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| author | Atish Patra <atish.patra@wdc.com> | 2018-10-02 12:15:03 -0700 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@sifive.com> | 2018-10-22 17:03:37 -0700 |
| commit | a37d56fc401108f39dec9ba83ed923a453937a26 (patch) | |
| tree | b050e592dc352a44bddc333ead5602abbab2e7a4 | |
| parent | 46373cb442c56d2f8a4c8b3f777c89d20546c9d5 (diff) | |
| download | linux-a37d56fc401108f39dec9ba83ed923a453937a26.tar.bz2 | |
RISC-V: Use WRITE_ONCE instead of direct access
The secondary harts spin on couple of per cpu variables until both of
these are non-zero so it's not necessary to have any ordering here.
However, WRITE_ONCE should be used to avoid tearing.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
| -rw-r--r-- | arch/riscv/kernel/smpboot.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 17e748312afd..1e478615017c 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -81,8 +81,9 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle) * the spinning harts that they can continue the boot process. */ smp_mb(); - __cpu_up_stack_pointer[cpu] = task_stack_page(tidle) + THREAD_SIZE; - __cpu_up_task_pointer[cpu] = tidle; + WRITE_ONCE(__cpu_up_stack_pointer[cpu], + task_stack_page(tidle) + THREAD_SIZE); + WRITE_ONCE(__cpu_up_task_pointer[cpu], tidle); while (!cpu_online(cpu)) cpu_relax(); |