[PATCH 3/5] csky: Remove simple spinlock implementation

guoren
2020-11-24T13:52:07Z

From: Guo Ren <guoren@linux.alibaba.com>

There are two implementation of spinlock in csky:
- simple one (NR_CPU = 1,2)
- tick's one (NR_CPU = 3,4,5...)

We needn't the baby codes of simple one now.

Link: https://lore.kernel.org/linux-csky/20200807081253.GD2674@hirez.programming.kicks-ass.net/#t
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Peter Zijlstra <peterz@infradead.org>
---
arch/csky/Kconfig | 2 +-
arch/csky/include/asm/spinlock.h | 164 ---------------------------------
arch/csky/include/asm/spinlock_types.h | 10 --
3 files changed, 1 insertion(+), 175 deletions(-)

diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
index 268fad5..14ee229 100644
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -7,7 +7,7 @@ config CSKY
select ARCH_HAS_SYNC_DMA_FOR_CPU
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select ARCH_USE_BUILTIN_BSWAP
- select ARCH_USE_QUEUED_RWLOCKS if NR_CPUS>2
+ select ARCH_USE_QUEUED_RWLOCKS
select ARCH_WANT_FRAME_POINTERS if !CPU_CK610
select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
select COMMON_CLK
diff --git a/arch/csky/include/asm/spinlock.h b/arch/csky/include/asm/spinlock.h
index 7cf3f2b..9feb0fd 100644
--- a/arch/csky/include/asm/spinlock.h
+++ b/arch/csky/include/asm/spinlock.h
@@ -6,8 +6,6 @@
#include <linux/spinlock_types.h>
#include <asm/barrier.h>

-#ifdef CONFIG_QUEUED_RWLOCKS
-
/*
* Ticket-based spin-locking.
*/
@@ -91,166 +89,4 @@ static inline int arch_spin_is_contended(arch_spinlock_t *lock)
/* See include/linux/spinlock.h */
#define smp_mb__after_spinlock() smp_mb()

-#else /* CONFIG_QUEUED_RWLOCKS */
-
-/*
- * Test-and-set spin-locking.
- */
-static inline void arch_spin_lock(arch_spinlock_t *lock)
-{
- u32 *p = &lock->lock;
- u32 tmp;
-
- asm volatile (
- "1: ldex.w %0, (%1) \n"
- " bnez %0, 1b \n"
- " movi %0, 1 \n"
- " stex.w %0, (%1) \n"
- " bez %0, 1b \n"
- : "=&r" (tmp)
- : "r"(p)
- : "cc");
- smp_mb();
-}
-
-static inline void arch_spin_unlock(arch_spinlock_t *lock)
-{
- smp_mb();
- WRITE_ONCE(lock->lock, 0);
-}
-
-static inline int arch_spin_trylock(arch_spinlock_t *lock)
-{
- u32 *p = &lock->lock;
- u32 tmp;
-
- asm volatile (
- "1: ldex.w %0, (%1) \n"
- " bnez %0, 2f \n"
- " movi %0, 1 \n"
- " stex.w %0, (%1) \n"
- " bez %0, 1b \n"
- " movi %0, 0 \n"
- "2: \n"
- : "=&r" (tmp)
- : "r"(p)
- : "cc");
-
- if (!tmp)
- smp_mb();
-
- return !tmp;
-}
-
-#define arch_spin_is_locked(x) (READ_ONCE((x)->lock) != 0)
-
-/*
- * read lock/unlock/trylock
- */
-static inline void arch_read_lock(arch_rwlock_t *lock)
-{
- u32 *p = &lock->lock;
- u32 tmp;
-
- asm volatile (
- "1: ldex.w %0, (%1) \n"
- " blz %0, 1b \n"
- " addi %0, 1 \n"
- " stex.w %0, (%1) \n"
- " bez %0, 1b \n"
- : "=&r" (tmp)
- : "r"(p)
- : "cc");
- smp_mb();
-}
-
-static inline void arch_read_unlock(arch_rwlock_t *lock)
-{
- u32 *p = &lock->lock;
- u32 tmp;
-
- smp_mb();
- asm volatile (
- "1: ldex.w %0, (%1) \n"
- " subi %0, 1 \n"
- " stex.w %0, (%1) \n"
- " bez %0, 1b \n"
- : "=&r" (tmp)
- : "r"(p)
- : "cc");
-}
-
-static inline int arch_read_trylock(arch_rwlock_t *lock)
-{
- u32 *p = &lock->lock;
- u32 tmp;
-
- asm volatile (
- "1: ldex.w %0, (%1) \n"
- " blz %0, 2f \n"
- " addi %0, 1 \n"
- " stex.w %0, (%1) \n"
- " bez %0, 1b \n"
- " movi %0, 0 \n"
- "2: \n"
- : "=&r" (tmp)
- : "r"(p)
- : "cc");
-
- if (!tmp)
- smp_mb();
-
- return !tmp;
-}
-
-/*
- * write lock/unlock/trylock
- */
-static inline void arch_write_lock(arch_rwlock_t *lock)
-{
- u32 *p = &lock->lock;
- u32 tmp;
-
- asm volatile (
- "1: ldex.w %0, (%1) \n"
- " bnez %0, 1b \n"
- " subi %0, 1 \n"
- " stex.w %0, (%1) \n"
- " bez %0, 1b \n"
- : "=&r" (tmp)
- : "r"(p)
- : "cc");
- smp_mb();
-}
-
-static inline void arch_write_unlock(arch_rwlock_t *lock)
-{
- smp_mb();
- WRITE_ONCE(lock->lock, 0);
-}
-
-static inline int arch_write_trylock(arch_rwlock_t *lock)
-{
- u32 *p = &lock->lock;
- u32 tmp;
-
- asm volatile (
- "1: ldex.w %0, (%1) \n"
- " bnez %0, 2f \n"
- " subi %0, 1 \n"
- " stex.w %0, (%1) \n"
- " bez %0, 1b \n"
- " movi %0, 0 \n"
- "2: \n"
- : "=&r" (tmp)
- : "r"(p)
- : "cc");
-
- if (!tmp)
- smp_mb();
-
- return !tmp;
-}
-
-#endif /* CONFIG_QUEUED_RWLOCKS */
#endif /* __ASM_CSKY_SPINLOCK_H */
diff --git a/arch/csky/include/asm/spinlock_types.h b/arch/csky/include/asm/spinlock_types.h
index 88b8243..8ff0f6f 100644
--- a/arch/csky/include/asm/spinlock_types.h
+++ b/arch/csky/include/asm/spinlock_types.h
@@ -22,16 +22,6 @@ typedef struct {

#define __ARCH_SPIN_LOCK_UNLOCKED { { 0 } }

-#ifdef CONFIG_QUEUED_RWLOCKS
#include <asm-generic/qrwlock_types.h>

-#else /* CONFIG_NR_CPUS > 2 */
-
-typedef struct {
- u32 lock;
-} arch_rwlock_t;
-
-#define __ARCH_RW_LOCK_UNLOCKED { 0 }
-
-#endif /* CONFIG_QUEUED_RWLOCKS */
#endif /* __ASM_CSKY_SPINLOCK_TYPES_H */
--
2.7.4