15b497af4SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 27b6be844SDan Williams /* 37b6be844SDan Williams * Copyright(c) 2017 Intel Corporation. All rights reserved. 47b6be844SDan Williams */ 57b6be844SDan Williams #include <linux/pagemap.h> 67b6be844SDan Williams #include <linux/module.h> 77b6be844SDan Williams #include <linux/mount.h> 875d4e06fSDavid Howells #include <linux/pseudo_fs.h> 97b6be844SDan Williams #include <linux/magic.h> 10569d0365SDan Williams #include <linux/pfn_t.h> 117b6be844SDan Williams #include <linux/cdev.h> 127b6be844SDan Williams #include <linux/slab.h> 137e026c8cSDan Williams #include <linux/uio.h> 146568b08bSDan Williams #include <linux/dax.h> 157b6be844SDan Williams #include <linux/fs.h> 1651cf784cSDan Williams #include "dax-private.h" 177b6be844SDan Williams 181b764601SChristoph Hellwig /** 191b764601SChristoph Hellwig * struct dax_device - anchor object for dax services 201b764601SChristoph Hellwig * @inode: core vfs 211b764601SChristoph Hellwig * @cdev: optional character interface for "device dax" 221b764601SChristoph Hellwig * @private: dax driver private data 231b764601SChristoph Hellwig * @flags: state and boolean properties 241b764601SChristoph Hellwig */ 251b764601SChristoph Hellwig struct dax_device { 261b764601SChristoph Hellwig struct inode inode; 271b764601SChristoph Hellwig struct cdev cdev; 281b764601SChristoph Hellwig void *private; 291b764601SChristoph Hellwig unsigned long flags; 301b764601SChristoph Hellwig const struct dax_operations *ops; 311b764601SChristoph Hellwig }; 321b764601SChristoph Hellwig 337b6be844SDan Williams static dev_t dax_devt; 347b6be844SDan Williams DEFINE_STATIC_SRCU(dax_srcu); 357b6be844SDan Williams static struct vfsmount *dax_mnt; 367b6be844SDan Williams static DEFINE_IDA(dax_minor_ida); 377b6be844SDan Williams static struct kmem_cache *dax_cache __read_mostly; 387b6be844SDan Williams static struct super_block *dax_superblock __read_mostly; 397b6be844SDan Williams 407b6be844SDan Williams int dax_read_lock(void) 417b6be844SDan Williams { 427b6be844SDan Williams return srcu_read_lock(&dax_srcu); 437b6be844SDan Williams } 447b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_read_lock); 457b6be844SDan Williams 467b6be844SDan Williams void dax_read_unlock(int id) 477b6be844SDan Williams { 487b6be844SDan Williams srcu_read_unlock(&dax_srcu, id); 497b6be844SDan Williams } 507b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_read_unlock); 517b6be844SDan Williams 525d2a228bSChristoph Hellwig #if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX) 53e765f13eSChristoph Hellwig #include <linux/blkdev.h> 54e765f13eSChristoph Hellwig 55fb08a190SChristoph Hellwig static DEFINE_XARRAY(dax_hosts); 56fb08a190SChristoph Hellwig 57fb08a190SChristoph Hellwig int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk) 58fb08a190SChristoph Hellwig { 59fb08a190SChristoph Hellwig return xa_insert(&dax_hosts, (unsigned long)disk, dax_dev, GFP_KERNEL); 60fb08a190SChristoph Hellwig } 61fb08a190SChristoph Hellwig EXPORT_SYMBOL_GPL(dax_add_host); 62fb08a190SChristoph Hellwig 63fb08a190SChristoph Hellwig void dax_remove_host(struct gendisk *disk) 64fb08a190SChristoph Hellwig { 65fb08a190SChristoph Hellwig xa_erase(&dax_hosts, (unsigned