Futexes for MIPS, for the time being only the R10000_LLSC_WAR version.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/include/asm-mips/futex.h b/include/asm-mips/futex.h
index 9feff4ce..2454c44 100644
--- a/include/asm-mips/futex.h
+++ b/include/asm-mips/futex.h
@@ -3,10 +3,45 @@
#ifdef __KERNEL__
+#include <linux/config.h>
#include <linux/futex.h>
#include <asm/errno.h>
#include <asm/uaccess.h>
+#ifdef CONFIG_SMP
+#define __FUTEX_SMP_SYNC " sync \n"
+#else
+#define __FUTEX_SMP_SYNC
+#endif
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+{ \
+ __asm__ __volatile__( \
+ " .set push \n" \
+ " .set noat \n" \
+ " .set mips3 \n" \
+ "1: ll %1, (%3) # __futex_atomic_op1 \n" \
+ " .set mips0 \n" \
+ " " insn " \n" \
+ " .set mips3 \n" \
+ "2: sc $1, (%3) \n" \
+ " beqzl $1, 1b \n" \
+ __FUTEX_SMP_SYNC \
+ "3: \n" \
+ " .set pop \n" \
+ " .set mips0 \n" \
+ " .section .fixup,\"ax\" \n" \
+ "4: li %0, %5 \n" \
+ " j 2b \n" \
+ " .previous \n" \
+ " .section __ex_table,\"a\" \n" \
+ " "__UA_ADDR "\t1b, 4b \n" \
+ " "__UA_ADDR "\t2b, 4b \n" \
+ " .previous \n" \
+ : "=r" (ret), "=r" (oldval) \
+ : "0" (0), "r" (uaddr), "Jr" (oparg), "i" (-EFAULT)); \
+}
+
static inline int
futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
{
@@ -25,10 +60,25 @@
switch (op) {
case FUTEX_OP_SET:
+ __futex_atomic_op("move $1, %z4", ret, oldval, uaddr, oparg);
+ break;
+
case FUTEX_OP_ADD:
+ __futex_atomic_op("addu $1, %1, %z4",
+ ret, oldval, uaddr, oparg);
+ break;
case FUTEX_OP_OR:
+ __futex_atomic_op("or $1, %1, %z4",
+ ret, oldval, uaddr, oparg);
+ break;
case FUTEX_OP_ANDN:
+ __futex_atomic_op("and $1, %1, %z4",
+ ret, oldval, uaddr, ~oparg);
+ break;
case FUTEX_OP_XOR:
+ __futex_atomic_op("xor $1, %1, %z4",
+ ret, oldval, uaddr, oparg);
+ break;
default:
ret = -ENOSYS;
}