mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
![Vivek Goyal](/assets/img/avatar_default.png)
zero_page_range() dax operation is mandatory for dax devices. Right now that check happens in dax_zero_page_range() function. Dan thinks that's too late and its better to do the check earlier in alloc_dax(). I also modified alloc_dax() to return pointer with error code in it in case of failure. Right now it returns NULL and caller assumes failure happened due to -ENOMEM. But with this ->zero_page_range() check, I need to return -EINVAL instead. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Link: https://lore.kernel.org/r/20200401161125.GB9398@redhat.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
536 lines
13 KiB
C
536 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/* Copyright(c) 2017-2018 Intel Corporation. All rights reserved. */
|
|
#include <linux/memremap.h>
|
|
#include <linux/device.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/list.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/dax.h>
|
|
#include "dax-private.h"
|
|
#include "bus.h"
|
|
|
|
static struct class *dax_class;
|
|
|
|
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)
|
|
{
|
|
/*
|
|
* 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 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;
|
|
}
|
|
|
|
enum id_action {
|
|
ID_REMOVE,
|
|
ID_ADD,
|
|
};
|
|
|
|
static ssize_t do_id_store(struct device_driver *drv, const char *buf,
|
|
size_t count, enum id_action action)
|
|
{
|
|
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 (action == ID_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 (action == ID_REMOVE) {
|
|
list_del(&dax_id->list);
|
|
kfree(dax_id);
|
|
} else
|
|
/* dax_id already added */;
|
|
mutex_unlock(&dax_bus_lock);
|
|
|
|
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, 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, ID_REMOVE);
|
|
}
|
|
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);
|
|
|
|
/*
|
|
* All but the 'device-dax' driver, which has 'match_always'
|
|
* set, requires an exact id match.
|
|
*/
|
|
if (dax_drv->match_always)
|
|
return 1;
|
|
|
|
return dax_match_id(dax_drv, dev);
|
|
}
|
|
|
|
/*
|
|
* 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, int target_node, unsigned int align,
|
|
unsigned long 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;
|
|
dax_region->target_node = target_node;
|
|
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 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 unsigned long long dev_dax_resource(struct dev_dax *dev_dax)
|
|
{
|
|
struct dax_region *dax_region = dev_dax->region;
|
|
|
|
return dax_region->res.start;
|
|
}
|
|
|
|
static ssize_t resource_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct dev_dax *dev_dax = to_dev_dax(dev);
|
|
|
|
return sprintf(buf, "%#llx\n", dev_dax_resource(dev_dax));
|
|
}
|
|
static DEVICE_ATTR(resource, 0400, resource_show, NULL);
|
|
|
|
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 ssize_t numa_node_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", dev_to_node(dev));
|
|
}
|
|
static DEVICE_ATTR_RO(numa_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;
|
|
if (a == &dev_attr_numa_node.attr && !IS_ENABLED(CONFIG_NUMA))
|
|
return 0;
|
|
return a->mode;
|
|
}
|
|
|
|
static struct attribute *dev_dax_attributes[] = {
|
|
&dev_attr_modalias.attr,
|
|
&dev_attr_size.attr,
|
|
&dev_attr_target_node.attr,
|
|
&dev_attr_resource.attr,
|
|
&dev_attr_numa_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[] = {
|
|
&dev_dax_attribute_group,
|
|
NULL,
|
|
};
|
|
|
|
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);
|
|
|
|
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;
|
|
|
|
dax_region_put(dax_region);
|
|
put_dax(dax_dev);
|
|
kfree(dev_dax);
|
|
}
|
|
|
|
static const struct device_type dev_dax_type = {
|
|
.release = dev_dax_release,
|
|
.groups = dax_attribute_groups,
|
|
};
|
|
|
|
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);
|
|
device_del(dev);
|
|
put_device(dev);
|
|
}
|
|
|
|
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;
|
|
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);
|
|
|
|
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.
|
|
*/
|
|
dax_dev = alloc_dax(dev_dax, NULL, NULL, DAXDEV_F_SYNC);
|
|
if (IS_ERR(dax_dev)) {
|
|
rc = PTR_ERR(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;
|
|
dev_dax->target_node = dax_region->target_node;
|
|
kref_get(&dax_region->kref);
|
|
|
|
inode = dax_inode(dax_dev);
|
|
dev->devt = inode->i_rdev;
|
|
if (subsys == DEV_DAX_BUS)
|
|
dev->bus = &dax_bus_type;
|
|
else
|
|
dev->class = dax_class;
|
|
dev->parent = parent;
|
|
dev->type = &dev_dax_type;
|
|
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);
|
|
|
|
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 device_driver *drv = &dax_drv->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);
|
|
driver_unregister(drv);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dax_driver_unregister);
|
|
|
|
int __init dax_bus_init(void)
|
|
{
|
|
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);
|
|
}
|