reminder / safeguard for
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* developers of device-dax drivers.
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*/
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if (dev_get_drvdata(parent)) {
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dev_WARN(parent, "dax core failed to setup private data\n");
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return NULL;
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}
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if (!IS_ALIGNED(res->start, align)
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|| !IS_ALIGNED(resource_size(res), align))
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return NULL;
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dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL);
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if (!dax_region)
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return NULL;
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dev_set_drvdata(parent, dax_region);
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memcpy(&dax_region->res, res, sizeof(*res));
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dax_region->pfn_flags = pfn_flags;
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kref_init(&dax_region->kref);
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dax_region->id = region_id;
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ida_init(&dax_region->ida);
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dax_region->align = align;
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dax_region->dev = parent;
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dax_region->base = addr;
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if (sysfs_create_groups(&parent->kobj, dax_region_attribute_groups)) {
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kfree(dax_region);
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return NULL;
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}
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kref_get(&dax_region->kref);
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if (devm_add_action_or_reset(parent, dax_region_unregister, dax_region))
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return NULL;
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return dax_region;
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}
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EXPORT_SYMBOL_GPL(alloc_dax_region);
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static struct dev_dax *to_dev_dax(struct device *dev)
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{
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return container_of(dev, struct dev_dax, dev);
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}
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static ssize_t size_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct dev_dax *dev_dax = to_dev_dax(dev);
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unsigned long long size = 0;
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int i;
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for (i = 0; i < dev_dax->num_resources; i++)
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size += resource_size(&dev_dax->res[i]);
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return sprintf(buf, "%llu\n", size);
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}
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static DEVICE_ATTR_RO(size);
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static struct attribute *dev_dax_attributes[] = {
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&dev_attr_size.attr,
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NULL,
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};
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static const struct attribute_group dev_dax_attribute_group = {
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.attrs = dev_dax_attributes,
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};
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static const struct attribute_group *dax_attribute_groups[] = {
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&dev_dax_attribute_group,
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NULL,
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};
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static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
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const char *func)
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{
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struct dax_region *dax_region = dev_dax->region;
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struct device *dev = &dev_dax->dev;
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unsigned long mask;
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if (!dax_alive(dev_dax->dax_dev))
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return -ENXIO;
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/* prevent private mappings from being established */
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if ((vma->vm_flags & VM_MAYSHARE) != VM_MAYSHARE) {
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dev_info(dev, "%s: %s: fail, attempted private mapping\n",
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current->comm, func);
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return -EINVAL;
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}
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mask = dax_region->align - 1;
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if (vma->vm_start & mask || vma->vm_end & mask) {
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dev_info(dev, "%s: %s: fail, unaligned vma (%#lx - %#lx, %#lx)\n",
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current->comm, func, vma->vm_start, vma->vm_end,
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mask);
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return -EINVAL;
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}
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if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) == PFN_DEV
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&& (vma->vm_flags & VM_DONTCOPY) == 0) {
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dev_info(dev, "%s: %s: fail, dax range requires MADV_DONTFORK\n",
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current->comm, func);
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return -EINVAL;
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}
