[PATCH 2/7] dax: reorder dax_fops function definitions

From: Dan Williams
Date: Mon Aug 15 2016 - 23:27:38 EST


In order to convert devm_create_dax_dev() to use cdev, it will need
access to dax_fops. Move dax_fops and related function definitions
before devm_create_dax_dev().

Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/dax/dax.c | 337 ++++++++++++++++++++++++++---------------------------
1 file changed, 168 insertions(+), 169 deletions(-)

diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c
index 736c03830fd0..3774fc9709bb 100644
--- a/drivers/dax/dax.c
+++ b/drivers/dax/dax.c
@@ -145,175 +145,6 @@ static const struct attribute_group *dax_attribute_groups[] = {
NULL,
};

-static void unregister_dax_dev(void *_dev)
-{
- struct device *dev = _dev;
- struct dax_dev *dax_dev = dev_get_drvdata(dev);
- struct dax_region *dax_region = dax_dev->region;
-
- dev_dbg(dev, "%s\n", __func__);
-
- /*
- * Note, rcu is not protecting the liveness of dax_dev, rcu is
- * ensuring that any fault handlers that might have seen
- * dax_dev->alive == true, have completed. Any fault handlers
- * that start after synchronize_rcu() has started will abort
- * upon seeing dax_dev->alive == false.
- */
- dax_dev->alive = false;
- synchronize_rcu();
-
- get_device(dev);
- device_unregister(dev);
- ida_simple_remove(&dax_region->ida, dax_dev->id);
- ida_simple_remove(&dax_minor_ida, MINOR(dev->devt));
- put_device(dev);
- dax_dev_put(dax_dev);
-}
-
-int devm_create_dax_dev(struct dax_region *dax_region, struct resource *res,
- int count)
-{
- struct device *parent = dax_region->dev;
- struct dax_dev *dax_dev;
- struct device *dev;
- int rc, minor;
- dev_t dev_t;
-
- dax_dev = kzalloc(sizeof(*dax_dev) + sizeof(*res) * count, GFP_KERNEL);
- if (!dax_dev)
- return -ENOMEM;
- memcpy(dax_dev->res, res, sizeof(*res) * count);
- dax_dev->num_resources = count;
- kref_init(&dax_dev->kref);
- dax_dev->alive = true;
- dax_dev->region = dax_region;
- kref_get(&dax_region->kref);
-
- dax_dev->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL);
- if (dax_dev->id < 0) {
- rc = dax_dev->id;
- goto err_id;
- }
-
- minor = ida_simple_get(&dax_minor_ida, 0, 0, GFP_KERNEL);
- if (minor < 0) {
- rc = minor;
- goto err_minor;
- }
-
- dev_t = MKDEV(dax_major, minor);
- dev = device_create_with_groups(dax_class, parent, dev_t, dax_dev,
- dax_attribute_groups, "dax%d.%d", dax_region->id,
- dax_dev->id);
- if (IS_ERR(dev)) {
- rc = PTR_ERR(dev);
- goto err_create;
- }
- dax_dev->dev = dev;
-
- rc = devm_add_action_or_reset(dax_region->dev, unregister_dax_dev, dev);
- if (rc)
- return rc;
-
- return 0;
-
- err_create:
- ida_simple_remove(&dax_minor_ida, minor);
- err_minor:
- ida_simple_remove(&dax_region->ida, dax_dev->id);
- err_id:
- dax_dev_put(dax_dev);
-
- return rc;
-}
-EXPORT_SYMBOL_GPL(devm_create_dax_dev);
-
-/* return an unmapped area aligned to the dax region specified alignment */
-static unsigned long dax_dev_get_unmapped_area(struct file *filp,
- unsigned long addr, unsigned long len, unsigned long pgoff,
- unsigned long flags)
-{
- unsigned long off, off_end, off_align, len_align, addr_align, align;
- struct dax_dev *dax_dev = filp ? filp->private_data : NULL;
- struct dax_region *dax_region;
-
- if (!dax_dev || addr)
- goto out;
-
- dax_region = dax_dev->region;
- align = dax_region->align;
- off = pgoff << PAGE_SHIFT;
- off_end = off + len;
- off_align = round_up(off, align);
-
