Passing the attribute to the low level IO functions allows all kinds
of cleanups, by sharing low level IO code without requiring
an own function for every piece of data.

Also drivers can extend the attributes with own data fields
and use that in the low level function.

This makes the class attributes the same as sysdev_class attributes
and plain attributes.

This will allow further cleanups in drivers.

Full tree sweep converting all users.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The anon_inodes interface has been split to allow creating a bare
(non-installed) file pointer and also extended to allow specifying
O_RDONLY in the flags.  This makes it a suitable replacement for the
private "infinibandeventfs" pseudo-filesystem used by uverbs, and this
replacement saves a small chunk of boilerplate code.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Clean up the errors as shown when 'let c_space_errors=1' is set in vim.
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Some large systems may support more than IB_UVERBS_MAX_DEVICES
(currently 32).

This change allows us to support more devices in a backwards-compatible
manner.  The first IB_UVERBS_MAX_DEVICES keep the same major/minor
device numbers that they've always had.

If there are more than IB_UVERBS_MAX_DEVICES, we then dynamically
request a new major device number (new minors start at 0).

This change increases the maximum number of HCAs to 64 (from 32).
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

This change is not useful by itself, but sets us up for a future change
that allows us to support more than IB_UVERBS_MAX_DEVICES in a system.
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

This change is not useful by itself, but it sets us up for a future
change that allows us to dynamically allocate device numbers in case
we have more than IB_UVERBS_MAX_DEVICES in the system.
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

dev_table's raison d'etre was to associate an inode back to a struct
ib_uverbs_device.

However, now that we've converted ib_uverbs_device to contain an
embedded cdev (instead of a *cdev), we can use the container_of()
macro and cast back to the containing device.

There's no longer any need for dev_table, so get rid of it.
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Instead of storing a pointer to a cdev, embed the entire struct cdev.

This change allows us to use the container_of() macro in
ib_uverbs_open() in a future patch.

This change increases the size of struct ib_uverbs_device to 168 bytes
across 3 cachelines from 80 bytes in 2 cachelines.  However, we
rearrange the members so that everything fits into the first cacheline
except for the struct cdev. Finally, we don't touch the cdev in any
fastpaths, so this change shouldn't negatively affect performance.
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

... and have the caller grab both mnt and dentry; kill
leak in infiniband, while we are at it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since the original commit 883a99c7 ("[IB] uverbs: Add a mask of device
methods allowed for userspace"), the uverbs core returns EINVAL for
commands not implemented by a specific low-level driver.

This creates a problem that there is no way to tell the difference
between an unimplemented command and an implemented one which is
incorrectly invoked (which also returns EINVAL).

The fix is to have unimplemented commands return ENOSYS.
Signed-off-by: NJack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Rather than just defining static spinlock_t variables and then
initializing them later in init functions, simply define them with
DEFINE_SPINLOCK() and remove the calls to spin_lock_init().  This cleans
up the source a tad and also shrinks the compiled code; eg on x86-64:

add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-40 (-40)
function                                     old     new   delta
ib_uverbs_init                               336     326     -10
ib_mad_init_module                           147     137     -10
ib_sa_init                                   123     103     -20
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

As it is, all instances of ->release() for files that have ->fasync()
need to remember to evict file from fasync lists; forgetting that
creates a hole and we actually have a bunch that *does* forget.

So let's keep our lives simple - let __fput() check FASYNC in
file->f_flags and call ->fasync() there if it's been set.  And lose that
crap in ->release() instances - leaving it there is still valid, but we
don't have to bother anymore.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that device_create() has been audited, rename things back to the
original call to be sane.

Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

They don't get updated by git and so they're worse than useless.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Remove explicit lock_kernel() calls and document why the code is safe.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Be extra-cautious and protect the remaining open() functions.
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Commit 1ae5c187 ("IB/uverbs: Don't store struct file * for event
files") changed the way that closed files are handled in the uverbs
code.  However, after the conversion, is_closed flag is checked
incorrectly in ib_uverbs_async_handler().  As a result, no async
events are ever passed to applications.