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if (!vma_is_dax(vma)) {
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dev_info(dev, "%s: %s: fail, vma is not DAX capable\n",
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current->comm, func);
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return -EINVAL;
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}
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return 0;
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}
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/* see "strong" declaration in tools/testing/nvdimm/dax-dev.c */
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__weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
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unsigned long size)
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{
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struct resource *res;
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/* gcc-4.6.3-nolibc for i386 complains that this is uninitialized */
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phys_addr_t uninitialized_var(phys);
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int i;
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for (i = 0; i < dev_dax->num_resources; i++) {
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res = &dev_dax->res[i];
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phys = pgoff * PAGE_SIZE + res->start;
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if (phys >= res->start && phys <= res->end)
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break;
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pgoff -= PHYS_PFN(resource_size(res));
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}
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if (i < dev_dax->num_resources) {
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res = &dev_dax->res[i];
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if (phys + size - 1 <= res->end)
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return phys;
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}
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return -1;
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}
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static int __dev_dax_pte_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
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{
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struct device *dev = &dev_dax->dev;
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struct dax_region *dax_region;
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int rc = VM_FAULT_SIGBUS;
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phys_addr_t phys;
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pfn_t pfn;
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unsigned int fault_size = PAGE_SIZE;
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if (check_vma(dev_dax, vmf->vma, __func__))
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return VM_FAULT_SIGBUS;
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dax_region = dev_dax->region;
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if (dax_region->align > PAGE_SIZE) {
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dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
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dax_region->align, fault_size);
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return VM_FAULT_SIGBUS;
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}
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if (fault_size != dax_region->align)
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return VM_FAULT_SIGBUS;
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phys = dax_pgoff_to_phys(dev_dax, vmf->pgoff, PAGE_SIZE);
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if (phys == -1) {
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dev_dbg(dev, "pgoff_to_phys(%#lx) failed\n", vmf->pgoff);
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return VM_FAULT_SIGBUS;
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}
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pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
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rc = vm_insert_mixed(vmf->vma, vmf->address, pfn);
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if (rc == -ENOMEM)
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return VM_FAULT_OOM;
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if (rc < 0 && rc != -EBUSY)
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return VM_FAULT_SIGBUS;
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return VM_FAULT_NOPAGE;
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}
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static int __dev_dax_pmd_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
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{
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unsigned long pmd_addr = vmf->address & PMD_MASK;
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struct device *dev = &dev_dax->dev;
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struct dax_region *dax_region;
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phys_addr_t phys;
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pgoff_t pgoff;
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pfn_t pfn;
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unsigned int fault_size = PMD_SIZE;
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if (check_vma(dev_dax, vmf->vma, __func__))
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return VM_FAULT_SIGBUS;
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dax_region = dev_dax->region;
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if (dax_region->align > PMD_SIZE) {
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dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
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dax_region->align, fault_size);
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return VM_FAULT_SIGBUS;
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}
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/* dax pmd mappings require pfn_t_devmap() */
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if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
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dev_dbg(dev, "region lacks devmap flags\n");
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return VM_FAULT_SIGBUS;
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}
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if (fault_size < dax_region->align)
