linux-kernel - [PATCH] RISC-V: Use a local variable instead of smp_processor

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Date:   Mon, 22 Jun 2020 16:47:25 -0700
From:   Atish Patra <atish.patra@....com>
To:     linux-kernel@...r.kernel.org
Cc:     Greentime Hu <greentime.hu@...ive.com>,
        Atish Patra <atish.patra@....com>,
        Albert Ou <aou@...s.berkeley.edu>,
        Anup Patel <anup@...infault.org>,
        linux-riscv@...ts.infradead.org,
        Palmer Dabbelt <palmer@...belt.com>,
        Paul Walmsley <paul.walmsley@...ive.com>
Subject: [PATCH] RISC-V: Use a local variable instead of smp_processor_id()

From: Greentime Hu <greentime.hu@...ive.com>

Store the smp_processor_id() in a local variable to save some
pointer chasing.

Signed-off-by: Greentime Hu <greentime.hu@...ive.com>
Signed-off-by: Atish Patra <atish.patra@....com>
---
 arch/riscv/kernel/smpboot.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index 4e9922790f6e..3e033e97dd08 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -146,6 +146,7 @@ void __init smp_cpus_done(unsigned int max_cpus)
 asmlinkage __visible void smp_callin(void)
 {
 	struct mm_struct *mm = &init_mm;
+	unsigned int curr_cpuid = smp_processor_id();
 
 	if (!IS_ENABLED(CONFIG_RISCV_SBI))
 		clint_clear_ipi(cpuid_to_hartid_map(smp_processor_id()));
@@ -155,9 +156,9 @@ asmlinkage __visible void smp_callin(void)
 	current->active_mm = mm;
 
 	trap_init();
-	notify_cpu_starting(smp_processor_id());
-	update_siblings_masks(smp_processor_id());
-	set_cpu_online(smp_processor_id(), 1);
+	notify_cpu_starting(curr_cpuid);
+	update_siblings_masks(curr_cpuid);
+	set_cpu_online(curr_cpuid, 1);
 	/*
 	 * Remote TLB flushes are ignored while the CPU is offline, so emit
 	 * a local TLB flush right now just in case.
-- 
2.26.2