- if ((off_end <= off_align) || ((off_end - off_align) < align))
- goto out;
-
- len_align = len + align;
- if ((off + len_align) < off)
- goto out;
-
- addr_align = current->mm->get_unmapped_area(filp, addr, len_align,
- pgoff, flags);
- if (!IS_ERR_VALUE(addr_align)) {
- addr_align += (off - addr_align) & (align - 1);
- return addr_align;
- }
- out:
- return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags);
-}
-
-static int __match_devt(struct device *dev, const void *data)
-{
- const dev_t *devt = data;
-
- return dev->devt == *devt;
-}
-
-static struct device *dax_dev_find(dev_t dev_t)
-{
- return class_find_device(dax_class, NULL, &dev_t, __match_devt);
-}
-
-static int dax_dev_open(struct inode *inode, struct file *filp)
-{
- struct dax_dev *dax_dev = NULL;
- struct device *dev;
-
- dev = dax_dev_find(inode->i_rdev);
- if (!dev)
- return -ENXIO;
-
- device_lock(dev);
- dax_dev = dev_get_drvdata(dev);
- if (dax_dev) {
- dev_dbg(dev, "%s\n", __func__);
- filp->private_data = dax_dev;
- kref_get(&dax_dev->kref);
- inode->i_flags = S_DAX;
- }
- device_unlock(dev);
-
- if (!dax_dev) {
- put_device(dev);
- return -ENXIO;
- }
- return 0;
-}
-
-static int dax_dev_release(struct inode *inode, struct file *filp)
-{
- struct dax_dev *dax_dev = filp->private_data;
- struct device *dev = dax_dev->dev;
-
- dev_dbg(dax_dev->dev, "%s\n", __func__);
- dax_dev_put(dax_dev);
- put_device(dev);
-
- return 0;
-}
-
static int check_vma(struct dax_dev *dax_dev, struct vm_area_struct *vma,
const char *func)
{
@@ -531,7 +362,91 @@ static int dax_dev_mmap(struct file *filp, struct vm_area_struct *vma)
vma->vm_ops = &dax_dev_vm_ops;
vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
return 0;
+}
+
+/* return an unmapped area aligned to the dax region specified alignment */
+static unsigned long dax_dev_get_unmapped_area(struct file *filp,
+ unsigned long addr, unsigned long len, unsigned long pgoff,
+ unsigned long flags)
+{
+ unsigned long off, off_end, off_align, len_align, addr_align, align;
+ struct dax_dev *dax_dev = filp ? filp->private_data : NULL;
+ struct dax_region *dax_region;
+
+ if (!dax_dev || addr)
+ goto out;
+
+ dax_region = dax_dev->region;
+ align = dax_region->align;
+ off = pgoff << PAGE_SHIFT;
+ off_end = off + len;
+ off_align = round_up(off, align);
+
+ if ((off_end <= off_align) || ((off_end - off_align) < align))
+ goto out;
+
+ len_align = len + align;
+ if ((off + len_align) < off)
+ goto out;
+
+ addr_align = current->mm->get_unmapped_area(filp, addr, len_align,
+ pgoff, flags);
+ if (!IS_ERR_VALUE(addr_align)) {
+ addr_align += (off - addr_align) & (align - 1);
+ return addr_align;
+ }
+ out:
+ return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags);
+}
+
+static int __match_devt(struct device *dev, const void *data)
+{
+ const dev_t *devt = data;
+
+ return dev->devt == *devt;
+}
+
+static struct device *dax_dev_find(dev_t dev_t)
+{
+ return class_find_device(dax_class, NULL, &dev_t, __match_devt);
+}
+
+static int dax_dev_open(struct inode *inode, struct file *filp)
+{
+ struct dax_dev *dax_dev = NULL;
+ struct device *dev;
+
+ dev = dax_dev_find(inode->i_rdev);
+ if (!dev)
+ return -ENXIO;
+
+ device_lock(dev);
+ dax_dev = dev_get_drvdata(dev);
+ if (dax_dev) {
+ dev_dbg(dev, "%s\n", __func__);
+ filp->private_data = dax_dev;
+ kref_get(&dax_dev->kref);
+ inode->i_flags = S_DAX;
+ }
+ device_unlock(dev);
+
+ if (!dax_dev) {
+ put_device(dev);
+ return -ENXIO;
+ }
+ return 0;
+}

