[PATCH V12 09/24] LoongArch: Add atomic/locking headers
From: Huacai Chen
Date: Wed Jun 01 2022 - 06:01:59 EST
Add common headers (atomic, bitops, barrier and locking) for basic
LoongArch support.
Reviewed-by: WANG Xuerui <git@xxxxxxxxxx>
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
arch/loongarch/include/asm/atomic.h | 358 +++++++++++++++++++++++++++
arch/loongarch/include/asm/barrier.h | 51 ++++
arch/loongarch/include/asm/bitops.h | 33 +++
arch/loongarch/include/asm/bitrev.h | 34 +++
arch/loongarch/include/asm/cmpxchg.h | 122 +++++++++
arch/loongarch/include/asm/local.h | 138 +++++++++++
arch/loongarch/include/asm/percpu.h | 20 ++
7 files changed, 756 insertions(+)
create mode 100644 arch/loongarch/include/asm/atomic.h
create mode 100644 arch/loongarch/include/asm/barrier.h
create mode 100644 arch/loongarch/include/asm/bitops.h
create mode 100644 arch/loongarch/include/asm/bitrev.h
create mode 100644 arch/loongarch/include/asm/cmpxchg.h
create mode 100644 arch/loongarch/include/asm/local.h
create mode 100644 arch/loongarch/include/asm/percpu.h
diff --git a/arch/loongarch/include/asm/atomic.h b/arch/loongarch/include/asm/atomic.h
new file mode 100644
index 000000000000..932352342b12
--- /dev/null
+++ b/arch/loongarch/include/asm/atomic.h
@@ -0,0 +1,358 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Atomic operations.
+ *
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_ATOMIC_H
+#define _ASM_ATOMIC_H
+
+#include <linux/types.h>
+#include <asm/barrier.h>
+#include <asm/cmpxchg.h>
+#include <asm/compiler.h>
+
+#if __SIZEOF_LONG__ == 4
+#define __LL "ll.w "
+#define __SC "sc.w "
+#define __AMADD "amadd.w "
+#define __AMAND_DB "amand_db.w "
+#define __AMOR_DB "amor_db.w "
+#define __AMXOR_DB "amxor_db.w "
+#elif __SIZEOF_LONG__ == 8
+#define __LL "ll.d "
+#define __SC "sc.d "
+#define __AMADD "amadd.d "
+#define __AMAND_DB "amand_db.d "
+#define __AMOR_DB "amor_db.d "
+#define __AMXOR_DB "amxor_db.d "
+#endif
+
+#define ATOMIC_INIT(i) { (i) }
+
+/*
+ * arch_atomic_read - read atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically reads the value of @v.
+ */
+#define arch_atomic_read(v) READ_ONCE((v)->counter)
+
+/*
+ * arch_atomic_set - set atomic variable
+ * @v: pointer of type atomic_t
+ * @i: required value
+ *
+ * Atomically sets the value of @v to @i.
