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
24db8cd5efSIra Weiny * @ops: operations for this device
258012b866SShiyang Ruan * @holder_data: holder of a dax_device: could be filesystem or mapped device
268012b866SShiyang Ruan * @holder_ops: operations for the inner holder
271b764601SChristoph Hellwig */
281b764601SChristoph Hellwig struct dax_device {
291b764601SChristoph Hellwig struct inode inode;
301b764601SChristoph Hellwig struct cdev cdev;
311b764601SChristoph Hellwig void *private;
321b764601SChristoph Hellwig unsigned long flags;
331b764601SChristoph Hellwig const struct dax_operations *ops;
348012b866SShiyang Ruan void *holder_data;
358012b866SShiyang Ruan const struct dax_holder_operations *holder_ops;
361b764601SChristoph Hellwig };
371b764601SChristoph Hellwig
387b6be844SDan Williams static dev_t dax_devt;
397b6be844SDan Williams DEFINE_STATIC_SRCU(dax_srcu);
407b6be844SDan Williams static struct vfsmount *dax_mnt;
417b6be844SDan Williams static DEFINE_IDA(dax_minor_ida);
427b6be844SDan Williams static struct kmem_cache *dax_cache __read_mostly;
437b6be844SDan Williams static struct super_block *dax_superblock __read_mostly;
447b6be844SDan Williams
dax_read_lock(void)457b6be844SDan Williams int dax_read_lock(void)
467b6be844SDan Williams {
477b6be844SDan Williams return srcu_read_lock(&dax_srcu);
487b6be844SDan Williams }
497b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_read_lock);
507b6be844SDan Williams
dax_read_unlock(int id)517b6be844SDan Williams void dax_read_unlock(int id)
527b6be844SDan Williams {
537b6be844SDan Williams srcu_read_unlock(&dax_srcu, id);
547b6be844SDan Williams }
557b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_read_unlock);
567b6be844SDan Williams
575d2a228bSChristoph Hellwig #if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX)
58e765f13eSChristoph Hellwig #include <linux/blkdev.h>
59e765f13eSChristoph Hellwig
60fb08a190SChristoph Hellwig static DEFINE_XARRAY(dax_hosts);
61fb08a190SChristoph Hellwig
dax_add_host(struct dax_device * dax_dev,struct gendisk * disk)62fb08a190SChristoph Hellwig int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk)
63fb08a190SChristoph Hellwig {
64fb08a190SChristoph Hellwig return xa_insert(&dax_hosts, (unsigned long)disk, dax_dev, GFP_KERNEL);
65fb08a190SChristoph Hellwig }
66fb08a190SChristoph Hellwig EXPORT_SYMBOL_GPL(dax_add_host);
67fb08a190SChristoph Hellwig
dax_remove_host(struct gendisk * disk)68fb08a190SChristoph Hellwig void dax_remove_host(struct gendisk *disk)
69fb08a190SChristoph Hellwig {
70fb08a190SChristoph Hellwig xa_erase(&dax_hosts, (unsigned long)disk);
71fb08a190SChristoph Hellwig }
72fb08a190SChristoph Hellwig EXPORT_SYMBOL_GPL(dax_remove_host);
73fb08a190SChristoph Hellwig
741b764601SChristoph Hellwig /**
75fb08a190SChristoph Hellwig * fs_dax_get_by_bdev() - temporary lookup mechanism for filesystem-dax
76fb08a190SChristoph Hellwig * @bdev: block device to find a dax_device for
77cd913c76SChristoph Hellwig * @start_off: returns the byte offset into the dax_device that @bdev starts
788012b866SShiyang Ruan * @holder: filesystem or mapped device inside the dax_device
798012b866SShiyang Ruan * @ops: operations for the inner holder
801b764601SChristoph Hellwig */
fs_dax_get_by_bdev(struct block_device * bdev,u64 * start_off,void * holder,const struct dax_holder_operations * ops)818012b866SShiyang Ruan struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev, u64 *start_off,
828012b866SShiyang Ruan void *holder, const struct dax_holder_operations *ops)
8378f35473SDan Williams {
84fb08a190SChristoph Hellwig struct dax_device *dax_dev;
85cd913c76SChristoph Hellwig u64 part_size;
