v4.19.13 snapshot.
diff --git a/arch/riscv/include/asm/bitops.h b/arch/riscv/include/asm/bitops.h
new file mode 100644
index 0000000..f30daf2
--- /dev/null
+++ b/arch/riscv/include/asm/bitops.h
@@ -0,0 +1,218 @@
+/*
+ * Copyright (C) 2012 Regents of the University of California
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _ASM_RISCV_BITOPS_H
+#define _ASM_RISCV_BITOPS_H
+
+#ifndef _LINUX_BITOPS_H
+#error "Only <linux/bitops.h> can be included directly"
+#endif /* _LINUX_BITOPS_H */
+
+#include <linux/compiler.h>
+#include <linux/irqflags.h>
+#include <asm/barrier.h>
+#include <asm/bitsperlong.h>
+
+#ifndef smp_mb__before_clear_bit
+#define smp_mb__before_clear_bit() smp_mb()
+#define smp_mb__after_clear_bit() smp_mb()
+#endif /* smp_mb__before_clear_bit */
+
+#include <asm-generic/bitops/__ffs.h>
+#include <asm-generic/bitops/ffz.h>
+#include <asm-generic/bitops/fls.h>
+#include <asm-generic/bitops/__fls.h>
+#include <asm-generic/bitops/fls64.h>
+#include <asm-generic/bitops/find.h>
+#include <asm-generic/bitops/sched.h>
+#include <asm-generic/bitops/ffs.h>
+
+#include <asm-generic/bitops/hweight.h>
+
+#if (BITS_PER_LONG == 64)
+#define __AMO(op) "amo" #op ".d"
+#elif (BITS_PER_LONG == 32)
+#define __AMO(op) "amo" #op ".w"
+#else
+#error "Unexpected BITS_PER_LONG"
+#endif
+
+#define __test_and_op_bit_ord(op, mod, nr, addr, ord) \
+({ \
+ unsigned long __res, __mask; \
+ __mask = BIT_MASK(nr); \
+ __asm__ __volatile__ ( \
+ __AMO(op) #ord " %0, %2, %1" \
+ : "=r" (__res), "+A" (addr[BIT_WORD(nr)]) \
+ : "r" (mod(__mask)) \
+ : "memory"); \
+ ((__res & __mask) != 0); \
+})
+
+#define __op_bit_ord(op, mod, nr, addr, ord) \
+ __asm__ __volatile__ ( \
+ __AMO(op) #ord " zero, %1, %0" \
+ : "+A" (addr[BIT_WORD(nr)]) \
+ : "r" (mod(BIT_MASK(nr))) \
+ : "memory");
+
+#define __test_and_op_bit(op, mod, nr, addr) \
+ __test_and_op_bit_ord(op, mod, nr, addr, .aqrl)
+#define __op_bit(op, mod, nr, addr) \
+ __op_bit_ord(op, mod, nr, addr, )
+
+/* Bitmask modifiers */
+#define __NOP(x) (x)
+#define __NOT(x) (~(x))
+
+/**
+ * test_and_set_bit - Set a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation may be reordered on other architectures than x86.
+ */
+static inline int test_and_set_bit(int nr, volatile unsigned long *addr)
+{
+ return __test_and_op_bit(or, __NOP, nr, addr);
+}
+
+/**
+ * test_and_clear_bit - Clear a bit and return its old value
+ * @nr: Bit to clear
+ * @addr: Address to count from
+ *
+ * This operation can be reordered on other architectures other than x86.
+ */
+static inline int test_and_clear_bit(int nr, volatile unsigned long *addr)
+{
+ return __test_and_op_bit(and, __NOT, nr, addr);
+}
+
+/**
+ * test_and_change_bit - Change a bit and return its old value
+ * @nr: Bit to change
+ * @addr: Address to count from
+ *
+ * This operation is atomic and cannot be reordered.
+ * It also implies a memory barrier.
+ */
+static inline int test_and_change_bit(int nr, volatile unsigned long *addr)
+{
+ return __test_and_op_bit(xor, __NOP, nr, addr);
+}
+
+/**
+ * set_bit - Atomically set a bit in memory
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * Note: there are no guarantees that this function will not be reordered
+ * on non x86 architectures, so if you are writing portable code,
+ * make sure not to rely on its reordering guarantees.
+ *
+ * Note that @nr may be almost arbitrarily large; this function is not
+ * restricted to acting on a single-word quantity.
+ */
+static inline void set_bit(int nr, volatile unsigned long *addr)
+{
+ __op_bit(or, __NOP, nr, addr);
+}
+
+/**
+ * clear_bit - Clears a bit in memory
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ *
+ * Note: there are no guarantees that this function will not be reordered
+ * on non x86 architectures, so if you are writing portable code,
+ * make sure not to rely on its reordering guarantees.
+ */
+static inline void clear_bit(int nr, volatile unsigned long *addr)
+{
+ __op_bit(and, __NOT, nr, addr);
+}
+
+/**
+ * change_bit - Toggle a bit in memory
+ * @nr: Bit to change
+ * @addr: Address to start counting from
+ *
+ * change_bit() may be reordered on other architectures than x86.
+ * Note that @nr may be almost arbitrarily large; this function is not
+ * restricted to acting on a single-word quantity.
+ */
+static inline void change_bit(int nr, volatile unsigned long *addr)
+{
+ __op_bit(xor, __NOP, nr, addr);
+}
+
+/**
+ * test_and_set_bit_lock - Set a bit and return its old value, for lock
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is atomic and provides acquire barrier semantics.
+ * It can be used to implement bit locks.
+ */
+static inline int test_and_set_bit_lock(
+ unsigned long nr, volatile unsigned long *addr)
+{
+ return __test_and_op_bit_ord(or, __NOP, nr, addr, .aq);
+}
+
+/**
+ * clear_bit_unlock - Clear a bit in memory, for unlock
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * This operation is atomic and provides release barrier semantics.
+ */
+static inline void clear_bit_unlock(
+ unsigned long nr, volatile unsigned long *addr)
+{
+ __op_bit_ord(and, __NOT, nr, addr, .rl);
+}
+
+/**
+ * __clear_bit_unlock - Clear a bit in memory, for unlock
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * This operation is like clear_bit_unlock, however it is not atomic.
+ * It does provide release barrier semantics so it can be used to unlock
+ * a bit lock, however it would only be used if no other CPU can modify
+ * any bits in the memory until the lock is released (a good example is
+ * if the bit lock itself protects access to the other bits in the word).
+ *
+ * On RISC-V systems there seems to be no benefit to taking advantage of the
+ * non-atomic property here: it's a lot more instructions and we still have to
+ * provide release semantics anyway.
+ */
+static inline void __clear_bit_unlock(
+ unsigned long nr, volatile unsigned long *addr)
+{
+ clear_bit_unlock(nr, addr);
+}
+
+#undef __test_and_op_bit
+#undef __op_bit
+#undef __NOP
+#undef __NOT
+#undef __AMO
+
+#include <asm-generic/bitops/non-atomic.h>
+#include <asm-generic/bitops/le.h>
+#include <asm-generic/bitops/ext2-atomic.h>
+
+#endif /* _ASM_RISCV_BITOPS_H */