- Expand the set of atomic operations to optionally include memory barriers
in most of the atomic operations. Now for these operations, you can
use the normal atomic operation, you can use the o

- Expand the set of atomic operations to optionally include memory barriers
in most of the atomic operations. Now for these operations, you can
use the normal atomic operation, you can use the operation with a read
barrier, or you can use the operation with a write barrier. The function
names follow the same semantics used in the ia64 instruction set. An
atomic operation with a read barrier has the extra suffix 'acq', due to
it having "acquire" semantics. An atomic operation with a write barrier
has the extra suffix 'rel'. These suffixes are inserted between the
name of the operation to perform and the typename. For example, the
atomic_add_int() function now has 3 variants:
- atomic_add_int() - this is the same as the previous function
- atomic_add_acq_int() - this function combines the add operation with a
read memory barrier
- atomic_add_rel_int() - this function combines the add operation with a
write memory barrier
- Add 'ptr' to the list of types that we can perform atomic operations
on. This allows one to do atomic operations on uintptr_t's. This is
useful in the mutex code, for example, because the actual mutex lock is
a pointer.
- Add two new operations for doing loads and stores with memory barriers.
The new load operations use a read barrier before the load, and the
new store operations use a write barrier after the load. For example,
atomic_load_acq_int() will atomically load an integer as well as
enforcing a read barrier.

show more ...

Add atomic_readandclear_int and atomic_readandclear_long.

Introduce atomic_cmpset_int() and atomic_cmpset_long() from SMPng a
few hours earlier than the rest.

The next DEVFS commit needs these functions.

Alpha versions by: dfr
i386 versions by: jakeb

App

Introduce atomic_cmpset_int() and atomic_cmpset_long() from SMPng a
few hours earlier than the rest.

The next DEVFS commit needs these functions.

Alpha versions by: dfr
i386 versions by: jakeb

Approved by: SMPng

show more ...

When using _asm{} in GCC, one must specify the operand's size if one
specifies the instruction's operation size. GCC will default to 32-bit
operands reguardless of the prototype (ie, formal paramete

When using _asm{} in GCC, one must specify the operand's size if one
specifies the instruction's operation size. GCC will default to 32-bit
operands reguardless of the prototype (ie, formal parameters' type)
of an inline function.

show more ...

Use the rev 1.1.2.1 code from RELENG_3 for atomic operations rather
than the non-atomic C macros.

Typo: s/__GNUC_MINOR_/__GNUC_MINOR__/
(__GNUC_MINOR__ on egcs in -current is "91" and is going to be "95" soon)

Allow compilation with older versions of GCC, in order to make it possible
to bootstrap and work with -current from older versions of FreeBSD.

$Id$ -> $FreeBSD$

Create callable (non-inline) versions of the atomic_OP_TYPE functions
that are linked into the kernel. The KLD compilation options are
changed to call these functions, rather than in-lining the
atom

Create callable (non-inline) versions of the atomic_OP_TYPE functions
that are linked into the kernel. The KLD compilation options are
changed to call these functions, rather than in-lining the
atomic operations.

This approach makes atomic operations from KLDs significantly
faster on UP systems (though somewhat slower on SMP systems).

PR: i386/13111
Submitted by: peter.jeremy@alcatel.com.au

show more ...

atomic.h:
Change "void *" to "volatile TYPE *", improving type safety
and eliminating some warnings (e.g., mp_machdep.c rev 1.106).

cpufunc.h:
Eliminate setbits. As defined, it's not precisely c

atomic.h:
Change "void *" to "volatile TYPE *", improving type safety
and eliminating some warnings (e.g., mp_machdep.c rev 1.106).

cpufunc.h:
Eliminate setbits. As defined, it's not precisely correct;
and it's redundant. (Use atomic_set_int instead.)

ipl_funcs.c:
Use atomic_set_int instead of setbits.

systm.h:
Include atomic.h.

Reviewed by: bde

show more ...

