Subject: [PATCH 1a/17] powerpc/qspinlock: Prepare qspinlock code

From: Nicholas Piggin <[email-masked]>
Date: Thu, 28 Jul 2022 16:31:04 +1000

I have a bunch of parallel patches that clean up the generic queued
spinlock code, but the powerpc implementation does not use or depend
on any of that except patch collision. I've based the powerpc series
on top of that work, but it's annoying to post or carry around all
those patches as well. This shim patch takes the powerpc changes and
should be applied first. If powerpc series is to go ahead of the
generic series, then this patch would just be merged into patch 1
of this series. This patch won't compile or do anything useful alone.
---
 arch/powerpc/include/asm/qspinlock.h          | 45 ++++++-------------
 arch/powerpc/include/asm/qspinlock_paravirt.h |  7 ---
 arch/powerpc/include/asm/spinlock.h           |  2 +-
 3 files changed, 15 insertions(+), 39 deletions(-)
 delete mode 100644 arch/powerpc/include/asm/qspinlock_paravirt.h

diff --git a/arch/powerpc/include/asm/qspinlock.h b/arch/powerpc/include/asm/qspinlock.h
index b676c4fb90fd..39c1c7f80579 100644
--- a/arch/powerpc/include/asm/qspinlock.h
+++ b/arch/powerpc/include/asm/qspinlock.h
@@ -7,42 +7,32 @@
 
 #define _Q_PENDING_LOOPS	(1 << 9) /* not tuned */
 
-#ifdef CONFIG_PARAVIRT_SPINLOCKS
-extern void native_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
-extern void __pv_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
-extern void __pv_queued_spin_unlock(struct qspinlock *lock);
+void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
+void __pv_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
+void __pv_queued_spin_unlock(struct qspinlock *lock);
 
-static __always_inline void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
+static __always_inline void queued_spin_lock(struct qspinlock *lock)
 {
-	if (!is_shared_processor())
-		native_queued_spin_lock_slowpath(lock, val);
+	u32 val = 0;
+
+	if (likely(arch_atomic_try_cmpxchg_lock(&lock->val, &val, _Q_LOCKED_VAL)))
+		return;
+
+	if (!IS_ENABLED(CONFIG_PARAVIRT_SPINLOCKS) || !is_shared_processor())
+		queued_spin_lock_slowpath(lock, val);
 	else
 		__pv_queued_spin_lock_slowpath(lock, val);
 }
+#define queued_spin_lock queued_spin_lock
 
-#define queued_spin_unlock queued_spin_unlock
 static inline void queued_spin_unlock(struct qspinlock *lock)
 {
-	if (!is_shared_processor())
+	if (!IS_ENABLED(CONFIG_PARAVIRT_SPINLOCKS) || !is_shared_processor())
 		smp_store_release(&lock->locked, 0);
 	else
 		__pv_queued_spin_unlock(lock);
 }
-
-#else
-extern void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
-#endif
-
-static __always_inline void queued_spin_lock(struct qspinlock *lock)
-{
-	u32 val = 0;
-
-	if (likely(arch_atomic_try_cmpxchg_lock(&lock->val, &val, _Q_LOCKED_VAL)))
-		return;
-
-	queued_spin_lock_slowpath(lock, val);
-}
-#define queued_spin_lock queued_spin_lock
+#define queued_spin_unlock queued_spin_unlock
 
 #ifdef CONFIG_PARAVIRT_SPINLOCKS
 #define SPIN_THRESHOLD (1<<15) /* not tuned */
@@ -63,13 +53,6 @@ static __always_inline void pv_kick(int cpu)
 	prod_cpu(cpu);
 }
 
-extern void __pv_init_lock_hash(void);
-
-static inline void pv_spinlocks_init(void)
-{
-	__pv_init_lock_hash();
-}
-
 #endif
 
 /*
diff --git a/arch/powerpc/include/asm/qspinlock_paravirt.h b/arch/powerpc/include/asm/qspinlock_paravirt.h
deleted file mode 100644
index 6b60e7736a47..000000000000
--- a/arch/powerpc/include/asm/qspinlock_paravirt.h
+++ /dev/null
@@ -1,7 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
-#ifndef _ASM_POWERPC_QSPINLOCK_PARAVIRT_H
-#define _ASM_POWERPC_QSPINLOCK_PARAVIRT_H
-
-EXPORT_SYMBOL(__pv_queued_spin_unlock);
-
-#endif /* _ASM_POWERPC_QSPINLOCK_PARAVIRT_H */
diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h
index bd75872a6334..7dafca8e3f02 100644
--- a/arch/powerpc/include/asm/spinlock.h
+++ b/arch/powerpc/include/asm/spinlock.h
@@ -13,7 +13,7 @@
 /* See include/linux/spinlock.h */
 #define smp_mb__after_spinlock()	smp_mb()
 
-#ifndef CONFIG_PARAVIRT_SPINLOCKS
+#ifndef CONFIG_PPC_QUEUED_SPINLOCKS
 static inline void pv_spinlocks_init(void) { }
 #endif
 
-- 
2.35.1