86fb08a190SChristoph Hellwig int id;
87fb08a190SChristoph Hellwig
88e556f6baSChristoph Hellwig if (!blk_queue_dax(bdev->bd_disk->queue))
8978f35473SDan Williams return NULL;
90fb08a190SChristoph Hellwig
91cd913c76SChristoph Hellwig *start_off = get_start_sect(bdev) * SECTOR_SIZE;
92cd913c76SChristoph Hellwig part_size = bdev_nr_sectors(bdev) * SECTOR_SIZE;
93cd913c76SChristoph Hellwig if (*start_off % PAGE_SIZE || part_size % PAGE_SIZE) {
940c445871SChristoph Hellwig pr_info("%pg: error: unaligned partition for dax\n", bdev);
950c445871SChristoph Hellwig return NULL;
960c445871SChristoph Hellwig }
970c445871SChristoph Hellwig
98fb08a190SChristoph Hellwig id = dax_read_lock();
99fb08a190SChristoph Hellwig dax_dev = xa_load(&dax_hosts, (unsigned long)bdev->bd_disk);
100fb08a190SChristoph Hellwig if (!dax_dev || !dax_alive(dax_dev) || !igrab(&dax_dev->inode))
101fb08a190SChristoph Hellwig dax_dev = NULL;
1028012b866SShiyang Ruan else if (holder) {
1038012b866SShiyang Ruan if (!cmpxchg(&dax_dev->holder_data, NULL, holder))
1048012b866SShiyang Ruan dax_dev->holder_ops = ops;
1058012b866SShiyang Ruan else
1068012b866SShiyang Ruan dax_dev = NULL;
1078012b866SShiyang Ruan }
108fb08a190SChristoph Hellwig dax_read_unlock(id);
109fb08a190SChristoph Hellwig
110fb08a190SChristoph Hellwig return dax_dev;
11178f35473SDan Williams }
11278f35473SDan Williams EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev);
1138012b866SShiyang Ruan
fs_put_dax(struct dax_device * dax_dev,void * holder)1148012b866SShiyang Ruan void fs_put_dax(struct dax_device *dax_dev, void *holder)
1158012b866SShiyang Ruan {
1168012b866SShiyang Ruan if (dax_dev && holder &&
1178012b866SShiyang Ruan cmpxchg(&dax_dev->holder_data, holder, NULL) == holder)
1188012b866SShiyang Ruan dax_dev->holder_ops = NULL;
1198012b866SShiyang Ruan put_dax(dax_dev);
1208012b866SShiyang Ruan }
1218012b866SShiyang Ruan EXPORT_SYMBOL_GPL(fs_put_dax);
1225d2a228bSChristoph Hellwig #endif /* CONFIG_BLOCK && CONFIG_FS_DAX */
123ef510424SDan Williams
1249a60c3efSDan Williams enum dax_device_flags {
1259a60c3efSDan Williams /* !alive + rcu grace period == no new operations / mappings */
1269a60c3efSDan Williams DAXDEV_ALIVE,
1276e0c90d6SDan Williams /* gate whether dax_flush() calls the low level flush routine */
1286e0c90d6SDan Williams DAXDEV_WRITE_CACHE,
129fefc1d97SPankaj Gupta /* flag to check if device supports synchronous flush */
130fefc1d97SPankaj Gupta DAXDEV_SYNC,
1317ac5360cSChristoph Hellwig /* do not leave the caches dirty after writes */
1327ac5360cSChristoph Hellwig DAXDEV_NOCACHE,
1337ac5360cSChristoph Hellwig /* handle CPU fetch exceptions during reads */
1347ac5360cSChristoph Hellwig DAXDEV_NOMC,
1359a60c3efSDan Williams };
1369a60c3efSDan Williams
137b0686260SDan Williams /**
138b0686260SDan Williams * dax_direct_access() - translate a device pgoff to an absolute pfn
139b0686260SDan Williams * @dax_dev: a dax_device instance representing the logical memory range
140b0686260SDan Williams * @pgoff: offset in pages from the start of the device to translate
141b0686260SDan Williams * @nr_pages: number of consecutive pages caller can handle relative to @pfn
142e511c4a3SJane Chu * @mode: indicator on normal access or recovery write
143b0686260SDan Williams * @kaddr: output parameter that returns a virtual address mapping of pfn
144b0686260SDan Williams * @pfn: output parameter that returns an absolute pfn translation of @pgoff
145b0686260SDan Williams *
146b0686260SDan Williams * Return: negative errno if an error occurs, otherwise the number of
147b0686260SDan Williams * pages accessible at the device relative @pgoff.
