v4.19.13 snapshot.
diff --git a/arch/mips/include/asm/futex.h b/arch/mips/include/asm/futex.h
new file mode 100644
index 0000000..a9e61ea
--- /dev/null
+++ b/arch/mips/include/asm/futex.h
@@ -0,0 +1,201 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (c) 2006 Ralf Baechle (ralf@linux-mips.org)
+ */
+#ifndef _ASM_FUTEX_H
+#define _ASM_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <asm/asm-eva.h>
+#include <asm/barrier.h>
+#include <asm/compiler.h>
+#include <asm/errno.h>
+#include <asm/war.h>
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+{ \
+ if (cpu_has_llsc && R10000_LLSC_WAR) { \
+ __asm__ __volatile__( \
+ " .set push \n" \
+ " .set noat \n" \
+ " .set arch=r4000 \n" \
+ "1: ll %1, %4 # __futex_atomic_op \n" \
+ " .set mips0 \n" \
+ " " insn " \n" \
+ " .set arch=r4000 \n" \
+ "2: sc $1, %2 \n" \
+ " beqzl $1, 1b \n" \
+ __WEAK_LLSC_MB \
+ "3: \n" \
+ " .insn \n" \
+ " .set pop \n" \
+ " .set mips0 \n" \
+ " .section .fixup,\"ax\" \n" \
+ "4: li %0, %6 \n" \
+ " j 3b \n" \
+ " .previous \n" \
+ " .section __ex_table,\"a\" \n" \
+ " "__UA_ADDR "\t1b, 4b \n" \
+ " "__UA_ADDR "\t2b, 4b \n" \
+ " .previous \n" \
+ : "=r" (ret), "=&r" (oldval), \
+ "=" GCC_OFF_SMALL_ASM() (*uaddr) \
+ : "0" (0), GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oparg), \
+ "i" (-EFAULT) \
+ : "memory"); \
+ } else if (cpu_has_llsc) { \
+ __asm__ __volatile__( \
+ " .set push \n" \
+ " .set noat \n" \
+ " .set "MIPS_ISA_ARCH_LEVEL" \n" \
+ "1: "user_ll("%1", "%4")" # __futex_atomic_op\n" \
+ " .set mips0 \n" \
+ " " insn " \n" \
+ " .set "MIPS_ISA_ARCH_LEVEL" \n" \
+ "2: "user_sc("$1", "%2")" \n" \
+ " beqz $1, 1b \n" \
+ __WEAK_LLSC_MB \
+ "3: \n" \
+ " .insn \n" \
+ " .set pop \n" \
+ " .set mips0 \n" \
+ " .section .fixup,\"ax\" \n" \
+ "4: li %0, %6 \n" \
+ " j 3b \n" \
+ " .previous \n" \
+ " .section __ex_table,\"a\" \n" \
+ " "__UA_ADDR "\t1b, 4b \n" \
+ " "__UA_ADDR "\t2b, 4b \n" \
+ " .previous \n" \
+ : "=r" (ret), "=&r" (oldval), \
+ "=" GCC_OFF_SMALL_ASM() (*uaddr) \
+ : "0" (0), GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oparg), \
+ "i" (-EFAULT) \
+ : "memory"); \
+ } else \
+ ret = -ENOSYS; \
+}
+
+static inline int
+arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
+{
+ int oldval = 0, ret;
+
+ pagefault_disable();
+
+ switch (op) {
+ case FUTEX_OP_SET:
+ __futex_atomic_op("move $1, %z5", ret, oldval, uaddr, oparg);
+ break;
+
+ case FUTEX_OP_ADD:
+ __futex_atomic_op("addu $1, %1, %z5",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_OR:
+ __futex_atomic_op("or $1, %1, %z5",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ANDN:
+ __futex_atomic_op("and $1, %1, %z5",
+ ret, oldval, uaddr, ~oparg);
+ break;
+ case FUTEX_OP_XOR:
+ __futex_atomic_op("xor $1, %1, %z5",
+ ret, oldval, uaddr, oparg);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+
+ pagefault_enable();
+
+ if (!ret)
+ *oval = oldval;
+
+ return ret;
+}
+
+static inline int
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+ u32 oldval, u32 newval)
+{
+ int ret = 0;
+ u32 val;
+
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ if (cpu_has_llsc && R10000_LLSC_WAR) {
+ __asm__ __volatile__(
+ "# futex_atomic_cmpxchg_inatomic \n"
+ " .set push \n"
+ " .set noat \n"
+ " .set arch=r4000 \n"
+ "1: ll %1, %3 \n"
+ " bne %1, %z4, 3f \n"
+ " .set mips0 \n"
+ " move $1, %z5 \n"
+ " .set arch=r4000 \n"
+ "2: sc $1, %2 \n"
+ " beqzl $1, 1b \n"
+ __WEAK_LLSC_MB
+ "3: \n"
+ " .insn \n"
+ " .set pop \n"
+ " .section .fixup,\"ax\" \n"
+ "4: li %0, %6 \n"
+ " j 3b \n"
+ " .previous \n"
+ " .section __ex_table,\"a\" \n"
+ " "__UA_ADDR "\t1b, 4b \n"
+ " "__UA_ADDR "\t2b, 4b \n"
+ " .previous \n"
+ : "+r" (ret), "=&r" (val), "=" GCC_OFF_SMALL_ASM() (*uaddr)
+ : GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oldval), "Jr" (newval),
+ "i" (-EFAULT)
+ : "memory");
+ } else if (cpu_has_llsc) {
+ __asm__ __volatile__(
+ "# futex_atomic_cmpxchg_inatomic \n"
+ " .set push \n"
+ " .set noat \n"
+ " .set "MIPS_ISA_ARCH_LEVEL" \n"
+ "1: "user_ll("%1", "%3")" \n"
+ " bne %1, %z4, 3f \n"
+ " .set mips0 \n"
+ " move $1, %z5 \n"
+ " .set "MIPS_ISA_ARCH_LEVEL" \n"
+ "2: "user_sc("$1", "%2")" \n"
+ " beqz $1, 1b \n"
+ __WEAK_LLSC_MB
+ "3: \n"
+ " .insn \n"
+ " .set pop \n"
+ " .section .fixup,\"ax\" \n"
+ "4: li %0, %6 \n"
+ " j 3b \n"
+ " .previous \n"
+ " .section __ex_table,\"a\" \n"
+ " "__UA_ADDR "\t1b, 4b \n"
+ " "__UA_ADDR "\t2b, 4b \n"
+ " .previous \n"
+ : "+r" (ret), "=&r" (val), "=" GCC_OFF_SMALL_ASM() (*uaddr)
+ : GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oldval), "Jr" (newval),
+ "i" (-EFAULT)
+ : "memory");
+ } else
+ return -ENOSYS;
+
+ *uval = val;
+ return ret;
+}
+
+#endif
+#endif /* _ASM_FUTEX_H */