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| /* SPDX-License-Identifier: GPL-2.0 */
| #ifndef _ASM_POWERPC_FUTEX_H
| #define _ASM_POWERPC_FUTEX_H
|
| #ifdef __KERNEL__
|
| #include <linux/futex.h>
| #include <linux/uaccess.h>
| #include <asm/errno.h>
| #include <asm/synch.h>
|
| #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
| __asm__ __volatile ( \
| PPC_ATOMIC_ENTRY_BARRIER \
| "1: lwarx %0,0,%2\n" \
| insn \
| "2: stwcx. %1,0,%2\n" \
| "bne- 1b\n" \
| PPC_ATOMIC_EXIT_BARRIER \
| "li %1,0\n" \
| "3: .section .fixup,\"ax\"\n" \
| "4: li %1,%3\n" \
| "b 3b\n" \
| ".previous\n" \
| EX_TABLE(1b, 4b) \
| EX_TABLE(2b, 4b) \
| : "=&r" (oldval), "=&r" (ret) \
| : "b" (uaddr), "i" (-EFAULT), "r" (oparg) \
| : "cr0", "memory")
|
| static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
| u32 __user *uaddr)
| {
| int oldval = 0, ret;
|
| if (!access_ok(uaddr, sizeof(u32)))
| return -EFAULT;
| allow_read_write_user(uaddr, uaddr, sizeof(*uaddr));
|
| switch (op) {
| case FUTEX_OP_SET:
| __futex_atomic_op("mr %1,%4\n", ret, oldval, uaddr, oparg);
| break;
| case FUTEX_OP_ADD:
| __futex_atomic_op("add %1,%0,%4\n", ret, oldval, uaddr, oparg);
| break;
| case FUTEX_OP_OR:
| __futex_atomic_op("or %1,%0,%4\n", ret, oldval, uaddr, oparg);
| break;
| case FUTEX_OP_ANDN:
| __futex_atomic_op("andc %1,%0,%4\n", ret, oldval, uaddr, oparg);
| break;
| case FUTEX_OP_XOR:
| __futex_atomic_op("xor %1,%0,%4\n", ret, oldval, uaddr, oparg);
| break;
| default:
| ret = -ENOSYS;
| }
|
| *oval = oldval;
|
| prevent_read_write_user(uaddr, uaddr, sizeof(*uaddr));
| return ret;
| }
|
| static inline int
| futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
| u32 oldval, u32 newval)
| {
| int ret = 0;
| u32 prev;
|
| if (!access_ok(uaddr, sizeof(u32)))
| return -EFAULT;
|
| allow_read_write_user(uaddr, uaddr, sizeof(*uaddr));
|
| __asm__ __volatile__ (
| PPC_ATOMIC_ENTRY_BARRIER
| "1: lwarx %1,0,%3 # futex_atomic_cmpxchg_inatomic\n\
| cmpw 0,%1,%4\n\
| bne- 3f\n"
| "2: stwcx. %5,0,%3\n\
| bne- 1b\n"
| PPC_ATOMIC_EXIT_BARRIER
| "3: .section .fixup,\"ax\"\n\
| 4: li %0,%6\n\
| b 3b\n\
| .previous\n"
| EX_TABLE(1b, 4b)
| EX_TABLE(2b, 4b)
| : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
| : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)
| : "cc", "memory");
|
| *uval = prev;
| prevent_read_write_user(uaddr, uaddr, sizeof(*uaddr));
|
| return ret;
| }
|
| #endif /* __KERNEL__ */
| #endif /* _ASM_POWERPC_FUTEX_H */
|
|
