include/asm/futex.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _ASM_S390_FUTEX_H
0003 #define _ASM_S390_FUTEX_H
0004
0005 #include <linux/uaccess.h>
0006 #include <linux/futex.h>
0007 #include <asm/asm-extable.h>
0008 #include <asm/mmu_context.h>
0009 #include <asm/errno.h>
0010
0011 #define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg)  \
0012     asm volatile(                           \
0013         "   sacf  256\n"                    \
0014         "0: l     %1,0(%6)\n"                   \
0015         "1:"insn                        \
0016         "2: cs    %1,%2,0(%6)\n"                \
0017         "3: jl    1b\n"                     \
0018         "   lhi   %0,0\n"                   \
0019         "4: sacf  768\n"                    \
0020         EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b)     \
0021         : "=d" (ret), "=&d" (oldval), "=&d" (newval),       \
0022           "=m" (*uaddr)                     \
0023         : "0" (-EFAULT), "d" (oparg), "a" (uaddr),      \
0024           "m" (*uaddr) : "cc");
0025
0026 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
0027         u32 __user *uaddr)
0028 {
0029     int oldval = 0, newval, ret;
0030
0031     switch (op) {
0032     case FUTEX_OP_SET:
0033         __futex_atomic_op("lr %2,%5\n",
0034                   ret, oldval, newval, uaddr, oparg);
0035         break;
0036     case FUTEX_OP_ADD:
0037         __futex_atomic_op("lr %2,%1\nar %2,%5\n",
0038                   ret, oldval, newval, uaddr, oparg);
0039         break;
0040     case FUTEX_OP_OR:
0041         __futex_atomic_op("lr %2,%1\nor %2,%5\n",
0042                   ret, oldval, newval, uaddr, oparg);
0043         break;
0044     case FUTEX_OP_ANDN:
0045         __futex_atomic_op("lr %2,%1\nnr %2,%5\n",
0046                   ret, oldval, newval, uaddr, oparg);
0047         break;
0048     case FUTEX_OP_XOR:
0049         __futex_atomic_op("lr %2,%1\nxr %2,%5\n",
0050                   ret, oldval, newval, uaddr, oparg);
0051         break;
0052     default:
0053         ret = -ENOSYS;
0054     }
0055
0056     if (!ret)
0057         *oval = oldval;
0058
0059     return ret;
0060 }
0061
0062 static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
0063                         u32 oldval, u32 newval)
0064 {
0065     int ret;
0066
0067     asm volatile(
0068         "   sacf 256\n"
0069         "0: cs   %1,%4,0(%5)\n"
0070         "1: la   %0,0\n"
0071         "2: sacf 768\n"
0072         EX_TABLE(0b,2b) EX_TABLE(1b,2b)
0073         : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
0074         : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
0075         : "cc", "memory");
0076     *uval = oldval;
0077     return ret;
0078 }
0079
0080 #endif /* _ASM_S390_FUTEX_H */