new file mode 100644
@@ -0,0 +1,137 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2012 Regents of the University of California */
+
+#ifndef _ASM_RISCV_BITOPS_H
+#define _ASM_RISCV_BITOPS_H
+
+#include <asm/system.h>
+
+#if BITOP_BITS_PER_WORD == 64
+#define __AMO(op) "amo" #op ".d"
+#elif BITOP_BITS_PER_WORD == 32
+#define __AMO(op) "amo" #op ".w"
+#else
+#error "Unexpected BITS_PER_LONG"
+#endif
+
+/* Based on linux/arch/include/asm/bitops.h */
+
+/*
+ * Non-atomic bit manipulation.
+ *
+ * Implemented using atomics to be interrupt safe. Could alternatively
+ * implement with local interrupt masking.
+ */
+#define __set_bit(n, p) set_bit(n, p)
+#define __clear_bit(n, p) clear_bit(n, p)
+
+#define test_and_op_bit_ord(op, mod, nr, addr, ord) \
+({ \
+ bitop_uint_t res, mask; \
+ mask = BITOP_MASK(nr); \
+ asm volatile ( \
+ __AMO(op) #ord " %0, %2, %1" \
+ : "=r" (res), "+A" (addr[BITOP_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[BITOP_WORD(nr)]) \
+ : "r" (mod(BITOP_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
+ */
+static inline bool test_and_set_bit(int nr, volatile void *p)
+{
+ volatile bitop_uint_t *addr = p;
+
+ 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
+ */
+static inline bool test_and_clear_bit(int nr, volatile void *p)
+{
+ volatile bitop_uint_t *addr = p;
+
+ return test_and_op_bit(and, NOT, nr, addr);
+}
+
+/**
+ * test_and_change_bit - Toggle (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 bool test_and_change_bit(int nr, volatile void *p)
+{
+ volatile bitop_uint_t *addr = p;
+
+ 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 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 void *p)
+{
+ volatile bitop_uint_t *addr = p;
+
+ op_bit(or, NOP, nr, addr);
+}
+
+/**
+ * clear_bit - Clears a bit in memory
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ */
+static inline void clear_bit(int nr, volatile void *p)
+{
+ volatile bitop_uint_t *addr = p;
+
+ op_bit(and, NOT, nr, addr);
+}
+
+#undef test_and_op_bit
+#undef op_bit
+#undef NOP
+#undef NOT
+#undef __AMO
+
+#endif /* _ASM_RISCV_BITOPS_H */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
Taken from Linux-6.4.0-rc1 Xen's bitops.h consists of several Linux's headers: * linux/arch/include/asm/bitops.h: * The following function were removed as they aren't used in Xen: * test_and_set_bit_lock * clear_bit_unlock * __clear_bit_unlock * The following functions were renamed in the way how they are used by common code: * __test_and_set_bit * __test_and_clear_bit * The declaration and implementation of the following functios were updated to make Xen build happy: * clear_bit * set_bit * __test_and_clear_bit * __test_and_set_bit Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com> Acked-by: Jan Beulich <jbeulich@suse.com> --- Changes in V9: - add Acked-by: Jan Beulich <jbeulich@suse.com> - drop redefinition of bitop_uint_t in asm/types.h as some operation in Xen common code expects to work with 32-bit quantities. - s/BITS_PER_LONG/BITOP_BITS_PER_WORD in asm/bitops.h around __AMO() macros. --- Changes in V8: - define bitop_uint_t in <asm/types.h> after the changes in patch related to introduction of "introduce generic non-atomic test_*bit()". - drop duplicated __set_bit() and __clear_bit(). - drop duplicated comment: /* Based on linux/arch/include/asm/bitops.h */. - update type of res and mask in test_and_op_bit_ord(): unsigned long -> bitop_uint_t. - drop 1 padding blank in test_and_op_bit_ord(). - update definition of test_and_set_bit(),test_and_clear_bit(),test_and_change_bit: change return type to bool. - change addr argument type of test_and_change_bit(): unsigned long * -> void *. - move test_and_change_bit() closer to other test_and-s function. - Code style fixes: tabs -> space. - s/#undef __op_bit/#undef op_bit. - update the commit message: delete information about generic-non-atomic.h changes as now it is a separate patch. --- Changes in V7: - Update the commit message. - Drop "__" for __op_bit and __op_bit_ord as they are atomic. - add comment above __set_bit and __clear_bit about why they are defined as atomic. - align bitops_uint_t with __AMO(). - make changes after generic non-atomic test_*bit() were changed. - s/__asm__ __volatile__/asm volatile --- Changes in V6: - rebase clean ups were done: drop unused asm-generic includes --- Changes in V5: - new patch --- xen/arch/riscv/include/asm/bitops.h | 137 ++++++++++++++++++++++++++++ 1 file changed, 137 insertions(+) create mode 100644 xen/arch/riscv/include/asm/bitops.h