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-rw-r--r--arch/tile/include/asm/futex.h141
1 files changed, 141 insertions, 0 deletions
diff --git a/arch/tile/include/asm/futex.h b/arch/tile/include/asm/futex.h
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+++ b/arch/tile/include/asm/futex.h
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+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ *
+ * These routines make two important assumptions:
+ *
+ * 1. atomic_t is really an int and can be freely cast back and forth
+ * (validated in __init_atomic_per_cpu).
+ *
+ * 2. userspace uses sys_cmpxchg() for all atomic operations, thus using
+ * the same locking convention that all the kernel atomic routines use.
+ */
+
+#ifndef _ASM_TILE_FUTEX_H
+#define _ASM_TILE_FUTEX_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <linux/errno.h>
+
+extern struct __get_user futex_set(int __user *v, int i);
+extern struct __get_user futex_add(int __user *v, int n);
+extern struct __get_user futex_or(int __user *v, int n);
+extern struct __get_user futex_andn(int __user *v, int n);
+extern struct __get_user futex_cmpxchg(int __user *v, int o, int n);
+
+#ifndef __tilegx__
+extern struct __get_user futex_xor(int __user *v, int n);
+#else
+static inline struct __get_user futex_xor(int __user *uaddr, int n)
+{
+ struct __get_user asm_ret = __get_user_4(uaddr);
+ if (!asm_ret.err) {
+ int oldval, newval;
+ do {
+ oldval = asm_ret.val;
+ newval = oldval ^ n;
+ asm_ret = futex_cmpxchg(uaddr, oldval, newval);
+ } while (asm_ret.err == 0 && oldval != asm_ret.val);
+ }
+ return asm_ret;
+}
+#endif
+
+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 ret;
+ struct __get_user asm_ret;
+
+ if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
+ oparg = 1 << oparg;
+
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+ return -EFAULT;
+
+ pagefault_disable();
+ switch (op) {
+ case FUTEX_OP_SET:
+ asm_ret = futex_set(uaddr, oparg);
+ break;
+ case FUTEX_OP_ADD:
+ asm_ret = futex_add(uaddr, oparg);
+ break;
+ case FUTEX_OP_OR:
+ asm_ret = futex_or(uaddr, oparg);
+ break;
+ case FUTEX_OP_ANDN:
+ asm_ret = futex_andn(uaddr, oparg);
+ break;
+ case FUTEX_OP_XOR:
+ asm_ret = futex_xor(uaddr, oparg);
+ break;
+ default:
+ asm_ret.err = -ENOSYS;
+ }
+ pagefault_enable();
+
+ ret = asm_ret.err;
+
+ if (!ret) {
+ switch (cmp) {
+ case FUTEX_OP_CMP_EQ:
+ ret = (asm_ret.val == cmparg);
+ break;
+ case FUTEX_OP_CMP_NE:
+ ret = (asm_ret.val != cmparg);
+ break;
+ case FUTEX_OP_CMP_LT:
+ ret = (asm_ret.val < cmparg);
+ break;
+ case FUTEX_OP_CMP_GE:
+ ret = (asm_ret.val >= cmparg);
+ break;
+ case FUTEX_OP_CMP_LE:
+ ret = (asm_ret.val <= cmparg);
+ break;
+ case FUTEX_OP_CMP_GT:
+ ret = (asm_ret.val > cmparg);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+ }
+ return ret;
+}
+
+static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval,
+ int newval)
+{
+ struct __get_user asm_ret;
+
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+ return -EFAULT;
+
+ asm_ret = futex_cmpxchg(uaddr, oldval, newval);
+ return asm_ret.err ? asm_ret.err : asm_ret.val;
+}
+
+#ifndef __tilegx__
+/* Return failure from the atomic wrappers. */
+struct __get_user __atomic_bad_address(int __user *addr);
+#endif
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_TILE_FUTEX_H */