148b0686260SDan Williams */
dax_direct_access(struct dax_device * dax_dev,pgoff_t pgoff,long nr_pages,enum dax_access_mode mode,void ** kaddr,pfn_t * pfn)149b0686260SDan Williams long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
150e511c4a3SJane Chu enum dax_access_mode mode, void **kaddr, pfn_t *pfn)
151b0686260SDan Williams {
152b0686260SDan Williams long avail;
153b0686260SDan Williams
154b0686260SDan Williams if (!dax_dev)
155b0686260SDan Williams return -EOPNOTSUPP;
156b0686260SDan Williams
157b0686260SDan Williams if (!dax_alive(dax_dev))
158b0686260SDan Williams return -ENXIO;
159b0686260SDan Williams
160b0686260SDan Williams if (nr_pages < 0)
161b05d4c57SIra Weiny return -EINVAL;
162b0686260SDan Williams
163b0686260SDan Williams avail = dax_dev->ops->direct_access(dax_dev, pgoff, nr_pages,
164e511c4a3SJane Chu mode, kaddr, pfn);
165b0686260SDan Williams if (!avail)
166b0686260SDan Williams return -ERANGE;
167b0686260SDan Williams return min(avail, nr_pages);
168b0686260SDan Williams }
169b0686260SDan Williams EXPORT_SYMBOL_GPL(dax_direct_access);
170b0686260SDan Williams
dax_copy_from_iter(struct dax_device * dax_dev,pgoff_t pgoff,void * addr,size_t bytes,struct iov_iter * i)1717e026c8cSDan Williams size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
1727e026c8cSDan Williams size_t bytes, struct iov_iter *i)
1737e026c8cSDan Williams {
1747e026c8cSDan Williams if (!dax_alive(dax_dev))
1757e026c8cSDan Williams return 0;
1767e026c8cSDan Williams
1777ac5360cSChristoph Hellwig /*
1787ac5360cSChristoph Hellwig * The userspace address for the memory copy has already been validated
1797ac5360cSChristoph Hellwig * via access_ok() in vfs_write, so use the 'no check' version to bypass
1807ac5360cSChristoph Hellwig * the HARDENED_USERCOPY overhead.
1817ac5360cSChristoph Hellwig */
1827ac5360cSChristoph Hellwig if (test_bit(DAXDEV_NOCACHE, &dax_dev->flags))
1837ac5360cSChristoph Hellwig return _copy_from_iter_flushcache(addr, bytes, i);
1847ac5360cSChristoph Hellwig return _copy_from_iter(addr, bytes, i);
1857e026c8cSDan Williams }
1867e026c8cSDan Williams
dax_copy_to_iter(struct dax_device * dax_dev,pgoff_t pgoff,void * addr,size_t bytes,struct iov_iter * i)187b3a9a0c3SDan Williams size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
188b3a9a0c3SDan Williams size_t bytes, struct iov_iter *i)
189b3a9a0c3SDan Williams {
190b3a9a0c3SDan Williams if (!dax_alive(dax_dev))
191b3a9a0c3SDan Williams return 0;
192b3a9a0c3SDan Williams
1937ac5360cSChristoph Hellwig /*
1947ac5360cSChristoph Hellwig * The userspace address for the memory copy has already been validated
1957ac5360cSChristoph Hellwig * via access_ok() in vfs_red, so use the 'no check' version to bypass
1967ac5360cSChristoph Hellwig * the HARDENED_USERCOPY overhead.
1977ac5360cSChristoph Hellwig */
1987ac5360cSChristoph Hellwig if (test_bit(DAXDEV_NOMC, &dax_dev->flags))
1997ac5360cSChristoph Hellwig return _copy_mc_to_iter(addr, bytes, i);
2007ac5360cSChristoph Hellwig return _copy_to_iter(addr, bytes, i);
201b3a9a0c3SDan Williams }
202b3a9a0c3SDan Williams
dax_zero_page_range(struct dax_device * dax_dev,pgoff_t pgoff,size_t nr_pages)203f605a263SVivek Goyal int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
204f605a263SVivek Goyal size_t nr_pages)
205f605a263SVivek Goyal {
206*1ea7ca1bSJane Chu int ret;
207*1ea7ca1bSJane Chu
208f605a263SVivek Goyal if (!dax_alive(dax_dev))
209f605a263SVivek Goyal return -ENXIO;
210f605a263SVivek Goyal /*
211f605a263SVivek Goyal * There are no callers that want to zero more than one page as of now.
212f605a263SVivek Goyal * Once users are there, this check can be removed after the
213f605a263SVivek Goyal * device mapper code has been updated to split ranges across targets.