Commit the correct patch, i.e., the one that actually corresponds
to the rev 1.2 log entry.

Changed the implementation of the primitives to guarantee atomicity
with respect to interrupts on UP systems. (The upgrade from gcc 2.7.x
to egcs 1.1.2 produced at least one non-atomic code sequence

Changed the implementation of the primitives to guarantee atomicity
with respect to interrupts on UP systems. (The upgrade from gcc 2.7.x
to egcs 1.1.2 produced at least one non-atomic code sequence in
swap_pager_getpages.)

In addition, the primitives are now SMP-safe, but only on SMPs. (For
portability between SMPs and UPs, modules are compiled with the SMP-safe
versions.)

Submitted by: dillon and myself
Reviewed by: bde

show more ...

Change various syscalls to use size_t arguments instead of u_int.

Add some overflow checks to read/write (from bde).

Change all modifications to vm_page::flags, vm_page::busy, vm_object::flags
and

Change various syscalls to use size_t arguments instead of u_int.

Add some overflow checks to read/write (from bde).

Change all modifications to vm_page::flags, vm_page::busy, vm_object::flags
and vm_object::paging_in_progress to use operations which are not
interruptable.

Reviewed by: Bruce Evans <bde@zeta.org.au>

show more ...

Remove checks for <sys/cdefs.h> being included.

These files no longer depend on the macros required when these checks
were added.

PR: 263102 (exp-run)
Reviewed by: brooks, imp, emaste
Differential

Remove checks for <sys/cdefs.h> being included.

These files no longer depend on the macros required when these checks
were added.

PR: 263102 (exp-run)
Reviewed by: brooks, imp, emaste
Differential Revision: https://reviews.freebsd.org/D34804

show more ...

Remove checks for __GNUCLIKE_ASM assuming it is always true.

All supported compilers (modern versions of GCC and clang) support
this.

Many places didn't have an #else so would just silently do the

Remove checks for __GNUCLIKE_ASM assuming it is always true.

All supported compilers (modern versions of GCC and clang) support
this.

Many places didn't have an #else so would just silently do the wrong
thing. Ancient versions of icc (the original motivation for this) are
no longer a compiler FreeBSD supports.

PR: 263102 (exp-run)
Reviewed by: brooks, imp
Differential Revision: https://reviews.freebsd.org/D34797

show more ...

x86 atomic.h: remove obsoleted comment

Modules no longer call kernel functions for atomic ops, and since the
previous commit, we always use lock prefix.

Submitted by: Elliott Mitchell <ehem+freebsd

x86 atomic.h: remove obsoleted comment

Modules no longer call kernel functions for atomic ops, and since the
previous commit, we always use lock prefix.

Submitted by: Elliott Mitchell <ehem+freebsd@m5p.com>
Reviewed by: jhb, markj
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D34153

show more ...

x86 atomics: use lock prefix unconditionally

Atomics have significant other use besides providing in-system
primitives for safe memory updates. They are used for implementing
communication with out

x86 atomics: use lock prefix unconditionally

Atomics have significant other use besides providing in-system
primitives for safe memory updates. They are used for implementing
communication with out of system software or hardware following some
protocols.

For instance, even UP kernel might require a protocol using atomics to
communicate with the software-emulated device on SMP hypervisor. Or
real hardware might need atomic accesses as part of the proper
management protocol.

Another point is that UP configurations on x86 are extinct, so slight
performance hit by unconditionally use proper atomics is not important.
It is compensated by less code clutter, which in fact improves the
UP/i386 lifetime expectations.

Requested by: Elliott Mitchell <ehem+freebsd@m5p.com>
Reviewed by: Elliott Mitchell, imp, jhb, markj, royger
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D34153

show more ...

x86 atomic.h: cleanup comments for preprocessor directives

Reviewed by: Elliott Mitchell, imp, jhb, markj, royger
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https:

x86 atomic.h: cleanup comments for preprocessor directives

Reviewed by: Elliott Mitchell, imp, jhb, markj, royger
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D34153

show more ...

