ARM: tlb: don't perform inner-shareable invalidation for local BP ops

Now that the ASID allocator doesn't require inner-shareable maintenance,
we can convert the local_bp_flush_all function to perform only
non-shareable flushing, in a similar manner to the TLB invalidation
routines.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

2 files changed, 21 insertions, 3 deletions

diff --git a/arch/arm/include/asm/tlbflush.h b/arch/arm/include/asm/tlbflush.h
index 9b725d2bcb6b..84718240340c 100644
--- a/arch/arm/include/asm/tlbflush.h
+++ b/arch/arm/include/asm/tlbflush.h
@@ -531,17 +531,35 @@ static inline void __flush_tlb_kernel_page(unsigned long kaddr)
  * Branch predictor maintenance is paired with full TLB invalidation, so
  * there is no need for any barriers here.
  */
+static inline void __local_flush_bp_all(void)
+{
+        const int zero = 0;
+        const unsigned int __tlb_flag = __cpu_tlb_flags;
+
+        if (tlb_flag(TLB_V6_BP))
+                asm("mcr p15, 0, %0, c7, c5, 6" : : "r" (zero));
+}
+
 static inline void local_flush_bp_all(void)
 {
         const int zero = 0;
         const unsigned int __tlb_flag = __cpu_tlb_flags;
 
+        __local_flush_bp_all();
         if (tlb_flag(TLB_V7_UIS_BP))
-                asm("mcr p15, 0, %0, c7, c1, 6" : : "r" (zero));
-        else if (tlb_flag(TLB_V6_BP))
                 asm("mcr p15, 0, %0, c7, c5, 6" : : "r" (zero));
 }
 
+static inline void __flush_bp_all(void)
+{
+        const int zero = 0;
+        const unsigned int __tlb_flag = __cpu_tlb_flags;
+
+        __local_flush_bp_all();
+        if (tlb_flag(TLB_V7_UIS_BP))
+                asm("mcr p15, 0, %0, c7, c1, 6" : : "r" (zero));
+}
+
 #include <asm/cputype.h>
 #ifdef CONFIG_ARM_ERRATA_798181
 static inline int erratum_a15_798181(void)
diff --git a/arch/arm/kernel/smp_tlb.c b/arch/arm/kernel/smp_tlb.c
index 5883b8ae77c8..83ccca303df8 100644
--- a/arch/arm/kernel/smp_tlb.c
+++ b/arch/arm/kernel/smp_tlb.c
@@ -173,5 +173,5 @@ void flush_bp_all(void)
         if (tlb_ops_need_broadcast())
                 on_each_cpu(ipi_flush_bp_all, NULL, 1);
         else
-                local_flush_bp_all();
+                __flush_bp_all();
 }