On Tue, Nov 23, 2021 at 9:34 AM Sebastian Huber <sebastian.hu...@embedded-brains.de> wrote: > > Affected components are the GR712RC, UT699, UT699E, UT700, and > LEON3FT-RTAX. Strictly, the workaround is only necessary if the MMU is > enabled. Use __FIX_LEON3FT_B2BST to enable the workaround. This is not > 100% appropriate, but the best thing we can use to enable the > workaround. > > Close #4551. > --- > cpukit/score/cpu/sparc/cpu_asm.S | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/cpukit/score/cpu/sparc/cpu_asm.S > b/cpukit/score/cpu/sparc/cpu_asm.S > index 45d1495af7..04b2b0119f 100644 > --- a/cpukit/score/cpu/sparc/cpu_asm.S > +++ b/cpukit/score/cpu/sparc/cpu_asm.S > @@ -190,6 +190,16 @@ done_flushing: > ! Try to update the is executing indicator of the heir context > mov 1, %g1 > > +#if defined(__FIX_LEON3FT_B2BST) > + /* > + * This is a workaround for GRLIB-TN-0011. Affected components are > the > + * GR712RC, UT699, UT699E, UT700, and LEON3FT-RTAX. Strictly, the > + * workaround is only necessary if the MMU is enabled. Using the > + * __FIX_LEON3FT_B2BST is not 100% appropriate, but the best thing we > + * can use to enable the workaround. > + */ > +.align 16 > +#endif
Is there an assumption on the fill pattern here? If the "move 1, %g1" is executed, it looks like the code will fall into the alignment fill area. If those are not guaranteed to be nops, then what instruction(s) are executed? It probably is a nop but that should be checked and in the comment. And this is in an SMP conditional section but I am unsure if all of those are multi-core models. What does this errata actually cover? Is it that swap needs to be aligned? And it is just a coincidence that this is only in an SMP build of RTEMS? I'm ok with it but the comments and implicit assumptions need to be enhanced. > .Ltry_update_is_executing: > > swap [%o1 + SPARC_CONTEXT_CONTROL_IS_EXECUTING_OFFSET], %g1 > -- > 2.31.1 > > _______________________________________________ > devel mailing list > devel@rtems.org > http://lists.rtems.org/mailman/listinfo/devel _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
