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>
diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
index 07a58f2..4d2481b 100644
--- a/arch/arc/kernel/head.S
+++ b/arch/arc/kernel/head.S
@@ -77,10 +77,11 @@
; 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 2555f58..dd35bde 100644
--- a/arch/arc/kernel/vmlinux.lds.S
+++ b/arch/arc/kernel/vmlinux.lds.S
@@ -116,7 +116,7 @@
_edata = .;
- BSS_SECTION(0, 0, 0)
+ BSS_SECTION(4, 4, 4)
#ifdef CONFIG_ARC_DW2_UNWIND
. = ALIGN(PAGE_SIZE);