diff options
| author | Ivan Kokshaysky <ink@jurassic.park.msu.ru> | 2009-04-30 18:08:48 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-05-02 18:36:10 -0400 |
| commit | 77b4cf5cb0c9d6010a18030a0e0a8d2aaf6b43ec (patch) | |
| tree | b9b0b9f25e4495499ae5a35f1beaca7a5b240201 /arch/alpha/include/asm/futex.h | |
| parent | 08a42e86bce511b45ca3eee40f51674b02a777d1 (diff) | |
alpha: futex implementation
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Richard Henderson <rth@twiddle.net
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/alpha/include/asm/futex.h')
| -rw-r--r-- | arch/alpha/include/asm/futex.h | 118 |
1 files changed, 114 insertions, 4 deletions
diff --git a/arch/alpha/include/asm/futex.h b/arch/alpha/include/asm/futex.h index 6a332a9f099c..945de222ab91 100644 --- a/arch/alpha/include/asm/futex.h +++ b/arch/alpha/include/asm/futex.h | |||
| @@ -1,6 +1,116 @@ | |||
| 1 | #ifndef _ASM_FUTEX_H | 1 | #ifndef _ASM_ALPHA_FUTEX_H |
| 2 | #define _ASM_FUTEX_H | 2 | #define _ASM_ALPHA_FUTEX_H |
| 3 | 3 | ||
| 4 | #include <asm-generic/futex.h> | 4 | #ifdef __KERNEL__ |
| 5 | 5 | ||
| 6 | #endif | 6 | #include <linux/futex.h> |
| 7 | #include <linux/uaccess.h> | ||
| 8 | #include <asm/errno.h> | ||
| 9 | #include <asm/barrier.h> | ||
| 10 | |||
| 11 | #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ | ||
| 12 | __asm__ __volatile__( \ | ||
| 13 | __ASM_SMP_MB \ | ||
| 14 | "1: ldl_l %0,0(%2)\n" \ | ||
| 15 | insn \ | ||
| 16 | "2: stl_c %1,0(%2)\n" \ | ||
| 17 | " beq %1,4f\n" \ | ||
| 18 | " mov $31,%1\n" \ | ||
| 19 | "3: .subsection 2\n" \ | ||
| 20 | "4: br 1b\n" \ | ||
| 21 | " .previous\n" \ | ||
| 22 | " .section __ex_table,\"a\"\n" \ | ||
| 23 | " .long 1b-.\n" \ | ||
| 24 | " lda $31,3b-1b(%1)\n" \ | ||
| 25 | " .long 2b-.\n" \ | ||
| 26 | " lda $31,3b-2b(%1)\n" \ | ||
| 27 | " .previous\n" \ | ||
| 28 | : "=&r" (oldval), "=&r"(ret) \ | ||
| 29 | : "r" (uaddr), "r"(oparg) \ | ||
| 30 | : "memory") | ||
| 31 | |||
| 32 | static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) | ||
| 33 | { | ||
| 34 | int op = (encoded_op >> 28) & 7; | ||
| 35 | int cmp = (encoded_op >> 24) & 15; | ||
| 36 | int oparg = (encoded_op << 8) >> 20; | ||
| 37 | int cmparg = (encoded_op << 20) >> 20; | ||
| 38 | int oldval = 0, ret; | ||
| 39 | if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) | ||
| 40 | oparg = 1 << oparg; | ||
| 41 | |||
| 42 | if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) | ||
| 43 | return -EFAULT; | ||
| 44 | |||
| 45 | pagefault_disable(); | ||
| 46 | |||
| 47 | switch (op) { | ||
| 48 | case FUTEX_OP_SET: | ||
| 49 | __futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg); | ||
| 50 | break; | ||
| 51 | case FUTEX_OP_ADD: | ||
| 52 | __futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg); | ||
| 53 | break; | ||
| 54 | case FUTEX_OP_OR: | ||
| 55 | __futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg); | ||
| 56 | break; | ||
| 57 | case FUTEX_OP_ANDN: | ||
| 58 | __futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg); | ||
| 59 | break; | ||
| 60 | case FUTEX_OP_XOR: | ||
| 61 | __futex_atomic_op("xor %0,%3,%1\n", ret, oldval, uaddr, oparg); | ||
| 62 | break; | ||
| 63 | default: | ||
| 64 | ret = -ENOSYS; | ||
| 65 | } | ||
| 66 | |||
| 67 | pagefault_enable(); | ||
| 68 | |||
| 69 | if (!ret) { | ||
| 70 | switch (cmp) { | ||
| 71 | case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break; | ||
| 72 | case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break; | ||
| 73 | case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break; | ||
| 74 | case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break; | ||
| 75 | case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break; | ||
| 76 | case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break; | ||
| 77 | default: ret = -ENOSYS; | ||
| 78 | } | ||
| 79 | } | ||
| 80 | return ret; | ||
| 81 | } | ||
| 82 | |||
| 83 | static inline int | ||
| 84 | futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) | ||
| 85 | { | ||
| 86 | int prev, cmp; | ||
| 87 | |||
| 88 | if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) | ||
| 89 | return -EFAULT; | ||
| 90 | |||
| 91 | __asm__ __volatile__ ( | ||
| 92 | __ASM_SMP_MB | ||
| 93 | "1: ldl_l %0,0(%2)\n" | ||
| 94 | " cmpeq %0,%3,%1\n" | ||
| 95 | " beq %1,3f\n" | ||
| 96 | " mov %4,%1\n" | ||
| 97 | "2: stl_c %1,0(%2)\n" | ||
| 98 | " beq %1,4f\n" | ||
| 99 | "3: .subsection 2\n" | ||
| 100 | "4: br 1b\n" | ||
| 101 | " .previous\n" | ||
| 102 | " .section __ex_table,\"a\"\n" | ||
| 103 | " .long 1b-.\n" | ||
| 104 | " lda $31,3b-1b(%0)\n" | ||
| 105 | " .long 2b-.\n" | ||
| 106 | " lda $31,3b-2b(%0)\n" | ||
| 107 | " .previous\n" | ||
| 108 | : "=&r"(prev), "=&r"(cmp) | ||
| 109 | : "r"(uaddr), "r"((long)oldval), "r"(newval) | ||
| 110 | : "memory"); | ||
| 111 | |||
| 112 | return prev; | ||
| 113 | } | ||
| 114 | |||
| 115 | #endif /* __KERNEL__ */ | ||
| 116 | #endif /* _ASM_ALPHA_FUTEX_H */ | ||