[PATCH v6 02/14] entry: Pass pt_regs to irqentry_exit_cond_resched()

[Josef Bacik <josef@toxicpanda.com>]

The irq-exit preemption path is about to need the interrupted context's
registers to decide whether the preemption may be reported to Tasks RCU
as a quiescent state.  irqentry_exit_to_kernel_mode_preempt() already
has them; hand them down through irqentry_exit_cond_resched(), its
PREEMPT_DYNAMIC static-call and static-key variants, and
raw_irqentry_exit_cond_resched().  The only caller outside the generic
entry code is Xen PV's upcall handler, which has regs as well.

No functional change.

Assisted-by: LLM
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 arch/x86/xen/enlighten_pv.c      |  2 +-
 include/linux/irq-entry-common.h | 13 +++++++------
 kernel/entry/common.c            |  6 +++---
 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 2c64b388f616..3d85035f5624 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -739,7 +739,7 @@ __visible noinstr void xen_pv_evtchn_do_upcall(struct pt_regs *regs)
 
 	inhcall = get_and_clear_inhcall();
 	if (inhcall && !WARN_ON_ONCE(state.exit_rcu)) {
-		irqentry_exit_cond_resched();
+		irqentry_exit_cond_resched(regs);
 		instrumentation_end();
 		restore_inhcall(inhcall);
 	} else {
diff --git a/include/linux/irq-entry-common.h b/include/linux/irq-entry-common.h
index 0bb6c03481fa..e19b41ee6b18 100644
--- a/include/linux/irq-entry-common.h
+++ b/include/linux/irq-entry-common.h
@@ -343,24 +343,25 @@ typedef struct irqentry_state {
 
 /**
  * irqentry_exit_cond_resched - Conditionally reschedule on return from interrupt
+ * @regs:	Pointer to pt_regs of interrupted context
  *
  * Conditional reschedule with additional sanity checks.
  */
-void raw_irqentry_exit_cond_resched(void);
+void raw_irqentry_exit_cond_resched(struct pt_regs *regs);
 
 #ifdef CONFIG_PREEMPT_DYNAMIC
 #if defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
 #define irqentry_exit_cond_resched_dynamic_enabled	raw_irqentry_exit_cond_resched
 #define irqentry_exit_cond_resched_dynamic_disabled	NULL
 DECLARE_STATIC_CALL(irqentry_exit_cond_resched, raw_irqentry_exit_cond_resched);
-#define irqentry_exit_cond_resched()	static_call(irqentry_exit_cond_resched)()
+#define irqentry_exit_cond_resched(regs)	static_call(irqentry_exit_cond_resched)(regs)
 #elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
 DECLARE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched);
-void dynamic_irqentry_exit_cond_resched(void);
-#define irqentry_exit_cond_resched()	dynamic_irqentry_exit_cond_resched()
+void dynamic_irqentry_exit_cond_resched(struct pt_regs *regs);
+#define irqentry_exit_cond_resched(regs)	dynamic_irqentry_exit_cond_resched(regs)
 #endif
 #else /* CONFIG_PREEMPT_DYNAMIC */
-#define irqentry_exit_cond_resched()	raw_irqentry_exit_cond_resched()
+#define irqentry_exit_cond_resched(regs)	raw_irqentry_exit_cond_resched(regs)
 #endif /* CONFIG_PREEMPT_DYNAMIC */
 
 /**
@@ -465,7 +466,7 @@ static inline void irqentry_exit_to_kernel_mode_preempt(struct pt_regs *regs,
 		return;
 
 	if (IS_ENABLED(CONFIG_PREEMPTION))
-		irqentry_exit_cond_resched();
+		irqentry_exit_cond_resched(regs);
 }
 
 /**
diff --git a/kernel/entry/common.c b/kernel/entry/common.c
index e3d381fd3d25..e4acd50bd81a 100644
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -134,7 +134,7 @@ static inline bool arch_irqentry_exit_need_resched(void);
 static inline bool arch_irqentry_exit_need_resched(void) { return true; }
 #endif
 
-void raw_irqentry_exit_cond_resched(void)
+void raw_irqentry_exit_cond_resched(struct pt_regs *regs)
 {
 	if (!preempt_count()) {
 		/* Sanity check RCU and thread stack */
@@ -150,11 +150,11 @@ void raw_irqentry_exit_cond_resched(void)
 DEFINE_STATIC_CALL(irqentry_exit_cond_resched, raw_irqentry_exit_cond_resched);
 #elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
 DEFINE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched);
-void dynamic_irqentry_exit_cond_resched(void)
+void dynamic_irqentry_exit_cond_resched(struct pt_regs *regs)
 {
 	if (!static_branch_unlikely(&sk_dynamic_irqentry_exit_cond_resched))
 		return;
-	raw_irqentry_exit_cond_resched();
+	raw_irqentry_exit_cond_resched(regs);
 }
 #endif
 #endif

-- 
2.55.0