MIPS: cpu-probe: ingenic: Fix broken BUG_ON
authorPaul Cercueil <paul@crapouillou.net>
Sun, 6 Sep 2020 19:29:24 +0000 (21:29 +0200)
committerThomas Bogendoerfer <tsbogend@alpha.franken.de>
Fri, 18 Sep 2020 14:27:32 +0000 (16:27 +0200)
The previous code was doing:
BUG_ON(!__builtin_constant_p(cpu_has_counter) || cpu_has_counter);

This only worked as the "cpu_has_counter" macro was overridden in
<cpu-feature-overrides.h>. The default "cpu_has_counter" macro is
non-constant, which triggered the BUG_ON() independently of the value
returned by the macro.

What we want to check here, is that *if* the macro was overridden to a
compile-time constant, then must be defined to zero, otherwise it's a
bug.

So the correct check is:
BUG_ON(__builtin_constant_p(cpu_has_counter) && cpu_has_counter);

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
arch/mips/kernel/cpu-probe.c

index a07e66a..6be23f2 100644 (file)
@@ -2123,7 +2123,7 @@ static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu)
 
        /* XBurst does not implement the CP0 counter. */
        c->options &= ~MIPS_CPU_COUNTER;
-       BUG_ON(!__builtin_constant_p(cpu_has_counter) || cpu_has_counter);
+       BUG_ON(__builtin_constant_p(cpu_has_counter) && cpu_has_counter);
 
        /* XBurst has virtually tagged icache */
        c->icache.flags |= MIPS_CACHE_VTAG;