1 files changed, 256 insertions, 0 deletions
diff --git a/arch/csky/include/asm/spinlock.h b/arch/csky/include/asm/spinlock.h
new file mode 100644
index 000000000000..7cf3f2b34cea
--- /dev/null
+++ b/arch/csky/include/asm/spinlock.h
@@ -0,0 +1,256 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_SPINLOCK_H
+#define __ASM_CSKY_SPINLOCK_H
+
+#include <linux/spinlock_types.h>
+#include <asm/barrier.h>
+
+#ifdef CONFIG_QUEUED_RWLOCKS
+
+/*
+ * Ticket-based spin-locking.
+ */
+static inline void arch_spin_lock(arch_spinlock_t *lock)
+{
+	arch_spinlock_t lockval;
+	u32 ticket_next = 1 << TICKET_NEXT;
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%2) \n"
+		"	mov		%1, %0	 \n"
+		"	add		%0, %3	 \n"
+		"	stex.w		%0, (%2) \n"
+		"	bez		%0, 1b   \n"
+		: "=&r" (tmp), "=&r" (lockval)
+		: "r"(p), "r"(ticket_next)
+		: "cc");
+
+	while (lockval.tickets.next != lockval.tickets.owner)
+		lockval.tickets.owner = READ_ONCE(lock->tickets.owner);
+
+	smp_mb();
+}
+
+static inline int arch_spin_trylock(arch_spinlock_t *lock)
+{
+	u32 tmp, contended, res;
+	u32 ticket_next = 1 << TICKET_NEXT;
+	u32 *p = &lock->lock;
+
+	do {
+		asm volatile (
+		"	ldex.w		%0, (%3)   \n"
+		"	movi		%2, 1	   \n"
+		"	rotli		%1, %0, 16 \n"
+		"	cmpne		%1, %0     \n"
+		"	bt		1f         \n"
+		"	movi		%2, 0	   \n"
+		"	add		%0, %0, %4 \n"
+		"	stex.w		%0, (%3)   \n"
+		"1:				   \n"
+		: "=&r" (res), "=&r" (tmp), "=&r" (contended)
+		: "r"(p), "r"(ticket_next)
+		: "cc");
+	} while (!res);
+
+	if (!contended)
+		smp_mb();
+
+	return !contended;
+}
+
+static inline void arch_spin_unlock(arch_spinlock_t *lock)
+{
+	smp_mb();
+	WRITE_ONCE(lock->tickets.owner, lock->tickets.owner + 1);
+}
+
+static inline int arch_spin_value_unlocked(arch_spinlock_t lock)
+{
+	return lock.tickets.owner == lock.tickets.next;
+}
+
+static inline int arch_spin_is_locked(arch_spinlock_t *lock)
+{
+	return !arch_spin_value_unlocked(READ_ONCE(*lock));
+}
+
+static inline int arch_spin_is_contended(arch_spinlock_t *lock)
+{
+	struct __raw_tickets tickets = READ_ONCE(lock->tickets);
+
+	return (tickets.next - tickets.owner) > 1;
+}
+#define arch_spin_is_contended	arch_spin_is_contended
+
+#include <asm/qrwlock.h>
+
+/* 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 */