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dax: add region 'id', 'size', and 'align' attributes 

While this information is available by looking at the nvdimm parent
device that may not always be the case when/if we add support for other
memory regions. Tooling should not depend on walking a given ancestor
topology that is not guaranteed by the device's class. For example, a
device-dax instance will always have a dax_region parent, but it may not
always have a libnvdimm "dax" device as a grandparent.

Reported-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2016-12-17 14:50:04 -08:00
parent 868f036fee
commit d7fe1a67f6
1 changed files with 94 additions and 0 deletions
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94
drivers/dax/dax.c
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@ -75,6 +75,73 @@ struct dax_dev {
struct resource res[0];
};
static ssize_t id_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct dax_region *dax_region;
ssize_t rc = -ENXIO;
device_lock(dev);
dax_region = dev_get_drvdata(dev);
if (dax_region)
rc = sprintf(buf, "%d\n", dax_region->id);
device_unlock(dev);
return rc;
}
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;
ssize_t rc = -ENXIO;
device_lock(dev);
dax_region = dev_get_drvdata(dev);
if (dax_region)
rc = sprintf(buf, "%llu\n", (unsigned long long)
resource_size(&dax_region->res));
device_unlock(dev);
return rc;
}
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;
ssize_t rc = -ENXIO;
device_lock(dev);
dax_region = dev_get_drvdata(dev);
if (dax_region)
rc = sprintf(buf, "%u\n", dax_region->align);
device_unlock(dev);
return rc;
}
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 struct inode *dax_alloc_inode(struct super_block *sb)
{
return kmem_cache_alloc(dax_cache, GFP_KERNEL);
@ -200,12 +267,31 @@ void dax_region_put(struct dax_region *dax_region)
}
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, void *addr,
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;
@ -214,6 +300,7 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
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);
@ -222,7 +309,14 @@ struct dax_region *alloc_dax_region(struct device *parent, int 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;;
}
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);