diff mbox series

[v4,1/3] powerpc/spinlocks: Refactor SHARED_PROCESSOR

Message ID 20190813031314.1828-2-cmr@informatik.wtf (mailing list archive)
State Accepted
Commit d57b78353a99f5d813248954dd7d0527a01751ac
Headers show
Series Fix oops in shared-processor spinlocks | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch next (da206bd46848568e1aaf35f00e2d78bf9bc94f95)
snowpatch_ozlabs/checkpatch success total: 0 errors, 0 warnings, 0 checks, 61 lines checked

Commit Message

Christopher M. Riedl Aug. 13, 2019, 3:13 a.m. UTC 
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@informatik.wtf>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
---
 arch/powerpc/include/asm/spinlock.h | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

Comments

Michael Ellerman Aug. 28, 2019, 4:24 a.m. UTC | #1 
On Tue, 2019-08-13 at 03:13:12 UTC, "Christopher M. Riedl" wrote:
> 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@informatik.wtf>
> Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/d57b78353a99f5d813248954dd7d0527a01751ac

cheers
diff mbox series

Patch

diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h
index a47f827bc5f1..e9c60fbcc8fe 100644
--- a/arch/powerpc/include/asm/spinlock.h
+++ b/arch/powerpc/include/asm/spinlock.h
@@ -101,15 +101,27 @@  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)
+{
+/*
+ * LPPACA is only available on Pseries so guard anything LPPACA related to
+ * allow other platforms (which include this common header) to compile.
+ */
+#ifdef CONFIG_PPC_PSERIES
+	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 +129,7 @@  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 +148,7 @@  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 +238,7 @@  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 +252,7 @@  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();