+ */
+#define arch_atomic_set(v, i) WRITE_ONCE((v)->counter, (i))
+
+#define ATOMIC_OP(op, I, asm_op) \
+static inline void arch_atomic_##op(int i, atomic_t *v) \
+{ \
+ __asm__ __volatile__( \
+ "am"#asm_op"_db.w" " $zero, %1, %0 \n" \
+ : "+ZB" (v->counter) \
+ : "r" (I) \
+ : "memory"); \
+}
+
+#define ATOMIC_OP_RETURN(op, I, asm_op, c_op) \
+static inline int arch_atomic_##op##_return_relaxed(int i, atomic_t *v) \
+{ \
+ int result; \
+ \
+ __asm__ __volatile__( \
+ "am"#asm_op"_db.w" " %1, %2, %0 \n" \
+ : "+ZB" (v->counter), "=&r" (result) \
+ : "r" (I) \
+ : "memory"); \
+ \
+ return result c_op I; \
+}
+
+#define ATOMIC_FETCH_OP(op, I, asm_op) \
+static inline int arch_atomic_fetch_##op##_relaxed(int i, atomic_t *v) \
+{ \
+ int result; \
+ \
+ __asm__ __volatile__( \
+ "am"#asm_op"_db.w" " %1, %2, %0 \n" \
+ : "+ZB" (v->counter), "=&r" (result) \
+ : "r" (I) \
+ : "memory"); \
+ \
+ return result; \
+}
+
+#define ATOMIC_OPS(op, I, asm_op, c_op) \
+ ATOMIC_OP(op, I, asm_op) \
+ ATOMIC_OP_RETURN(op, I, asm_op, c_op) \
+ ATOMIC_FETCH_OP(op, I, asm_op)
+
+ATOMIC_OPS(add, i, add, +)
+ATOMIC_OPS(sub, -i, add, +)
+
+#define arch_atomic_add_return_relaxed arch_atomic_add_return_relaxed
+#define arch_atomic_sub_return_relaxed arch_atomic_sub_return_relaxed
+#define arch_atomic_fetch_add_relaxed arch_atomic_fetch_add_relaxed
+#define arch_atomic_fetch_sub_relaxed arch_atomic_fetch_sub_relaxed
+
+#undef ATOMIC_OPS
+
+#define ATOMIC_OPS(op, I, asm_op) \
+ ATOMIC_OP(op, I, asm_op) \
+ ATOMIC_FETCH_OP(op, I, asm_op)
+
+ATOMIC_OPS(and, i, and)
+ATOMIC_OPS(or, i, or)
+ATOMIC_OPS(xor, i, xor)
+
+#define arch_atomic_fetch_and_relaxed arch_atomic_fetch_and_relaxed
+#define arch_atomic_fetch_or_relaxed arch_atomic_fetch_or_relaxed
+#define arch_atomic_fetch_xor_relaxed arch_atomic_fetch_xor_relaxed
+
+#undef ATOMIC_OPS
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+static inline int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)
+{
+ int prev, rc;
+
+ __asm__ __volatile__ (
+ "0: ll.w %[p], %[c]\n"
+ " beq %[p], %[u], 1f\n"
+ " add.w %[rc], %[p], %[a]\n"
+ " sc.w %[rc], %[c]\n"
+ " beqz %[rc], 0b\n"
+ " b 2f\n"
+ "1:\n"
+ __WEAK_LLSC_MB
+ "2:\n"
+ : [p]"=&r" (prev), [rc]"=&r" (rc),
+ [c]"=ZB" (v->counter)
+ : [a]"r" (a), [u]"r" (u)
+ : "memory");
+
+ return prev;
+}
+#define arch_atomic_fetch_add_unless arch_atomic_fetch_add_unless
+
+/*
+ * arch_atomic_sub_if_positive - conditionally subtract integer from atomic variable
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically test @v and subtract @i if @v is greater or equal than @i.
+ * The function returns the old value of @v minus @i.