Expand generic subword atomic primitives

The goal of this change is to make the atomic_load_acq_{8,16},
atomic_testandset{,_acq}_long, and atomic_testandclear_long primitives
available in MI-namespa

Expand generic subword atomic primitives

The goal of this change is to make the atomic_load_acq_{8,16},
atomic_testandset{,_acq}_long, and atomic_testandclear_long primitives
available in MI-namespace.

The second goal is to get this draft out of my local tree, as anything that
requires a full tinderbox is a big burden out of tree. MD specifics can be
refined individually afterwards.

The generic implementations may not be ideal for your architecture; feel
free to implement better versions. If no subword_atomic definitions are
needed, the include can be removed from your arch's machine/atomic.h.
Generic definitions are guarded by defined macros of the same name. To
avoid picking up conflicting generic definitions, some macro defines are
added to various MD machine/atomic.h to register an existing implementation.

Include _atomic_subword.h in arm and arm64 machine/atomic.h.

For some odd reason, KCSAN only generates some versions of primitives.
Generate the _acq variants of atomic_load.*_8, atomic_load.*_16, and
atomic_testandset.*_long. There are other questionably disabled primitives,
but I didn't run into them, so I left them alone. KCSAN is only built for
amd64 in tinderbox for now.

Add atomic_subword implementations of atomic_load_acq_{8,16} implemented
using masking and atomic_load_acq_32.

Add generic atomic_subword implementations of atomic_testandset_long(),
atomic_testandclear_long(), and atomic_testandset_acq_long(), using
atomic_fcmpset_long() and atomic_fcmpset_acq_long().

On x86, add atomic_testandset_acq_long as an alias for
atomic_testandset_long.

Reviewed by: kevans, rlibby (previous versions both)
Differential Revision: https://reviews.freebsd.org/D22963

show more ...

i386: hide more of atomic 64-bit definitions under _KERNEL

At the moment i386 does not provide 64-bit atomic operations in
userland. Exposing some atomic_*_64 defines can cause unnecessary
confusio

i386: hide more of atomic 64-bit definitions under _KERNEL

At the moment i386 does not provide 64-bit atomic operations in
userland. Exposing some atomic_*_64 defines can cause unnecessary
confusion.

Discussed with: kib
MFC after: 2 weeks

show more ...

i386: Implement atomic_load_64(9) and atomic_store_64(9).

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Implement missing atomic_fcmpset_XXX() support for i386.

This also fixes i386 build after r337527.

MFC after: 1 week
Sponsored by: Mellanox Technologies

Make sure kernel modules built by default are portable between UP and
SMP systems by extending defined(SMP) to include defined(KLD_MODULE).

This is a regression issue after r335873 .

Discussed with

Make sure kernel modules built by default are portable between UP and
SMP systems by extending defined(SMP) to include defined(KLD_MODULE).

This is a regression issue after r335873 .

Discussed with: mmacy@
Sponsored by: Mellanox Technologies

show more ...

inline atomics and allow tied modules to inline locks

- inline atomics in modules on i386 and amd64 (they were always
inline on other arches)
- allow modules to opt in to inlining locks by specify

inline atomics and allow tied modules to inline locks

- inline atomics in modules on i386 and amd64 (they were always
inline on other arches)
- allow modules to opt in to inlining locks by specifying
MODULE_TIED=1 in the makefile

Reviewed by: kib
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D16079

show more ...

Implement atomic_add_64() and atomic_subtract_64() for the i386 target.

While at it add missing _acq_ and _rel_ variants for 64-bit atomic
operations under i386.

Reviewed by: kib @
MFC after: 1 wee

Implement atomic_add_64() and atomic_subtract_64() for the i386 target.

While at it add missing _acq_ and _rel_ variants for 64-bit atomic
operations under i386.

Reviewed by: kib @
MFC after: 1 week
Sponsored by: Mellanox Technologies

show more ...