long)disk); 66fb08a190SChristoph Hellwig } 67fb08a190SChristoph Hellwig EXPORT_SYMBOL_GPL(dax_remove_host); 68fb08a190SChristoph Hellwig 69e765f13eSChristoph Hellwig int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, 70e765f13eSChristoph Hellwig pgoff_t *pgoff) 71e765f13eSChristoph Hellwig { 72e765f13eSChristoph Hellwig sector_t start_sect = bdev ? get_start_sect(bdev) : 0; 73e765f13eSChristoph Hellwig phys_addr_t phys_off = (start_sect + sector) * 512; 74e765f13eSChristoph Hellwig 75e765f13eSChristoph Hellwig if (pgoff) 76e765f13eSChristoph Hellwig *pgoff = PHYS_PFN(phys_off); 77e765f13eSChristoph Hellwig if (phys_off % PAGE_SIZE || size % PAGE_SIZE) 78e765f13eSChristoph Hellwig return -EINVAL; 79e765f13eSChristoph Hellwig return 0; 80e765f13eSChristoph Hellwig } 81e765f13eSChristoph Hellwig EXPORT_SYMBOL(bdev_dax_pgoff); 82e765f13eSChristoph Hellwig 831b764601SChristoph Hellwig /** 84fb08a190SChristoph Hellwig * fs_dax_get_by_bdev() - temporary lookup mechanism for filesystem-dax 85fb08a190SChristoph Hellwig * @bdev: block device to find a dax_device for 861b764601SChristoph Hellwig */ 8778f35473SDan Williams struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) 8878f35473SDan Williams { 89fb08a190SChristoph Hellwig struct dax_device *dax_dev; 90fb08a190SChristoph Hellwig int id; 91fb08a190SChristoph Hellwig 92e556f6baSChristoph Hellwig if (!blk_queue_dax(bdev->bd_disk->queue)) 9378f35473SDan Williams return NULL; 94fb08a190SChristoph Hellwig 95*0c445871SChristoph Hellwig if ((get_start_sect(bdev) * SECTOR_SIZE) % PAGE_SIZE || 96*0c445871SChristoph Hellwig (bdev_nr_sectors(bdev) * SECTOR_SIZE) % PAGE_SIZE) { 97*0c445871SChristoph Hellwig pr_info("%pg: error: unaligned partition for dax\n", bdev); 98*0c445871SChristoph Hellwig return NULL; 99*0c445871SChristoph Hellwig } 100*0c445871SChristoph Hellwig 101fb08a190SChristoph Hellwig id = dax_read_lock(); 102fb08a190SChristoph Hellwig dax_dev = xa_load(&dax_hosts, (unsigned long)bdev->bd_disk); 103fb08a190SChristoph Hellwig if (!dax_dev || !dax_alive(dax_dev) || !igrab(&dax_dev->inode)) 104fb08a190SChristoph Hellwig dax_dev = NULL; 105fb08a190SChristoph Hellwig dax_read_unlock(id); 106fb08a190SChristoph Hellwig 107fb08a190SChristoph Hellwig return dax_dev; 10878f35473SDan Williams } 10978f35473SDan Williams EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev); 11078f35473SDan Williams 111cd93a2a4SChristoph Hellwig bool generic_fsdax_supported(struct dax_device *dax_dev, 1127bf7eac8SDan Williams struct block_device *bdev, int blocksize, sector_t start, 1137bf7eac8SDan Williams sector_t sectors) 114ef510424SDan Williams { 115ef510424SDan Williams if (blocksize != PAGE_SIZE) { 11639b6389aSChristoph Hellwig pr_info("%pg: error: unsupported blocksize for dax\n", bdev); 11780660f20SDave Jiang return false; 118ef510424SDan Williams } 119ef510424SDan Williams 120d4c5da50SAdrian Huang if (!dax_dev) { 12139b6389aSChristoph Hellwig pr_debug("%pg: error: dax unsupported by block device\n", bdev); 122d4c5da50SAdrian Huang return false; 123d4c5da50SAdrian Huang } 124d4c5da50SAdrian Huang 12580660f20SDave Jiang return true; 126ef510424SDan Williams } 127cd93a2a4SChristoph Hellwig EXPORT_SYMBOL_GPL(generic_fsdax_supported); 12860b8340fSChristoph Hellwig 