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xtensa: clean up inline assembly in futex.h

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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>
This commit is contained in:
Max Filippov 2019-05-06 12:02:26 -07:00
parent 8f8d5745bb
commit d065fcf12c
1 changed files with 42 additions and 38 deletions
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80
arch/xtensa/include/asm/futex.h
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@ -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 */