1 files changed, 139 insertions, 0 deletions
diff --git a/arch/loongarch/include/asm/barrier.h b/arch/loongarch/include/asm/barrier.h
new file mode 100644
index 0000000000..4b663f1977
--- /dev/null
+++ b/arch/loongarch/include/asm/barrier.h
@@ -0,0 +1,139 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef __ASM_BARRIER_H
+#define __ASM_BARRIER_H
+
+/*
+ * Hint encoding:
+ *
+ * Bit4: ordering or completion (0: completion, 1: ordering)
+ * Bit3: barrier for previous read (0: true, 1: false)
+ * Bit2: barrier for previous write (0: true, 1: false)
+ * Bit1: barrier for succeeding read (0: true, 1: false)
+ * Bit0: barrier for succeeding write (0: true, 1: false)
+ *
+ * Hint 0x700: barrier for "read after read" from the same address
+ */
+
+#define DBAR(hint) __asm__ __volatile__("dbar %0 " : : "I"(hint) : "memory")
+
+#define crwrw		0b00000
+#define cr_r_		0b00101
+#define c_w_w		0b01010
+
+#define orwrw		0b10000
+#define or_r_		0b10101
+#define o_w_w		0b11010
+
+#define orw_w		0b10010
+#define or_rw		0b10100
+
+#define c_sync()	DBAR(crwrw)
+#define c_rsync()	DBAR(cr_r_)
+#define c_wsync()	DBAR(c_w_w)
+
+#define o_sync()	DBAR(orwrw)
+#define o_rsync()	DBAR(or_r_)
+#define o_wsync()	DBAR(o_w_w)
+
+#define ldacq_mb()	DBAR(or_rw)
+#define strel_mb()	DBAR(orw_w)
+
+#define mb()		c_sync()
+#define rmb()		c_rsync()
+#define wmb()		c_wsync()
+#define iob()		c_sync()
+#define wbflush()	c_sync()
+
+#define __smp_mb()	o_sync()
+#define __smp_rmb()	o_rsync()
+#define __smp_wmb()	o_wsync()
+
+#ifdef CONFIG_SMP
+#define __WEAK_LLSC_MB		"	dbar 0x700	\n"
+#else
+#define __WEAK_LLSC_MB		"			\n"
+#endif
+
+#define __smp_mb__before_atomic()	barrier()
+#define __smp_mb__after_atomic()	barrier()
+
+/**
+ * array_index_mask_nospec() - generate a ~0 mask when index < size, 0 otherwise
+ * @index: array element index
+ * @size: number of elements in array
+ *
+ * Returns:
+ *     0 - (@index < @size)
+ */
+#define array_index_mask_nospec array_index_mask_nospec
+static inline unsigned long array_index_mask_nospec(unsigned long index,
+						    unsigned long size)
+{
+	unsigned long mask;
+
+	__asm__ __volatile__(
+		"sltu	%0, %1, %2\n\t"
+#if (__SIZEOF_LONG__ == 4)
+		"sub.w	%0, $zero, %0\n\t"
+#elif (__SIZEOF_LONG__ == 8)
+		"sub.d	%0, $zero, %0\n\t"
+#endif
+		: "=r" (mask)
+		: "r" (index), "r" (size)
+		:);
+
+	return mask;
+}
+
+#define __smp_load_acquire(p)				\
+({							\
+	typeof(*p) ___p1 = READ_ONCE(*p);		\
+	compiletime_assert_atomic_type(*p);		\
+	ldacq_mb();					\
+	___p1;						\
+})
+
+#define __smp_store_release(p, v)			\
+do {							\
+	compiletime_assert_atomic_type(*p);		\
+	strel_mb();					\
+	WRITE_ONCE(*p, v);				\
+} while (0)
+
+#define __smp_store_mb(p, v)							\
+do {										\
+	union { typeof(p) __val; char __c[1]; } __u =				\
+		{ .__val = (__force typeof(p)) (v) };				\
+	unsigned long __tmp;							\
+	switch (sizeof(p)) {							\
+	case 1:									\
+		*(volatile __u8 *)&p = *(__u8 *)__u.__c;			\
+		__smp_mb();							\
+		break;								\
+	case 2:									\
+		*(volatile __u16 *)&p = *(__u16 *)__u.__c;			\
+		__smp_mb();							\
+		break;								\
+	case 4:									\
+		__asm__ __volatile__(						\
+		"amswap_db.w %[tmp], %[val], %[mem]	\n"			\
+		: [mem] "+ZB" (*(u32 *)&p), [tmp] "=&r" (__tmp)			\
+		: [val] "r" (*(__u32 *)__u.__c)					\
+		: );								\
+		break;								\
+	case 8:									\
+		__asm__ __volatile__(						\
+		"amswap_db.d %[tmp], %[val], %[mem]	\n"			\
+		: [mem] "+ZB" (*(u64 *)&p), [tmp] "=&r" (__tmp)			\
+		: [val] "r" (*(__u64 *)__u.__c)					\
+		: );								\
+		break;								\
+	}									\
+} while (0)
+
+#include <asm-generic/barrier.h>
+
+#endif /* __ASM_BARRIER_H */