MIPS: ftrace: Tweak safe_load()/safe_store() macros

Due to name collision in ftrace safe_load and safe_store macros,
these macros cannot take expressions as operands.

For example, compiler will complain for a macro call like the following:
  safe_store_code(new_code2, ip + 4, faulted);

  arch/mips/include/asm/ftrace.h:61:6: note: in definition of macro 'safe_store'
     : [dst] "r" (dst), [src] "r" (src)\
        ^
  arch/mips/kernel/ftrace.c:118:2: note: in expansion of macro 'safe_store_code'
    safe_store_code(new_code2, ip + 4, faulted);
    ^
  arch/mips/kernel/ftrace.c:118:32: error: undefined named operand 'ip + 4'
    safe_store_code(new_code2, ip + 4, faulted);
                                  ^
  arch/mips/include/asm/ftrace.h:61:6: note: in definition of macro 'safe_store'
     : [dst] "r" (dst), [src] "r" (src)\
        ^
  arch/mips/kernel/ftrace.c:118:2: note: in expansion of macro 'safe_store_code'
    safe_store_code(new_code2, ip + 4, faulted);
    ^

This build error is triggered by a467109 [MIPS: ftrace: Fix icache flush
range error].  Tweak variable naming in those macros to allow flexible
operands.

Signed-off-by: Viller Hsiao <villerhsiao@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: rostedt@goodmis.org
Cc: fweisbec@gmail.com
Cc: mingo@redhat.com
Cc: Qais.Yousef@imgtec.com
Patchwork: https://patchwork.linux-mips.org/patch/6622/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/ftrace.h

@@ -22,43 +22,43 @@ extern void _mcount(void);
 #define safe_load(load, src, dst, error) \
 do { \
  asm volatile ( \
- "1: " load " %[" STR(dst) "], 0(%[" STR(src) "])\n"\
- " li %[" STR(error) "], 0\n" \
+ "1: " load " %[tmp_dst], 0(%[tmp_src])\n" \
+ " li %[tmp_err], 0\n"  \
  "2:\n" \
  \
  ".section .fixup, \"ax\"\n" \
- "3: li %[" STR(error) "], 1\n" \
+ "3: li %[tmp_err], 1\n"  \
  " j 2b\n" \
  ".previous\n" \
  \
  ".section\t__ex_table,\"a\"\n\t" \
  STR(PTR) "\t1b, 3b\n\t" \
  ".previous\n" \
  \
- : [dst] "=&r" (dst), [error] "=r" (error)\
- : [src] "r" (src) \
+ : [tmp_dst] "=&r" (dst), [tmp_err] "=r" (error)\
+ : [tmp_src] "r" (src) \
  : "memory" \
  ); \
 } while (0)
 
 #define safe_store(store, src, dst, error) \
 do { \
  asm volatile ( \
- "1: " store " %[" STR(src) "], 0(%[" STR(dst) "])\n"\
- " li %[" STR(error) "], 0\n" \
+ "1: " store " %[tmp_src], 0(%[tmp_dst])\n"\
+ " li %[tmp_err], 0\n"  \
  "2:\n" \
  \
  ".section .fixup, \"ax\"\n" \
- "3: li %[" STR(error) "], 1\n" \
+ "3: li %[tmp_err], 1\n"  \
  " j 2b\n" \
  ".previous\n" \
  \
  ".section\t__ex_table,\"a\"\n\t"\
  STR(PTR) "\t1b, 3b\n\t" \
  ".previous\n" \
  \
- : [error] "=r" (error)  \
- : [dst] "r" (dst), [src] "r" (src)\
+ : [tmp_err] "=r" (error) \
+ : [tmp_dst] "r" (dst), [tmp_src] "r" (src)\
  : "memory" \
  ); \
 } while (0)