+ */
+static inline int arch_atomic_sub_if_positive(int i, atomic_t *v)
+{
+ int result;
+ int temp;
+
+ if (__builtin_constant_p(i)) {
+ __asm__ __volatile__(
+ "1: ll.w %1, %2 # atomic_sub_if_positive\n"
+ " addi.w %0, %1, %3 \n"
+ " or %1, %0, $zero \n"
+ " blt %0, $zero, 2f \n"
+ " sc.w %1, %2 \n"
+ " beq $zero, %1, 1b \n"
+ "2: \n"
+ : "=&r" (result), "=&r" (temp),
+ "+" GCC_OFF_SMALL_ASM() (v->counter)
+ : "I" (-i));
+ } else {
+ __asm__ __volatile__(
+ "1: ll.w %1, %2 # atomic_sub_if_positive\n"
+ " sub.w %0, %1, %3 \n"
+ " or %1, %0, $zero \n"
+ " blt %0, $zero, 2f \n"
+ " sc.w %1, %2 \n"
+ " beq $zero, %1, 1b \n"
+ "2: \n"
+ : "=&r" (result), "=&r" (temp),
+ "+" GCC_OFF_SMALL_ASM() (v->counter)
+ : "r" (i));
+ }
+
+ return result;
+}
+
+#define arch_atomic_cmpxchg(v, o, n) (arch_cmpxchg(&((v)->counter), (o), (n)))
+#define arch_atomic_xchg(v, new) (arch_xchg(&((v)->counter), (new)))
+
+/*
+ * arch_atomic_dec_if_positive - decrement by 1 if old value positive
+ * @v: pointer of type atomic_t
+ */
+#define arch_atomic_dec_if_positive(v) arch_atomic_sub_if_positive(1, v)
+
+#ifdef CONFIG_64BIT
+
+#define ATOMIC64_INIT(i) { (i) }
+
+/*
+ * arch_atomic64_read - read atomic variable
+ * @v: pointer of type atomic64_t
+ *
+ */
+#define arch_atomic64_read(v) READ_ONCE((v)->counter)
+
+/*
+ * arch_atomic64_set - set atomic variable
+ * @v: pointer of type atomic64_t
+ * @i: required value
+ */
+#define arch_atomic64_set(v, i) WRITE_ONCE((v)->counter, (i))
+
+#define ATOMIC64_OP(op, I, asm_op) \
+static inline void arch_atomic64_##op(long i, atomic64_t *v) \
+{ \
+ __asm__ __volatile__( \
+ "am"#asm_op"_db.d " " $zero, %1, %0 \n" \
+ : "+ZB" (v->counter) \
+ : "r" (I) \
+ : "memory"); \
+}
+
+#define ATOMIC64_OP_RETURN(op, I, asm_op, c_op) \
+static inline long arch_atomic64_##op##_return_relaxed(long i, atomic64_t *v) \
+{ \
+ long result; \
+ __asm__ __volatile__( \
+ "am"#asm_op"_db.d " " %1, %2, %0 \n" \
+ : "+ZB" (v->counter), "=&r" (result) \
+ : "r" (I) \
+ : "memory"); \
+ \
+ return result c_op I; \
+}
+
+#define ATOMIC64_FETCH_OP(op, I, asm_op) \
+static inline long arch_atomic64_fetch_##op##_relaxed(long i, atomic64_t *v) \
+{ \
+ long result; \
+ \
+ __asm__ __volatile__( \
+ "am"#asm_op"_db.d " " %1, %2, %0 \n" \
+ : "+ZB" (v->counter), "=&r" (result) \
+ : "r" (I) \
+ : "memory"); \
+ \
+ return result; \
+}
+
+#define ATOMIC64_OPS(op, I, asm_op, c_op) \
+ ATOMIC64_OP(op, I, asm_op) \
+ ATOMIC64_OP_RETURN(op, I, asm_op, c_op) \
+ ATOMIC64_FETCH_OP(op, I, asm_op)
+
+ATOMIC64_OPS(add, i, add, +)
+ATOMIC64_OPS(sub, -i, add, +)
+
+#define arch_atomic64_add_return_relaxed arch_atomic64_add_return_relaxed
+#define arch_atomic64_sub_return_relaxed arch_atomic64_sub_return_relaxed
+#define arch_atomic64_fetch_add_relaxed arch_atomic64_fetch_add_relaxed
+#define arch_atomic64_fetch_sub_relaxed arch_atomic64_fetch_sub_relaxed
+
+#undef ATOMIC64_OPS
+
+#define ATOMIC64_OPS(op, I, asm_op) \
+ ATOMIC64_OP(op, I, asm_op) \
+ ATOMIC64_FETCH_OP(op, I, asm_op)
+
+ATOMIC64_OPS(and, i, and)
