From 9567da0b408a2553d32ca83cba4f1fc5a8aad459 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 12 Jul 2017 17:58:21 -0700 Subject: device-dax: Introduce bus + driver model In support of multiple device-dax instances per device-dax-region and allowing the 'kmem' driver to attach to dax-instances instead of the current device-node access, convert the dax sub-system from a class to a bus. Recall that the kmem driver takes reserved / special purpose memories and assigns them to be managed by the core-mm. Aside from the fact the device-dax instances are registered and probed on a bus, two other lifetime-management changes are made: 1/ Delay attaching a cdev until driver probe time 2/ A new run_dax() helper is introduced to allow restoring dax-operation after a kill_dax() event. So, at driver ->probe() time we run_dax() and at ->remove() time we kill_dax() and invalidate all mappings. Signed-off-by: Dan Williams --- drivers/dax/device.c | 95 ++++++++++++++++++---------------------------------- 1 file changed, 32 insertions(+), 63 deletions(-) (limited to 'drivers/dax/device.c') diff --git a/drivers/dax/device.c b/drivers/dax/device.c index 1fc375783e0b..f55829404a24 100644 --- a/drivers/dax/device.c +++ b/drivers/dax/device.c @@ -13,8 +13,6 @@ #include "dax-private.h" #include "bus.h" -static struct class *dax_class; - static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma, const char *func) { @@ -404,93 +402,64 @@ static const struct file_operations dax_fops = { .mmap_supported_flags = MAP_SYNC, }; -static void dev_dax_release(struct device *dev) +static void dev_dax_cdev_del(void *cdev) { - 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; + cdev_del(cdev); +} - dax_region_put(dax_region); - put_dax(dax_dev); - kfree(dev_dax); +static void dev_dax_kill(void *dev_dax) +{ + kill_dev_dax(dev_dax); } -struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id) +static int dev_dax_probe(struct device *dev) { - struct device *parent = dax_region->dev; - struct dax_device *dax_dev; - struct dev_dax *dev_dax; + struct dev_dax *dev_dax = to_dev_dax(dev); + struct dax_device *dax_dev = dev_dax->dax_dev; struct inode *inode; - struct device *dev; struct cdev *cdev; int rc; - dev_dax = kzalloc(sizeof(*dev_dax), GFP_KERNEL); - if (!dev_dax) - return ERR_PTR(-ENOMEM); - - /* - * 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); - if (!dax_dev) { - rc = -ENOMEM; - goto err; - } - - /* from here on we're committed to teardown via dax_dev_release() */ - dev = &dev_dax->dev; - device_initialize(dev); - inode = dax_inode(dax_dev); cdev = inode->i_cdev; cdev_init(cdev, &dax_fops); - cdev->owner = parent->driver->owner; - - dev_dax->dax_dev = dax_dev; - dev_dax->region = dax_region; - kref_get(&dax_region->kref); - - dev->devt = inode->i_rdev; - 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 = cdev_device_add(cdev, 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); + cdev->owner = dev->driver->owner; + cdev_set_parent(cdev, &dev->kobj); + rc = cdev_add(cdev, dev->devt, 1); if (rc) - return ERR_PTR(rc); + return rc; - return dev_dax; + rc = devm_add_action_or_reset(dev, dev_dax_cdev_del, cdev); + if (rc) + return rc; - err: - kfree(dev_dax); + run_dax(dax_dev); + return devm_add_action_or_reset(dev, dev_dax_kill, dev_dax); +} - return ERR_PTR(rc); +static int dev_dax_remove(struct device *dev) +{ + /* all probe actions are unwound by devm */ + return 0; } -EXPORT_SYMBOL_GPL(devm_create_dev_dax); + +static struct device_driver device_dax_driver = { + .probe = dev_dax_probe, + .remove = dev_dax_remove, +}; static int __init dax_init(void) { - dax_class = class_create(THIS_MODULE, "dax"); - return PTR_ERR_OR_ZERO(dax_class); + return dax_driver_register(&device_dax_driver); } static void __exit dax_exit(void) { - class_destroy(dax_class); + driver_unregister(&device_dax_driver); } MODULE_AUTHOR("Intel Corporation"); MODULE_LICENSE("GPL v2"); -subsys_initcall(dax_init); +module_init(dax_init); module_exit(dax_exit); +MODULE_ALIAS_DAX_DEVICE(0); -- cgit v1.2.3