Commit Graph

15 Commits

Author SHA1 Message Date
Jason Gunthorpe
669dac1e00 RDMA/uverbs: Add structure size info to write commands
We need the structure sizes to compute the location of the udata in the
core code. Annotate the sizes into the new macro language.

This is generated largely by script and checked by comparing against the
similar list in rdma-core.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-11-26 16:48:07 -07:00
Jason Gunthorpe
7106a97697 RDMA/uverbs: Make write() handlers return 0 on success
Currently they return the command length, while all other handlers return
0. This makes the write path closer to the write_ex and ioctl path.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-11-26 16:48:07 -07:00
Jason Gunthorpe
8313c10fa8 RDMA/uverbs: Replace ib_uverbs_file with uverbs_attr_bundle for write
Now that we can add meta-data to the description of write() methods we
need to pass the uverbs_attr_bundle into all write based handlers so
future patches can use it as a container for any new data transferred out
of the core.

This is the first step to bringing the write() and ioctl() methods to a
common interface signature.

This is a simple search/replace, and we push the attr down into the uobj
and other APIs to keep changes minimal.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-11-26 16:48:07 -07:00
Jason Gunthorpe
a140692a52 RDMA/uverbs: Check for NULL driver methods for every write call
Add annotations to the uverbs_api structure indicating which driver
methods are called by the implementation. If the required method
is NULL the write API will be not be callable.

This effectively duplicates the cmd_mask system, however it does it by
expressing invariants required by the core code, not by delegating
decision making to the driver. This is another step toward eliminating
cmd_mask.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-11-22 11:57:33 -07:00
Jason Gunthorpe
d120c3c918 RDMA/uverbs: Convert the write interface to use uverbs_api
This organizes the write commands into objects and links them to the
uverbs_api data structure. The command path is reworked to use uapi
instead of its internal structures.

The command mask is moved from a runtime check to a registration time
check in the uapi.

Since the write interface does not have the object ID as part of the
command, the radix bins are converted into linear lists to support the
lookup.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-11-22 11:57:33 -07:00
Jason Gunthorpe
6884c6c4bd RDMA/verbs: Store the write/write_ex uapi entry points in the uverbs_api
Bringing all uapi entry points into one place lets us deal with them
consistently. For instance the write, write_ex and ioctl paths can be
disabled when an API is not supported by the driver.

This will replace the uverbs_cmd_table static arrays.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-11-22 11:57:33 -07:00
Jason Gunthorpe
0bd01f3d09 RDMA/uverbs: Require all objects to have a driver destroy function
If we can't destroy the object then we certainly shouldn't allow it be
created or used. Remove it from the uverbs_uapi in this case.

This also disables methods of other objects that have mandatory object
handle inputs - ie REG_DM_MR is now automatically removed if DM objects
cannot be created.

Typically drivers not supporting an interface will mark all of the
supporting functions as NULL, including destroy.

This is intended to automatically eliminate entire corner cases in the API
that are difficult to test.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-11-22 11:57:32 -07:00
Jason Gunthorpe
6829c1c2b3 RDMA/uverbs: Add helpers to mark uapi functions as unsupported
We have many cases where parts of the uapi are not supported in a driver,
needs a certain protocol, or whatever. It is best to reflect this directly
into the struct uverbs_api when it is built so that everything is simply
blocked off, and future introspection can report a proper supported list.

This is done by adding some additional helpers to the definition list
language that disable objects based on a 'supported' call back, and a
helper that disables based on a NULL struct ib_device function pointer.

Disablement is global. For instance, if a driver disables an object then
everything connected to that object is removed, including core methods.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-11-22 11:57:32 -07:00
Jason Gunthorpe
c27f6aa8c9 RDMA/uverbs: Factor out the add/get pattern into a helper
The next patch needs another copy of this, provide a simple helper to
reduce the coding. uapi_add_get_elm() returns an existing entry or adds a
new one.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-11-22 11:57:32 -07:00
Jason Gunthorpe
0cbf432db4 RDMA/uverbs: Use a linear list to describe the compiled-in uapi
The 'tree' data structure is very hard to build at compile time, and this
makes it very limited. The new radix tree based compiler can handle a more
complex input language that does not require the compiler to perfectly
group everything into a neat tree structure.