12960b8340fSChristoph Hellwig bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev, 13060b8340fSChristoph Hellwig int blocksize, sector_t start, sector_t len) 13160b8340fSChristoph Hellwig { 13260b8340fSChristoph Hellwig bool ret = false; 13360b8340fSChristoph Hellwig int id; 13460b8340fSChristoph Hellwig 13560b8340fSChristoph Hellwig if (!dax_dev) 13660b8340fSChristoph Hellwig return false; 13760b8340fSChristoph Hellwig 13860b8340fSChristoph Hellwig id = dax_read_lock(); 13960b8340fSChristoph Hellwig if (dax_alive(dax_dev) && dax_dev->ops->dax_supported) 14060b8340fSChristoph Hellwig ret = dax_dev->ops->dax_supported(dax_dev, bdev, blocksize, 14160b8340fSChristoph Hellwig start, len); 14260b8340fSChristoph Hellwig dax_read_unlock(id); 14360b8340fSChristoph Hellwig return ret; 14460b8340fSChristoph Hellwig } 14560b8340fSChristoph Hellwig EXPORT_SYMBOL_GPL(dax_supported); 1465d2a228bSChristoph Hellwig #endif /* CONFIG_BLOCK && CONFIG_FS_DAX */ 147ef510424SDan Williams 1489a60c3efSDan Williams enum dax_device_flags { 1499a60c3efSDan Williams /* !alive + rcu grace period == no new operations / mappings */ 1509a60c3efSDan Williams DAXDEV_ALIVE, 1516e0c90d6SDan Williams /* gate whether dax_flush() calls the low level flush routine */ 1526e0c90d6SDan Williams DAXDEV_WRITE_CACHE, 153fefc1d97SPankaj Gupta /* flag to check if device supports synchronous flush */ 154fefc1d97SPankaj Gupta DAXDEV_SYNC, 1559a60c3efSDan Williams }; 1569a60c3efSDan Williams 157b0686260SDan Williams /** 158b0686260SDan Williams * dax_direct_access() - translate a device pgoff to an absolute pfn 159b0686260SDan Williams * @dax_dev: a dax_device instance representing the logical memory range 160b0686260SDan Williams * @pgoff: offset in pages from the start of the device to translate 161b0686260SDan Williams * @nr_pages: number of consecutive pages caller can handle relative to @pfn 162b0686260SDan Williams * @kaddr: output parameter that returns a virtual address mapping of pfn 163b0686260SDan Williams * @pfn: output parameter that returns an absolute pfn translation of @pgoff 164b0686260SDan Williams * 165b0686260SDan Williams * Return: negative errno if an error occurs, otherwise the number of 166b0686260SDan Williams * pages accessible at the device relative @pgoff. 167b0686260SDan Williams */ 168b0686260SDan Williams long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, 169b0686260SDan Williams void **kaddr, pfn_t *pfn) 170b0686260SDan Williams { 171b0686260SDan Williams long avail; 172b0686260SDan Williams 173b0686260SDan Williams if (!dax_dev) 174b0686260SDan Williams return -EOPNOTSUPP; 175b0686260SDan Williams 176b0686260SDan Williams if (!dax_alive(dax_dev)) 177b0686260SDan Williams return -ENXIO; 178b0686260SDan Williams 179b0686260SDan Williams if (nr_pages < 0) 180b05d4c57SIra Weiny return -EINVAL; 181b0686260SDan Williams 182b0686260SDan Williams avail = dax_dev->ops->direct_access(dax_dev, pgoff, nr_pages, 183b0686260SDan Williams kaddr, pfn); 184b0686260SDan Williams if (!avail) 185b0686260SDan Williams return -ERANGE; 186b0686260SDan Williams return min(avail, nr_pages); 187b0686260SDan Williams } 188b0686260SDan Williams EXPORT_SYMBOL_GPL(dax_direct_access); 189b0686260SDan Williams 1907e026c8cSDan Williams