diff options
| -rw-r--r-- | drivers/dax/super.c | 79 | ||||
| -rw-r--r-- | drivers/nvdimm/pmem.c | 10 | ||||
| -rw-r--r-- | include/linux/dax.h | 3 |
3 files changed, 92 insertions, 0 deletions
diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 8bf71195921b..4827251782a1 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -119,6 +119,8 @@ EXPORT_SYMBOL_GPL(__bdev_dax_supported); enum dax_device_flags { /* !alive + rcu grace period == no new operations / mappings */ DAXDEV_ALIVE, + /* gate whether dax_flush() calls the low level flush routine */ + DAXDEV_WRITE_CACHE, }; /** @@ -139,6 +141,71 @@ struct dax_device { const struct dax_operations *ops; }; +static ssize_t write_cache_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); + ssize_t rc; + + WARN_ON_ONCE(!dax_dev); + if (!dax_dev) + return -ENXIO; + + rc = sprintf(buf, "%d\n", !!test_bit(DAXDEV_WRITE_CACHE, + &dax_dev->flags)); + put_dax(dax_dev); + return rc; +} + +static ssize_t write_cache_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + bool write_cache; + int rc = strtobool(buf, &write_cache); + struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); + + WARN_ON_ONCE(!dax_dev); + if (!dax_dev) + return -ENXIO; + + if (rc) + len = rc; + else if (write_cache) + set_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); + else + clear_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); + + put_dax(dax_dev); + return len; +} +static DEVICE_ATTR_RW(write_cache); + +static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n) +{ + struct device *dev = container_of(kobj, typeof(*dev), kobj); + struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); + + WARN_ON_ONCE(!dax_dev); + if (!dax_dev) + return 0; + + if (a == &dev_attr_write_cache.attr && !dax_dev->ops->flush) + return 0; + return a->mode; +} + +static struct attribute *dax_attributes[] = { + &dev_attr_write_cache.attr, + NULL, +}; + +struct attribute_group dax_attribute_group = { + .name = "dax", + .attrs = dax_attributes, + .is_visible = dax_visible, +}; +EXPORT_SYMBOL_GPL(dax_attribute_group); + /** * dax_direct_access() - translate a device pgoff to an absolute pfn * @dax_dev: a dax_device instance representing the logical memory range @@ -194,11 +261,23 @@ void dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, if (!dax_alive(dax_dev)) return; + if (!test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags)) + return; + if (dax_dev->ops->flush) dax_dev->ops->flush(dax_dev, pgoff, addr, size); } EXPORT_SYMBOL_GPL(dax_flush); +void dax_write_cache(struct dax_device *dax_dev, bool wc) +{ + if (wc) + set_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); + else + clear_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(dax_write_cache); + bool dax_alive(struct dax_device *dax_dev) { lockdep_assert_held(&dax_srcu); diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 06f6c27ec1e9..7339d184070e 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -253,6 +253,11 @@ static const struct dax_operations pmem_dax_ops = { .flush = pmem_dax_flush, }; +static const struct attribute_group *pmem_attribute_groups[] = { + &dax_attribute_group, + NULL, +}; + static void pmem_release_queue(void *q) { blk_cleanup_queue(q); @@ -287,6 +292,7 @@ static int pmem_attach_disk(struct device *dev, struct pmem_device *pmem; struct resource pfn_res; struct request_queue *q; + struct device *gendev; struct gendisk *disk; void *addr; @@ -384,8 +390,12 @@ static int pmem_attach_disk(struct device *dev, put_disk(disk); return -ENOMEM; } + dax_write_cache(dax_dev, true); pmem->dax_dev = dax_dev; + gendev = disk_to_dev(disk); + gendev->groups = pmem_attribute_groups; + device_add_disk(dev, disk); if (devm_add_action_or_reset(dev, pmem_release_disk, pmem)) return -ENOMEM; diff --git a/include/linux/dax.h b/include/linux/dax.h index 73fca1bebaf3..8f39db7439c3 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -23,6 +23,8 @@ struct dax_operations { void (*flush)(struct dax_device *, pgoff_t, void *, size_t); }; +extern struct attribute_group dax_attribute_group; + #if IS_ENABLED(CONFIG_DAX) struct dax_device *dax_get_by_host(const char *host); void put_dax(struct dax_device *dax_dev); @@ -84,6 +86,7 @@ size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i); void dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t size); +void dax_write_cache(struct dax_device *dax_dev, bool wc); /* * We use lowest available bit in exceptional entry for locking, one bit for |