#include <linux/pagemap.h>
#include <linux/module.h>
#include <linux/device.h>
+#include <linux/mount.h>
#include <linux/pfn_t.h>
+#include <linux/hash.h>
+#include <linux/cdev.h>
#include <linux/slab.h>
#include <linux/dax.h>
#include <linux/fs.h>
#include <linux/mm.h>
+#include "dax.h"
-static int dax_major;
+static dev_t dax_devt;
static struct class *dax_class;
static DEFINE_IDA(dax_minor_ida);
+static int nr_dax = CONFIG_NR_DEV_DAX;
+module_param(nr_dax, int, S_IRUGO);
+static struct vfsmount *dax_mnt;
+static struct kmem_cache *dax_cache __read_mostly;
+static struct super_block *dax_superblock __read_mostly;
+MODULE_PARM_DESC(nr_dax, "max number of device-dax instances");
/**
* struct dax_region - mapping infrastructure for dax devices
* struct dax_dev - subdivision of a dax region
* @region - parent region
* @dev - device backing the character device
- * @kref - enable this data to be tracked in filp->private_data
+ * @cdev - core chardev data
* @alive - !alive + rcu grace period == no new mappings can be established
* @id - child id in the region
* @num_resources - number of physical address extents in this device
*/
struct dax_dev {
struct dax_region *region;
- struct device *dev;
- struct kref kref;
+ struct inode *inode;
+ struct device dev;
+ struct cdev cdev;
bool alive;
int id;
int num_resources;
struct resource res[0];
};
-static void dax_region_free(struct kref *kref)
+static struct inode *dax_alloc_inode(struct super_block *sb)
{
- struct dax_region *dax_region;
+ return kmem_cache_alloc(dax_cache, GFP_KERNEL);
+}
- dax_region = container_of(kref, struct dax_region, kref);
- kfree(dax_region);
+static void dax_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+
+ kmem_cache_free(dax_cache, inode);
}
-void dax_region_put(struct dax_region *dax_region)
+static void dax_destroy_inode(struct inode *inode)
{
- kref_put(&dax_region->kref, dax_region_free);
+ call_rcu(&inode->i_rcu, dax_i_callback);
}
-EXPORT_SYMBOL_GPL(dax_region_put);
-static void dax_dev_free(struct kref *kref)
+static const struct super_operations dax_sops = {
+ .statfs = simple_statfs,
+ .alloc_inode = dax_alloc_inode,
+ .destroy_inode = dax_destroy_inode,
+ .drop_inode = generic_delete_inode,
+};
+
+static struct dentry *dax_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
{
- struct dax_dev *dax_dev;
+ return mount_pseudo(fs_type, "dax:", &dax_sops, NULL, DAXFS_MAGIC);
+}
- dax_dev = container_of(kref, struct dax_dev, kref);
- dax_region_put(dax_dev->region);
- kfree(dax_dev);
+static struct file_system_type dax_type = {
+ .name = "dax",
+ .mount = dax_mount,
+ .kill_sb = kill_anon_super,
+};
+
+static int dax_test(struct inode *inode, void *data)
+{
+ return inode->i_cdev == data;
+}
+
+static int dax_set(struct inode *inode, void *data)
+{
+ inode->i_cdev = data;
+ return 0;
+}
+
+static struct inode *dax_inode_get(struct cdev *cdev, dev_t devt)
+{
+ struct inode *inode;
+
+ inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31),
+ dax_test, dax_set, cdev);
+
+ if (!inode)
+ return NULL;
+
+ if (inode->i_state & I_NEW) {
+ inode->i_mode = S_IFCHR;
+ inode->i_flags = S_DAX;
+ inode->i_rdev = devt;
+ mapping_set_gfp_mask(&inode->i_data, GFP_USER);
+ unlock_new_inode(inode);
+ }
+ return inode;
+}
+
+static void init_once(void *inode)
+{
+ inode_init_once(inode);
+}
+
+static int dax_inode_init(void)
+{
+ int rc;
+
+ dax_cache = kmem_cache_create("dax_cache", sizeof(struct inode), 0,
+ (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
+ SLAB_MEM_SPREAD|SLAB_ACCOUNT),
+ init_once);
+ if (!dax_cache)
+ return -ENOMEM;
+
+ rc = register_filesystem(&dax_type);
+ if (rc)
+ goto err_register_fs;
+
+ dax_mnt = kern_mount(&dax_type);
+ if (IS_ERR(dax_mnt)) {
+ rc = PTR_ERR(dax_mnt);
+ goto err_mount;
+ }
+ dax_superblock = dax_mnt->mnt_sb;
+
+ return 0;
+
+ err_mount:
+ unregister_filesystem(&dax_type);
+ err_register_fs:
