1 files changed, 84 insertions, 0 deletions

diff --git a/include/asm-powerpc/futex.h b/include/asm-powerpc/futex.h
new file mode 100644
index 000000000000..37c94e52ab6d
--- /dev/null
+++ b/include/asm-powerpc/futex.h
@@ -0,0 +1,84 @@
+#ifndef _ASM_POWERPC_FUTEX_H
+#define _ASM_POWERPC_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <asm/errno.h>
+#include <asm/synch.h>
+#include <asm/uaccess.h>
+#include <asm/ppc_asm.h>
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+  __asm__ __volatile ( \
+        SYNC_ON_SMP \
+"1:     lwarx   %0,0,%2\n" \
+        insn \
+"2:     stwcx.  %1,0,%2\n" \
+        "bne-   1b\n" \
+        "li     %1,0\n" \
+"3:     .section .fixup,\"ax\"\n" \
+"4:     li      %1,%3\n" \
+        "b      3b\n" \
+        ".previous\n" \
+        ".section __ex_table,\"a\"\n" \
+        ".align 3\n" \
+        DATAL " 1b,4b,2b,4b\n" \
+        ".previous" \
+        : "=&r" (oldval), "=&r" (ret) \
+        : "b" (uaddr), "i" (-EFAULT), "1" (oparg) \
+        : "cr0", "memory")
+
+static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
+{
+        int op = (encoded_op >> 28) & 7;
+        int cmp = (encoded_op >> 24) & 15;
+        int oparg = (encoded_op << 8) >> 20;
+        int cmparg = (encoded_op << 20) >> 20;
+        int oldval = 0, ret;
+        if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
+                oparg = 1 << oparg;
+
+        if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
+                return -EFAULT;
+
+        inc_preempt_count();
+
+        switch (op) {
+        case FUTEX_OP_SET:
+                __futex_atomic_op("", ret, oldval, uaddr, oparg);
+                break;
+        case FUTEX_OP_ADD:
+                __futex_atomic_op("add %1,%0,%1\n", ret, oldval, uaddr, oparg);
+                break;
+        case FUTEX_OP_OR:
+                __futex_atomic_op("or %1,%0,%1\n", ret, oldval, uaddr, oparg);
+                break;
+        case FUTEX_OP_ANDN:
+                __futex_atomic_op("andc %1,%0,%1\n", ret, oldval, uaddr, oparg);
+                break;
+        case FUTEX_OP_XOR:
+                __futex_atomic_op("xor %1,%0,%1\n", ret, oldval, uaddr, oparg);
+                break;
+        default:
+                ret = -ENOSYS;
+        }
+
+        dec_preempt_count();
+
+        if (!ret) {
+                switch (cmp) {
+                case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
+                case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
+                case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
+                case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
+                case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
+                case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
+                default: ret = -ENOSYS;
+                }
+        }
+        return ret;
+}
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_POWERPC_FUTEX_H */