size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, 1917e026c8cSDan Williams size_t bytes, struct iov_iter *i) 1927e026c8cSDan Williams { 1937e026c8cSDan Williams if (!dax_alive(dax_dev)) 1947e026c8cSDan Williams return 0; 1957e026c8cSDan Williams 1967e026c8cSDan Williams return dax_dev->ops->copy_from_iter(dax_dev, pgoff, addr, bytes, i); 1977e026c8cSDan Williams } 1987e026c8cSDan Williams EXPORT_SYMBOL_GPL(dax_copy_from_iter); 1997e026c8cSDan Williams 200b3a9a0c3SDan Williams size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, 201b3a9a0c3SDan Williams size_t bytes, struct iov_iter *i) 202b3a9a0c3SDan Williams { 203b3a9a0c3SDan Williams if (!dax_alive(dax_dev)) 204b3a9a0c3SDan Williams return 0; 205b3a9a0c3SDan Williams 206b3a9a0c3SDan Williams return dax_dev->ops->copy_to_iter(dax_dev, pgoff, addr, bytes, i); 207b3a9a0c3SDan Williams } 208b3a9a0c3SDan Williams EXPORT_SYMBOL_GPL(dax_copy_to_iter); 209b3a9a0c3SDan Williams 210f605a263SVivek Goyal int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, 211f605a263SVivek Goyal size_t nr_pages) 212f605a263SVivek Goyal { 213f605a263SVivek Goyal if (!dax_alive(dax_dev)) 214f605a263SVivek Goyal return -ENXIO; 215f605a263SVivek Goyal /* 216f605a263SVivek Goyal * There are no callers that want to zero more than one page as of now. 217f605a263SVivek Goyal * Once users are there, this check can be removed after the 218f605a263SVivek Goyal * device mapper code has been updated to split ranges across targets. 219f605a263SVivek Goyal */ 220f605a263SVivek Goyal if (nr_pages != 1) 221f605a263SVivek Goyal return -EIO; 222f605a263SVivek Goyal 223f605a263SVivek Goyal return dax_dev->ops->zero_page_range(dax_dev, pgoff, nr_pages); 224f605a263SVivek Goyal } 225f605a263SVivek Goyal EXPORT_SYMBOL_GPL(dax_zero_page_range); 226f605a263SVivek Goyal 227c3ca015fSMikulas Patocka #ifdef CONFIG_ARCH_HAS_PMEM_API 228c3ca015fSMikulas Patocka void arch_wb_cache_pmem(void *addr, size_t size); 229c3ca015fSMikulas Patocka void dax_flush(struct dax_device *dax_dev, void *addr, size_t size) 230abebfbe2SDan Williams { 231808c340bSRoss Zwisler if (unlikely(!dax_write_cache_enabled(dax_dev))) 2326e0c90d6SDan Williams return; 2336e0c90d6SDan Williams 234c3ca015fSMikulas Patocka arch_wb_cache_pmem(addr, size); 235abebfbe2SDan Williams } 236c3ca015fSMikulas Patocka #else 237c3ca015fSMikulas Patocka void dax_flush(struct dax_device *dax_dev, void *addr, size_t size) 238c3ca015fSMikulas Patocka { 239c3ca015fSMikulas Patocka } 240c3ca015fSMikulas Patocka #endif 241abebfbe2SDan Williams EXPORT_SYMBOL_GPL(dax_flush); 242abebfbe2SDan Williams 2436e0c90d6SDan Williams void dax_write_cache(struct dax_device *dax_dev, bool wc) 2446e0c90d6SDan Williams { 2456e0c90d6SDan Williams if (wc) 2466e0c90d6SDan Williams set_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); 2476e0c90d6SDan Williams else 2486e0c90d6SDan Williams clear_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); 2496e0c90d6SDan Williams } 2506e0c90d6SDan Williams EXPORT_SYMBOL_GPL(dax_write_cache); 2516e0c90d6SDan Williams 252273752c9SVivek Goyal bool dax_write_cache_enabled(struct dax_device *dax_dev) 253273752c9SVivek Goyal { 254273752c9SVivek Goyal return test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); 