Commit graph

13 commits

Author SHA1 Message Date
Hans Petter Selasky
f3de9af633 Fix problem regarding priority inversion when using the concurrency
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
2017-04-19 13:03:29 +00:00
Hans Petter Selasky
22cbd6ef2e Create the LinuxKPI current task structure on the fly if it doesn't
exist when the current macro is used.

MFC after:		1 week
Sponsored by:		Mellanox Technologies
2017-04-07 14:43:28 +00:00
Hans Petter Selasky
c9dd0b48c9 Cleanup the bitmap_xxx() functions in the LinuxKPI:
- 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
2017-04-06 13:30:31 +00:00
Hans Petter Selasky
fc51649e31 Implement need_resched() in the LinuxKPI.
Obtained from:		kmacy @
MFC after:		1 week
Sponsored by:		Mellanox Technologies
2017-04-06 10:29:54 +00:00
Hans Petter Selasky
8402f058ad Fix implementation of task_pid_group_leader() in the LinuxKPI.
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
2017-04-06 10:26:03 +00:00
Hans Petter Selasky
a0699ebf77 Implement get_pid_task(), pid_task() and some other PID helper
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
2017-03-17 15:40:24 +00:00
Hans Petter Selasky
05d4f501dc Implement minimalistic memory mapping structure, struct mm_struct, and
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
2017-03-17 10:30:06 +00:00
Hans Petter Selasky
b8a8ed7c96 Define some more LinuxKPI task related macros.
Obtained from:		kmacy @
MFC after:		1 week
Sponsored by:		Mellanox Technologies
2017-03-16 12:33:34 +00:00
Hans Petter Selasky
1e3db1de0c Make the LinuxKPI task struct persistent accross system calls.
A set of helper functions have been added to manage the life of the
LinuxKPI task struct. When an external system call or task is invoked,
a check is made to create the task struct by demand. A thread
destructor callback is registered to free the task struct when a
thread exits to avoid memory leaks.

This change lays the ground for emulating the Linux kernel more
closely which is a dependency by the code using the LinuxKPI APIs.

Add new dedicated td_lkpi_task field has been added to struct thread
instead of abusing td_retval[1].

Fix some header file inclusions to make LINT kernel build properly
after this change.

Bump the __FreeBSD_version to force a rebuild of all kernel modules.

MFC after:		1 week
Sponsored by:		Mellanox Technologies
2017-02-21 12:43:02 +00:00
Hans Petter Selasky
8571421886 Add checks for SCHEDULER_STOPPED() so that code using the LinuxKPI can
run after a panic(). This for example allows a LinuxKPI based graphics
stack to receive prints during a panic.

Obtained from:	kmacy @
MFC after:	1 week
Sponsored by:	Mellanox Technologies
2016-05-25 09:04:06 +00:00
Hans Petter Selasky
3a8bec33ef Fix handling of IOCTLs in the LinuxKPI.
Linux requires that all IOCTL data resides in userspace. FreeBSD
always moves the main IOCTL structure into a kernel buffer before
invoking the IOCTL handler and then copies it back into userspace,
before returning. Hide this difference in the "linux_copyin()" and
"linux_copyout()" functions by remapping userspace addresses in the
range from 0x10000 to 0x20000, to the kernel IOCTL data buffer.

It is assumed that the userspace code, data and stack segments starts
no lower than memory address 0x400000, which is also stated by "man 1
ld", which means any valid userspace pointer can be passed to regular
LinuxKPI handled IOCTLs.

Bump the FreeBSD version to force recompilation of all kernel modules.

Discussed with:	kmacy @
MFC after:	1 week
Sponsored by:	Mellanox Technologies
2016-05-12 11:38:28 +00:00
Hans Petter Selasky
464d20bcc8 Create a dummy "task_struct" on the stack which is returned by
"current" inside all LinuxKPI file operation callbacks. The "current"
is frequently used for various debug prints, printing the thread name
and thread ID for example.

Obtained from:	kmacy @
MFC after:	1 week
Sponsored by:	Mellanox Technologies
2016-05-12 09:06:54 +00:00
Hans Petter Selasky
8d59ecb214 Finish process of moving the LinuxKPI module into the default kernel build.
- Move all files related to the LinuxKPI into sys/compat/linuxkpi and
  its subfolders.
- Update sys/conf/files and some Makefiles to use new file locations.
- Added description of COMPAT_LINUXKPI to sys/conf/NOTES which in turn
  adds the LinuxKPI to all LINT builds.
- The LinuxKPI can be added to the kernel by setting the
  COMPAT_LINUXKPI option. The OFED kernel option no longer builds the
  LinuxKPI into the kernel. This was done to keep the build rules for
  the LinuxKPI in sys/conf/files simple.
- Extend the LinuxKPI module to include support for USB by moving the
  Linux USB compat from usb.ko to linuxkpi.ko.
- Bump the FreeBSD_version.
- A universe kernel build has been done.

Reviewed by:	np @ (cxgb and cxgbe related changes only)
Sponsored by:	Mellanox Technologies
2015-10-29 08:28:39 +00:00
Renamed from sys/ofed/include/linux/sched.h (Browse further)