+ kmem_cache_destroy(dax_cache);
+
+ return rc;
}
-static void dax_dev_put(struct dax_dev *dax_dev)
+static void dax_inode_exit(void)
+{
+ kern_unmount(dax_mnt);
+ unregister_filesystem(&dax_type);
+ kmem_cache_destroy(dax_cache);
+}
+
+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_dev->kref, dax_dev_free);
+ kref_put(&dax_region->kref, dax_region_free);
}
+EXPORT_SYMBOL_GPL(dax_region_put);
struct dax_region *alloc_dax_region(struct device *parent, int region_id,
struct resource *res, unsigned int align, void *addr,
{
struct dax_region *dax_region;
- dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL);
+ 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;
}
EXPORT_SYMBOL_GPL(alloc_dax_region);
+static struct dax_dev *to_dax_dev(struct device *dev)
+{
+ return container_of(dev, struct dax_dev, dev);
+}
+
static ssize_t size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct dax_dev *dax_dev = dev_get_drvdata(dev);
+ struct dax_dev *dax_dev = to_dax_dev(dev);
unsigned long long size = 0;
int i;
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)
{
struct dax_region *dax_region = dax_dev->region;
- struct device *dev = dax_dev->dev;
+ struct device *dev = &dax_dev->dev;
unsigned long mask;
if (!dax_dev->alive)
struct vm_fault *vmf)
{
unsigned long vaddr = (unsigned long) vmf->virtual_address;
- struct device *dev = dax_dev->dev;
+ struct device *dev = &dax_dev->dev;
struct dax_region *dax_region;
int rc = VM_FAULT_SIGBUS;
phys_addr_t phys;
struct file *filp = vma->vm_file;
struct dax_dev *dax_dev = filp->private_data;
- dev_dbg(dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__,
+ dev_dbg(&dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__,
current->comm, (vmf->flags & FAULT_FLAG_WRITE)
? "write" : "read", vma->vm_start, vma->vm_end);
rcu_read_lock();
unsigned int flags)
{
unsigned long pmd_addr = addr & PMD_MASK;
- struct device *dev = dax_dev->dev;
+ struct device *dev = &dax_dev->dev;
struct dax_region *dax_region;
phys_addr_t phys;
pgoff_t pgoff;
struct file *filp = vma->vm_file;
struct dax_dev *dax_dev = filp->private_data;
- dev_dbg(dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__,
+ dev_dbg(&dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__,
current->comm, (flags & FAULT_FLAG_WRITE)
? "write" : "read", vma->vm_start, vma->vm_end);
return rc;
}
-static void dax_dev_vm_open(struct vm_area_struct *vma)
-{
- struct file *filp = vma->vm_file;
- struct dax_dev *dax_dev = filp->private_data;
-
- dev_dbg(dax_dev->dev, "%s\n", __func__);
- kref_get(&dax_dev->kref);
-}
-
-static void dax_dev_vm_close(struct vm_area_struct *vma)
-{
- struct file *filp = vma->vm_file;
- struct dax_dev *dax_dev = filp->private_data;
-
- dev_dbg(dax_dev->dev, "%s\n", __func__);
- dax_dev_put(dax_dev);
-}
-
static const struct vm_operations_struct dax_dev_vm_ops = {
.fault = dax_dev_fault,
.pmd_fault = dax_dev_pmd_fault,
- .open = dax_dev_vm_open,
- .close = dax_dev_vm_close,
};
-static int dax_dev_mmap(struct file *filp, struct vm_area_struct *vma)
+static int dax_mmap(struct file *filp, struct vm_area_struct *vma)
{
struct dax_dev *dax_dev = filp->private_data;
int rc;
- dev_dbg(dax_dev->dev, "%s\n", __func__);
+ dev_dbg(&dax_dev->dev, "%s\n", __func__);
rc = check_vma(dax_dev, vma, __func__);
if (rc)
return rc;
- kref_get(&dax_dev->kref);
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_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 dax_open(struct inode *inode, struct file *filp)
+{
+ struct dax_dev *dax_dev;
+
+ dax_dev = container_of(inode->i_cdev, struct dax_dev, cdev);
+ dev_dbg(&dax_dev->dev, "%s\n", __func__);
+ inode->i_mapping = dax_dev->inode->i_mapping;
+ inode->i_mapping->host = dax_dev->inode;
+ filp->f_mapping = inode->i_mapping;
+ filp->private_data = dax_dev;
+ inode->i_flags = S_DAX;
+
+ return 0;
+}
+
+static int dax_release(struct inode *inode, struct file *filp)
+{
