ARC: optimize kernel bss clearing in early boot code

using ARC ZOL which reduces tot num of instructions by half

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

2 files changed, 5 insertions, 4 deletions

diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
index 07a58f2d3077..4d2481bd8b98 100644
--- a/arch/arc/kernel/head.S
+++ b/arch/arc/kernel/head.S
@@ -77,10 +77,11 @@ stext:
         ; Clear BSS before updating any globals
         ; XXX: use ZOL here
         mov     r5, __bss_start
-        mov     r6, __bss_stop
+        sub     r6, __bss_stop, r5
+        lsr.f   lp_count, r6, 2
+        lpnz    1f
+        st.ab   0, [r5, 4]
 1:
-        st.ab   0, [r5,4]
-        brlt    r5, r6, 1b
 
         ; Uboot - kernel ABI
         ;    r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2
diff --git a/arch/arc/kernel/vmlinux.lds.S b/arch/arc/kernel/vmlinux.lds.S
index 2555f5886af6..dd35bde39f69 100644
--- a/arch/arc/kernel/vmlinux.lds.S
+++ b/arch/arc/kernel/vmlinux.lds.S
@@ -116,7 +116,7 @@ SECTIONS
 
         _edata = .;
 
-        BSS_SECTION(0, 0, 0)
+        BSS_SECTION(4, 4, 4)
 
 #ifdef CONFIG_ARC_DW2_UNWIND
         . = ALIGN(PAGE_SIZE);