214f605a263SVivek Goyal */
215f605a263SVivek Goyal if (nr_pages != 1)
216f605a263SVivek Goyal return -EIO;
217f605a263SVivek Goyal
218*1ea7ca1bSJane Chu ret = dax_dev->ops->zero_page_range(dax_dev, pgoff, nr_pages);
219*1ea7ca1bSJane Chu return dax_mem2blk_err(ret);
220f605a263SVivek Goyal }
221f605a263SVivek Goyal EXPORT_SYMBOL_GPL(dax_zero_page_range);
222f605a263SVivek Goyal
dax_recovery_write(struct dax_device * dax_dev,pgoff_t pgoff,void * addr,size_t bytes,struct iov_iter * iter)223047218ecSJane Chu size_t dax_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff,
224047218ecSJane Chu void *addr, size_t bytes, struct iov_iter *iter)
225047218ecSJane Chu {
226047218ecSJane Chu if (!dax_dev->ops->recovery_write)
227047218ecSJane Chu return 0;
228047218ecSJane Chu return dax_dev->ops->recovery_write(dax_dev, pgoff, addr, bytes, iter);
229047218ecSJane Chu }
230047218ecSJane Chu EXPORT_SYMBOL_GPL(dax_recovery_write);
231047218ecSJane Chu
dax_holder_notify_failure(struct dax_device * dax_dev,u64 off,u64 len,int mf_flags)2328012b866SShiyang Ruan int dax_holder_notify_failure(struct dax_device *dax_dev, u64 off,
2338012b866SShiyang Ruan u64 len, int mf_flags)
2348012b866SShiyang Ruan {
2358012b866SShiyang Ruan int rc, id;
2368012b866SShiyang Ruan
2378012b866SShiyang Ruan id = dax_read_lock();
2388012b866SShiyang Ruan if (!dax_alive(dax_dev)) {
2398012b866SShiyang Ruan rc = -ENXIO;
2408012b866SShiyang Ruan goto out;
2418012b866SShiyang Ruan }
2428012b866SShiyang Ruan
2438012b866SShiyang Ruan if (!dax_dev->holder_ops) {
2448012b866SShiyang Ruan rc = -EOPNOTSUPP;
2458012b866SShiyang Ruan goto out;
2468012b866SShiyang Ruan }
2478012b866SShiyang Ruan
2488012b866SShiyang Ruan rc = dax_dev->holder_ops->notify_failure(dax_dev, off, len, mf_flags);
2498012b866SShiyang Ruan out:
2508012b866SShiyang Ruan dax_read_unlock(id);
2518012b866SShiyang Ruan return rc;
2528012b866SShiyang Ruan }
2538012b866SShiyang Ruan EXPORT_SYMBOL_GPL(dax_holder_notify_failure);
2548012b866SShiyang Ruan
255c3ca015fSMikulas Patocka #ifdef CONFIG_ARCH_HAS_PMEM_API
256c3ca015fSMikulas Patocka void arch_wb_cache_pmem(void *addr, size_t size);
dax_flush(struct dax_device * dax_dev,void * addr,size_t size)257c3ca015fSMikulas Patocka void dax_flush(struct dax_device *dax_dev, void *addr, size_t size)
258abebfbe2SDan Williams {
259808c340bSRoss Zwisler if (unlikely(!dax_write_cache_enabled(dax_dev)))
2606e0c90d6SDan Williams return;
2616e0c90d6SDan Williams
262c3ca015fSMikulas Patocka arch_wb_cache_pmem(addr, size);
263abebfbe2SDan Williams }
264c3ca015fSMikulas Patocka #else
dax_flush(struct dax_device * dax_dev,void * addr,size_t size)265c3ca015fSMikulas Patocka void dax_flush(struct dax_device *dax_dev, void *addr, size_t size)
266c3ca015fSMikulas Patocka {
267c3ca015fSMikulas Patocka }
268c3ca015fSMikulas Patocka #endif
269abebfbe2SDan Williams EXPORT_SYMBOL_GPL(dax_flush);
270abebfbe2SDan Williams
dax_write_cache(struct dax_device * dax_dev,bool wc)2716e0c90d6SDan Williams void dax_write_cache(struct dax_device *dax_dev, bool wc)
2726e0c90d6SDan Williams {
2736e0c90d6SDan Williams if (wc)
2746e0c90d6SDan Williams set_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags);
2756e0c90d6SDan Williams else
2766e0c90d6SDan Williams clear_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags);
2776e0c90d6SDan Williams }
2786e0c90d6SDan Williams EXPORT_SYMBOL_GPL(dax_write_cache);
2796e0c90d6SDan Williams
dax_write_cache_enabled(struct dax_device * dax_dev)280273752c9SVivek Goyal bool dax_write_cache_enabled(struct dax_device *dax_dev)
281273752c9SVivek Goyal {