+static int dax_dev_release(struct inode *inode, struct file *filp)
+{
+ struct dax_dev *dax_dev = filp->private_data;
+ struct device *dev = dax_dev->dev;
+
+ dev_dbg(dax_dev->dev, "%s\n", __func__);
+ dax_dev_put(dax_dev);
+ put_device(dev);
+
+ return 0;
}

static const struct file_operations dax_fops = {
@@ -543,6 +458,90 @@ static const struct file_operations dax_fops = {
.mmap = dax_dev_mmap,
};

+static void unregister_dax_dev(void *_dev)
+{
+ struct device *dev = _dev;
+ struct dax_dev *dax_dev = dev_get_drvdata(dev);
+ struct dax_region *dax_region = dax_dev->region;
+
+ dev_dbg(dev, "%s\n", __func__);
+
+ /*
+ * Note, rcu is not protecting the liveness of dax_dev, rcu is
+ * ensuring that any fault handlers that might have seen
+ * dax_dev->alive == true, have completed. Any fault handlers
+ * that start after synchronize_rcu() has started will abort
+ * upon seeing dax_dev->alive == false.
+ */
+ dax_dev->alive = false;
+ synchronize_rcu();
+
+ get_device(dev);
+ device_unregister(dev);
+ ida_simple_remove(&dax_region->ida, dax_dev->id);
+ ida_simple_remove(&dax_minor_ida, MINOR(dev->devt));
+ put_device(dev);
+ dax_dev_put(dax_dev);
+}
+
+int devm_create_dax_dev(struct dax_region *dax_region, struct resource *res,
+ int count)
+{
+ struct device *parent = dax_region->dev;
+ struct dax_dev *dax_dev;
+ struct device *dev;
+ int rc, minor;
+ dev_t dev_t;
+
+ dax_dev = kzalloc(sizeof(*dax_dev) + sizeof(*res) * count, GFP_KERNEL);
+ if (!dax_dev)
+ return -ENOMEM;
+ memcpy(dax_dev->res, res, sizeof(*res) * count);
+ dax_dev->num_resources = count;
+ kref_init(&dax_dev->kref);
+ dax_dev->alive = true;
+ dax_dev->region = dax_region;
+ kref_get(&dax_region->kref);
+
+ dax_dev->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL);
+ if (dax_dev->id < 0) {
+ rc = dax_dev->id;
+ goto err_id;
+ }
+
+ minor = ida_simple_get(&dax_minor_ida, 0, 0, GFP_KERNEL);
+ if (minor < 0) {
+ rc = minor;
+ goto err_minor;
+ }
+
+ dev_t = MKDEV(dax_major, minor);
+ dev = device_create_with_groups(dax_class, parent, dev_t, dax_dev,
+ dax_attribute_groups, "dax%d.%d", dax_region->id,
+ dax_dev->id);
+ if (IS_ERR(dev)) {
+ rc = PTR_ERR(dev);
+ goto err_create;
+ }
+ dax_dev->dev = dev;
+
+ rc = devm_add_action_or_reset(dax_region->dev, unregister_dax_dev, dev);
+ if (rc)
+ return rc;
+
+ return 0;
+
+ err_create:
+ ida_simple_remove(&dax_minor_ida, minor);
+ err_minor:
+ ida_simple_remove(&dax_region->ida, dax_dev->id);
+ err_id:
+ dax_dev_put(dax_dev);
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(devm_create_dax_dev);
+
static int __init dax_init(void)
{
int rc;