+ATOMIC64_OPS(or, i, or)
+ATOMIC64_OPS(xor, i, xor)
+
+#define arch_atomic64_fetch_and_relaxed arch_atomic64_fetch_and_relaxed
+#define arch_atomic64_fetch_or_relaxed arch_atomic64_fetch_or_relaxed
+#define arch_atomic64_fetch_xor_relaxed arch_atomic64_fetch_xor_relaxed
+
+#undef ATOMIC64_OPS
+#undef ATOMIC64_FETCH_OP
+#undef ATOMIC64_OP_RETURN
+#undef ATOMIC64_OP
+
+static inline long arch_atomic64_fetch_add_unless(atomic64_t *v, long a, long u)
+{
+ long prev, rc;
+
+ __asm__ __volatile__ (
+ "0: ll.d %[p], %[c]\n"
+ " beq %[p], %[u], 1f\n"
+ " add.d %[rc], %[p], %[a]\n"
+ " sc.d %[rc], %[c]\n"
+ " beqz %[rc], 0b\n"
+ " b 2f\n"
+ "1:\n"
+ __WEAK_LLSC_MB
+ "2:\n"
+ : [p]"=&r" (prev), [rc]"=&r" (rc),
+ [c] "=ZB" (v->counter)
+ : [a]"r" (a), [u]"r" (u)
+ : "memory");
+
+ return prev;
+}
+#define arch_atomic64_fetch_add_unless arch_atomic64_fetch_add_unless
+
+/*
+ * arch_atomic64_sub_if_positive - conditionally subtract integer from atomic variable
+ * @i: integer value to subtract
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically test @v and subtract @i if @v is greater or equal than @i.
+ * The function returns the old value of @v minus @i.
+ */
+static inline long arch_atomic64_sub_if_positive(long i, atomic64_t *v)
+{
+ long result;
+ long temp;
+
+ if (__builtin_constant_p(i)) {
+ __asm__ __volatile__(
+ "1: ll.d %1, %2 # atomic64_sub_if_positive \n"
+ " addi.d %0, %1, %3 \n"
+ " or %1, %0, $zero \n"
+ " blt %0, $zero, 2f \n"
+ " sc.d %1, %2 \n"
+ " beq %1, $zero, 1b \n"
+ "2: \n"
+ : "=&r" (result), "=&r" (temp),
+ "+" GCC_OFF_SMALL_ASM() (v->counter)
+ : "I" (-i));
+ } else {
+ __asm__ __volatile__(
+ "1: ll.d %1, %2 # atomic64_sub_if_positive \n"
+ " sub.d %0, %1, %3 \n"
+ " or %1, %0, $zero \n"
+ " blt %0, $zero, 2f \n"
+ " sc.d %1, %2 \n"
+ " beq %1, $zero, 1b \n"
+ "2: \n"
+ : "=&r" (result), "=&r" (temp),
+ "+" GCC_OFF_SMALL_ASM() (v->counter)
+ : "r" (i));
+ }
+
+ return result;
+}
+
+#define arch_atomic64_cmpxchg(v, o, n) \
+ ((__typeof__((v)->counter))arch_cmpxchg(&((v)->counter), (o), (n)))
+#define arch_atomic64_xchg(v, new) (arch_xchg(&((v)->counter), (new)))
+
+/*
+ * arch_atomic64_dec_if_positive - decrement by 1 if old value positive
+ * @v: pointer of type atomic64_t
+ */
+#define arch_atomic64_dec_if_positive(v) arch_atomic64_sub_if_positive(1, v)
+
+#endif /* CONFIG_64BIT */
+
+#endif /* _ASM_ATOMIC_H */
diff --git a/arch/loongarch/include/asm/barrier.h b/arch/loongarch/include/asm/barrier.h
new file mode 100644
index 000000000000..e57571bcaf4f
--- /dev/null
+++ b/arch/loongarch/include/asm/barrier.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef __ASM_BARRIER_H
+#define __ASM_BARRIER_H
+
+#define __sync() __asm__ __volatile__("dbar 0" : : : "memory")
+
+#define fast_wmb() __sync()
+#define fast_rmb() __sync()
+#define fast_mb() __sync()
+#define fast_iob() __sync()
+#define wbflush() __sync()
+
+#define wmb() fast_wmb()
+#define rmb() fast_rmb()
+#define mb() fast_mb()
+#define iob() fast_iob()
+
+/**
