MIPS: Allow R2 CPUs to turn off generation of 'ehb' instructions.

Some CPUs do not need ehb instructions after writing CP0 registers.
By allowing ehb generation to be overridden in
cpu-feature-overrides.h, we can save a few instructions in the TLB
handler hot paths.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index d9a18b2b7f8..0e34faaadb5 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -259,7 +259,8 @@ static void __cpuinit build_tlb_write_entry(u32 **p, struct uasm_label **l,
 	}
 
 	if (cpu_has_mips_r2) {
-		uasm_i_ehb(p);
+		if (cpu_has_mips_r2_exec_hazard)
+			uasm_i_ehb(p);
 		tlbw(p);
 		return;
 	}