> > b) The SWP instruction is gone. It may fault, it may get fixed up by > > the kernel (slowly), but it shouldn't be used anymore (it's not > > compatible with mutli-core designs, Load/store exclusive should be > > used instead). > > swp is currently replaced with ldrex/strex in the run time library in > you target ARMv6 or above.
For linux systems where you can't use ldrex unconditionally you should be using the __kuser_cmpxchg helper. See linux Documentation/arm/kernel_user_helpers.txt This should still give a fairly efficient implementation on later cores. Paul -- To UNSUBSCRIBE, email to debian-arm-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/201109071155.17096.p...@codesourcery.com
