ARM64 requires an additional check whether to reschedule on return
from interrupt.
Add arch_irqentry_exit_need_resched() as the default NOP
implementation and hook it up into the need_resched() condition in
raw_irqentry_exit_cond_resched().
This allows ARM64 to implement the architecture specific version for
switching over to the generic entry code.
Suggested-by: Mark Rutland <mark.rutl...@arm.com>
Suggested-by: Kevin Brodsky <kevin.brod...@arm.com>
Suggested-by: Thomas Gleixner <t...@linutronix.de>
Signed-off-by: Jinjie Ruan <ruanjin...@huawei.com>
---
kernel/entry/common.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/kernel/entry/common.c b/kernel/entry/common.c
index b82032777310..4aa9656fa1b4 100644
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -142,6 +142,20 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs
*regs)
return ret;
}
+/**
+ * arch_irqentry_exit_need_resched - Architecture specific need resched
function
+ *
+ * Invoked from raw_irqentry_exit_cond_resched() to check if need resched.
+ * Defaults return true.
+ *
+ * The main purpose is to permit arch to skip preempt a task from an IRQ.
+ */
+static inline bool arch_irqentry_exit_need_resched(void);
+
+#ifndef arch_irqentry_exit_need_resched
+static inline bool arch_irqentry_exit_need_resched(void) { return true; }
+#endif
+
void raw_irqentry_exit_cond_resched(void)
{
if (!preempt_count()) {
@@ -149,7 +163,7 @@ void raw_irqentry_exit_cond_resched(void)
rcu_irq_exit_check_preempt();
if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
WARN_ON_ONCE(!on_thread_stack());
- if (need_resched())
+ if (need_resched() && arch_irqentry_exit_need_resched())
preempt_schedule_irq();
}
}
--
2.34.1
