diff options
Diffstat (limited to 'drivers/dax/bus.c')
| -rw-r--r-- | drivers/dax/bus.c | 174 |
1 files changed, 174 insertions, 0 deletions
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 <linux/device.h> +#include <linux/slab.h> +#include <linux/dax.h> +#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); |