Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
new file mode 100644
index 0000000..8fafbea
--- /dev/null
+++ b/drivers/dax/bus.c
@@ -0,0 +1,522 @@
+// 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 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_RO(resource);
+
+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 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_resource.attr)
+ return 0400;
+ 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,
+ 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 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 (!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->groups = dax_attribute_groups;
+ dev->release = dev_dax_release;
+ 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);
+}