+ struct dax_dev *dax_dev = filp->private_data;
+
+ dev_dbg(&dax_dev->dev, "%s\n", __func__);
+ return 0;
}
static const struct file_operations dax_fops = {
.llseek = noop_llseek,
.owner = THIS_MODULE,
- .open = dax_dev_open,
- .release = dax_dev_release,
- .get_unmapped_area = dax_dev_get_unmapped_area,
- .mmap = dax_dev_mmap,
+ .open = dax_open,
+ .release = dax_release,
+ .get_unmapped_area = dax_get_unmapped_area,
+ .mmap = dax_mmap,
};
+static void dax_dev_release(struct device *dev)
+{
+ struct dax_dev *dax_dev = to_dax_dev(dev);
+ struct dax_region *dax_region = dax_dev->region;
+
+ ida_simple_remove(&dax_region->ida, dax_dev->id);
+ ida_simple_remove(&dax_minor_ida, MINOR(dev->devt));
+ dax_region_put(dax_region);
+ iput(dax_dev->inode);
+ kfree(dax_dev);
+}
+
+static void unregister_dax_dev(void *dev)
+{
+ struct dax_dev *dax_dev = to_dax_dev(dev);
+ struct cdev *cdev = &dax_dev->cdev;
+
+ 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();
+ unmap_mapping_range(dax_dev->inode->i_mapping, 0, 0, 1);
+ cdev_del(cdev);
+ device_unregister(dev);
+}
+
+struct dax_dev *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;
+ int rc = 0, minor, i;
+ struct device *dev;
+ struct cdev *cdev;
+ dev_t dev_t;
+
+ dax_dev = kzalloc(sizeof(*dax_dev) + sizeof(*res) * count, GFP_KERNEL);
+ if (!dax_dev)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < count; i++) {
+ if (!IS_ALIGNED(res[i].start, dax_region->align)
+ || !IS_ALIGNED(resource_size(&res[i]),
+ dax_region->align)) {
+ rc = -EINVAL;
+ break;
+ }
+ dax_dev->res[i].start = res[i].start;
+ dax_dev->res[i].end = res[i].end;
+ }
+
+ if (i < count)
+ goto err_id;
+
+ 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(MAJOR(dax_devt), minor);
+ dev = &dax_dev->dev;
+ dax_dev->inode = dax_inode_get(&dax_dev->cdev, dev_t);
+ if (!dax_dev->inode) {
+ rc = -ENOMEM;
+ goto err_inode;
+ }
+
+ /* device_initialize() so cdev can reference kobj parent */
+ device_initialize(dev);
+
+ cdev = &dax_dev->cdev;
+ cdev_init(cdev, &dax_fops);
+ cdev->owner = parent->driver->owner;
+ cdev->kobj.parent = &dev->kobj;
+ rc = cdev_add(&dax_dev->cdev, dev_t, 1);
+ if (rc)
+ goto err_cdev;
+
+ /* from here on we're committed to teardown via dax_dev_release() */
+ dax_dev->num_resources = count;
+ dax_dev->alive = true;
+ dax_dev->region = dax_region;
+ kref_get(&dax_region->kref);
+
+ dev->devt = dev_t;
+ dev->class = dax_class;
+ dev->parent = parent;
+ dev->groups = dax_attribute_groups;
+ dev->release = dax_dev_release;
+ dev_set_name(dev, "dax%d.%d", dax_region->id, dax_dev->id);
+ rc = device_add(dev);
+ if (rc) {
+ put_device(dev);
+ return ERR_PTR(rc);
+ }
+
+ rc = devm_add_action_or_reset(dax_region->dev, unregister_dax_dev, dev);
+ if (rc)
+ return ERR_PTR(rc);
+
+ return dax_dev;
+
+ err_cdev:
+ iput(dax_dev->inode);
+ err_inode:
+ ida_simple_remove(&dax_minor_ida, minor);
+ err_minor:
+ ida_simple_remove(&dax_region->ida, dax_dev->id);
+ err_id:
+ kfree(dax_dev);
+
+ return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_GPL(devm_create_dax_dev);
+
static int __init dax_init(void)
{
int rc;
- rc = register_chrdev(0, "dax", &dax_fops);
- if (rc < 0)
+ rc = dax_inode_init();
+ if (rc)
return rc;
- dax_major = rc;
+
+ nr_dax = max(nr_dax, 256);
+ rc = alloc_chrdev_region(&dax_devt, 0, nr_dax, "dax");
+ if (rc)
+ goto err_chrdev;
dax_class = class_create(THIS_MODULE, "dax");
if (IS_ERR(dax_class)) {
- unregister_chrdev(dax_major, "dax");
- return PTR_ERR(dax_class);
+ rc = PTR_ERR(dax_class);
+ goto err_class;
}
return 0;
+
+ err_class:
+ unregister_chrdev_region(dax_devt, nr_dax);
+ err_chrdev:
+ dax_inode_exit();
+ return rc;
}
static void __exit dax_exit(void)
{
class_destroy(dax_class);
- unregister_chrdev(dax_major, "dax");
+ unregister_chrdev_region(dax_devt, nr_dax);
ida_destroy(&dax_minor_ida);
+ dax_inode_exit();
}
MODULE_AUTHOR("Intel Corporation");
projects / cascardo / linux.git / blobdiff