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return VM_FAULT_SIGBUS;
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else if (fault_size > dax_region->align)
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return VM_FAULT_FALLBACK;
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/* if we are outside of the VMA */
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if (pmd_addr < vmf->vma->vm_start ||
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(pmd_addr + PMD_SIZE) > vmf->vma->vm_end)
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return VM_FAULT_SIGBUS;
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pgoff = linear_page_index(vmf->vma, pmd_addr);
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phys = dax_pgoff_to_phys(dev_dax, pgoff, PMD_SIZE);
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if (phys == -1) {
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dev_dbg(dev, "pgoff_to_phys(%#lx) failed\n", pgoff);
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return VM_FAULT_SIGBUS;
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}
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pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
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return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, pfn,
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vmf->flags & FAULT_FLAG_WRITE);
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}
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#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
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static int __dev_dax_pud_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
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{
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unsigned long pud_addr = vmf->address & PUD_MASK;
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struct device *dev = &dev_dax->dev;
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struct dax_region *dax_region;
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phys_addr_t phys;
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pgoff_t pgoff;
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pfn_t pfn;
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unsigned int fault_size = PUD_SIZE;
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if (check_vma(dev_dax, vmf->vma, __func__))
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return VM_FAULT_SIGBUS;
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dax_region = dev_dax->region;
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if (dax_region->align > PUD_SIZE) {
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dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
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dax_region->align, fault_size);
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return VM_FAULT_SIGBUS;
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}
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/* dax pud mappings require pfn_t_devmap() */
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if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
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dev_dbg(dev, "region lacks devmap flags\n");
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return VM_FAULT_SIGBUS;
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}
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if (fault_size < dax_region->align)
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return VM_FAULT_SIGBUS;
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else if (fault_size > dax_region->align)
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return VM_FAULT_FALLBACK;
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/* if we are outside of the VMA */
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if (pud_addr < vmf->vma->vm_start ||
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(pud_addr + PUD_SIZE) > vmf->vma->vm_end)
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return VM_FAULT_SIGBUS;
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pgoff = linear_page_index(vmf->vma, pud_addr);
|
|
phys = dax_pgoff_to_phys(dev_dax, pgoff, PUD_SIZE);
|
|
if (phys == -1) {
|
|
dev_dbg(dev, "pgoff_to_phys(%#lx) failed\n", pgoff);
|
|
return VM_FAULT_SIGBUS;
|
|
}
|
|
|
|
pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
|
|
|
|
return vmf_insert_pfn_pud(vmf->vma, vmf->address, vmf->pud, pfn,
|
|
vmf->flags & FAULT_FLAG_WRITE);
|
|
}
|
|
#else
|
|
static int __dev_dax_pud_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
|
|
{
|
|
return VM_FAULT_FALLBACK;
|
|
}
|
|
#endif /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
|
|
|
|
static int dev_dax_huge_fault(struct vm_fault *vmf,
|
|
enum page_entry_size pe_size)
|
|
{
|
|
int rc, id;
|
|
struct file *filp = vmf->vma->vm_file;
|
|
struct dev_dax *dev_dax = filp->private_data;
|
|
|
|
dev_dbg(&dev_dax->dev, "%s: %s (%#lx - %#lx) size = %d\n", current->comm,
|
|
(vmf->flags & FAULT_FLAG_WRITE) ? "write" : "read",
|
|
vmf->vma->vm_start, vmf->vma->vm_end, pe_size);
|
|
|
|
id = dax_read_lock();
|
|
switch (pe_size) {
|
|
case PE_SIZE_PTE:
|
|
rc = __dev_dax_pte_fault(dev_dax, vmf);
|
|
break;
|
|
case PE_SIZE_PMD:
|
|
rc = __dev_dax_pmd_fault(dev_dax, vmf);
|
|
break;
|
|
case PE_SIZE_PUD:
|
|
rc = __dev_dax_pud_fault(dev_dax, vmf);
|
|
break;
|
|
default:
|
|
rc = VM_FAULT_SIGBUS;
|
|
}
|
|
dax_read_unlock(id);
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int dev_dax_fault(struct vm_fault *vmf)
|
|
{
|
|
return dev_dax_huge_fault(vmf, PE_SIZE_PTE);
|
|
}
|
|
|
|
static int dev_dax_split(struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
struct file *filp = vma->vm_file;
|
|
struct dev_dax *dev_dax = filp->private_data;
|
|
struct dax_region *dax_region = dev_dax->region;
|
|
|
|
if (!IS_ALIGNED(addr, dax_region->align))
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
static unsigned long dev_dax_pagesize(struct vm_area_struct *vma)
|
|
{
|
|
struct file *filp = vma->vm_file;
|
|
struct dev_dax *dev_dax = filp->private_data;
|
|
struct dax_region *dax_region = dev_dax->region;
|
|
|
|
return dax_region->align;
|
|
}
|
|
|
|
static const struct vm_operations_struct dax_vm_ops = {
|
|
.fault = dev_dax_fault,
|
|
.huge_fault = dev_dax_huge_fault,
|
|
.split = dev_dax_split,
|
|
.pagesize = dev_dax_pagesize,
|
|
};
|
|
|
|
static int dax_mmap(struct file *filp, struct vm_area_struct *vma)
|
|
{
|
|
struct dev_dax *dev_dax = filp->private_data;
|
|
int rc, id;
|
|
|
|
dev_dbg(&dev_dax->dev, "trace\n");
|
|
|
|
/*
|
|
* We lock to check dax_dev liveness and will re-check at
|
|
* fault time.
