On 29/06/2020 13:27, Daniel Hellstrom wrote:
From: Daniel Cederman <ceder...@gaisler.com>--- cpukit/score/cpu/sparc/cpu_asm.S | 6 ++++-- cpukit/score/cpu/sparc/syscall.S | 3 ++- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/cpukit/score/cpu/sparc/cpu_asm.S b/cpukit/score/cpu/sparc/cpu_asm.S index d5afd5f..bfad3fb 100644 --- a/cpukit/score/cpu/sparc/cpu_asm.S +++ b/cpukit/score/cpu/sparc/cpu_asm.S @@ -683,11 +683,13 @@ isr_dispatch: cmp %l6, %l7 bne,a .Ldisable_fp andn %l0, %l5, %l0 + st %g0, [%g6 + SPARC_PER_CPU_FP_OWNER_OFFSET] ba .Lthread_dispatch_done - st %g0, [%g6 + SPARC_PER_CPU_FP_OWNER_OFFSET] + nop .Ldisable_fp: + st %l0, [%fp + ISF_PSR_OFFSET] ba .Lthread_dispatch_done - st %l0, [%fp + ISF_PSR_OFFSET] + nop .Lnon_fp_thread_dispatch: #elif defined(SPARC_USE_SYNCHRONOUS_FP_SWITCH) /* Test if we interrupted a floating point thread (PSR[EF] == 1) */ diff --git a/cpukit/score/cpu/sparc/syscall.S b/cpukit/score/cpu/sparc/syscall.S index 4f4ef32..737a501 100644 --- a/cpukit/score/cpu/sparc/syscall.S +++ b/cpukit/score/cpu/sparc/syscall.S @@ -218,9 +218,10 @@ SYM(syscall_lazy_fp_switch): .Lfp_save_done:/* Restore the floating point context if necessary */+ st %g0, [%l4 + %lo(SPARC_THREAD_CONTROL_REGISTERS_FP_CONTEXT_OFFSET)] cmp %l6, 0 be .Lfp_restore_done - st %g0, [%l4 + %lo(SPARC_THREAD_CONTROL_REGISTERS_FP_CONTEXT_OFFSET)] + nop ldd [%l6 + SPARC_FP_CONTEXT_OFFSET_F0_F1], %f0 ldd [%l6 + SPARC_FP_CONTEXT_OFFSET_F2_F3], %f2 ldd [%l6 + SPARC_FP_CONTEXT_OFFSET_F4_F5], %f4
Some areas use the __FIX_LEON3FT_B2BST define to enable this workaround. I am not sure if using the delay slots gives a measurable performance boost. It would be good to mention the errata in the documentation and give some advice how the workarounds should be applied to RTEMS.
https://docs.rtems.org/branches/master/cpu-supplement/sparc.html -- Sebastian Huber, embedded brains GmbH Address : Dornierstr. 4, D-82178 Puchheim, Germany Phone : +49 89 189 47 41-16 Fax : +49 89 189 47 41-09 E-Mail : sebastian.hu...@embedded-brains.de PGP : Public key available on request. Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