255273752c9SVivek Goyal } 256273752c9SVivek Goyal EXPORT_SYMBOL_GPL(dax_write_cache_enabled); 257273752c9SVivek Goyal 258fefc1d97SPankaj Gupta bool __dax_synchronous(struct dax_device *dax_dev) 259fefc1d97SPankaj Gupta { 260fefc1d97SPankaj Gupta return test_bit(DAXDEV_SYNC, &dax_dev->flags); 261fefc1d97SPankaj Gupta } 262fefc1d97SPankaj Gupta EXPORT_SYMBOL_GPL(__dax_synchronous); 263fefc1d97SPankaj Gupta 264fefc1d97SPankaj Gupta void __set_dax_synchronous(struct dax_device *dax_dev) 265fefc1d97SPankaj Gupta { 266fefc1d97SPankaj Gupta set_bit(DAXDEV_SYNC, &dax_dev->flags); 267fefc1d97SPankaj Gupta } 268fefc1d97SPankaj Gupta EXPORT_SYMBOL_GPL(__set_dax_synchronous); 269fefc1d97SPankaj Gupta 2707b6be844SDan Williams bool dax_alive(struct dax_device *dax_dev) 2717b6be844SDan Williams { 2727b6be844SDan Williams lockdep_assert_held(&dax_srcu); 2739a60c3efSDan Williams return test_bit(DAXDEV_ALIVE, &dax_dev->flags); 2747b6be844SDan Williams } 2757b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_alive); 2767b6be844SDan Williams 2777b6be844SDan Williams /* 2787b6be844SDan Williams * Note, rcu is not protecting the liveness of dax_dev, rcu is ensuring 2797b6be844SDan Williams * that any fault handlers or operations that might have seen 2807b6be844SDan Williams * dax_alive(), have completed. Any operations that start after 2817b6be844SDan Williams * synchronize_srcu() has run will abort upon seeing !dax_alive(). 2827b6be844SDan Williams */ 2837b6be844SDan Williams void kill_dax(struct dax_device *dax_dev) 2847b6be844SDan Williams { 2857b6be844SDan Williams if (!dax_dev) 2867b6be844SDan Williams return; 2877b6be844SDan Williams 2889a60c3efSDan Williams clear_bit(DAXDEV_ALIVE, &dax_dev->flags); 2897b6be844SDan Williams synchronize_srcu(&dax_srcu); 2907b6be844SDan Williams } 2917b6be844SDan Williams EXPORT_SYMBOL_GPL(kill_dax); 2927b6be844SDan Williams 2939567da0bSDan Williams void run_dax(struct dax_device *dax_dev) 2949567da0bSDan Williams { 2959567da0bSDan Williams set_bit(DAXDEV_ALIVE, &dax_dev->flags); 2969567da0bSDan Williams } 2979567da0bSDan Williams EXPORT_SYMBOL_GPL(run_dax); 2989567da0bSDan Williams 2997b6be844SDan Williams static struct inode *dax_alloc_inode(struct super_block *sb) 3007b6be844SDan Williams { 3017b6be844SDan Williams struct dax_device *dax_dev; 302b9d39d17SDan Williams struct inode *inode; 3037b6be844SDan Williams 3047b6be844SDan Williams dax_dev = kmem_cache_alloc(dax_cache, GFP_KERNEL); 3059f586fffSMikulas Patocka if (!dax_dev) 3069f586fffSMikulas Patocka return NULL; 3079f586fffSMikulas Patocka 308b9d39d17SDan Williams inode = &dax_dev->inode; 309b9d39d17SDan Williams inode->i_rdev = 0; 310b9d39d17SDan Williams return inode; 3117b6be844SDan Williams } 3127b6be844SDan Williams 3137b6be844SDan Williams static struct dax_device *to_dax_dev(struct inode *inode) 3147b6be844SDan Williams { 3157b6be844SDan Williams return container_of(inode, struct dax_device, inode); 3167b6be844SDan Williams } 3177b6be844SDan Williams 31853e22829SAl Viro static void dax_free_inode(struct inode *inode) 3197b6be844SDan Williams { 3207b6be844SDan Williams struct dax_device *dax_dev = to_dax_dev(inode); 321b9d39d17SDan Williams if (inode->i_rdev) 3226f24784fSAl Viro ida_simple_remove(&dax_minor_ida, iminor(inode)); 