ARM: 7660/1: tlb: add branch predictor maintenance operations

The ARM architecture requires explicit branch predictor maintenance
when updating an instruction stream for a given virtual address. In
reality, this isn't so much of a burden because the branch predictor
is flushed during the cache maintenance required to make the new
instructions visible to the I-side of the processor.

However, there are still some cases where explicit flushing is required,
so add a local_bp_flush_all operation to deal with this.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/arm/kernel/smp_tlb.c b/arch/arm/kernel/smp_tlb.c
index 02c5d2ce23bf..bd0300531399 100644
--- a/arch/arm/kernel/smp_tlb.c
+++ b/arch/arm/kernel/smp_tlb.c
@@ -64,6 +64,11 @@ static inline void ipi_flush_tlb_kernel_range(void *arg)
 	local_flush_tlb_kernel_range(ta->ta_start, ta->ta_end);
 }
 
+static inline void ipi_flush_bp_all(void *ignored)
+{
+	local_flush_bp_all();
+}
+
 void flush_tlb_all(void)
 {
 	if (tlb_ops_need_broadcast())
@@ -127,3 +132,10 @@ void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 		local_flush_tlb_kernel_range(start, end);
 }
 
+void flush_bp_all(void)
+{
+	if (tlb_ops_need_broadcast())
+		on_each_cpu(ipi_flush_bp_all, NULL, 1);
+	else
+		local_flush_bp_all();
+}