linux.git/drivers/dax/device.c, branch v5.1 Linux kernel source tree device-dax: Add /sys/class/dax backwards compatibility 2019-01-07T05:41:57+00:00 Dan Williams dan.j.williams@intel.com 2017-07-16T20:51:53+00:00 730926c3b0998943654019f00296cf8e3b02277e On the expectation that some environments may not upgrade libdaxctl (userspace component that depends on the /sys/class/dax hierarchy), provide a default / legacy dax_pmem_compat driver. The dax_pmem_compat driver implements the original /sys/class/dax sysfs layout rather than /sys/bus/dax. When userspace is upgraded it can blacklist this module and switch to the dax_pmem driver going forward. CONFIG_DEV_DAX_PMEM_COMPAT and supporting code will be deleted according to the dax_pmem entry in Documentation/ABI/obsolete/. Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
On the expectation that some environments may not upgrade libdaxctl
(userspace component that depends on the /sys/class/dax hierarchy),
provide a default / legacy dax_pmem_compat driver. The dax_pmem_compat
driver implements the original /sys/class/dax sysfs layout rather than
/sys/bus/dax. When userspace is upgraded it can blacklist this module
and switch to the dax_pmem driver going forward.

CONFIG_DEV_DAX_PMEM_COMPAT and supporting code will be deleted according
to the dax_pmem entry in Documentation/ABI/obsolete/.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
device-dax: Add support for a dax override driver 2019-01-07T05:41:55+00:00 Dan Williams dan.j.williams@intel.com 2018-11-07T23:31:23+00:00 d200781ef237a354d918ceff5cee350d88a93d42 Introduce the 'new_id' concept for enabling a custom device-driver attach policy for dax-bus drivers. The intended use is to have a mechanism for hot-plugging device-dax ranges into the page allocator on-demand. With this in place the default policy of using device-dax for performance differentiated memory can be overridden by user-space policy that can arrange for the memory range to be managed as 'System RAM' with user-defined NUMA and other performance attributes. Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
Introduce the 'new_id' concept for enabling a custom device-driver attach
policy for dax-bus drivers. The intended use is to have a mechanism for
hot-plugging device-dax ranges into the page allocator on-demand. With
this in place the default policy of using device-dax for performance
differentiated memory can be overridden by user-space policy that can
arrange for the memory range to be managed as 'System RAM' with
user-defined NUMA and other performance attributes.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
 device-dax: Move resource pinning+mapping into the common driver 2019-01-07T05:26:21+00:00 Dan Williams dan.j.williams@intel.com 2018-10-29T22:52:42+00:00 89ec9f2cfa36cc5fca2fb445ed221bb9add7b536 Move the responsibility of calling devm_request_resource() and devm_memremap_pages() into the common device-dax driver. This is another preparatory step to allowing an alternate personality driver for a device-dax range. Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
Move the responsibility of calling devm_request_resource() and
devm_memremap_pages() into the common device-dax driver. This is another
preparatory step to allowing an alternate personality driver for a
device-dax range.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
 device-dax: Introduce bus + driver model 2019-01-07T05:24:46+00:00 Dan Williams dan.j.williams@intel.com 2017-07-13T00:58:21+00:00 9567da0b408a2553d32ca83cba4f1fc5a8aad459 In support of multiple device-dax instances per device-dax-region and allowing the 'kmem' driver to attach to dax-instances instead of the current device-node access, convert the dax sub-system from a class to a bus. Recall that the kmem driver takes reserved / special purpose memories and assigns them to be managed by the core-mm. Aside from the fact the device-dax instances are registered and probed on a bus, two other lifetime-management changes are made: 1/ Delay attaching a cdev until driver probe time 2/ A new run_dax() helper is introduced to allow restoring dax-operation after a kill_dax() event. So, at driver ->probe() time we run_dax() and at ->remove() time we kill_dax() and invalidate all mappings. Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
In support of multiple device-dax instances per device-dax-region and
allowing the 'kmem' driver to attach to dax-instances instead of the
current device-node access, convert the dax sub-system from a class to a
bus. Recall that the kmem driver takes reserved / special purpose
memories and assigns them to be managed by the core-mm.