3237b6be844SDan Williams kmem_cache_free(dax_cache, dax_dev); 3247b6be844SDan Williams } 3257b6be844SDan Williams 3267b6be844SDan Williams static void dax_destroy_inode(struct inode *inode) 3277b6be844SDan Williams { 3287b6be844SDan Williams struct dax_device *dax_dev = to_dax_dev(inode); 3299a60c3efSDan Williams WARN_ONCE(test_bit(DAXDEV_ALIVE, &dax_dev->flags), 3307b6be844SDan Williams "kill_dax() must be called before final iput()\n"); 3317b6be844SDan Williams } 3327b6be844SDan Williams 3337b6be844SDan Williams static const struct super_operations dax_sops = { 3347b6be844SDan Williams .statfs = simple_statfs, 3357b6be844SDan Williams .alloc_inode = dax_alloc_inode, 3367b6be844SDan Williams .destroy_inode = dax_destroy_inode, 33753e22829SAl Viro .free_inode = dax_free_inode, 3387b6be844SDan Williams .drop_inode = generic_delete_inode, 3397b6be844SDan Williams }; 3407b6be844SDan Williams 34175d4e06fSDavid Howells static int dax_init_fs_context(struct fs_context *fc) 3427b6be844SDan Williams { 34375d4e06fSDavid Howells struct pseudo_fs_context *ctx = init_pseudo(fc, DAXFS_MAGIC); 34475d4e06fSDavid Howells if (!ctx) 34575d4e06fSDavid Howells return -ENOMEM; 34675d4e06fSDavid Howells ctx->ops = &dax_sops; 34775d4e06fSDavid Howells return 0; 3487b6be844SDan Williams } 3497b6be844SDan Williams 3507b6be844SDan Williams static struct file_system_type dax_fs_type = { 3517b6be844SDan Williams .name = "dax", 35275d4e06fSDavid Howells .init_fs_context = dax_init_fs_context, 3537b6be844SDan Williams .kill_sb = kill_anon_super, 3547b6be844SDan Williams }; 3557b6be844SDan Williams 3567b6be844SDan Williams static int dax_test(struct inode *inode, void *data) 3577b6be844SDan Williams { 3587b6be844SDan Williams dev_t devt = *(dev_t *) data; 3597b6be844SDan Williams 3607b6be844SDan Williams return inode->i_rdev == devt; 3617b6be844SDan Williams } 3627b6be844SDan Williams 3637b6be844SDan Williams static int dax_set(struct inode *inode, void *data) 3647b6be844SDan Williams { 3657b6be844SDan Williams dev_t devt = *(dev_t *) data; 3667b6be844SDan Williams 3677b6be844SDan Williams inode->i_rdev = devt; 3687b6be844SDan Williams return 0; 3697b6be844SDan Williams } 3707b6be844SDan Williams 3717b6be844SDan Williams static struct dax_device *dax_dev_get(dev_t devt) 3727b6be844SDan Williams { 3737b6be844SDan Williams struct dax_device *dax_dev; 3747b6be844SDan Williams struct inode *inode; 3757b6be844SDan Williams 3767b6be844SDan Williams inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31), 3777b6be844SDan Williams dax_test, dax_set, &devt); 3787b6be844SDan Williams 3797b6be844SDan Williams if (!inode) 3807b6be844SDan Williams return NULL; 3817b6be844SDan Williams 3827b6be844SDan Williams dax_dev = to_dax_dev(inode); 3837b6be844SDan Williams if (inode->i_state & I_NEW) { 3849a60c3efSDan Williams set_bit(DAXDEV_ALIVE, &dax_dev->flags); 3857b6be844SDan Williams inode->i_cdev = &dax_dev->cdev; 3867b6be844SDan Williams inode->i_mode = S_IFCHR; 3877b6be844SDan Williams inode->i_flags = S_DAX; 3887b6be844SDan Williams mapping_set_gfp_mask(&inode->i_data, GFP_USER); 3897b6be844SDan Williams unlock_new_inode(inode); 3907b6be844SDan Williams } 3917b6be844SDan Williams 3927b6be844SDan Williams return dax_dev; 3937b6be844SDan