[PATCH v2 18/19] ARC: [plat-eznps] replace sync with proper cpu barrier

From: Noam Camus
Date: Sat Nov 07 2015 - 06:01:18 EST


From: Tal Zilcer <talz@xxxxxxxxxx>

In SMT system like we have the generic "sync" is not working with
HW threads. The replacement is "schd.rw" instruction that is served
as cpu barrier for HW threads.
Signed-off-by: Noam Camus <noamc@xxxxxxxxxx>
---
arch/arc/kernel/ctx_sw.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/arch/arc/kernel/ctx_sw.c b/arch/arc/kernel/ctx_sw.c
index 92e2e82..2a2f50e 100644
--- a/arch/arc/kernel/ctx_sw.c
+++ b/arch/arc/kernel/ctx_sw.c
@@ -61,7 +61,11 @@ __switch_to(struct task_struct *prev_task, struct task_struct *next_task)
"st sp, [r24] \n\t"
#endif

+#ifdef CONFIG_EZNPS_MTM_EXT
+ ".word %5 \n\t"
+#else
"sync \n\t"
+#endif

/*
* setup _current_task with incoming tsk.
@@ -122,6 +126,9 @@ __switch_to(struct task_struct *prev_task, struct task_struct *next_task)
#ifdef CONFIG_ARC_PLAT_EZNPS
, "i"(CTOP_AUX_LOGIC_GLOBAL_ID)
#endif
+#ifdef CONFIG_EZNPS_MTM_EXT
+ , "i"(CTOP_INST_SCHD_RW)
+#endif
: "blink"
);

--
1.7.1

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