= Atomic support =

= Architectures atomic support =


The following table summarizes the atomic support among the CPU architectures supported by the git development head.  The RTEMS-SMP means whether the SMP mode is supported by the latest SMP. The atomic-hardware means whether the architecture has atomic hardware instruction support. 


|| '''Architecture''' || '''Target CPU''' || '''RTEMS SMP''' || '''atomic-hardware''' || '''atomic-instruction''' || '''memory-ordering''' ||
|| X86 || i386 || Unusable || Yes || cmpxchg || Stronger ||
|| PowerPC || powerpc || Yes || Yes || lwarx/stwcx || Weaker ||
|| SPARC (V7-V8) || sparc || Yes || Yes || ldstub/swap/cas(optional) || Stronger (TSO-mode) ||
|| SPARC V9 || sparc64 || No || Yes || ldstub/swap/cas || Stronger (TSO-mode) ||
|| MIPS || mips || No || Yes || ll/sc || Weaker ||
|| ARM || arm || Yes || Yes (V6 above) || ldstub/swap (V6 above) || Weaker ||
|| M68K || m68k || No || Yes || cad/cas32/tas || ||
|| Blackfin || bfin || No || no || no || ||
|| SH || sh || No || Yes ||  || ||
|| Lattice Mico32 || lm32 || || ||  || ||
|| Altera NIOS II || nios2 || || ||  || ||

= References =

 *  http://www.oracle.com/technetwork/server-storage/solaris10/index-142944.html
 *  http://semipublic.comp-arch.net/wiki/Load-linked/store-conditional_%28LL/SC%29
 *  http://en.wikipedia.org/wiki/Memory_ordering
 *  http://www.sigma.me/2011/12/14/mips-llsc-instruction.html