282273752c9SVivek Goyal return test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags);
283273752c9SVivek Goyal }
284273752c9SVivek Goyal EXPORT_SYMBOL_GPL(dax_write_cache_enabled);
285273752c9SVivek Goyal
dax_synchronous(struct dax_device * dax_dev)286fd1d00ecSChristoph Hellwig bool dax_synchronous(struct dax_device *dax_dev)
287fefc1d97SPankaj Gupta {
288fefc1d97SPankaj Gupta return test_bit(DAXDEV_SYNC, &dax_dev->flags);
289fefc1d97SPankaj Gupta }
290fd1d00ecSChristoph Hellwig EXPORT_SYMBOL_GPL(dax_synchronous);
291fefc1d97SPankaj Gupta
set_dax_synchronous(struct dax_device * dax_dev)292fd1d00ecSChristoph Hellwig void set_dax_synchronous(struct dax_device *dax_dev)
293fefc1d97SPankaj Gupta {
294fefc1d97SPankaj Gupta set_bit(DAXDEV_SYNC, &dax_dev->flags);
295fefc1d97SPankaj Gupta }
296fd1d00ecSChristoph Hellwig EXPORT_SYMBOL_GPL(set_dax_synchronous);
297fefc1d97SPankaj Gupta
set_dax_nocache(struct dax_device * dax_dev)2987ac5360cSChristoph Hellwig void set_dax_nocache(struct dax_device *dax_dev)
2997ac5360cSChristoph Hellwig {
3007ac5360cSChristoph Hellwig set_bit(DAXDEV_NOCACHE, &dax_dev->flags);
3017ac5360cSChristoph Hellwig }
3027ac5360cSChristoph Hellwig EXPORT_SYMBOL_GPL(set_dax_nocache);
3037ac5360cSChristoph Hellwig
set_dax_nomc(struct dax_device * dax_dev)3047ac5360cSChristoph Hellwig void set_dax_nomc(struct dax_device *dax_dev)
3057ac5360cSChristoph Hellwig {
3067ac5360cSChristoph Hellwig set_bit(DAXDEV_NOMC, &dax_dev->flags);
3077ac5360cSChristoph Hellwig }
3087ac5360cSChristoph Hellwig EXPORT_SYMBOL_GPL(set_dax_nomc);
3097ac5360cSChristoph Hellwig
dax_alive(struct dax_device * dax_dev)3107b6be844SDan Williams bool dax_alive(struct dax_device *dax_dev)
3117b6be844SDan Williams {
3127b6be844SDan Williams lockdep_assert_held(&dax_srcu);
3139a60c3efSDan Williams return test_bit(DAXDEV_ALIVE, &dax_dev->flags);
3147b6be844SDan Williams }
3157b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_alive);
3167b6be844SDan Williams
3177b6be844SDan Williams /*
3187b6be844SDan Williams * Note, rcu is not protecting the liveness of dax_dev, rcu is ensuring
3197b6be844SDan Williams * that any fault handlers or operations that might have seen
3207b6be844SDan Williams * dax_alive(), have completed. Any operations that start after
3217b6be844SDan Williams * synchronize_srcu() has run will abort upon seeing !dax_alive().
3227b6be844SDan Williams */
kill_dax(struct dax_device * dax_dev)3237b6be844SDan Williams void kill_dax(struct dax_device *dax_dev)
3247b6be844SDan Williams {
3257b6be844SDan Williams if (!dax_dev)
3267b6be844SDan Williams return;
3277b6be844SDan Williams
3288012b866SShiyang Ruan if (dax_dev->holder_data != NULL)
3298012b866SShiyang Ruan dax_holder_notify_failure(dax_dev, 0, U64_MAX, 0);
3308012b866SShiyang Ruan
3319a60c3efSDan Williams clear_bit(DAXDEV_ALIVE, &dax_dev->flags);
3327b6be844SDan Williams synchronize_srcu(&dax_srcu);
3338012b866SShiyang Ruan
3348012b866SShiyang Ruan /* clear holder data */
3358012b866SShiyang Ruan dax_dev->holder_ops = NULL;
3368012b866SShiyang Ruan dax_dev->holder_data = NULL;
3377b6be844SDan Williams }
3387b6be844SDan Williams EXPORT_SYMBOL_GPL(kill_dax);
3397b6be844SDan Williams
run_dax(struct dax_device * dax_dev)3409567da0bSDan Williams void run_dax(struct dax_device *dax_dev)
3419567da0bSDan Williams {
3429567da0bSDan Williams set_bit(DAXDEV_ALIVE, &dax_dev->flags);
3439567da0bSDan Williams }
3449567da0bSDan Williams EXPORT_SYMBOL_GPL(run_dax);
3459567da0bSDan Williams
dax_alloc_inode(struct super_block * sb)3467b6be844SDan Williams static struct inode *dax_alloc_inode(struct super_block *sb)
3477b6be844SDan Williams {
3487b6be844SDan Williams struct dax_device *dax_dev;
