linux/arch/x86/kernel/cpu/addon_cpuid_features.c
Jeremy Fitzhardinge 53756d3722 x86: add set/clear_cpu_cap operations
The patch to suppress bitops-related warnings added a pile of ugly
casts.  Many of these were related to the management of x86 CPU
capabilities.  Clean these up by adding specific set/clear_cpu_cap
macros, and use them consistently.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:55 +01:00

51 lines
899 B
C

/*
* Routines to indentify additional cpu features that are scattered in
* cpuid space.
*/
#include <linux/cpu.h>
#include <asm/processor.h>
struct cpuid_bit {
u16 feature;
u8 reg;
u8 bit;
u32 level;
};
enum cpuid_regs {
CR_EAX = 0,
CR_ECX,
CR_EDX,
CR_EBX
};
void __cpuinit init_scattered_cpuid_features(struct cpuinfo_x86 *c)
{
u32 max_level;
u32 regs[4];
const struct cpuid_bit *cb;
static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_IDA, CR_EAX, 1, 0x00000006 },
{ 0, 0, 0, 0 }
};
for (cb = cpuid_bits; cb->feature; cb++) {
/* Verify that the level is valid */
max_level = cpuid_eax(cb->level & 0xffff0000);
if (max_level < cb->level ||
max_level > (cb->level | 0xffff))
continue;
cpuid(cb->level, &regs[CR_EAX], &regs[CR_EBX],
&regs[CR_ECX], &regs[CR_EDX]);
if (regs[cb->reg] & (1 << cb->bit))
set_cpu_cap(c, cb->feature);
}
}