[RFC PATCH v2 4/9] fork: Add arch override for do_shoot_lazy_tlb()

[Xu Lu <luxu.kernel@bytedance.com>]

When both CONFIG_RISCV_LAZY_TLB_FLUSH and CONFIG_MMU_LSYZ_TLB_SHOOTDOWN
is enabled, riscv needs an arch special method to free the mm that needs
to be shot down. Thus we add arch override for  do_shoot_lazy_tlb().

Signed-off-by: Xu Lu <luxu.kernel@bytedance.com>
---
 kernel/fork.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/fork.c b/kernel/fork.c
index 3da0f08615a95..b6d11acd6ac10 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -612,7 +612,8 @@ static void do_check_lazy_tlb(void *arg)
 	WARN_ON_ONCE(current->active_mm == mm);
 }
 
-static void do_shoot_lazy_tlb(void *arg)
+#ifndef arch_do_shoot_lazy_tlb
+static void arch_do_shoot_lazy_tlb(void *arg)
 {
 	struct mm_struct *mm = arg;
 
@@ -622,6 +623,7 @@ static void do_shoot_lazy_tlb(void *arg)
 		switch_mm(mm, &init_mm, current);
 	}
 }
+#endif
 
 static void cleanup_lazy_tlbs(struct mm_struct *mm)
 {
@@ -661,7 +663,7 @@ static void cleanup_lazy_tlbs(struct mm_struct *mm)
 	 * - A delayed freeing and RCU-like quiescing sequence based on mm
 	 *   switching to avoid IPIs completely.
 	 */
-	on_each_cpu_mask(mm_cpumask(mm), do_shoot_lazy_tlb, (void *)mm, 1);
+	on_each_cpu_mask(mm_cpumask(mm), arch_do_shoot_lazy_tlb, (void *)mm, 1);
 	if (IS_ENABLED(CONFIG_DEBUG_VM_SHOOT_LAZIES))
 		on_each_cpu(do_check_lazy_tlb, (void *)mm, 1);
 }
-- 
2.20.1