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

[guoren at kernel.org]

From: Guo Ren <guoren at 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 at linux.alibaba.com>
Cc: Peter Zijlstra <peterz at 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