From: Vineet Gupta <vgupta@synopsys.com>
Date: Mon, 9 Sep 2013 10:34:15 +0000 (+0530)
Subject: ARC: [SMP] Disallow RTSC
X-Git-Tag: accepted/tizen/common/20141203.182822~1189^2~2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7d0857a54aedbd47b3de503933d65ce462970bd6;p=platform%2Fkernel%2Flinux-arm64.git

ARC: [SMP] Disallow RTSC

RTSC is strictly incore and must not be allowed in SMP configs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index fb4177e..5ede546 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -136,9 +136,6 @@ if SMP
 config ARC_HAS_COH_CACHES
 	def_bool n
 
-config ARC_HAS_COH_RTSC
-	def_bool n
-
 config ARC_HAS_REENTRANT_IRQ_LV2
 	def_bool n
 
@@ -332,8 +329,7 @@ config ARC_HAS_RTSC
 	bool "Insn: RTSC (64-bit r/o cycle counter)"
 	default y
 	depends on ARC_CPU_REL_4_10
-	# if SMP, enable RTSC only if counter is coherent across cores
-	depends on !SMP || ARC_HAS_COH_RTSC
+	depends on !SMP
 
 endmenu   # "ARC CPU Configuration"
 
diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c
index 0a9b6b2..e5f3a83 100644
--- a/arch/arc/kernel/time.c
+++ b/arch/arc/kernel/time.c
@@ -63,9 +63,10 @@
 
 int arc_counter_setup(void)
 {
-	/* RTSC insn taps into cpu clk, needs no setup */
-
-	/* For SMP, only allowed if cross-core-sync, hence usable as cs */
+	/*
+	 * For SMP this needs to be 0. However Kconfig glue doesn't
+	 * enable this option for SMP configs
+	 */
 	return 1;
 }