Found by: Ronni Zimmerman <ronniz@mellanox.co.il>
Signed-off-by: NJack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.

This patch fixes the problem by using the new function,
device_create_drvdata().

Cc: Kay Sievers <kay.sievers@vrfy.org>
Reviewed-by: NRoland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This converts the main ib_device to use struct device instead of struct
class_device as class_device is going away.
Signed-off-by: NTony Jones <tonyj@suse.de>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Christoph Hellwig wants to unexport get_empty_filp(), which is an ugly
internal interface.  Change the modular user in ib_uverbs_alloc_event_file()
to use the better alloc_file() interface; this makes the code cleaner too.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

The file member of struct ib_uverbs_event_file was only used to keep
track of whether the file had been closed or not.  The only thing we
ever did with the value was check if it was NULL or not.  Simplify the
code and get rid of the need to keep track of the struct file * we
allocate by replacing the file member with an is_closed member.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

ib_uverbs_release_event_file() is only used in uverbs_main.c, so make it
static to that file.  Also move the definition before the first use, so
a forward declaration is not needed.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Export ib_umem_get()/ib_umem_release() and put low-level drivers in
control of when to call ib_umem_get() to pin and DMA map userspace,
rather than always calling it in ib_uverbs_reg_mr() before calling the
low-level driver's reg_user_mr method.

Also move these functions to be in the ib_core module instead of
ib_uverbs, so that driver modules using them do not depend on
ib_uverbs.

This has a number of advantages:
 - It is better design from the standpoint of making generic code a
   library that can be used or overridden by device-specific code as
   the details of specific devices dictate.
 - Drivers that do not need to pin userspace memory regions do not
   need to take the performance hit of calling ib_mem_get().  For
   example, although I have not tried to implement it in this patch,
   the ipath driver should be able to avoid pinning memory and just
   use copy_{to,from}_user() to access userspace memory regions.
 - Buffers that need special mapping treatment can be identified by
   the low-level driver.  For example, it may be possible to solve
   some Altix-specific memory ordering issues with mthca CQs in
   userspace by mapping CQ buffers with extra flags.
 - Drivers that need to pin and DMA map userspace memory for things
   other than memory regions can use ib_umem_get() directly, instead
   of hacks using extra parameters to their reg_phys_mr method.  For
   example, the mlx4 driver that is pending being merged needs to pin
   and DMA map QP and CQ buffers, but it does not need to create a
   memory key for these buffers.  So the cleanest solution is for mlx4
   to call ib_umem_get() in the create_qp and create_cq methods.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add a num_comp_vectors member to struct ib_device and extend
ib_create_cq() to pass in a comp_vector parameter -- this parallels
the userspace libibverbs API.  Update all hardware drivers to set
num_comp_vectors to 1 and have all ULPs pass 0 for the comp_vector
value.  Pass the value of num_comp_vectors to userspace rather than
hard-coding a value of 1.

We want multiple CQ event vector support (via MSI-X or similar for
adapters that can generate multiple interrupts), but it's not clear
how many vectors we want, or how we want to deal with policy issues
such as how to decide which vector to use or how to set up interrupt
affinity.  This patch is useful for experimenting, since no core
changes will be necessary when updating a driver to support multiple
vectors, and we know that we want to make at least these changes
anyway.
Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJosef Sipek <jsipek@fsl.cs.sunysb.edu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Wait until all users have closed their device context before allowing
device unregistration to complete.  This prevents a crash caused by
referring to stale data structures.

A better solution would be to have a way to revoke contexts rather
than waiting for userspace to close the context, but that's a much
bigger change that will have to wait.  For now let's at least avoid
the crash.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Extend the get_sb() filesystem operation to take an extra argument that
permits the VFS to pass in the target vfsmount that defines the mountpoint.

The filesystem is then required to manually set the superblock and root dentry
pointers.  For most filesystems, this should be done with simple_set_mnt()
which will set the superblock pointer and then set the root dentry to the
superblock's s_root (as per the old default behaviour).

The get_sb() op now returns an integer as there's now no need to return the
superblock pointer.

