| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef _ASM_MICROBLAZE_FUTEX_H |
| 3 | #define _ASM_MICROBLAZE_FUTEX_H |
| 4 | |
| 5 | #ifdef __KERNEL__ |
| 6 | |
| 7 | #include <linux/futex.h> |
| 8 | #include <linux/uaccess.h> |
| 9 | #include <asm/errno.h> |
| 10 | |
| 11 | #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ |
| 12 | ({ \ |
| 13 | __asm__ __volatile__ ( \ |
| 14 | "1: lwx %0, %2, r0; " \ |
| 15 | insn \ |
| 16 | "2: swx %1, %2, r0; \ |
| 17 | addic %1, r0, 0; \ |
| 18 | bnei %1, 1b; \ |
| 19 | 3: \ |
| 20 | .section .fixup,\"ax\"; \ |
| 21 | 4: brid 3b; \ |
| 22 | addik %1, r0, %3; \ |
| 23 | .previous; \ |
| 24 | .section __ex_table,\"a\"; \ |
| 25 | .word 1b,4b,2b,4b; \ |
| 26 | .previous;" \ |
| 27 | : "=&r" (oldval), "=&r" (ret) \ |
| 28 | : "r" (uaddr), "i" (-EFAULT), "r" (oparg) \ |
| 29 | ); \ |
| 30 | }) |
| 31 | |
| 32 | static inline int |
| 33 | arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr) |
| 34 | { |
| 35 | int oldval = 0, ret; |
| 36 | |
| 37 | pagefault_disable(); |
| 38 | |
| 39 | switch (op) { |
| 40 | case FUTEX_OP_SET: |
| 41 | __futex_atomic_op("or %1,%4,%4;", ret, oldval, uaddr, oparg); |
| 42 | break; |
| 43 | case FUTEX_OP_ADD: |
| 44 | __futex_atomic_op("add %1,%0,%4;", ret, oldval, uaddr, oparg); |
| 45 | break; |
| 46 | case FUTEX_OP_OR: |
| 47 | __futex_atomic_op("or %1,%0,%4;", ret, oldval, uaddr, oparg); |
| 48 | break; |
| 49 | case FUTEX_OP_ANDN: |
| 50 | __futex_atomic_op("andn %1,%0,%4;", ret, oldval, uaddr, oparg); |
| 51 | break; |
| 52 | case FUTEX_OP_XOR: |
| 53 | __futex_atomic_op("xor %1,%0,%4;", ret, oldval, uaddr, oparg); |
| 54 | break; |
| 55 | default: |
| 56 | ret = -ENOSYS; |
| 57 | } |
| 58 | |
| 59 | pagefault_enable(); |
| 60 | |
| 61 | if (!ret) |
| 62 | *oval = oldval; |
| 63 | |
| 64 | return ret; |
| 65 | } |
| 66 | |
| 67 | static inline int |
| 68 | futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, |
| 69 | u32 oldval, u32 newval) |
| 70 | { |
| 71 | int ret = 0, cmp; |
| 72 | u32 prev; |
| 73 | |
| David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 74 | if (!access_ok(uaddr, sizeof(u32))) |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 75 | return -EFAULT; |
| 76 | |
| 77 | __asm__ __volatile__ ("1: lwx %1, %3, r0; \ |
| 78 | cmp %2, %1, %4; \ |
| 79 | bnei %2, 3f; \ |
| 80 | 2: swx %5, %3, r0; \ |
| 81 | addic %2, r0, 0; \ |
| 82 | bnei %2, 1b; \ |
| 83 | 3: \ |
| 84 | .section .fixup,\"ax\"; \ |
| 85 | 4: brid 3b; \ |
| 86 | addik %0, r0, %6; \ |
| 87 | .previous; \ |
| 88 | .section __ex_table,\"a\"; \ |
| 89 | .word 1b,4b,2b,4b; \ |
| 90 | .previous;" \ |
| 91 | : "+r" (ret), "=&r" (prev), "=&r"(cmp) \ |
| 92 | : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)); |
| 93 | |
| 94 | *uval = prev; |
| 95 | return ret; |
| 96 | } |
| 97 | |
| 98 | #endif /* __KERNEL__ */ |
| 99 | |
| 100 | #endif |