m68k: Fix assembler constraint to prevent overeager gcc optimisation

Passing the address of a variable as an operand to an asm statement
doesn't mark the value of this variable as used, so gcc may optimize its
initialisation away.  Fix this by using the "m" constraint instead.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org
This commit is contained in:
Andreas Schwab 2012-01-09 15:10:15 +01:00 committed by Geert Uytterhoeven
parent c808d3d839
commit 2a3535069e
5 changed files with 28 additions and 30 deletions

View file

@ -414,9 +414,9 @@ void __init config_atari(void)
* FDC val = 4 -> Supervisor only */
asm volatile ("\n"
" .chip 68030\n"
" pmove %0@,%/tt1\n"
" pmove %0,%/tt1\n"
" .chip 68k"
: : "a" (&tt1_val));
: : "m" (tt1_val));
} else {
asm volatile ("\n"
" .chip 68040\n"
@ -569,10 +569,10 @@ static void atari_reset(void)
: "d0");
} else
asm volatile ("\n"
" pmove %0@,%%tc\n"
" pmove %0,%%tc\n"
" jmp %1@"
: /* no outputs */
: "a" (&tc_val), "a" (reset_addr));
: "m" (tc_val), "a" (reset_addr));
}

View file

@ -189,8 +189,8 @@ void flush_thread(void)
current->thread.fs = __USER_DS;
if (!FPU_IS_EMU)
asm volatile (".chip 68k/68881\n\t"
"frestore %0@\n\t"
".chip 68k" : : "a" (&zero));
"frestore %0\n\t"
".chip 68k" : : "m" (zero));
}
/*

View file

@ -163,8 +163,8 @@ void flush_thread(void)
#ifdef CONFIG_FPU
if (!FPU_IS_EMU)
asm volatile (".chip 68k/68881\n\t"
"frestore %0@\n\t"
".chip 68k" : : "a" (&zero));
"frestore %0\n\t"
".chip 68k" : : "m" (zero));
#endif
}

View file

@ -552,13 +552,13 @@ static inline void bus_error030 (struct frame *fp)
#ifdef DEBUG
asm volatile ("ptestr %3,%2@,#7,%0\n\t"
"pmove %%psr,%1@"
: "=a&" (desc)
: "a" (&temp), "a" (addr), "d" (ssw));
"pmove %%psr,%1"
: "=a&" (desc), "=m" (temp)
: "a" (addr), "d" (ssw));
#else
asm volatile ("ptestr %2,%1@,#7\n\t"
"pmove %%psr,%0@"
: : "a" (&temp), "a" (addr), "d" (ssw));
"pmove %%psr,%0"
: "=m" (temp) : "a" (addr), "d" (ssw));
#endif
mmusr = temp;
@ -605,20 +605,18 @@ static inline void bus_error030 (struct frame *fp)
!(ssw & RW) ? "write" : "read", addr,
fp->ptregs.pc, ssw);
asm volatile ("ptestr #1,%1@,#0\n\t"
"pmove %%psr,%0@"
: /* no outputs */
: "a" (&temp), "a" (addr));
"pmove %%psr,%0"
: "=m" (temp)
: "a" (addr));
mmusr = temp;
printk ("level 0 mmusr is %#x\n", mmusr);
#if 0
asm volatile ("pmove %%tt0,%0@"
: /* no outputs */
: "a" (&tlong));
asm volatile ("pmove %%tt0,%0"
: "=m" (tlong));
printk("tt0 is %#lx, ", tlong);
asm volatile ("pmove %%tt1,%0@"
: /* no outputs */
: "a" (&tlong));
asm volatile ("pmove %%tt1,%0"
: "=m" (tlong));
printk("tt1 is %#lx\n", tlong);
#endif
#ifdef DEBUG
@ -668,13 +666,13 @@ static inline void bus_error030 (struct frame *fp)
#ifdef DEBUG
asm volatile ("ptestr #1,%2@,#7,%0\n\t"
"pmove %%psr,%1@"
: "=a&" (desc)
: "a" (&temp), "a" (addr));
"pmove %%psr,%1"
: "=a&" (desc), "=m" (temp)
: "a" (addr));
#else
asm volatile ("ptestr #1,%1@,#7\n\t"
"pmove %%psr,%0@"
: : "a" (&temp), "a" (addr));
"pmove %%psr,%0"
: "=m" (temp) : "a" (addr));
#endif
mmusr = temp;

View file

@ -52,9 +52,9 @@ static unsigned long virt_to_phys_slow(unsigned long vaddr)
unsigned long *descaddr;
asm volatile ("ptestr %3,%2@,#7,%0\n\t"
"pmove %%psr,%1@"
: "=a&" (descaddr)
: "a" (&mmusr), "a" (vaddr), "d" (get_fs().seg));
"pmove %%psr,%1"
: "=a&" (descaddr), "=m" (mmusr)
: "a" (vaddr), "d" (get_fs().seg));
if (mmusr & (MMU_I|MMU_B|MMU_L))
return 0;
descaddr = phys_to_virt((unsigned long)descaddr);