kit, CK, in the LinuxKPI.
When threads are pinned to a CPU core or when there is only one CPU,
it can happen that a higher priority thread can call the CK
synchronize function while a lower priority thread holds the read
lock. Because the CK's synchronize is a simple wait loop this can lead
to a deadlock situation. To solve this problem use the recently
introduced CK's wait callback function.
When detecting a CK blocking condition figure out the lowest priority
among the blockers and update the calling thread's priority and
yield. If another CPU core is holding the read lock, pin the thread to
the blocked CPU core and update the priority. The calling threads
priority and CPU bindings are restored before return.
If a thread holding a CK read lock is detected to be sleeping, pause()
will be used instead of yield().
MFC after: 1 week
Sponsored by: Mellanox Technologies
CPUs when allocating a LinuxKPI workqueue. This also ensures that the
created taskqueue always have a non-zero number of worker threads.
MFC after: 1 week
Sponsored by: Mellanox Technologies
- Move all bitmap related functions from bitops.h to bitmap.h, similar
to what Linux does.
- Apply some minor code cleanup and simplifications to optimize the
generated code when using static inline functions.
- Implement the following list of bitmap functions which are needed by
drm-next and ibcore:
- bitmap_find_next_zero_area_off()
- bitmap_find_next_zero_area()
- bitmap_or()
- bitmap_and()
- bitmap_xor()
- Add missing include directives to the qlnxe driver
(davidcs@ has been notified)
MFC after: 1 week
Sponsored by: Mellanox Technologies
In FreeBSD thread IDs and procedure IDs have distinct number
spaces. When asking for the group leader task ID in the LinuxKPI,
return the procedure ID and let this resolve to the first task in the
procedure having a valid LinuxKPI task structure pointer.
MFC after: 1 week
Sponsored by: Mellanox Technologies
like open, close and fault using the character device pager.
Some notes about the implementation:
1) Linux drivers set the vm_ops and vm_private_data fields during a
mmap() call to indicate that the driver wants to use the LinuxKPI VM
operations. Else these operations are not used.
2) The vm_private_data pointer is associated with a VM area structure
and inserted into an internal LinuxKPI list. If the vm_private_data
pointer already exists, the existing VM area structure is used instead
of the allocated one which gets freed.
3) The LinuxKPI's vm_private_data pointer is used as the callback
handle for the FreeBSD VM object. The VM subsystem in FreeBSD has a
similar list to identify equal handles and will only call the
character device pager's close function once.
4) All LinuxKPI VM operations are serialized through the mmap_sem
sempaphore, which is per procedure, which prevents simultaneous access
to the shared VM area structure when receiving page faults.
Obtained from: kmacy @
MFC after: 1 week
Sponsored by: Mellanox Technologies
tasks in the belonging procedure already have a valid mm_struct and
reference that instead.
The mm_struct in the LinuxKPI should be shared among all tasks
belonging to the same procedure. This has to do with with the mmap_sem
semaphore which should serialize all VM operations inside a given
procedure. Linux based drivers depend on this behaviour.
MFC after: 1 week
Sponsored by: Mellanox Technologies
Make sure the character device poll callback function does not return
an error code, but a POLLXXX value, in case of failure.
MFC after: 1 week
Sponsored by: Mellanox Technologies
the LinuxKPI for accessing user-space memory in the kernel.
Add functions to hold and wire physical page(s) based on a given range
of user-space virtual addresses.
Add functions to get and put a reference on, wire, hold, mark
accessed, copy and dirty a physical page.
Add new VM related structures and defines as a preparation step for
advancing the memory map capabilities of the LinuxKPI.
Add function to figure out if a virtual address was allocated using
malloc().
Add function to convert a virtual kernel address into its physical
page pointer.
Obtained from: kmacy @
MFC after: 1 week
Sponsored by: Mellanox Technologies
functions in the LinuxKPI. Add a usage atomic to the task_struct
structure to facilitate refcounting the task structure when returned
from get_pid_task(). The get_task_struct() and put_task_struct()
function is used to manage atomic refcounting. After this change the
task_struct should only be freed through put_task_struct().