+ * 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, $r0, %0\n\t"
+#elif (__SIZEOF_LONG__ == 8)
+ "sub.d %0, $r0, %0\n\t"
+#endif
+ : "=r" (mask)
+ : "r" (index), "r" (size)
+ :);
+
+ return mask;
+}
+
+#include <asm-generic/barrier.h>
+
+#endif /* __ASM_BARRIER_H */
diff --git a/arch/loongarch/include/asm/bitops.h b/arch/loongarch/include/asm/bitops.h
new file mode 100644
index 000000000000..69e00f8d8034
--- /dev/null
+++ b/arch/loongarch/include/asm/bitops.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_BITOPS_H
+#define _ASM_BITOPS_H
+
+#include <linux/compiler.h>
+
+#ifndef _LINUX_BITOPS_H
+#error only <linux/bitops.h> can be included directly
+#endif
+
+#include <asm/barrier.h>
+
+#include <asm-generic/bitops/builtin-ffs.h>
+#include <asm-generic/bitops/builtin-fls.h>
+#include <asm-generic/bitops/builtin-__ffs.h>
+#include <asm-generic/bitops/builtin-__fls.h>
+
+#include <asm-generic/bitops/ffz.h>
+#include <asm-generic/bitops/fls64.h>
+
+#include <asm-generic/bitops/sched.h>
+#include <asm-generic/bitops/hweight.h>
+
+#include <asm-generic/bitops/atomic.h>
+#include <asm-generic/bitops/non-atomic.h>
+#include <asm-generic/bitops/lock.h>
+#include <asm-generic/bitops/le.h>
+#include <asm-generic/bitops/ext2-atomic.h>
+
+#endif /* _ASM_BITOPS_H */
diff --git a/arch/loongarch/include/asm/bitrev.h b/arch/loongarch/include/asm/bitrev.h
new file mode 100644
index 000000000000..46f275b9cdf7
--- /dev/null
+++ b/arch/loongarch/include/asm/bitrev.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef __LOONGARCH_ASM_BITREV_H__
+#define __LOONGARCH_ASM_BITREV_H__
+
+#include <linux/swab.h>
+
+static __always_inline __attribute_const__ u32 __arch_bitrev32(u32 x)
+{
+ u32 ret;
+
+ asm("bitrev.4b %0, %1" : "=r"(ret) : "r"(__swab32(x)));
+ return ret;
+}
+
+static __always_inline __attribute_const__ u16 __arch_bitrev16(u16 x)
+{
+ u16 ret;
+
+ asm("bitrev.4b %0, %1" : "=r"(ret) : "r"(__swab16(x)));
+ return ret;
+}
+
+static __always_inline __attribute_const__ u8 __arch_bitrev8(u8 x)
+{
+ u8 ret;
+
+ asm("bitrev.4b %0, %1" : "=r"(ret) : "r"(x));
+ return ret;
+}
+
+#endif /* __LOONGARCH_ASM_BITREV_H__ */
diff --git a/arch/loongarch/include/asm/cmpxchg.h b/arch/loongarch/include/asm/cmpxchg.h
new file mode 100644
index 000000000000..48613b872bc8
--- /dev/null
+++ b/arch/loongarch/include/asm/cmpxchg.h
@@ -0,0 +1,122 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef __ASM_CMPXCHG_H
+#define __ASM_CMPXCHG_H
+
+#include <asm/barrier.h>
+#include <linux/build_bug.h>
+
+#define __xchg_asm(amswap_db, m, val) \
+({ \
+ __typeof(val) __ret; \
+ \
+ __asm__ __volatile__ ( \
+ " "amswap_db" %1, %z2, %0 \n" \
+ : "+ZB" (*m), "=&r" (__ret) \
+ : "Jr" (val) \
+ : "memory"); \
+ \
+ __ret; \
+})
+
+static inline unsigned long __xchg(volatile void *ptr, unsigned long x,
+ int size)
+{
+ switch (size) {
+ case 4:
+ return __xchg_asm("amswap_db.w", (volatile u32 *)ptr, (u32)x);
+
+ case 8:
+ return __xchg_asm("amswap_db.d", (volatile u64 *)ptr, (u64)x);
+
+ default:
+ BUILD_BUG();
+ }
+
+ return 0;
+}
+
