0f58189d4a
As noticed by Mikulas Patocka, the backoff macros don't completely nop out for UP builds, we still get a branch always and a delay slot nop. Fix this by making the branch to the backoff spin loop selective, then we can nop out the spin loop completely. Signed-off-by: David S. Miller <davem@davemloft.net>
37 lines
618 B
C
37 lines
618 B
C
#ifndef _SPARC64_BACKOFF_H
|
|
#define _SPARC64_BACKOFF_H
|
|
|
|
#define BACKOFF_LIMIT (4 * 1024)
|
|
|
|
#ifdef CONFIG_SMP
|
|
|
|
#define BACKOFF_SETUP(reg) \
|
|
mov 1, reg
|
|
|
|
#define BACKOFF_LABEL(spin_label, continue_label) \
|
|
spin_label
|
|
|
|
#define BACKOFF_SPIN(reg, tmp, label) \
|
|
mov reg, tmp; \
|
|
88: brnz,pt tmp, 88b; \
|
|
sub tmp, 1, tmp; \
|
|
set BACKOFF_LIMIT, tmp; \
|
|
cmp reg, tmp; \
|
|
bg,pn %xcc, label; \
|
|
nop; \
|
|
ba,pt %xcc, label; \
|
|
sllx reg, 1, reg;
|
|
|
|
#else
|
|
|
|
#define BACKOFF_SETUP(reg)
|
|
|
|
#define BACKOFF_LABEL(spin_label, continue_label) \
|
|
continue_label
|
|
|
|
#define BACKOFF_SPIN(reg, tmp, label)
|
|
|
|
#endif
|
|
|
|
#endif /* _SPARC64_BACKOFF_H */
|