xtensa: use a14 instead of a15 in inline assembly

a15 is a frame pointer in the call0 xtensa ABI, don't use it explicitly
in the inline assembly. Use a14 instead, as it has the same properties
as a15 w.r.t. window overflow.

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

diff --git a/arch/xtensa/include/asm/atomic.h b/arch/xtensa/include/asm/atomic.h
index 4361fe4..52da614 100644 (file)
--- a/arch/xtensa/include/asm/atomic.h
+++ b/arch/xtensa/include/asm/atomic.h
@@ -25,15 +25,15 @@
  *
  * Locking interrupts looks like this:
  *
- *    rsil a15, TOPLEVEL
+ *    rsil a14, TOPLEVEL
  *    <code>
- *    wsr  a15, PS
+ *    wsr  a14, PS
  *    rsync
  *
- * Note that a15 is used here because the register allocation
+ * Note that a14 is used here because the register allocation
  * done by the compiler is not guaranteed and a window overflow
  * may not occur between the rsil and wsr instructions. By using
- * a15 in the rsil, the machine is guaranteed to be in a state
+ * a14 in the rsil, the machine is guaranteed to be in a state
  * where no register reference will cause an overflow.
  */
 
@@ -185,15 +185,15 @@ static inline void arch_atomic_##op(int i, atomic_t * v)          \
        unsigned int vval;                                              \
                                                                        \
        __asm__ __volatile__(                                           \
-                       "       rsil    a15, "__stringify(TOPLEVEL)"\n" \
+                       "       rsil    a14, "__stringify(TOPLEVEL)"\n" \
                        "       l32i    %[result], %[mem]\n"            \
                        "       " #op " %[result], %[result], %[i]\n"   \
                        "       s32i    %[result], %[mem]\n"            \
-                       "       wsr     a15, ps\n"                      \
+                       "       wsr     a14, ps\n"                      \
                        "       rsync\n"                                \
                        : [result] "=&a" (vval), [mem] "+m" (*v)        \
                        : [i] "a" (i)                                   \
-                       : "a15", "memory"                               \
+                       : "a14", "memory"                               \
                        );                                              \
 }                                                                      \
 
@@ -203,15 +203,15 @@ static inline int arch_atomic_##op##_return(int i, atomic_t * v)  \
        unsigned int vval;                                              \
                                                                        \
        __asm__ __volatile__(                                           \
-                       "       rsil    a15,"__stringify(TOPLEVEL)"\n"  \
+                       "       rsil    a14,"__stringify(TOPLEVEL)"\n"  \
                        "       l32i    %[result], %[mem]\n"            \
                        "       " #op " %[result], %[result], %[i]\n"   \
                        "       s32i    %[result], %[mem]\n"            \
-                       "       wsr     a15, ps\n"                      \
+                       "       wsr     a14, ps\n"                      \
                        "       rsync\n"                                \
                        : [result] "=&a" (vval), [mem] "+m" (*v)        \
                        : [i] "a" (i)                                   \
-                       : "a15", "memory"                               \
+                       : "a14", "memory"                               \
                        );                                              \
                                                                        \
        return vval;                                                    \
@@ -223,16 +223,16 @@ static inline int arch_atomic_fetch_##op(int i, atomic_t * v)             \
        unsigned int tmp, vval;                                         \
                                                                        \
        __asm__ __volatile__(                                           \
-                       "       rsil    a15,"__stringify(TOPLEVEL)"\n"  \
+                       "       rsil    a14,"__stringify(TOPLEVEL)"\n"  \
                        "       l32i    %[result], %[mem]\n"            \
                        "       " #op " %[tmp], %[result], %[i]\n"      \
                        "       s32i    %[tmp], %[mem]\n"               \
-                       "       wsr     a15, ps\n"                      \
+                       "       wsr     a14, ps\n"                      \
                        "       rsync\n"                                \
                        : [result] "=&a" (vval), [tmp] "=&a" (tmp),     \
                          [mem] "+m" (*v)                               \
                        : [i] "a" (i)                                   \
-                       : "a15", "memory"                               \
+                       : "a14", "memory"                               \
                        );                                              \
                                                                        \
        return vval;                                                    \

diff --git a/arch/xtensa/include/asm/cmpxchg.h b/arch/xtensa/include/asm/cmpxchg.h
index 3699e28..eb87810 100644 (file)
--- a/arch/xtensa/include/asm/cmpxchg.h
+++ b/arch/xtensa/include/asm/cmpxchg.h
@@ -52,16 +52,16 @@ __cmpxchg_u32(volatile int *p, int old, int new)
        return new;
 #else
        __asm__ __volatile__(
-                       "       rsil    a15, "__stringify(TOPLEVEL)"\n"
+                       "       rsil    a14, "__stringify(TOPLEVEL)"\n"
                        "       l32i    %[old], %[mem]\n"
                        "       bne     %[old], %[cmp], 1f\n"
                        "       s32i    %[new], %[mem]\n"
                        "1:\n"
-                       "       wsr     a15, ps\n"
+                       "       wsr     a14, ps\n"
                        "       rsync\n"
                        : [old] "=&a" (old), [mem] "+m" (*p)
                        : [cmp] "a" (old), [new] "r" (new)
-                       : "a15", "memory");
+                       : "a14", "memory");
        return old;
 #endif
 }
@@ -116,10 +116,10 @@ static inline unsigned long __cmpxchg_local(volatile void *ptr,
 /*
  * xchg_u32
  *
- * Note that a15 is used here because the register allocation
+ * Note that a14 is used here because the register allocation
  * done by the compiler is not guaranteed and a window overflow
  * may not occur between the rsil and wsr instructions. By using
- * a15 in the rsil, the machine is guaranteed to be in a state
+ * a14 in the rsil, the machine is guaranteed to be in a state
  * where no register reference will cause an overflow.
  */
 
@@ -157,14 +157,14 @@ static inline unsigned long xchg_u32(volatile int * m, unsigned long val)
 #else
        unsigned long tmp;
        __asm__ __volatile__(
-                       "       rsil    a15, "__stringify(TOPLEVEL)"\n"
+                       "       rsil    a14, "__stringify(TOPLEVEL)"\n"
                        "       l32i    %[tmp], %[mem]\n"
                        "       s32i    %[val], %[mem]\n"
-                       "       wsr     a15, ps\n"
+                       "       wsr     a14, ps\n"
                        "       rsync\n"
                        : [tmp] "=&a" (tmp), [mem] "+m" (*m)
                        : [val] "a" (val)
-                       : "a15", "memory");
+                       : "a14", "memory");
        return tmp;
 #endif
 }