| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef _ASM_ALPHA_FUTEX_H |
| 3 | #define _ASM_ALPHA_FUTEX_H |
| 4 | |
| 5 | #ifdef __KERNEL__ |
| 6 | |
| 7 | #include <linux/futex.h> |
| 8 | #include <linux/uaccess.h> |
| 9 | #include <asm/errno.h> |
| 10 | #include <asm/barrier.h> |
| 11 | |
| 12 | #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ |
| 13 | __asm__ __volatile__( \ |
| 14 | __ASM_SMP_MB \ |
| 15 | "1: ldl_l %0,0(%2)\n" \ |
| 16 | insn \ |
| 17 | "2: stl_c %1,0(%2)\n" \ |
| 18 | " beq %1,4f\n" \ |
| 19 | " mov $31,%1\n" \ |
| 20 | "3: .subsection 2\n" \ |
| 21 | "4: br 1b\n" \ |
| 22 | " .previous\n" \ |
| 23 | EXC(1b,3b,$31,%1) \ |
| 24 | EXC(2b,3b,$31,%1) \ |
| 25 | : "=&r" (oldval), "=&r"(ret) \ |
| 26 | : "r" (uaddr), "r"(oparg) \ |
| 27 | : "memory") |
| 28 | |
| 29 | static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, |
| 30 | u32 __user *uaddr) |
| 31 | { |
| 32 | int oldval = 0, ret; |
| 33 | |
| 34 | pagefault_disable(); |
| 35 | |
| 36 | switch (op) { |
| 37 | case FUTEX_OP_SET: |
| 38 | __futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg); |
| 39 | break; |
| 40 | case FUTEX_OP_ADD: |
| 41 | __futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg); |
| 42 | break; |
| 43 | case FUTEX_OP_OR: |
| 44 | __futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg); |
| 45 | break; |
| 46 | case FUTEX_OP_ANDN: |
| 47 | __futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg); |
| 48 | break; |
| 49 | case FUTEX_OP_XOR: |
| 50 | __futex_atomic_op("xor %0,%3,%1\n", ret, oldval, uaddr, oparg); |
| 51 | break; |
| 52 | default: |
| 53 | ret = -ENOSYS; |
| 54 | } |
| 55 | |
| 56 | pagefault_enable(); |
| 57 | |
| 58 | if (!ret) |
| 59 | *oval = oldval; |
| 60 | |
| 61 | return ret; |
| 62 | } |
| 63 | |
| 64 | static inline int |
| 65 | futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, |
| 66 | u32 oldval, u32 newval) |
| 67 | { |
| 68 | int ret = 0, cmp; |
| 69 | u32 prev; |
| 70 | |
| 71 | if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) |
| 72 | return -EFAULT; |
| 73 | |
| 74 | __asm__ __volatile__ ( |
| 75 | __ASM_SMP_MB |
| 76 | "1: ldl_l %1,0(%3)\n" |
| 77 | " cmpeq %1,%4,%2\n" |
| 78 | " beq %2,3f\n" |
| 79 | " mov %5,%2\n" |
| 80 | "2: stl_c %2,0(%3)\n" |
| 81 | " beq %2,4f\n" |
| 82 | "3: .subsection 2\n" |
| 83 | "4: br 1b\n" |
| 84 | " .previous\n" |
| 85 | EXC(1b,3b,$31,%0) |
| 86 | EXC(2b,3b,$31,%0) |
| 87 | : "+r"(ret), "=&r"(prev), "=&r"(cmp) |
| 88 | : "r"(uaddr), "r"((long)(int)oldval), "r"(newval) |
| 89 | : "memory"); |
| 90 | |
| 91 | *uval = prev; |
| 92 | return ret; |
| 93 | } |
| 94 | |
| 95 | #endif /* __KERNEL__ */ |
| 96 | #endif /* _ASM_ALPHA_FUTEX_H */ |