[PATCH 1/3] powerpc/spinlocks: Refactor SHARED_PROCESSOR

[Christopher M. Riedl]

Determining if a processor is in shared processor mode is not a constant
so don't hide it behind a #define.

Signed-off-by: Christopher M. Riedl <cmr at informatik.wtf>
---
 arch/powerpc/include/asm/spinlock.h | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h
index a47f827bc5f1..8631b0b4e109 100644
--- a/arch/powerpc/include/asm/spinlock.h
+++ b/arch/powerpc/include/asm/spinlock.h
@@ -101,15 +101,24 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock)
 
 #if defined(CONFIG_PPC_SPLPAR)
 /* We only yield to the hypervisor if we are in shared processor mode */
-#define SHARED_PROCESSOR (lppaca_shared_proc(local_paca->lppaca_ptr))
 extern void __spin_yield(arch_spinlock_t *lock);
 extern void __rw_yield(arch_rwlock_t *lock);
 #else /* SPLPAR */
 #define __spin_yield(x)	barrier()
 #define __rw_yield(x)	barrier()
-#define SHARED_PROCESSOR	0
 #endif
 
+static inline bool is_shared_processor(void)
+{
+/* Only server processors have an lppaca struct */
+#ifdef CONFIG_PPC_BOOK3S
+	return (IS_ENABLED(CONFIG_PPC_SPLPAR) &&
+		lppaca_shared_proc(local_paca->lppaca_ptr));
+#else
+	return false;
+#endif
+}
+
 static inline void arch_spin_lock(arch_spinlock_t *lock)
 {
 	while (1) {
@@ -117,7 +126,7 @@ static inline void arch_spin_lock(arch_spinlock_t *lock)
 			break;
 		do {
 			HMT_low();
-			if (SHARED_PROCESSOR)
+			if (is_shared_processor())
 				__spin_yield(lock);
 		} while (unlikely(lock->slock != 0));
 		HMT_medium();
@@ -136,7 +145,7 @@ void arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)
 		local_irq_restore(flags);
 		do {
 			HMT_low();
-			if (SHARED_PROCESSOR)
+			if (is_shared_processor())
 				__spin_yield(lock);
 		} while (unlikely(lock->slock != 0));
 		HMT_medium();
@@ -226,7 +235,7 @@ static inline void arch_read_lock(arch_rwlock_t *rw)
 			break;
 		do {
 			HMT_low();
-			if (SHARED_PROCESSOR)
+			if (is_shared_processor())
 				__rw_yield(rw);
 		} while (unlikely(rw->lock < 0));
 		HMT_medium();
@@ -240,7 +249,7 @@ static inline void arch_write_lock(arch_rwlock_t *rw)
 			break;
 		do {
 			HMT_low();
-			if (SHARED_PROCESSOR)
+			if (is_shared_processor())
 				__rw_yield(rw);
 		} while (unlikely(rw->lock != 0));
 		HMT_medium();
-- 
2.22.0