From: "Christopher M. Riedl" <cmr@informatik.wtf>
To: linuxppc-dev@ozlabs.org
Cc: Andrew Donnellan <ajd@linux.ibm.com>
Subject: [PATCH v4 1/3] powerpc/spinlocks: Refactor SHARED_PROCESSOR
Date: Mon, 12 Aug 2019 22:13:12 -0500 [thread overview]
Message-ID: <20190813031314.1828-2-cmr@informatik.wtf> (raw)
In-Reply-To: <20190813031314.1828-1-cmr@informatik.wtf>
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(-)
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();
--
2.22.0
next prev parent reply other threads:[~2019-08-13 3:14 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-13 3:13 [PATCH v4 0/3] Fix oops in shared-processor spinlocks Christopher M. Riedl
2019-08-13 3:13 ` Christopher M. Riedl [this message]
2019-08-28 4:24 ` [PATCH v4 1/3] powerpc/spinlocks: Refactor SHARED_PROCESSOR Michael Ellerman
2019-08-13 3:13 ` [PATCH v4 2/3] powerpc/spinlocks: Rename SPLPAR-only spinlocks Christopher M. Riedl
2019-08-13 3:13 ` [PATCH v4 3/3] powerpc/spinlocks: Fix oops in shared-processor spinlocks Christopher M. Riedl
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