This patch permits a superblock to be implicitly shared amongst several mount
points, such as can be done with NFS to avoid potential inode aliasing.  In
such a case, simple_set_mnt() would not be called, and instead the mnt_root
and mnt_sb would be set directly.

The patch also makes the following changes:

 (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount
     pointer argument and return an integer, so most filesystems have to change
     very little.

 (*) If one of the convenience function is not used, then get_sb() should
     normally call simple_set_mnt() to instantiate the vfsmount. This will
     always return 0, and so can be tail-called from get_sb().

 (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the
     dcache upon superblock destruction rather than shrink_dcache_anon().

     This is required because the superblock may now have multiple trees that
     aren't actually bound to s_root, but that still need to be cleaned up. The
     currently called functions assume that the whole tree is rooted at s_root,
     and that anonymous dentries are not the roots of trees which results in
     dentries being left unculled.

     However, with the way NFS superblock sharing are currently set to be
     implemented, these assumptions are violated: the root of the filesystem is
     simply a dummy dentry and inode (the real inode for '/' may well be
     inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries
     with child trees.

     [*] Anonymous until discovered from another tree.

 (*) The documentation has been adjusted, including the additional bit of
     changing ext2_* into foo_* in the documentation.

[akpm@osdl.org: convert ipath_fs, do other stuff]
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In ib_uverbs_cleanup_ucontext(), when iterating through the lists of
objects, there's no reason to do list_del() to remove the objects,
since both the objects and the lists that contain them are about to be
freed anyway.  Since list_del() is a moderately big inline function,
getting rid of this extra work saves quite a bit of .text:

add/remove: 0/0 grow/shrink: 1/2 up/down: 3/-217 (-214)
function                                     old     new   delta
ib_uverbs_comp_handler                       225     228      +3
ib_uverbs_async_handler                      256     255      -1
ib_uverbs_close                              905     689    -216
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Currently, all userspace verbs operations that call into the kernel
are serialized by ib_uverbs_idr_mutex.  This can be a scalability
issue for some workloads, especially for devices driven by the ipath
driver, which needs to call into the kernel even for datapath
operations.

Fix this by adding reference counts to the userspace objects, and then
converting ib_uverbs_idr_mutex into a spinlock that only protects the
idrs long enough to take a reference on the object being looked up.
Because remove operations may fail, we have to do a slightly funky
two-step deletion, which is described in the comments at the top of
uverbs_cmd.c.

This also still leaves ib_uverbs_idr_lock as a single lock that is
possibly subject to contention.  However, the lock hold time will only
be a single idr operation, so multiple threads should still be able to
make progress, even if ib_uverbs_idr_lock is being ping-ponged.

Surprisingly, these changes even shrink the object code:

add/remove: 23/5 grow/shrink: 4/21 up/down: 633/-693 (-60)
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add support to uverbs to handle querying userspace SRQs (shared
receive queues), including adding an ABI for marshalling requests and
responses.  The kernel midlayer already has the underlying
ib_query_srq() function.
Signed-off-by: NDotan Barak <dotanb@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add support to uverbs to handle querying userspace QPs (queue pairs),
including adding an ABI for marshalling requests and responses.  The
kernel midlayer already has the underlying ib_query_qp() function.
Signed-off-by: NDotan Barak <dotanb@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Remove trailing whitespace and fix indentation that with spaces
instead of tabs.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add support to uverbs to handle resizing userspace CQs (completion
queues), including adding an ABI for marshalling requests and
responses.  The kernel midlayer already has ib_resize_cq().
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

uverbs might schedule work to clean up when a file is closed.  Make
sure that this work runs before allowing module text to go away.
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

semaphore to mutex conversion by Ingo and Arjan's script.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
[ Sanity-checked on real IB hardware ]
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

uverbs needs to track which multicast groups is each qp
attached to, in order to properly detach when cleanup
is performed on device file close.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Replace kmalloc()+memset(,0,) with kzalloc(), for a net savings of 35
source lines and about 500 bytes of text.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>