|
|
*/
|
|
id = dax_read_lock();
|
|
rc = check_vma(dev_dax, vma, __func__);
|
|
dax_read_unlock(id);
|
|
if (rc)
|
|
return rc;
|
|
|
|
vma->vm_ops = &dax_vm_ops;
|
|
vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
|
|
return 0;
|
|
}
|
|
|
|
/* return an unmapped area aligned to the dax region specified alignment */
|
|
static unsigned long dax_get_unmapped_area(struct file *filp,
|
|
unsigned long addr, unsigned long len, unsigned long pgoff,
|
|
unsigned long flags)
|
|
{
|
|
unsigned long off, off_end, off_align, len_align, addr_align, align;
|
|
struct dev_dax *dev_dax = filp ? filp->private_data : NULL;
|
|
struct dax_region *dax_region;
|
|
|
|
if (!dev_dax || addr)
|
|
goto out;
|
|
|
|
dax_region = dev_dax->region;
|
|
align = dax_region->align;
|
|
off = pgoff << PAGE_SHIFT;
|
|
off_end = off + len;
|
|
off_align = round_up(off, align);
|
|
|
|
if ((off_end <= off_align) || ((off_end - off_align) < align))
|
|
goto out;
|
|
|
|
len_align = len + align;
|
|
if ((off + len_align) < off)
|
|
goto out;
|
|
|
|
addr_align = current->mm->get_unmapped_area(filp, addr, len_align,
|
|
pgoff, flags);
|
|
if (!IS_ERR_VALUE(addr_align)) {
|
|
addr_align += (off - addr_align) & (align - 1);
|
|
return addr_align;
|
|
}
|
|
out:
|
|
return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags);
|
|
}
|
|
|
|
static int dax_open(struct inode *inode, struct file *filp)
|
|
{
|
|
struct dax_device *dax_dev = inode_dax(inode);
|
|
struct inode *__dax_inode = dax_inode(dax_dev);
|
|
struct dev_dax *dev_dax = dax_get_private(dax_dev);
|
|
|
|
dev_dbg(&dev_dax->dev, "trace\n");
|
|
inode->i_mapping = __dax_inode->i_mapping;
|
|
inode->i_mapping->host = __dax_inode;
|
|
filp->f_mapping = inode->i_mapping;
|
|
filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping);
|
|
filp->private_data = dev_dax;
|
|
inode->i_flags = S_DAX;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int dax_release(struct inode *inode, struct file *filp)
|
|
{
|
|
struct dev_dax *dev_dax = filp->private_data;
|
|
|
|
dev_dbg(&dev_dax->dev, "trace\n");
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations dax_fops = {
|
|
.llseek = noop_llseek,
|
|
.owner = THIS_MODULE,
|
|
.open = dax_open,
|
|
.release = dax_release,
|
|
.get_unmapped_area = dax_get_unmapped_area,
|
|
.mmap = dax_mmap,
|
|
};
|
|
|
|
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;
|
|
|
|
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);
|
|
}
|
|
|
|
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 resource *res, int count)
|
|
{
|
|
struct device *parent = dax_region->dev;
|
|
struct dax_device *dax_dev;
|
|
struct dev_dax *dev_dax;
|
|
struct inode *inode;
|
|
struct device *dev;
|
|
struct cdev *cdev;
|
|
int rc, i;
|
|
|
|
if (!count)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
dev_dax = kzalloc(sizeof(*dev_dax) + sizeof(*res) * count, 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_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;
|
|
}
|
|
|
|
/*
|
|
* 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_dax;
|
|
}
|
|
|
|
/* 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->num_resources = count;
|
|
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);
|
|
if (rc)
|
|
return ERR_PTR(rc);
|
|
|
|
return dev_dax;
|
|
|
|
err_dax:
|
|
if (dev_dax->id >= 0)
|
|
ida_simple_remove(&dax_region->ida, dev_dax->id);
|
|
err_id:
|
|
kfree(dev_dax);
|
|
|
|
return ERR_PTR(rc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_create_dev_dax);
|
|
|
|
static int __init dax_init(void)
|
|
{
|
|
dax_class = class_create(THIS_MODULE, "dax");
|
|
return PTR_ERR_OR_ZERO(dax_class);
|
|
}
|
|
|
|
static void __exit dax_exit(void)
|
|
{
|
|
class_destroy(dax_class);
|
|
}
|
|
|
|
MODULE_AUTHOR("Intel Corporation");
|
|
MODULE_LICENSE("GPL v2");
|
|
subsys_initcall(dax_init);
|
|
module_exit(dax_exit);
|