349b9d39d17SDan Williams struct inode *inode;
3507b6be844SDan Williams
351fd60b288SMuchun Song dax_dev = alloc_inode_sb(sb, dax_cache, GFP_KERNEL);
3529f586fffSMikulas Patocka if (!dax_dev)
3539f586fffSMikulas Patocka return NULL;
3549f586fffSMikulas Patocka
355b9d39d17SDan Williams inode = &dax_dev->inode;
356b9d39d17SDan Williams inode->i_rdev = 0;
357b9d39d17SDan Williams return inode;
3587b6be844SDan Williams }
3597b6be844SDan Williams
to_dax_dev(struct inode * inode)3607b6be844SDan Williams static struct dax_device *to_dax_dev(struct inode *inode)
3617b6be844SDan Williams {
3627b6be844SDan Williams return container_of(inode, struct dax_device, inode);
3637b6be844SDan Williams }
3647b6be844SDan Williams
dax_free_inode(struct inode * inode)36553e22829SAl Viro static void dax_free_inode(struct inode *inode)
3667b6be844SDan Williams {
3677b6be844SDan Williams struct dax_device *dax_dev = to_dax_dev(inode);
368b9d39d17SDan Williams if (inode->i_rdev)
3690f702033SBo Liu ida_free(&dax_minor_ida, iminor(inode));
3707b6be844SDan Williams kmem_cache_free(dax_cache, dax_dev);
3717b6be844SDan Williams }
3727b6be844SDan Williams
dax_destroy_inode(struct inode * inode)3737b6be844SDan Williams static void dax_destroy_inode(struct inode *inode)
3747b6be844SDan Williams {
3757b6be844SDan Williams struct dax_device *dax_dev = to_dax_dev(inode);
3769a60c3efSDan Williams WARN_ONCE(test_bit(DAXDEV_ALIVE, &dax_dev->flags),
3777b6be844SDan Williams "kill_dax() must be called before final iput()\n");
3787b6be844SDan Williams }
3797b6be844SDan Williams
3807b6be844SDan Williams static const struct super_operations dax_sops = {
3817b6be844SDan Williams .statfs = simple_statfs,
3827b6be844SDan Williams .alloc_inode = dax_alloc_inode,
3837b6be844SDan Williams .destroy_inode = dax_destroy_inode,
38453e22829SAl Viro .free_inode = dax_free_inode,
3857b6be844SDan Williams .drop_inode = generic_delete_inode,
3867b6be844SDan Williams };
3877b6be844SDan Williams
dax_init_fs_context(struct fs_context * fc)38875d4e06fSDavid Howells static int dax_init_fs_context(struct fs_context *fc)
3897b6be844SDan Williams {
39075d4e06fSDavid Howells struct pseudo_fs_context *ctx = init_pseudo(fc, DAXFS_MAGIC);
39175d4e06fSDavid Howells if (!ctx)
39275d4e06fSDavid Howells return -ENOMEM;
39375d4e06fSDavid Howells ctx->ops = &dax_sops;
39475d4e06fSDavid Howells return 0;
3957b6be844SDan Williams }
3967b6be844SDan Williams
3977b6be844SDan Williams static struct file_system_type dax_fs_type = {
3987b6be844SDan Williams .name = "dax",
39975d4e06fSDavid Howells .init_fs_context = dax_init_fs_context,
4007b6be844SDan Williams .kill_sb = kill_anon_super,
4017b6be844SDan Williams };
4027b6be844SDan Williams
dax_test(struct inode * inode,void * data)4037b6be844SDan Williams static int dax_test(struct inode *inode, void *data)
4047b6be844SDan Williams {
4057b6be844SDan Williams dev_t devt = *(dev_t *) data;
4067b6be844SDan Williams
4077b6be844SDan Williams return inode->i_rdev == devt;
4087b6be844SDan Williams }
4097b6be844SDan Williams
dax_set(struct inode * inode,void * data)4107b6be844SDan Williams static int dax_set(struct inode *inode, void *data)
4117b6be844SDan Williams {
4127b6be844SDan Williams dev_t devt = *(dev_t *) data;
4137b6be844SDan Williams
4147b6be844SDan Williams inode->i_rdev = devt;
4157b6be844SDan Williams return 0;
4167b6be844SDan Williams }
4177b6be844SDan Williams
dax_dev_get(dev_t devt)4187b6be844SDan Williams static struct dax_device *dax_dev_get(dev_t devt)
4197b6be844SDan Williams {
4207b6be844SDan Williams struct dax_device *dax_dev;
4217b6be844SDan Williams struct inode *inode;