+#define arch_xchg(ptr, x) \
+({ \
+ __typeof__(*(ptr)) __res; \
+ \
+ __res = (__typeof__(*(ptr))) \
+ __xchg((ptr), (unsigned long)(x), sizeof(*(ptr))); \
+ \
+ __res; \
+})
+
+#define __cmpxchg_asm(ld, st, m, old, new) \
+({ \
+ __typeof(old) __ret; \
+ \
+ __asm__ __volatile__( \
+ "1: " ld " %0, %2 # __cmpxchg_asm \n" \
+ " bne %0, %z3, 2f \n" \
+ " or $t0, %z4, $zero \n" \
+ " " st " $t0, %1 \n" \
+ " beq $zero, $t0, 1b \n" \
+ "2: \n" \
+ : "=&r" (__ret), "=ZB"(*m) \
+ : "ZB"(*m), "Jr" (old), "Jr" (new) \
+ : "t0", "memory"); \
+ \
+ __ret; \
+})
+
+static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
+ unsigned long new, unsigned int size)
+{
+ switch (size) {
+ case 4:
+ return __cmpxchg_asm("ll.w", "sc.w", (volatile u32 *)ptr,
+ (u32)old, new);
+
+ case 8:
+ return __cmpxchg_asm("ll.d", "sc.d", (volatile u64 *)ptr,
+ (u64)old, new);
+
+ default:
+ BUILD_BUG();
+ }
+
+ return 0;
+}
+
+#define arch_cmpxchg_local(ptr, old, new) \
+ ((__typeof__(*(ptr))) \
+ __cmpxchg((ptr), \
+ (unsigned long)(__typeof__(*(ptr)))(old), \
+ (unsigned long)(__typeof__(*(ptr)))(new), \
+ sizeof(*(ptr))))
+
+#define arch_cmpxchg(ptr, old, new) \
+({ \
+ __typeof__(*(ptr)) __res; \
+ \
+ __res = arch_cmpxchg_local((ptr), (old), (new)); \
+ \
+ __res; \
+})
+
+#ifdef CONFIG_64BIT
+#define arch_cmpxchg64_local(ptr, o, n) \
+ ({ \
+ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
+ arch_cmpxchg_local((ptr), (o), (n)); \
+ })
+
+#define arch_cmpxchg64(ptr, o, n) \
+ ({ \
+ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
+ arch_cmpxchg((ptr), (o), (n)); \
+ })
+#else
+#include <asm-generic/cmpxchg-local.h>
+#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
+#define arch_cmpxchg64(ptr, o, n) arch_cmpxchg64_local((ptr), (o), (n))
+#endif
+
+#endif /* __ASM_CMPXCHG_H */
diff --git a/arch/loongarch/include/asm/local.h b/arch/loongarch/include/asm/local.h
new file mode 100644
index 000000000000..2052a2267337
--- /dev/null
+++ b/arch/loongarch/include/asm/local.h
@@ -0,0 +1,138 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ARCH_LOONGARCH_LOCAL_H
+#define _ARCH_LOONGARCH_LOCAL_H
+
+#include <linux/percpu.h>
+#include <linux/bitops.h>
+#include <linux/atomic.h>
+#include <asm/cmpxchg.h>
+#include <asm/compiler.h>
+
+typedef struct {
+ atomic_long_t a;
+} local_t;
+
+#define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) }
+
+#define local_read(l) atomic_long_read(&(l)->a)
+#define local_set(l, i) atomic_long_set(&(l)->a, (i))
+
+#define local_add(i, l) atomic_long_add((i), (&(l)->a))
+#define local_sub(i, l) atomic_long_sub((i), (&(l)->a))
+#define local_inc(l) atomic_long_inc(&(l)->a)
+#define local_dec(l) atomic_long_dec(&(l)->a)
+
+/*
+ * Same as above, but return the result value
+ */
+static inline long local_add_return(long i, local_t *l)
+{
+ unsigned long result;
+
+ __asm__ __volatile__(
+ " " __AMADD " %1, %2, %0 \n"
+ : "+ZB" (l->a.counter), "=&r" (result)
+ : "r" (i)
+ : "memory");
+ result = result + i;
+
+ return result;
+}
+
+static inline long local_sub_return(long i, local_t *l)
