exceptions early enough during boot that the kernel will do ithe same.
Use lwsync only when compiling for LP64 and revert to the more proven isync
when compiling for ILP32. Note that in the end (i.e. between revision 222198
and this change) ILP32 changed from using sync to using isync. As per Nathan
the isync is needed to make sure I/O accesses are properly serialized with
locks and isync tends to be more effecient than sync.
While here, undefine __ATOMIC_ACQ and __ATOMIC_REL at the end of the file
so as not to leak their definitions.
Discussed with: nwhitehorn
- Use isync/lwsync unconditionally for acquire/release. Use of isync
guarantees a complete memory barrier, which is important for serialization
of bus space accesses with mutexes on multi-processor systems.
- Go back to using sync as the I/O memory barrier, which solves the same
problem as above with respect to mutex release using lwsync, while not
penalizing non-I/O operations like a return to sync on the atomic release
operations would.
- Place an acquisition barrier around thread lock acquisition in
cpu_switchin().
not provide general barriers, but only barriers in the context of the
atomic sequences here. As such, make them private and keep the global
*mb() routines using a variant of sync.
isync to implement read and write barriers, following Appendix B.2 of
Book II of the architecture manual. This provides a 25% speed increase
to fork() on the PowerPC G4.
of sync (lwsync is an alternate encoding of sync on systems that do not
support it, providing graceful fallback). This provides more than an order
of magnitude reduction in the time required to acquire or release a mutex.
MFC after: 2 months
Rewrite atomic operations for powerpc in order to achieve the following:
- Produce a type-clean implementation (in terms of functions arguments
and returned values) for the primitives.
- Fix errors with _long() atomics where they ended up with the wrong
arguments to be accepted.
- Follow the sys/type.h specifics that define the numbered types starting
from standard C types.
- Let _ptr() version to not auto-magically cast arguments, but leave
the burden on callers, as _ptr() atomic is intended to be used
relatively rarely.
Fix cfi in order to support the latest point.
In collabouration with: bde
Tested by: andreast, nwhitehorn, jceel
MFC after: 2 weeks
Kernel sources for 64-bit PowerPC, along with build-system changes to keep
32-bit kernels compiling (build system changes for 64-bit kernels are
coming later). Existing 32-bit PowerPC kernel configurations must be
updated after this change to specify their architecture.
and ifnet functions
- add memory barriers to <machine/atomic.h>
- update drivers to only conditionally define their own
- add lockless producer / consumer ring buffer
- remove ring buffer implementation from cxgb and update its callers
- add if_transmit(struct ifnet *ifp, struct mbuf *m) to ifnet to
allow drivers to efficiently manage multiple hardware queues
(i.e. not serialize all packets through one ifq)
- expose if_qflush to allow drivers to flush any driver managed queues
This work was supported by Bitgravity Inc. and Chelsio Inc.
so that all implemented variants have proper prototypes. The 8-bit,
16-bit and 64-bit variants are not implemented.
This really fixes the current build breakages caused by type casting
and struct aliasing rules.
cast as uint32_t which is defined as unsigned int. gcc doesn't want to
consider that there might not be much difference between an int and
a long on a 32 bit architecture.
variable and returns the previous value of the variable.
Tested on: i386, alpha, sparc64, arm (cognet)
Reviewed by: arch@
Submitted by: cognet (arm)
MFC after: 1 week
constraint is actually only allowed for register operands. Instead, use
separate input and output memory constraints.
Education from: alc
Reviewed by: alc
Tested on: i386, alpha
MFC after: 1 week
variables rather than void * variables. This makes it easier and simpler
to get asm constraints and volatile keywords correct.
MFC after: 3 days
Tested on: i386, alpha, sparc64
Compiled on: ia64, powerpc, amd64
Kernel toolchain busted on: arm
place.
This moves the dependency on GCC's and other compiler's features into
the central sys/cdefs.h file, while the individual source files can
then refer to #ifdef __COMPILER_FEATURE_FOO where they by now used to
refer to #if __GNUC__ > 3.1415 && __BARC__ <= 42.
By now, GCC and ICC (the Intel compiler) have been actively tested on
IA32 platforms by netchild. Extension to other compilers is supposed
to be possible, of course.
Submitted by: netchild
Reviewed by: various developers on arch@, some time ago
us our first minimal glimpse of PowerPC support.
With this code we can get to the "mountroot>" prompt on my Apple iMac. We
can't get any further due to lack of clock and interrupt handling, among other
things. This does however mean that pmap and VM are initialising.
We're fairly dependant on OpenFirmware at this point, but I hope to add
support for other classes of firmware at a later stage.
Reviewed by: obrien, dfr