Williams } 3947b6be844SDan Williams 395fb08a190SChristoph Hellwig struct dax_device *alloc_dax(void *private, const struct dax_operations *ops, 396fb08a190SChristoph Hellwig unsigned long flags) 3977b6be844SDan Williams { 3987b6be844SDan Williams struct dax_device *dax_dev; 3997b6be844SDan Williams dev_t devt; 4007b6be844SDan Williams int minor; 4017b6be844SDan Williams 402fb08a190SChristoph Hellwig if (WARN_ON_ONCE(ops && !ops->zero_page_range)) 4034e4ced93SVivek Goyal return ERR_PTR(-EINVAL); 40472058005SDan Williams 405cf1e2289SDan Williams minor = ida_simple_get(&dax_minor_ida, 0, MINORMASK+1, GFP_KERNEL); 4067b6be844SDan Williams if (minor < 0) 407fb08a190SChristoph Hellwig return ERR_PTR(-ENOMEM); 4087b6be844SDan Williams 4097b6be844SDan Williams devt = MKDEV(MAJOR(dax_devt), minor); 4107b6be844SDan Williams dax_dev = dax_dev_get(devt); 4117b6be844SDan Williams if (!dax_dev) 41272058005SDan Williams goto err_dev; 4137b6be844SDan Williams 4146568b08bSDan Williams dax_dev->ops = ops; 4157b6be844SDan Williams dax_dev->private = private; 416fefc1d97SPankaj Gupta if (flags & DAXDEV_F_SYNC) 417fefc1d97SPankaj Gupta set_dax_synchronous(dax_dev); 418fefc1d97SPankaj Gupta 4197b6be844SDan Williams return dax_dev; 4207b6be844SDan Williams 42172058005SDan Williams err_dev: 4227b6be844SDan Williams ida_simple_remove(&dax_minor_ida, minor); 4234e4ced93SVivek Goyal return ERR_PTR(-ENOMEM); 4247b6be844SDan Williams } 4257b6be844SDan Williams EXPORT_SYMBOL_GPL(alloc_dax); 4267b6be844SDan Williams 4277b6be844SDan Williams void put_dax(struct dax_device *dax_dev) 4287b6be844SDan Williams { 4297b6be844SDan Williams if (!dax_dev) 4307b6be844SDan Williams return; 4317b6be844SDan Williams iput(&dax_dev->inode); 4327b6be844SDan Williams } 4337b6be844SDan Williams EXPORT_SYMBOL_GPL(put_dax); 4347b6be844SDan Williams 4357b6be844SDan Williams /** 4367b6be844SDan Williams * inode_dax: convert a public inode into its dax_dev 4377b6be844SDan Williams * @inode: An inode with i_cdev pointing to a dax_dev 4387b6be844SDan Williams * 4397b6be844SDan Williams * Note this is not equivalent to to_dax_dev() which is for private 4407b6be844SDan Williams * internal use where we know the inode filesystem type == dax_fs_type. 4417b6be844SDan Williams */ 4427b6be844SDan Williams struct dax_device *inode_dax(struct inode *inode) 4437b6be844SDan Williams { 4447b6be844SDan Williams struct cdev *cdev = inode->i_cdev; 4457b6be844SDan Williams 4467b6be844SDan Williams return container_of(cdev, struct dax_device, cdev); 4477b6be844SDan Williams } 4487b6be844SDan Williams EXPORT_SYMBOL_GPL(inode_dax); 4497b6be844SDan Williams 4507b6be844SDan Williams struct inode *dax_inode(struct dax_device *dax_dev) 4517b6be844SDan Williams { 4527b6be844SDan Williams return &dax_dev->inode; 4537b6be844SDan Williams } 4547b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_inode); 4557b6be844SDan Williams 4567b6be844SDan Williams void *dax_get_private(struct dax_device *dax_dev) 4577b6be844SDan Williams { 4589567da0bSDan Williams if (!test_bit(DAXDEV_ALIVE, &dax_dev->flags)) 4599567da0bSDan Williams return NULL; 4607b6be844SDan Williams return dax_dev->private; 4617b6be844SDan Williams } 4627b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_get_private); 