- Fix atomic_load_* and atomic_store_* to generate functions for atomic.c
that modules can call.
- Remove the old gcc <= 2.8 versions of the atomic ops.
- Resort the order of some things in the fil

- Fix atomic_load_* and atomic_store_* to generate functions for atomic.c
that modules can call.
- Remove the old gcc <= 2.8 versions of the atomic ops.
- Resort the order of some things in the file so that there is only
one #ifdef for KLD_MODULE, and so that all WANT_FUNCTIONS stuff is
moved to the bottom of the file.
- Remove ATOMIC_ACQ_REL() and just use explicit macros instead.

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Fix the atomic_load_acq() and atomic_store_rel() functions to properly
implement memory fences for the 486+. The 386 still uses versions w/o
memory fences as all operations on the 386 are not progra

Fix the atomic_load_acq() and atomic_store_rel() functions to properly
implement memory fences for the 486+. The 386 still uses versions w/o
memory fences as all operations on the 386 are not program ordered.
The 386 versions are not MP safe.

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The x86 atomic operations are already locked, so they do not need an
additional locked instruction to guarantee a write barrier for the acquire
variants.

Approved by: dfr
Pointy hat to: jhb

- Add atomic_cmpset_{acq_,rel_,}_long
- Add in atomic operations for 8-bit, 16-bit, and 32-bit integers

- 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.

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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

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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.

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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

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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

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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

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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>

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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

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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

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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

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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

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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

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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

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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

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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

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