WireGuard implementation for the OpenBSD kernel https://git.zx2c4.com/wireguard-openbsd/atom/sys/arch/hppa/include/lock.h?h=jd%2Fqueueboosts 2015-02-11T00:14:11Z 2015-02-11T00:14:11Z dlg dlg@openbsd.org 2015-02-11T00:14:11Z urn:sha1:c7ee61963c3a9af7911e1d06422068d4e15ba0c0 each arch used to have to provide an rw_cas operation, but now we have the rwlock code build its own version. on smp machines it uses atomic_cas_ulong. on uniproc machines it avoids interlocked instructions by using straight loads and stores. this is safe because rwlocks are only used from process context and processes are currently not preemptible in our kernel. so alpha/ppc/etc might get a benefit. ok miod@ kettenis@ deraadt@ 2014-09-22T12:12:23Z dlg dlg@openbsd.org 2014-09-22T12:12:23Z urn:sha1:8bf031b6c9d14bce74cd445f935fd079a0ae10a6 atomic_{add,sub}_{int,long}_nv. sys/atomic.h turns these into the rest of the atomic api. on uniprocessor hppa systems "atomic" operations are implemented as a non-interruptable sequence by disabling all interrupts on the cpu, doing the operation, and then restoring the interrupt mask. this isnt enough on MP systems, so we added a global atomic memory mutex that is taken inside the interrupt disabling above to coordinate operations between cpus. this is a lot of overhead though cos mutexes dance around with ipls, which is unecessary in our case because of the interrupt disabling that is already done. also, hppa spinlocks are implemented with ldcw which requires the word it operates on to be 16 byte aligned. mutexes arent guaranteed to have this alignment so they compensate by having lots of words inside themselves so they can hit the appropriate one to use for the ldcw op. with this in mind, this change pulls __cpu_simple_locks, which are simply ldcw spinlocks with a 16 byte aligned word, out of src/sys/arch/hppa/include/lock.h into src/sys/arch/hppa/include/atomic.h so atomic.h can use them. lock.h includes atomic.h, so it still gets and provides the same functionality as before. finally, this also pulls the rwlock cas implementation apart. cas ops now share the same serialising lock on MP systems as the other memory operations, and rw_cas is defined as a wrapper around atomic_cas_uint. ok kettenis@ 2014-03-29T18:09:28Z guenther guenther@openbsd.org 2014-03-29T18:09:28Z urn:sha1:2df76cc2a0aee2cb2166e3799b7bb5c3f883f83d ok dlg@ mpi@ deraadt@ 2011-06-24T12:49:06Z jsing jsing@openbsd.org 2011-06-24T12:49:06Z urn:sha1:87b5afdea6215725a26fd8bd03cae29740d5e2fc __cpu_simple_lock_t - gcc most likely ignores the alignment for a stack variable anyway. Also remove unnecessary initialisation. ok kettenis@ miod@ 2011-03-23T16:54:33Z pirofti pirofti@openbsd.org 2011-03-23T16:54:33Z urn:sha1:2fa72412907ae78c4787a4a8f888c5f0486e225c Discussed and okay drahn@. Okay deraadt@. 2011-01-12T21:11:12Z kettenis kettenis@openbsd.org 2011-01-12T21:11:12Z urn:sha1:733b42de3925a0ed704bbbcf233467c3246971e3 ok jsing@, deraadt@ 2011-01-12T21:07:12Z kettenis kettenis@openbsd.org 2011-01-12T21:07:12Z urn:sha1:3b55f5b77c42691871feb991d8c59f68b1c740bb ok deraadt@, jsing@ 2010-07-01T03:38:50Z jsing jsing@openbsd.org 2010-07-01T03:38:50Z urn:sha1:baee291b76f0b9f41d108077e99f73c90ee2bec1 ok kettenis@ 2007-05-01T18:56:27Z miod miod@openbsd.org 2007-05-01T18:56:27Z urn:sha1:c3d82f71f72c9db0260420e22a4991f3d0a4fe04 unconditionnaly.