ARC: [plat-eznps] Fix TLB Errata

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

diff --git a/arch/arc/mm/tlbex.S b/arch/arc/mm/tlbex.S
index b30e4e3..0e1e47a 100644 (file)
--- 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 +294,8 @@ ex_saved_reg1:
 #else
        sr TLBInsertEntry, [ARC_REG_TLBCOMMAND]
 #endif
+
+88:
 .endm