[PATCH 7/8] RISC-V: Comment on the TLB flush in smp_callin()

From: Palmer Dabbelt
Date: Mon Aug 27 2018 - 14:58:56 EST


This isn't readily apparent from reading the code.

Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxx>
---
arch/riscv/kernel/smpboot.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index 5437a04babcd..953bc540207d 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -107,6 +107,8 @@ asmlinkage void __init smp_callin(void)
trap_init();
notify_cpu_starting(smp_processor_id());
set_cpu_online(smp_processor_id(), 1);
+ /* Remote TLB flushes are ignored while the CPU is offline, so emit a local
+ * TLB flush right now just in case. */
local_flush_tlb_all();
local_irq_enable();
preempt_disable();
--
2.16.4