4227b6be844SDan Williams
4237b6be844SDan Williams inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31),
4247b6be844SDan Williams dax_test, dax_set, &devt);
4257b6be844SDan Williams
4267b6be844SDan Williams if (!inode)
4277b6be844SDan Williams return NULL;
4287b6be844SDan Williams
4297b6be844SDan Williams dax_dev = to_dax_dev(inode);
4307b6be844SDan Williams if (inode->i_state & I_NEW) {
4319a60c3efSDan Williams set_bit(DAXDEV_ALIVE, &dax_dev->flags);
4327b6be844SDan Williams inode->i_cdev = &dax_dev->cdev;
4337b6be844SDan Williams inode->i_mode = S_IFCHR;
4347b6be844SDan Williams inode->i_flags = S_DAX;
4357b6be844SDan Williams mapping_set_gfp_mask(&inode->i_data, GFP_USER);
4367b6be844SDan Williams unlock_new_inode(inode);
4377b6be844SDan Williams }
4387b6be844SDan Williams
4397b6be844SDan Williams return dax_dev;
4407b6be844SDan Williams }
4417b6be844SDan Williams
alloc_dax(void * private,const struct dax_operations * ops)44230c6828aSChristoph Hellwig struct dax_device *alloc_dax(void *private, const struct dax_operations *ops)
4437b6be844SDan Williams {
4447b6be844SDan Williams struct dax_device *dax_dev;
4457b6be844SDan Williams dev_t devt;
4467b6be844SDan Williams int minor;
4477b6be844SDan Williams
448fb08a190SChristoph Hellwig if (WARN_ON_ONCE(ops && !ops->zero_page_range))
4494e4ced93SVivek Goyal return ERR_PTR(-EINVAL);
45072058005SDan Williams
4510f702033SBo Liu minor = ida_alloc_max(&dax_minor_ida, MINORMASK, GFP_KERNEL);
4527b6be844SDan Williams if (minor < 0)
453fb08a190SChristoph Hellwig return ERR_PTR(-ENOMEM);
4547b6be844SDan Williams
4557b6be844SDan Williams devt = MKDEV(MAJOR(dax_devt), minor);
4567b6be844SDan Williams dax_dev = dax_dev_get(devt);
4577b6be844SDan Williams if (!dax_dev)
45872058005SDan Williams goto err_dev;
4597b6be844SDan Williams
4606568b08bSDan Williams dax_dev->ops = ops;
4617b6be844SDan Williams dax_dev->private = private;
4627b6be844SDan Williams return dax_dev;
4637b6be844SDan Williams
46472058005SDan Williams err_dev:
4650f702033SBo Liu ida_free(&dax_minor_ida, minor);
4664e4ced93SVivek Goyal return ERR_PTR(-ENOMEM);
4677b6be844SDan Williams }
4687b6be844SDan Williams EXPORT_SYMBOL_GPL(alloc_dax);
4697b6be844SDan Williams
put_dax(struct dax_device * dax_dev)4707b6be844SDan Williams void put_dax(struct dax_device *dax_dev)
4717b6be844SDan Williams {
4727b6be844SDan Williams if (!dax_dev)
4737b6be844SDan Williams return;
4747b6be844SDan Williams iput(&dax_dev->inode);
4757b6be844SDan Williams }
4767b6be844SDan Williams EXPORT_SYMBOL_GPL(put_dax);
4777b6be844SDan Williams
4787b6be844SDan Williams /**
4798012b866SShiyang Ruan * dax_holder() - obtain the holder of a dax device
4808012b866SShiyang Ruan * @dax_dev: a dax_device instance
4811c88b9baSRandy Dunlap *
4828012b866SShiyang Ruan * Return: the holder's data which represents the holder if registered,
4838012b866SShiyang Ruan * otherwize NULL.
4848012b866SShiyang Ruan */
dax_holder(struct dax_device * dax_dev)4858012b866SShiyang Ruan void *dax_holder(struct dax_device *dax_dev)
4868012b866SShiyang Ruan {
4878012b866SShiyang Ruan return dax_dev->holder_data;
4888012b866SShiyang Ruan }
4898012b866SShiyang Ruan EXPORT_SYMBOL_GPL(dax_holder);
4908012b866SShiyang Ruan
4918012b866SShiyang Ruan /**
4927b6be844SDan Williams * inode_dax: convert a public inode into its dax_dev
4937b6be844SDan Williams * @inode: An inode with i_cdev pointing to a dax_dev
4947b6be844SDan Williams *
4957b6be844SDan Williams * Note this is not equivalent to to_dax_dev() which is for private
4967b6be844SDan Williams * internal use where we know the inode filesystem type == dax_fs_type.