Aside from the fact the device-dax instances are registered and probed
on a bus, two other lifetime-management changes are made:

1/ Delay attaching a cdev until driver probe time

2/ A new run_dax() helper is introduced to allow restoring dax-operation
   after a kill_dax() event. So, at driver ->probe() time we run_dax()
   and at ->remove() time we kill_dax() and invalidate all mappings.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
device-dax: Start defining a dax bus model 2019-01-07T05:24:46+00:00 Dan Williams dan.j.williams@intel.com 2017-07-13T00:58:21+00:00 51cf784c42d07fbd62cb604836a9270cf3361509 Towards eliminating the dax_class, move the dax-device-attribute enabling to a new bus.c file in the core. The amount of code thrash of sub-sequent patches is reduced as no logic changes are made, just pure code movement. A temporary export of unregister_dex_dax() and dax_attribute_groups is needed to preserve compilation, but those symbols become static again in a follow-on patch. Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
Towards eliminating the dax_class, move the dax-device-attribute
enabling to a new bus.c file in the core. The amount of code
thrash of sub-sequent patches is reduced as no logic changes are made,
just pure code movement.

A temporary export of unregister_dex_dax() and dax_attribute_groups is
needed to preserve compilation, but those symbols become static again in
a follow-on patch.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
device-dax: Remove multi-resource infrastructure 2019-01-07T05:24:46+00:00 Dan Williams dan.j.williams@intel.com 2017-07-14T20:54:50+00:00 753a0850e707e9a8c5861356222f9b9e4eba7945 The multi-resource implementation anticipated discontiguous sub-division support. That has not yet materialized, delete the infrastructure and related code. Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
The multi-resource implementation anticipated discontiguous sub-division
support. That has not yet materialized, delete the infrastructure and
related code.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
device-dax: Kill dax_region base 2019-01-07T05:24:46+00:00 Dan Williams dan.j.williams@intel.com 2017-07-19T22:57:44+00:00 93694f9630b0ed29cda61df58e480dcb34ef52fd Nothing consumes this attribute of a region and devres otherwise remembers the value for de-allocation purposes. Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
Nothing consumes this attribute of a region and devres otherwise
remembers the value for de-allocation purposes.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
device-dax: Kill dax_region ida 2019-01-07T05:24:45+00:00 Dan Williams dan.j.williams@intel.com 2017-07-19T21:55:26+00:00 21b9e979501fdb5f6797193d70428a2b00bd5247 Commit bbb3be170ac2 "device-dax: fix sysfs duplicate warnings" arranged for passing a dax instance-id to devm_create_dax_dev(), rather than generating one internally. Remove the dax_region ida and related code. Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
Commit bbb3be170ac2 "device-dax: fix sysfs duplicate warnings" arranged
for passing a dax instance-id to devm_create_dax_dev(), rather than
generating one internally. Remove the dax_region ida and related code.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
device-dax: Add missing address_space_operations 2018-09-22T16:07:33+00:00 Dave Jiang dave.jiang@intel.com 2018-09-10T23:18:29+00:00 41c9b1be335b5afc3b5fb71c5d16f9d5939cd13f With address_space_operations missing for device dax, namely the .set_page_dirty, we hit a kernel warning when running destructive ndctl unit test: make TESTS=device-dax check WARNING: CPU: 3 PID: 7380 at fs/buffer.c:581 __set_page_dirty+0xb1/0xc0 Setting address_space_operations to noop_set_page_dirty and noop_invalidatepage for device dax to prevent fallback to __set_page_dirty_buffers() and block_invalidatepage() respectively. Fixes: 2232c6382a ("device-dax: Enable page_mapping()") Acked-by: Jeff Moyer <jmoyer@redhat.com> Reported-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
With address_space_operations missing for device dax, namely the
.set_page_dirty, we hit a kernel warning when running destructive
ndctl unit test: make TESTS=device-dax check

WARNING: CPU: 3 PID: 7380 at fs/buffer.c:581 __set_page_dirty+0xb1/0xc0

Setting address_space_operations to noop_set_page_dirty and
noop_invalidatepage for device dax to prevent fallback to
__set_page_dirty_buffers() and block_invalidatepage() respectively.

Fixes: 2232c6382a ("device-dax: Enable page_mapping()")

Acked-by: Jeff Moyer <jmoyer@redhat.com>
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
drivers/dax/device.c: convert variable to vm_fault_t type 2018-09-04T23:45:02+00:00 Souptick Joarder jrdr.linux@gmail.com 2018-09-04T22:46:26+00:00 36bdac1e674debd2714cb3e80eaa18266c2426e4 As part of 226ab561075f ("device-dax: Convert to vmf_insert_mixed and vm_fault_t") in 4.19-rc1, 'rc' was not converted to vm_fault_t. Now converted. Link: http://lkml.kernel.org/r/20180830153813.GA26059@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
As part of 226ab561075f ("device-dax: Convert to vmf_insert_mixed and
vm_fault_t") in 4.19-rc1, 'rc' was not converted to vm_fault_t.  Now
converted.

Link: http://lkml.kernel.org/r/20180830153813.GA26059@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>