[PATCH] ARC: Elide redundant setup of DMA callbacks

From: Vineet Gupta
Date: Wed Aug 10 2016 - 14:35:35 EST


For resources shared by all cores such as SLC and IOC, only the master
core needs to do any setups / enabling / disabling etc.

Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
---
arch/arc/mm/cache.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index 5a294b2c3cb3..0b10efe3a6a7 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -921,6 +921,15 @@ void arc_cache_init(void)

printk(arc_cache_mumbojumbo(0, str, sizeof(str)));

+ /*
+ * Only master CPU needs to execute rest of function:
+ * - Assume SMP so all cores will have same cache config so
+ * any geomtry checks will be same for all
+ * - IOC setup / dma callbacks only need to be setup once
+ */
+ if (cpu)
+ return;
+
if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE)) {
struct cpuinfo_arc_cache *ic = &cpuinfo_arc700[cpu].icache;

--
2.7.4