4637b6be844SDan Williams 4647b6be844SDan Williams static void init_once(void *_dax_dev) 4657b6be844SDan Williams { 4667b6be844SDan Williams struct dax_device *dax_dev = _dax_dev; 4677b6be844SDan Williams struct inode *inode = &dax_dev->inode; 4687b6be844SDan Williams 469b9d39d17SDan Williams memset(dax_dev, 0, sizeof(*dax_dev)); 4707b6be844SDan Williams inode_init_once(inode); 4717b6be844SDan Williams } 4727b6be844SDan Williams 4739567da0bSDan Williams static int dax_fs_init(void) 4747b6be844SDan Williams { 4757b6be844SDan Williams int rc; 4767b6be844SDan Williams 4777b6be844SDan Williams dax_cache = kmem_cache_create("dax_cache", sizeof(struct dax_device), 0, 4787b6be844SDan Williams (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 4797b6be844SDan Williams SLAB_MEM_SPREAD|SLAB_ACCOUNT), 4807b6be844SDan Williams init_once); 4817b6be844SDan Williams if (!dax_cache) 4827b6be844SDan Williams return -ENOMEM; 4837b6be844SDan Williams 4847b6be844SDan Williams dax_mnt = kern_mount(&dax_fs_type); 4857b6be844SDan Williams if (IS_ERR(dax_mnt)) { 4867b6be844SDan Williams rc = PTR_ERR(dax_mnt); 4877b6be844SDan Williams goto err_mount; 4887b6be844SDan Williams } 4897b6be844SDan Williams dax_superblock = dax_mnt->mnt_sb; 4907b6be844SDan Williams 4917b6be844SDan Williams return 0; 4927b6be844SDan Williams 4937b6be844SDan Williams err_mount: 4947b6be844SDan Williams kmem_cache_destroy(dax_cache); 4957b6be844SDan Williams 4967b6be844SDan Williams return rc; 4977b6be844SDan Williams } 4987b6be844SDan Williams 4999567da0bSDan Williams static void dax_fs_exit(void) 5007b6be844SDan Williams { 5017b6be844SDan Williams kern_unmount(dax_mnt); 5027b6be844SDan Williams kmem_cache_destroy(dax_cache); 5037b6be844SDan Williams } 5047b6be844SDan Williams 5059567da0bSDan Williams static int __init dax_core_init(void) 5067b6be844SDan Williams { 5077b6be844SDan Williams int rc; 5087b6be844SDan Williams 5099567da0bSDan Williams rc = dax_fs_init(); 5107b6be844SDan Williams if (rc) 5117b6be844SDan Williams return rc; 5127b6be844SDan Williams 513cf1e2289SDan Williams rc = alloc_chrdev_region(&dax_devt, 0, MINORMASK+1, "dax"); 5147b6be844SDan Williams if (rc) 5159567da0bSDan Williams goto err_chrdev; 5169567da0bSDan Williams 5179567da0bSDan Williams rc = dax_bus_init(); 5189567da0bSDan Williams if (rc) 5199567da0bSDan Williams goto err_bus; 5209567da0bSDan Williams return 0; 5219567da0bSDan Williams 5229567da0bSDan Williams err_bus: 5239567da0bSDan Williams unregister_chrdev_region(dax_devt, MINORMASK+1); 5249567da0bSDan Williams err_chrdev: 5259567da0bSDan Williams dax_fs_exit(); 5269567da0bSDan Williams return 0; 5277b6be844SDan Williams } 5287b6be844SDan Williams 5299567da0bSDan Williams static void __exit dax_core_exit(void) 5307b6be844SDan Williams { 5311aa57431SWang Hai dax_bus_exit(); 532cf1e2289SDan Williams unregister_chrdev_region(dax_devt, MINORMASK+1); 5337b6be844SDan Williams ida_destroy(&dax_minor_ida); 5349567da0bSDan Williams dax_fs_exit(); 5357b6be844SDan Williams } 5367b6be844SDan Williams 5377b6be844SDan Williams MODULE_AUTHOR("Intel Corporation"); 5387b6be844SDan Williams MODULE_LICENSE("GPL v2"); 5399567da0bSDan Williams subsys_initcall(dax_core_init); 5409567da0bSDan Williams module_exit(dax_core_exit); 541