+{
+ unsigned long result;
+
+ __asm__ __volatile__(
+ " " __AMADD "%1, %2, %0 \n"
+ : "+ZB" (l->a.counter), "=&r" (result)
+ : "r" (-i)
+ : "memory");
+
+ result = result - i;
+
+ return result;
+}
+
+#define local_cmpxchg(l, o, n) \
+ ((long)cmpxchg_local(&((l)->a.counter), (o), (n)))
+#define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))
+
+/**
+ * local_add_unless - add unless the number is a given value
+ * @l: pointer of type local_t
+ * @a: the amount to add to l...
+ * @u: ...unless l is equal to u.
+ *
+ * Atomically adds @a to @l, so long as it was not @u.
+ * Returns non-zero if @l was not @u, and zero otherwise.
+ */
+#define local_add_unless(l, a, u) \
+({ \
+ long c, old; \
+ c = local_read(l); \
+ while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
+ c = old; \
+ c != (u); \
+})
+#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
+
+#define local_dec_return(l) local_sub_return(1, (l))
+#define local_inc_return(l) local_add_return(1, (l))
+
+/*
+ * local_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @l: pointer of type local_t
+ *
+ * Atomically subtracts @i from @l and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+#define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)
+
+/*
+ * local_inc_and_test - increment and test
+ * @l: pointer of type local_t
+ *
+ * Atomically increments @l by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+#define local_inc_and_test(l) (local_inc_return(l) == 0)
+
+/*
+ * local_dec_and_test - decrement by 1 and test
+ * @l: pointer of type local_t
+ *
+ * Atomically decrements @l by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+#define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
+
+/*
+ * local_add_negative - add and test if negative
+ * @l: pointer of type local_t
+ * @i: integer value to add
+ *
+ * Atomically adds @i to @l and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+#define local_add_negative(i, l) (local_add_return(i, (l)) < 0)
+
+/* Use these for per-cpu local_t variables: on some archs they are
+ * much more efficient than these naive implementations. Note they take
+ * a variable, not an address.
+ */
+
+#define __local_inc(l) ((l)->a.counter++)
+#define __local_dec(l) ((l)->a.counter++)
+#define __local_add(i, l) ((l)->a.counter += (i))
+#define __local_sub(i, l) ((l)->a.counter -= (i))
+
+#endif /* _ARCH_LOONGARCH_LOCAL_H */
diff --git a/arch/loongarch/include/asm/percpu.h b/arch/loongarch/include/asm/percpu.h
new file mode 100644
index 000000000000..b03d8f8b9fd3
--- /dev/null
+++ b/arch/loongarch/include/asm/percpu.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef __ASM_PERCPU_H
+#define __ASM_PERCPU_H
+
+/* Use r21 for fast access */
+register unsigned long __my_cpu_offset __asm__("$r21");
+
+static inline void set_my_cpu_offset(unsigned long off)
+{
+ __my_cpu_offset = off;
+ csr_write64(off, PERCPU_BASE_KS);
+}
+#define __my_cpu_offset __my_cpu_offset
+
+#include <asm-generic/percpu.h>
+
+#endif /* __ASM_PERCPU_H */
--
2.27.0