s390/mem_detect: use register pair instead of register asm

...and slightly cleanup the inline asm.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

diff --git a/arch/s390/boot/mem_detect.c b/arch/s390/boot/mem_detect.c
index 3f09355..2c5a9c6 100644 (file)
--- a/arch/s390/boot/mem_detect.c
+++ b/arch/s390/boot/mem_detect.c
@@ -64,33 +64,37 @@ void add_mem_detect_block(u64 start, u64 end)
 
 static int __diag260(unsigned long rx1, unsigned long rx2)
 {
-       register unsigned long _rx1 asm("2") = rx1;
-       register unsigned long _rx2 asm("3") = rx2;
-       register unsigned long _ry asm("4") = 0x10; /* storage configuration */
-       int rc = -1;                                /* fail */
-       unsigned long reg1, reg2;
+       unsigned long reg1, reg2, ry;
+       union register_pair rx;
        psw_t old;
+       int rc;
 
+       rx.even = rx1;
+       rx.odd  = rx2;
+       ry = 0x10; /* storage configuration */
+       rc = -1;   /* fail */
        asm volatile(
                "       mvc     0(16,%[psw_old]),0(%[psw_pgm])\n"
-               "       epsw    %0,%1\n"
-               "       st      %0,0(%[psw_pgm])\n"
-               "       st      %1,4(%[psw_pgm])\n"
-               "       larl    %0,1f\n"
-               "       stg     %0,8(%[psw_pgm])\n"
+               "       epsw    %[reg1],%[reg2]\n"
+               "       st      %[reg1],0(%[psw_pgm])\n"
+               "       st      %[reg2],4(%[psw_pgm])\n"
+               "       larl    %[reg1],1f\n"
+               "       stg     %[reg1],8(%[psw_pgm])\n"
                "       diag    %[rx],%[ry],0x260\n"
                "       ipm     %[rc]\n"
                "       srl     %[rc],28\n"
                "1:     mvc     0(16,%[psw_pgm]),0(%[psw_old])\n"
-               : "=&d" (reg1), "=&a" (reg2),
+               : [reg1] "=&d" (reg1),
+                 [reg2] "=&a" (reg2),
+                 [rc] "+&d" (rc),
+                 [ry] "+&d" (ry),
                  "+Q" (S390_lowcore.program_new_psw),
-                 "=Q" (old),
-                 [rc] "+&d" (rc), [ry] "+d" (_ry)
-               : [rx] "d" (_rx1), "d" (_rx2),
+                 "=Q" (old)
+               : [rx] "d" (rx.pair),
                  [psw_old] "a" (&old),
                  [psw_pgm] "a" (&S390_lowcore.program_new_psw)
                : "cc", "memory");
-       return rc == 0 ? _ry : -1;
+       return rc == 0 ? ry : -1;
 }
 
 static int diag260(void)