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authorSean Anderson2020-09-21 07:51:36 -0400
committerAndes2020-09-30 08:54:52 +0800
commitd4990a46485f2f6592ae29f2b822043dbdeae15d (patch)
treecd415656cc2c7d527feae832c5026e4a23052ac4 /arch/riscv
parentc41045411bbb64eeda2d404b79723f8d2802351c (diff)
riscv: Match memory barriers between send_ipi_many and handle_ipi
Without a matching barrier on the write side, the barrier in handle_ipi does nothing. It was entirely possible for the boot hart to write to addr, arg0, and arg1 *after* sending the IPI, because there was no barrier on the sending side. Fixes: 90ae281437 ("riscv: add option to wait for ack from secondary harts in smp functions") Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Bin Meng <bin.meng@windriver.com> Reviewed-by: Rick Chen <rick@andestech.com> Reviewed-by: Leo Liang <ycliang@andestech.com>
Diffstat (limited to 'arch/riscv')
-rw-r--r--arch/riscv/lib/smp.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/riscv/lib/smp.c b/arch/riscv/lib/smp.c
index ac22136314f..ab6d8bd7fa4 100644
--- a/arch/riscv/lib/smp.c
+++ b/arch/riscv/lib/smp.c
@@ -54,6 +54,8 @@ static int send_ipi_many(struct ipi_data *ipi, int wait)
gd->arch.ipi[reg].arg0 = ipi->arg0;
gd->arch.ipi[reg].arg1 = ipi->arg1;
+ __smp_mb();
+
ret = riscv_send_ipi(reg);
if (ret) {
pr_err("Cannot send IPI to hart %d\n", reg);