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 <dan.j.williams@intel.com>

1 files changed, 3 insertions, 182 deletions

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 <linux/pagemap.h>
 #include <linux/module.h>
 #include <linux/device.h>
@@ -21,156 +11,10 @@
 #include <linux/mm.h>
 #include <linux/mman.h>
 #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;