the destroying cdev.
Currently linux_destroy_dev() waits for the reference count on the
linux cdev to drain, and each open file hold the reference.
Practically it means that linux_destroy_dev() is blocked until all
userspace processes that have the cdev open, exit. FreeBSD devfs does
not have such problem, because device refcount only prevents freeing
of the cdev memory, and separate 'active methods' counter blocks
destroy_dev() until all threads leave the cdevsw methods. After that,
attempts to enter cdevsw methods are refused with an error.
Implement somewhat similar mechanism for LinuxKPI cdevs. Demote cdev
refcount to only mean a hold on the linux cdev memory. Add sirefs
count to track both number of threads inside the cdev methods, and for
single-bit indicator that cdev is being destroyed. In the later case,
the call is redirected to the dummy cdev.
Reviewed by: markj
Discussed with: hselasky
Tested by: zeising
MFC after: 1 week
Sponsored by: Mellanox Technologies
Differential revision: https://reviews.freebsd.org/D18606
Currently we always return false if for PCI offline query.
Try to read PCI config, if the return value if 0xffff probably the
PCI is offline.
Approved by: hselasky (mentor)
MFC after: 1 week
Sponsored by: Mellanox Technologies
Make sure we hold a reference on the character device for every opened file
to prevent the character device to be freed prematurely.
Submitted by: hselasky@
Approved by: hselasky (mentor)
MFC after: 1 week
Sponsored by: Mellanox Technologies
According to markj@:
pageproc contains the page daemon and laundry threads, which are
responsible for managing the LRU page queues and writing back dirty
pages. vmproc's main task is to swap out kernel stacks when the system
is under memory pressure, and swap them back in when necessary. It's a
somewhat legacy component of the system and isn't required. You can
build a kernel without it by specifying "options NO_SWAPPING" (which is
a somewhat misleading name), in which vm_swapout_dummy.c is compiled
instead of vm_swapout.c.
Based on this, we want pageproc to emulate kswapd, not vmproc.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D18061
These are used by kms-drm to determine various heuristics relate
memory conditions.
The number of free swap pages is just a variable, and it can be
much cheaper by either adding a new getter, or simply extern'ing
swap_total. However, this patch opts to use the more expensive,
existing interface - since this isn't an operation in a high per
path.
This allows us to remove some more gpl linuxkpi and do the follo
kms-drm:
git rm linuxkpi/gplv2/include/linux/swap.h
Reviewed by: mmacy, Johannes Lundberg <johalun0@gmail.com>
Approved by: emaste (mentor)
Differential Revision: https://reviews.freebsd.org/D18052
Currently the compiler picks up the definition in machine/cpufunc.h.
Add compiler memory barriers to read* and write*. The Linux x86
implementation of these functions uses inline asm with "memory" clobber.
The Linux x86 implementation of read_relaxed* and write_relaxed* uses the
same inline asm without "memory" clobber.
Implement ioread* and iowrite* in terms of read* and write* so they also
have memory barriers.
Qualify the addr parameter in write* as volatile.
Like Linux, define macros with the same name as the inline functions.
Only define 64-bit versions on 64-bit architectures because generally
32-bit architectures can't do atomic 64-bit loads and stores.
Regroup the functions a bit and add brief comments explaining what they do:
- __raw_read*, __raw_write*: atomic, no barriers, no byte swapping
- read_relaxed*, write_relaxed*: atomic, no barriers, little-endian
- read*, write*: atomic, with barriers, little-endian
Add a comment that says our implementation of ioread* and iowrite*
only handles MMIO and does not support port IO.
Reviewed by: hselasky
MFC after: 3 days
error in the function hypercall_memfree(), where the wrong arena was being
passed to kmem_free().
Introduce a per-page flag, VPO_KMEM_EXEC, to mark physical pages that are
mapped in kmem with execute permissions. Use this flag to determine which
arena the kmem virtual addresses are returned to.
Eliminate UMA_SLAB_KRWX. The introduction of VPO_KMEM_EXEC makes it
redundant.
Update the nearby comment for UMA_SLAB_KERNEL.
Reviewed by: kib, markj
Discussed with: jeff
Approved by: re (marius)
Differential Revision: https://reviews.freebsd.org/D16845
The timespecadd(3) family of macros were imported from NetBSD back in
r35029. However, they were initially guarded by #ifdef _KERNEL. In the
meantime, we have grown at least 28 syscalls that use timespecs in some
way, leading many programs both inside and outside of the base system to
redefine those macros. It's better just to make the definitions public.
Our kernel currently defines two-argument versions of timespecadd and
timespecsub. NetBSD, OpenBSD, and FreeDesktop.org's libbsd, however, define
three-argument versions. Solaris also defines a three-argument version, but
only in its kernel. This revision changes our definition to match the
common three-argument version.
Bump _FreeBSD_version due to the breaking KPI change.
Discussed with: cem, jilles, ian, bde
Differential Revision: https://reviews.freebsd.org/D14725
While at it rename hlist_add_after() into hlist_add_behind().
Submitted by: Johannes Lundberg <johalun0@gmail.com>
MFC after: 1 week
Sponsored by: Mellanox Technologies
Sponsored by: Limelight Networks
the LinuxKPI. Add a comment saying in which Linux version this change was made.
Submitted by: Johannes Lundberg <johalun0@gmail.com>
MFC after: 1 week
Sponsored by: Mellanox Technologies
Sponsored by: Limelight Networks
in the LinuxKPI. While at it document when to use the "virtual_address" or
the "address" field in the "vm_fault" structure.
Submitted by: Johannes Lundberg <johalun0@gmail.com>
MFC after: 1 week
Sponsored by: Mellanox Technologies
Sponsored by: Limelight Networks
sg_alloc_table_from_pages() function in the LinuxKPI.
This basically allow segments to have a limit, max_segment.
Submitted by: Johannes Lundberg <johalun0@gmail.com>
MFC after: 1 week
Sponsored by: Mellanox Technologies
Sponsored by: Limelight Networks
