diff options
| -rw-r--r-- | drivers/dax/Kconfig | 5 | ||||
| -rw-r--r-- | drivers/dax/dax.c | 82 |
2 files changed, 46 insertions, 41 deletions
diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig index cedab7572de3..daadd20aa936 100644 --- a/drivers/dax/Kconfig +++ b/drivers/dax/Kconfig @@ -23,4 +23,9 @@ config DEV_DAX_PMEM Say Y if unsure +config NR_DEV_DAX + int "Maximum number of Device-DAX instances" + default 32768 + range 256 2147483647 + endif diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c index 181d2a5a21e4..17715773c097 100644 --- a/drivers/dax/dax.c +++ b/drivers/dax/dax.c @@ -14,15 +14,19 @@ #include <linux/module.h> #include <linux/device.h> #include <linux/pfn_t.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); +MODULE_PARM_DESC(nr_dax, "max number of device-dax instances"); /** * struct dax_region - mapping infrastructure for dax devices @@ -49,6 +53,7 @@ struct dax_region { * struct dax_dev - subdivision of a dax region * @region - parent region * @dev - device backing the character device + * @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 @@ -57,6 +62,7 @@ struct dax_region { struct dax_dev { struct dax_region *region; struct device dev; + struct cdev cdev; bool alive; int id; int num_resources; @@ -367,29 +373,12 @@ static unsigned long dax_get_unmapped_area(struct file *filp, 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_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; + struct dax_dev *dax_dev; - dax_dev = to_dax_dev(dev); - dev_dbg(dev, "%s\n", __func__); + dax_dev = container_of(inode->i_cdev, struct dax_dev, cdev); + dev_dbg(&dax_dev->dev, "%s\n", __func__); filp->private_data = dax_dev; inode->i_flags = S_DAX; @@ -399,11 +388,8 @@ static int dax_open(struct inode *inode, struct file *filp) static int dax_release(struct inode *inode, struct file *filp) { struct dax_dev *dax_dev = filp->private_data; - struct device *dev = &dax_dev->dev; - - dev_dbg(dev, "%s\n", __func__); - put_device(dev); + dev_dbg(&dax_dev->dev, "%s\n", __func__); return 0; } @@ -430,6 +416,7 @@ static void dax_dev_release(struct device *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__); @@ -442,6 +429,7 @@ static void unregister_dax_dev(void *dev) */ dax_dev->alive = false; synchronize_rcu(); + cdev_del(cdev); device_unregister(dev); } @@ -451,17 +439,13 @@ int devm_create_dax_dev(struct dax_region *dax_region, struct resource *res, struct device *parent = dax_region->dev; struct dax_dev *dax_dev; struct device *dev; + struct cdev *cdev; 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; - 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) { @@ -475,10 +459,26 @@ int devm_create_dax_dev(struct dax_region *dax_region, struct resource *res, goto err_minor; } - dev_t = MKDEV(dax_major, minor); - + /* device_initialize() so cdev can reference kobj parent */ + dev_t = MKDEV(MAJOR(dax_devt), minor); dev = &dax_dev->dev; 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() */ + memcpy(dax_dev->res, res, sizeof(*res) * count); + 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; @@ -493,6 +493,8 @@ int devm_create_dax_dev(struct dax_region *dax_region, struct resource *res, return devm_add_action_or_reset(dax_region->dev, unregister_dax_dev, dev); + err_cdev: + ida_simple_remove(&dax_minor_ida, minor); err_minor: ida_simple_remove(&dax_region->ida, dax_dev->id); err_id: @@ -506,24 +508,22 @@ static int __init dax_init(void) { int rc; - rc = register_chrdev(0, "dax", &dax_fops); - if (rc < 0) + nr_dax = max(nr_dax, 256); + rc = alloc_chrdev_region(&dax_devt, 0, nr_dax, "dax"); + if (rc) return rc; - dax_major = rc; dax_class = class_create(THIS_MODULE, "dax"); - if (IS_ERR(dax_class)) { - unregister_chrdev(dax_major, "dax"); - return PTR_ERR(dax_class); - } + if (IS_ERR(dax_class)) + unregister_chrdev_region(dax_devt, nr_dax); - return 0; + return PTR_ERR_OR_ZERO(dax_class); } 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); } |