Obtained from: kmacy @
MFC after: 1 week
Sponsored by: Mellanox Technologies
some associated helper functions in the LinuxKPI. Let the existing
linux_alloc_current() function allocate and initialize the new
structure and let linux_free_current() drop the refcount on the memory
mapping structure. When the mm_struct's refcount reaches zero, the
structure is freed.
Obtained from: kmacy @
MFC after: 1 week
Sponsored by: Mellanox Technologies
pairwise to support the FreeBSD way of pushing and popping the page
fault flags. Ensure this by requiring every occurrence of pagefault
disable function call to have a corresponding pagefault enable call.
Obtained from: kmacy @
MFC after: 1 week
Sponsored by: Mellanox Technologies
Support is implemented by mapping Linux's "struct net" into FreeBSD's
"struct vnet". Currently only vnet0 is supported by ibcore.
MFC after: 1 week
Sponsored by: Mellanox Technologies
When locking a mutex and deadlock is detected the first mutex lock
call that sees the deadlock will return -EDEADLK .
MFC after: 1 week
Sponsored by: Mellanox Technologies
Add support for using mutexes during KDB and shutdown. This is also
required for doing mode-switching during panic for drm-next.
Add new mutex functions mutex_init_witness() and mutex_destroy()
allowing LinuxKPI mutexes to be tracked by witness.
Declare mutex_is_locked() and mutex_is_owned() like inline functions
to get cleaner warnings. These functions are used inside WARN_ON()
statements which might look a bit odd if these functions get fully
expanded.
Give mutexes better debug names through the mutex_name() macro when
WITNESS_ALL is defined. The mutex_name() macro can prefix parts of the
filename and line number before the mutex name.
MFC after: 1 week
Sponsored by: Mellanox Technologies
kthread_add() will assert it is called too soon. This fixes a startup
issue when COMPAT_LINUXKPI is in enabled the kernel configuration
file.
Reported by: Michael Butler <imb@protected-networks.net>
MFC after: 1 week
Sponsored by: Mellanox Technologies
Put large functions into linux_slab.c instead of declaring them static
inline.
Add support for more memory allocation wrappers like kmalloc_array()
and __vmalloc().
Make sure either the M_WAITOK or the M_NOWAIT flag is set and mask
away unused memory allocation flags before calling FreeBSD's malloc()
routine.
Move kmalloc_node() definition to slab.h where it belongs.
Implement support for the SLAB_DESTROY_BY_RCU feature when creating a
kmem_cache which basically means kmem_cache memory is freed using
call_rcu().
MFC after: 1 week
Sponsored by: Mellanox Technologies
LinuxKPI. When the type of the argument is constant the temporary
variable cannot be assigned after the barrier. Instead assign the
temporary variable by initialization.
MFC after: 1 week
Sponsored by: Mellanox Technologies
This avoids creating own per-CPU threads and also ensures the tasklet
execution happens on the same CPU core invoking the tasklet.
MFC after: 1 week
Sponsored by: Mellanox Technologies
This change makes the workqueue implementation behave more like in
Linux, both functionality wise and structure wise.
All workqueue code has been moved to linux_work.c
Add an atomic based statemachine to the work_struct to ensure proper
operation. Prior to this change struct_work was directly mapped to a
FreeBSD task. When a taskqueue has multiple threads the same task may
end up being executed on more than one worker thread simultaneously.
This might cause problems with code coming from Linux, which expects
serial behaviour, similar to Linux tasklets.
Move all global workqueue function names into the linux_xxx domain to
avoid symbol name clashes in the future.
Implement a few more workqueue related functions and macros.
Create two multithreaded taskqueues for the LinuxKPI during module
load, one for time-consuming callbacks and one for non-time consuming
callbacks.
MFC after: 1 week
Sponsored by: Mellanox Technologies