Instead use a simple list to describe to input, where the list elements
can be of various different 'opcodes' instructing the radix compiler what
to do. Start out with opcodes chaining to other definition lists and
chaining to the existing 'tree' definition.

Replace the very top level of the 'object tree' with this list type and
get rid of struct uverbs_object_tree_def and DECLARE_UVERBS_OBJECT_TREE.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-11-22 11:57:32 -07:00
Jason Gunthorpe
59bfc59a68 Merge branch 'for-rc' into rdma.git for-next
From git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git

This is required to resolve dependencies of the next series of RDMA
patches.

The code motion conflicts in drivers/infiniband/core/cache.c were
resolved.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-10-16 00:01:02 -06:00
Mark Bloch
a9360abd3d IB/uverbs: Free uapi on destroy
Make sure we free struct uverbs_api once we clean the radix tree. It was
allocated by uverbs_alloc_api().

Fixes: 9ed3e5f447 ("IB/uverbs: Build the specs into a radix tree at runtime")
Reported-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-09-25 14:47:33 -06:00
Guy Levi
70cd20aed0 IB/uverbs: Add IDRs array attribute type to ioctl() interface
Methods sometimes need to get a flexible set of IDRs and not a strict set
as can be achieved today by the conventional IDR attribute. Add a new
IDRS_ARRAY attribute to the generic uverbs ioctl layer.

IDRS_ARRAY points to array of idrs of the same object type and same access
rights, only write and read are supported.

Signed-off-by: Guy Levi <guyle@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>``
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-09-11 09:28:06 -06:00
Jason Gunthorpe
3a863577a7 IB/uverbs: Use uverbs_api to unmarshal ioctl commands
Convert the ioctl method syscall path to use the uverbs_api data
structures. The new uapi structure includes all the same information, just
in a different and more optimal way.

 - Use attr_bkey instead of 2 level radix trees for everything related to
   attributes. This includes the attribute storage, presence, and
   detection of missing mandatory attributes.
 - Avoid iterating over all attribute storage at finish, instead use
   find_first_bit with the attr_bkey to locate only those attrs that need
   cleanup.
 - Organize things to always run, and always rely on, cleanup. This
   avoids a bunch of tricky error unwind cases.
 - Locate the method using the radix tree, and locate the attributes
   using a very efficient incremental radix tree lookup
 - Use the precomputed destroy_bkey to handle uobject destruction
 - Use the precomputed allocation sizes and precomputed 'need_stack'
   to avoid maths in the fast path. This is optimal if userspace
   does not pass (many) unsupported attributes.

Overall this results in much better codegen for the attribute accessors,
everything is now stored in bitmaps or linear arrays indexed by attr_bkey.
The compiler can compute attr_bkey values at compile time for all method
attributes, meaning things like uverbs_attr_is_valid() now compile into
single instruction bit tests.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-13 09:17:16 -06:00
Jason Gunthorpe
9ed3e5f447 IB/uverbs: Build the specs into a radix tree at runtime
This radix tree datastructure is intended to replace the 'hash' structure
used today for parsing ioctl methods during system calls. This first
commit introduces the structure and builds it from the existing .rodata
descriptions.

The so-called hash arrangement is actually a 5 level open coded radix tree.
This new version uses a 3 level radix tree built using the radix tree
library.

Overall this is much less code and much easier to build as the radix tree
API allows for dynamic modification during the building. There is a small
memory penalty to pay for this, but since the radix tree is allocated on
a per device basis, a few kb of RAM seems immaterial considering the
gained simplicity.

The radix tree is similar to the existing tree, but also has a 'attr_bkey'
concept, which is a small value'd index for each method attribute. This is
used to simplify and improve performance of everything in the next
patches.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
2018-08-10 16:06:24 -06:00