[PATCH v1 14/20] ARC: [plat-eznps] Use dedicated SMP barriers

From: Noam Camus
Date: Sat Oct 31 2015 - 09:21:54 EST


From: Noam Camus <noamc@xxxxxxxxxx>

NPS device got 256 cores and each got 16 HW threads (SMT).
We use EZchip dedicated ISA to trigger HW scheduler of the
core that current HW thread belongs to.
This scheduling makes sure that data beyond barrier is available
to all HW threads in core and by that to all in device (4K).

Signed-off-by: Noam Camus <noamc@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
arch/arc/include/asm/barrier.h | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/arch/arc/include/asm/barrier.h b/arch/arc/include/asm/barrier.h
index a720998..c8229b8 100644
--- a/arch/arc/include/asm/barrier.h
+++ b/arch/arc/include/asm/barrier.h
@@ -34,6 +34,12 @@

#ifdef CONFIG_ISA_ARCOMPACT

+#ifdef CONFIG_ARC_PLAT_EZNPS
+#include <plat/ctop.h>
+#define mb() asm volatile (".word %0" : : "i"(CTOP_INST_SCHD_RW) : "memory")
+#define rmb() asm volatile (".word %0" : : "i"(CTOP_INST_SCHD_RD) : "memory")
+#else
+
/*
* ARCompact based cores (ARC700) only have SYNC instruction which is super
* heavy weight as it flushes the pipeline as well.
@@ -41,6 +47,8 @@
*/

#define mb() asm volatile("sync\n" : : : "memory")
+#endif /* CONFIG_ARC_PLAT_EZNPS */
+
#endif

#include <asm-generic/barrier.h>
--
1.7.1

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