xtensa: clean up inline assembly in futex.h

Replace numeric inline assembly parameters with named parameters.
Drop unused parameters from the futex_atomic_cmpxchg_inatomic.
Use new temporary variable to hold target address in the fixup code in
futex_atomic_cmpxchg_inatomic. Conditionalize function bodies so that
only 'return -ENOSYS' is left in configurations without futex support.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

diff --git a/arch/xtensa/include/asm/futex.h b/arch/xtensa/include/asm/futex.h
index 0fd58b7521aadd11b936375d774f8b3b72ae6465..a67f801aa303dc1d8cb87625807d9ee20fe26995 100644 (file)
--- a/arch/xtensa/include/asm/futex.h
+++ b/arch/xtensa/include/asm/futex.h
@@ -19,59 +19,58 @@
 #include <linux/uaccess.h>
 #include <linux/errno.h>
 
-#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+#define __futex_atomic_op(insn, ret, old, uaddr, arg)  \
        __asm__ __volatile(                             \
-       "1:     l32i    %0, %2, 0\n"                    \
+       "1:     l32i    %[oldval], %[addr], 0\n"        \
                insn "\n"                               \
-       "       wsr     %0, scompare1\n"                \
-       "2:     s32c1i  %1, %2, 0\n"                    \
-       "       bne     %1, %0, 1b\n"                   \
-       "       movi    %1, 0\n"                        \
+       "       wsr     %[oldval], scompare1\n"         \
+       "2:     s32c1i  %[newval], %[addr], 0\n"        \
+       "       bne     %[newval], %[oldval], 1b\n"     \
+       "       movi    %[newval], 0\n"                 \
        "3:\n"                                          \
        "       .section .fixup,\"ax\"\n"               \
        "       .align 4\n"                             \
        "       .literal_position\n"                    \
-       "5:     movi    %0, 3b\n"                       \
-       "       movi    %1, %3\n"                       \
-       "       jx      %0\n"                           \
+       "5:     movi    %[oldval], 3b\n"                \
+       "       movi    %[newval], %[fault]\n"          \
+       "       jx      %[oldval]\n"                    \
        "       .previous\n"                            \
        "       .section __ex_table,\"a\"\n"            \
-       "       .long 1b,5b,2b,5b\n"                    \
+       "       .long 1b, 5b, 2b, 5b\n"                 \
        "       .previous\n"                            \
-       : "=&r" (oldval), "=&r" (ret)                   \
-       : "r" (uaddr), "I" (-EFAULT), "r" (oparg)       \
+       : [oldval] "=&r" (old), [newval] "=&r" (ret)    \
+       : [addr] "r" (uaddr), [oparg] "r" (arg),        \
+         [fault] "I" (-EFAULT)                         \
        : "memory")
 
 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
                u32 __user *uaddr)
 {
+#if XCHAL_HAVE_S32C1I
        int oldval = 0, ret;
 
-#if !XCHAL_HAVE_S32C1I
-       return -ENOSYS;
-#endif
-
        pagefault_disable();
 
        switch (op) {
        case FUTEX_OP_SET:
-               __futex_atomic_op("mov %1, %4", ret, oldval, uaddr, oparg);
+               __futex_atomic_op("mov %[newval], %[oparg]",
+                                 ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_ADD:
-               __futex_atomic_op("add %1, %0, %4", ret, oldval, uaddr,
-                               oparg);
+               __futex_atomic_op("add %[newval], %[oldval], %[oparg]",
+                                 ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_OR:
-               __futex_atomic_op("or %1, %0, %4", ret, oldval, uaddr,
-                               oparg);
+               __futex_atomic_op("or %[newval], %[oldval], %[oparg]",
+                                 ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_ANDN:
-               __futex_atomic_op("and %1, %0, %4", ret, oldval, uaddr,
-                               ~oparg);
+               __futex_atomic_op("and %[newval], %[oldval], %[oparg]",
+                                 ret, oldval, uaddr, ~oparg);
                break;
        case FUTEX_OP_XOR:
-               __futex_atomic_op("xor %1, %0, %4", ret, oldval, uaddr,
-                               oparg);
+               __futex_atomic_op("xor %[newval], %[oldval], %[oparg]",
+                                 ret, oldval, uaddr, oparg);
                break;
        default:
                ret = -ENOSYS;
@@ -83,42 +82,47 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
                *oval = oldval;
 
        return ret;
+#else
+       return -ENOSYS;
+#endif
 }
 
 static inline int
 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
                              u32 oldval, u32 newval)
 {
+#if XCHAL_HAVE_S32C1I
+       unsigned long tmp;
        int ret = 0;
 
        if (!access_ok(uaddr, sizeof(u32)))
                return -EFAULT;
 
-#if !XCHAL_HAVE_S32C1I
-       return -ENOSYS;
-#endif
-
        __asm__ __volatile__ (
        "       # futex_atomic_cmpxchg_inatomic\n"
-       "       wsr     %5, scompare1\n"
-       "1:     s32c1i  %1, %4, 0\n"
-       "       s32i    %1, %6, 0\n"
+       "       wsr     %[oldval], scompare1\n"
+       "1:     s32c1i  %[newval], %[addr], 0\n"
+       "       s32i    %[newval], %[uval], 0\n"
        "2:\n"
        "       .section .fixup,\"ax\"\n"
        "       .align 4\n"
        "       .literal_position\n"
-       "4:     movi    %1, 2b\n"
-       "       movi    %0, %7\n"
-       "       jx      %1\n"
+       "4:     movi    %[tmp], 2b\n"
+       "       movi    %[ret], %[fault]\n"
+       "       jx      %[tmp]\n"
        "       .previous\n"
        "       .section __ex_table,\"a\"\n"
-       "       .long 1b,4b\n"
+       "       .long 1b, 4b\n"
        "       .previous\n"
-       : "+r" (ret), "+r" (newval), "+m" (*uaddr), "+m" (*uval)
-       : "r" (uaddr), "r" (oldval), "r" (uval), "I" (-EFAULT)
+       : [ret] "+r" (ret), [newval] "+r" (newval), [tmp] "=&r" (tmp)
+       : [addr] "r" (uaddr), [oldval] "r" (oldval), [uval] "r" (uval),
+         [fault] "I" (-EFAULT)
        : "memory");
 
        return ret;
+#else
+       return -ENOSYS;
+#endif
 }
 
 #endif /* _ASM_XTENSA_FUTEX_H */