[PATCH v5 04/12] RISC-V: Comment on the TLB flush in smp_callin()

From: Atish Patra
Date: Thu Sep 13 2018 - 14:37:54 EST


From: Palmer Dabbelt <palmer@xxxxxxxxxx>

This isn't readily apparent from reading the code.

Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxx>
[Atish: code comment formatting update]
Signed-off-by: Atish Patra <atish.patra@xxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
arch/riscv/kernel/smpboot.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index 56abab6a..712e9ca8 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -106,6 +106,10 @@ 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();
--
2.7.4