x86/cpuid: Replace set/clear_bit32()

Peter pointed out that the set/clear_bit32() variants are broken in various
aspects.

Replace them with open coded set/clear_bit() and type cast
cpu_info::x86_capability as it's done in all other places throughout x86.

Fixes: 0b00de857a64 ("x86/cpuid: Add generic table for CPUID dependencies")
Reported-by: Peter Ziljstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>

1 files changed, 11 insertions, 15 deletions

diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index c21f22d836ad..904b0a3c4e53 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -62,23 +62,19 @@ const static struct cpuid_dep cpuid_deps[] = {
         {}
 };
 
-static inline void __clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit)
-{
-        clear_bit32(bit, c->x86_capability);
-}
-
-static inline void __setup_clear_cpu_cap(unsigned int bit)
-{
-        clear_cpu_cap(&boot_cpu_data, bit);
-        set_bit32(bit, cpu_caps_cleared);
-}
-
 static inline void clear_feature(struct cpuinfo_x86 *c, unsigned int feature)
 {
-        if (!c)
-                __setup_clear_cpu_cap(feature);
-        else
-                __clear_cpu_cap(c, feature);
+        /*
+         * Note: This could use the non atomic __*_bit() variants, but the
+         * rest of the cpufeature code uses atomics as well, so keep it for
+         * consistency. Cleanup all of it separately.
+         */
+        if (!c) {
+                clear_cpu_cap(&boot_cpu_data, feature);
+                set_bit(feature, (unsigned long *)cpu_caps_cleared);
+        } else {
+                clear_bit(feature, (unsigned long *)c->x86_capability);
+        }
 }
 
 /* Take the capabilities and the BUG bits into account */