[PATCH v2 06/19] powerpc/pseries: drop RTAS-based timebase synchronization

Nathan Lynch via B4 Submission Endpoint devnull+nathanl.linux.ibm.com at kernel.org
Tue Feb 7 05:54:22 AEDT 2023


From: Nathan Lynch <nathanl at linux.ibm.com>

The pseries platform has been LPAR-only for several generations, and
the PAPR spec:

* Guarantees that timebase synchronization is performed by
  the platform ("The timebase registers are synchronized by the
  platform before CPUs are given to the OS" - 7.3.8 SMP Support).

* Completely omits the RTAS freeze-time-base and thaw-time-base RTAS
  functions, which are CHRP artifacts.

This code is effectively unused on currently supported models, so drop
it.

Signed-off-by: Nathan Lynch <nathanl at linux.ibm.com>
---
 arch/powerpc/platforms/pseries/smp.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/smp.c b/arch/powerpc/platforms/pseries/smp.c
index fd2174edfa1d..2bcfee86ff87 100644
--- a/arch/powerpc/platforms/pseries/smp.c
+++ b/arch/powerpc/platforms/pseries/smp.c
@@ -278,11 +278,5 @@ void __init smp_init_pseries(void)
 		cpumask_clear_cpu(boot_cpuid, of_spin_mask);
 	}
 
-	/* Non-lpar has additional take/give timebase */
-	if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) {
-		smp_ops->give_timebase = rtas_give_timebase;
-		smp_ops->take_timebase = rtas_take_timebase;
-	}
-
 	pr_debug(" <- smp_init_pSeries()\n");
 }

-- 
2.39.1



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