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authorSean Anderson <seanga2@gmail.com>2020-09-21 07:51:39 -0400
committerAndes <uboot@andestech.com>2020-09-30 08:54:52 +0800
commit309995b315b9ffef999810af212cccb7a50004bc (patch)
tree032296314ad07c1732b0a02873604bbb99c5abee /arch/riscv/cpu
parent768502e2a7f283a715dd1f62e304393a88422545 (diff)
riscv: Consolidate fences into AMOs for available_harts_lock
We can reduce the number of instructions needed to use available_harts_lock by using the aq and rl suffixes for AMOs. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Bin Meng <bin.meng@windriver.com> Reviewed-by: Rick Chen <rick@andestech.com>
Diffstat (limited to 'arch/riscv/cpu')
-rw-r--r--arch/riscv/cpu/start.S9
1 files changed, 3 insertions, 6 deletions
diff --git a/arch/riscv/cpu/start.S b/arch/riscv/cpu/start.S
index e3222b1ea7..66ca1c7020 100644
--- a/arch/riscv/cpu/start.S
+++ b/arch/riscv/cpu/start.S
@@ -125,14 +125,12 @@ call_board_init_f_0:
#ifndef CONFIG_XIP
la t0, available_harts_lock
- fence rw, w
- amoswap.w zero, zero, 0(t0)
+ amoswap.w.rl zero, zero, 0(t0)
wait_for_gd_init:
la t0, available_harts_lock
li t1, 1
-1: amoswap.w t1, t1, 0(t0)
- fence r, rw
+1: amoswap.w.aq t1, t1, 0(t0)
bnez t1, 1b
/* register available harts in the available_harts mask */
@@ -142,8 +140,7 @@ wait_for_gd_init:
or t2, t2, t1
SREG t2, GD_AVAILABLE_HARTS(gp)
- fence rw, w
- amoswap.w zero, zero, 0(t0)
+ amoswap.w.rl zero, zero, 0(t0)
/*
* Continue on hart lottery winner, others branch to