diff options
| -rw-r--r-- | drivers/dax/dax.c | 337 |
1 files changed, 168 insertions, 169 deletions
diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c index 736c038..3774fc9 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; |
