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-rw-r--r--arch/hexagon/include/asm/futex.h107
1 files changed, 107 insertions, 0 deletions
diff --git a/arch/hexagon/include/asm/futex.h b/arch/hexagon/include/asm/futex.h
new file mode 100644
index 0000000000..9fb00a0ae8
--- /dev/null
+++ b/arch/hexagon/include/asm/futex.h
@@ -0,0 +1,107 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_HEXAGON_FUTEX_H
+#define _ASM_HEXAGON_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <asm/errno.h>
+
+/* XXX TODO-- need to add sync barriers! */
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+ __asm__ __volatile( \
+ "1: %0 = memw_locked(%3);\n" \
+ /* For example: %1 = %4 */ \
+ insn \
+ "2: memw_locked(%3,p2) = %1;\n" \
+ " if (!p2) jump 1b;\n" \
+ " %1 = #0;\n" \
+ "3:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "4: %1 = #%5;\n" \
+ " jump ##3b\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ ".long 1b,4b,2b,4b\n" \
+ ".previous\n" \
+ : "=&r" (oldval), "=&r" (ret), "+m" (*uaddr) \
+ : "r" (uaddr), "r" (oparg), "i" (-EFAULT) \
+ : "p2", "memory")
+
+
+static inline int
+arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
+{
+ int oldval = 0, ret;
+
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ switch (op) {
+ case FUTEX_OP_SET:
+ __futex_atomic_op("%1 = %4\n", ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ADD:
+ __futex_atomic_op("%1 = add(%0,%4)\n", ret, oldval, uaddr,
+ oparg);
+ break;
+ case FUTEX_OP_OR:
+ __futex_atomic_op("%1 = or(%0,%4)\n", ret, oldval, uaddr,
+ oparg);
+ break;
+ case FUTEX_OP_ANDN:
+ __futex_atomic_op("%1 = not(%4); %1 = and(%0,%1)\n", ret,
+ oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_XOR:
+ __futex_atomic_op("%1 = xor(%0,%4)\n", ret, oldval, uaddr,
+ oparg);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+
+ if (!ret)
+ *oval = oldval;
+
+ return ret;
+}
+
+static inline int
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval,
+ u32 newval)
+{
+ int prev;
+ int ret;
+
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ __asm__ __volatile__ (
+ "1: %1 = memw_locked(%3)\n"
+ " {\n"
+ " p2 = cmp.eq(%1,%4)\n"
+ " if (!p2.new) jump:NT 3f\n"
+ " }\n"
+ "2: memw_locked(%3,p2) = %5\n"
+ " if (!p2) jump 1b\n"
+ "3:\n"
+ ".section .fixup,\"ax\"\n"
+ "4: %0 = #%6\n"
+ " jump ##3b\n"
+ ".previous\n"
+ ".section __ex_table,\"a\"\n"
+ ".long 1b,4b,2b,4b\n"
+ ".previous\n"
+ : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
+ : "r" (uaddr), "r" (oldval), "r" (newval), "i"(-EFAULT)
+ : "p2", "memory");
+
+ *uval = prev;
+ return ret;
+}
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_HEXAGON_FUTEX_H */