4977b6be844SDan Williams */
inode_dax(struct inode * inode)4987b6be844SDan Williams struct dax_device *inode_dax(struct inode *inode)
4997b6be844SDan Williams {
5007b6be844SDan Williams struct cdev *cdev = inode->i_cdev;
5017b6be844SDan Williams
5027b6be844SDan Williams return container_of(cdev, struct dax_device, cdev);
5037b6be844SDan Williams }
5047b6be844SDan Williams EXPORT_SYMBOL_GPL(inode_dax);
5057b6be844SDan Williams
dax_inode(struct dax_device * dax_dev)5067b6be844SDan Williams struct inode *dax_inode(struct dax_device *dax_dev)
5077b6be844SDan Williams {
5087b6be844SDan Williams return &dax_dev->inode;
5097b6be844SDan Williams }
5107b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_inode);
5117b6be844SDan Williams
dax_get_private(struct dax_device * dax_dev)5127b6be844SDan Williams void *dax_get_private(struct dax_device *dax_dev)
5137b6be844SDan Williams {
5149567da0bSDan Williams if (!test_bit(DAXDEV_ALIVE, &dax_dev->flags))
5159567da0bSDan Williams return NULL;
5167b6be844SDan Williams return dax_dev->private;
5177b6be844SDan Williams }
5187b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_get_private);
5197b6be844SDan Williams
init_once(void * _dax_dev)5207b6be844SDan Williams static void init_once(void *_dax_dev)
5217b6be844SDan Williams {
5227b6be844SDan Williams struct dax_device *dax_dev = _dax_dev;
5237b6be844SDan Williams struct inode *inode = &dax_dev->inode;
5247b6be844SDan Williams
525b9d39d17SDan Williams memset(dax_dev, 0, sizeof(*dax_dev));
5267b6be844SDan Williams inode_init_once(inode);
5277b6be844SDan Williams }
5287b6be844SDan Williams
dax_fs_init(void)5299567da0bSDan Williams static int dax_fs_init(void)
5307b6be844SDan Williams {
5317b6be844SDan Williams int rc;
5327b6be844SDan Williams
5337b6be844SDan Williams dax_cache = kmem_cache_create("dax_cache", sizeof(struct dax_device), 0,
5347b6be844SDan Williams (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
5357b6be844SDan Williams SLAB_MEM_SPREAD|SLAB_ACCOUNT),
5367b6be844SDan Williams init_once);
5377b6be844SDan Williams if (!dax_cache)
5387b6be844SDan Williams return -ENOMEM;
5397b6be844SDan Williams
5407b6be844SDan Williams dax_mnt = kern_mount(&dax_fs_type);
5417b6be844SDan Williams if (IS_ERR(dax_mnt)) {
5427b6be844SDan Williams rc = PTR_ERR(dax_mnt);
5437b6be844SDan Williams goto err_mount;
5447b6be844SDan Williams }
5457b6be844SDan Williams dax_superblock = dax_mnt->mnt_sb;
5467b6be844SDan Williams
5477b6be844SDan Williams return 0;
5487b6be844SDan Williams
5497b6be844SDan Williams err_mount:
5507b6be844SDan Williams kmem_cache_destroy(dax_cache);
5517b6be844SDan Williams
5527b6be844SDan Williams return rc;
5537b6be844SDan Williams }
5547b6be844SDan Williams
dax_fs_exit(void)5559567da0bSDan Williams static void dax_fs_exit(void)
5567b6be844SDan Williams {
5577b6be844SDan Williams kern_unmount(dax_mnt);
558a7e8de82STong Zhang rcu_barrier();
5597b6be844SDan Williams kmem_cache_destroy(dax_cache);
5607b6be844SDan Williams }
5617b6be844SDan Williams
dax_core_init(void)5629567da0bSDan Williams static int __init dax_core_init(void)
5637b6be844SDan Williams {
5647b6be844SDan Williams int rc;
5657b6be844SDan Williams
5669567da0bSDan Williams rc = dax_fs_init();
5677b6be844SDan Williams if (rc)
5687b6be844SDan Williams return rc;
5697b6be844SDan Williams
570cf1e2289SDan Williams rc = alloc_chrdev_region(&dax_devt, 0, MINORMASK+1, "dax");
5717b6be844SDan Williams if (rc)
5729567da0bSDan Williams goto err_chrdev;
5739567da0bSDan Williams
5749567da0bSDan Williams rc = dax_bus_init();
5759567da0bSDan Williams if (rc)
5769567da0bSDan Williams goto err_bus;
5779567da0bSDan Williams return 0;
5789567da0bSDan Williams
5799567da0bSDan Williams err_bus:
5809567da0bSDan Williams unregister_chrdev_region(dax_devt, MINORMASK+1);
5819567da0bSDan Williams err_chrdev:
5829567da0bSDan Williams dax_fs_exit();
5839567da0bSDan Williams return 0;
5847b6be844SDan Williams }
5857b6be844SDan Williams
dax_core_exit(void)5869567da0bSDan Williams static void __exit dax_core_exit(void)
5877b6be844SDan Williams {
5881aa57431SWang Hai dax_bus_exit();
589cf1e2289SDan Williams unregister_chrdev_region(dax_devt, MINORMASK+1);
5907b6be844SDan Williams ida_destroy(&dax_minor_ida);
5919567da0bSDan Williams dax_fs_exit();
5927b6be844SDan Williams }
5937b6be844SDan Williams
5947b6be844SDan Williams MODULE_AUTHOR("Intel Corporation");
5957b6be844SDan Williams MODULE_LICENSE("GPL v2");
5969567da0bSDan Williams subsys_initcall(dax_core_init);
5979567da0bSDan Williams module_exit(dax_core_exit);
598