[PATCH 06/10] ARC: [plat-eznps] Fix TLB Errata

Noam Camus
2017-05-25T02:35:54Z

From: Noam Camus <noamca@mellanox.com>

Due to a HW bug in NPS400 we get from time to time false TLB miss.
Workaround this by validating each miss.

Signed-off-by: Noam Camus <noamca@mellanox.com>
---
arch/arc/mm/tlbex.S | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/arch/arc/mm/tlbex.S b/arch/arc/mm/tlbex.S
index b30e4e3..1d48723 100644
--- a/arch/arc/mm/tlbex.S
+++ b/arch/arc/mm/tlbex.S
@@ -274,6 +274,13 @@ ex_saved_reg1:
.macro COMMIT_ENTRY_TO_MMU
#if (CONFIG_ARC_MMU_VER < 4)

+#ifdef CONFIG_EZNPS_MTM_EXT
+ /* verify if entry for this vaddr+ASID already exists */
+ sr TLBProbe, [ARC_REG_TLBCOMMAND]
+ lr r0, [ARC_REG_TLBINDEX]
+ bbit0 r0, 31, 88f
+#endif
+
/* Get free TLB slot: Set = computed from vaddr, way = random */
sr TLBGetIndex, [ARC_REG_TLBCOMMAND]

@@ -287,6 +294,9 @@ ex_saved_reg1:
#else
sr TLBInsertEntry, [ARC_REG_TLBCOMMAND]
#endif
+#ifdef CONFIG_EZNPS_MTM_EXT
+88:
+#endif
.endm

--
1.7.1