diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-07 18:44:06 +0200 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-07 18:44:06 +0200 |
commit | b6ffe9ba46016f8351896ccee33bebcd0e5ea7c0 (patch) | |
tree | 839a5a070eabe8851797330ea77ca7eb7c93bcc1 /drivers/dax | |
parent | Merge branch 'akpm' (patches from Andrew) (diff) | |
parent | Merge branch 'for-4.13/dax' into libnvdimm-for-next (diff) | |
download | linux-b6ffe9ba46016f8351896ccee33bebcd0e5ea7c0.tar.xz linux-b6ffe9ba46016f8351896ccee33bebcd0e5ea7c0.zip |
Merge tag 'libnvdimm-for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm updates from Dan Williams:
"libnvdimm updates for the latest ACPI and UEFI specifications. This
pull request also includes new 'struct dax_operations' enabling to
undo the abuse of copy_user_nocache() for copy operations to pmem.
The dax work originally missed 4.12 to address concerns raised by Al.
Summary:
- Introduce the _flushcache() family of memory copy helpers and use
them for persistent memory write operations on x86. The
_flushcache() semantic indicates that the cache is either bypassed
for the copy operation (movnt) or any lines dirtied by the copy
operation are written back (clwb, clflushopt, or clflush).
- Extend dax_operations with ->copy_from_iter() and ->flush()
operations. These operations and other infrastructure updates allow
all persistent memory specific dax functionality to be pushed into
libnvdimm and the pmem driver directly. It also allows dax-specific
sysfs attributes to be linked to a host device, for example:
/sys/block/pmem0/dax/write_cache
- Add support for the new NVDIMM platform/firmware mechanisms
introduced in ACPI 6.2 and UEFI 2.7. This support includes the v1.2
namespace label format, extensions to the address-range-scrub
command set, new error injection commands, and a new BTT
(block-translation-table) layout. These updates support inter-OS
and pre-OS compatibility.
- Fix a longstanding memory corruption bug in nfit_test.
- Make the pmem and nvdimm-region 'badblocks' sysfs files poll(2)
capable.
- Miscellaneous fixes and small updates across libnvdimm and the nfit
driver.
Acknowledgements that came after the branch was pushed: commit
6aa734a2f38e ("libnvdimm, region, pmem: fix 'badblocks'
sysfs_get_dirent() reference lifetime") was reviewed by Toshi Kani
<toshi.kani@hpe.com>"
* tag 'libnvdimm-for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (42 commits)
libnvdimm, namespace: record 'lbasize' for pmem namespaces
acpi/nfit: Issue Start ARS to retrieve existing records
libnvdimm: New ACPI 6.2 DSM functions
acpi, nfit: Show bus_dsm_mask in sysfs
libnvdimm, acpi, nfit: Add bus level dsm mask for pass thru.
acpi, nfit: Enable DSM pass thru for root functions.
libnvdimm: passthru functions clear to send
libnvdimm, btt: convert some info messages to warn/err
libnvdimm, region, pmem: fix 'badblocks' sysfs_get_dirent() reference lifetime
libnvdimm: fix the clear-error check in nsio_rw_bytes
libnvdimm, btt: fix btt_rw_page not returning errors
acpi, nfit: quiet invalid block-aperture-region warnings
libnvdimm, btt: BTT updates for UEFI 2.7 format
acpi, nfit: constify *_attribute_group
libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region
libnvdimm, pmem, dax: export a cache control attribute
dax: convert to bitmask for flags
dax: remove default copy_from_iter fallback
libnvdimm, nfit: enable support for volatile ranges
libnvdimm, pmem: fix persistence warning
...
Diffstat (limited to 'drivers/dax')
-rw-r--r-- | drivers/dax/super.c | 118 |
1 files changed, 112 insertions, 6 deletions
diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 922d0823f8ec..ce9e563e6e1d 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -18,6 +18,7 @@ #include <linux/cdev.h> #include <linux/hash.h> #include <linux/slab.h> +#include <linux/uio.h> #include <linux/dax.h> #include <linux/fs.h> @@ -115,13 +116,20 @@ int __bdev_dax_supported(struct super_block *sb, int blocksize) EXPORT_SYMBOL_GPL(__bdev_dax_supported); #endif +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, +}; + /** * struct dax_device - anchor object for dax services * @inode: core vfs * @cdev: optional character interface for "device dax" * @host: optional name for lookups where the device path is not available * @private: dax driver private data - * @alive: !alive + rcu grace period == no new operations / mappings + * @flags: state and boolean properties */ struct dax_device { struct hlist_node list; @@ -129,10 +137,75 @@ struct dax_device { struct cdev cdev; const char *host; void *private; - bool alive; + unsigned long flags; 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 @@ -172,10 +245,43 @@ long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, } EXPORT_SYMBOL_GPL(dax_direct_access); +size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, + size_t bytes, struct iov_iter *i) +{ + if (!dax_alive(dax_dev)) + return 0; + + return dax_dev->ops->copy_from_iter(dax_dev, pgoff, addr, bytes, i); +} +EXPORT_SYMBOL_GPL(dax_copy_from_iter); + +void dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, + size_t size) +{ + 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); - return dax_dev->alive; + return test_bit(DAXDEV_ALIVE, &dax_dev->flags); } EXPORT_SYMBOL_GPL(dax_alive); @@ -195,7 +301,7 @@ void kill_dax(struct dax_device *dax_dev) if (!dax_dev) return; - dax_dev->alive = false; + clear_bit(DAXDEV_ALIVE, &dax_dev->flags); synchronize_srcu(&dax_srcu); @@ -239,7 +345,7 @@ static void dax_destroy_inode(struct inode *inode) { struct dax_device *dax_dev = to_dax_dev(inode); - WARN_ONCE(dax_dev->alive, + WARN_ONCE(test_bit(DAXDEV_ALIVE, &dax_dev->flags), "kill_dax() must be called before final iput()\n"); call_rcu(&inode->i_rcu, dax_i_callback); } @@ -291,7 +397,7 @@ static struct dax_device *dax_dev_get(dev_t devt) dax_dev = to_dax_dev(inode); if (inode->i_state & I_NEW) { - dax_dev->alive = true; + set_bit(DAXDEV_ALIVE, &dax_dev->flags); inode->i_cdev = &dax_dev->cdev; inode->i_mode = S_IFCHR; inode->i_flags = S_DAX; |