C++ set_cpu_cap函数代码示例

static void __cpuinit early_init_centaur(struct cpuinfo_x86 *c)
{
	if (c->x86 == 0x6 && c->x86_model >= 0xf)
		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);

	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
}

static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
{
	/* Unmask CPUID levels if masked: */
	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
		u64 misc_enable;

		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);

		if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
			misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
			wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
			c->cpuid_level = cpuid_eax(0);
		}
	}

	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
		(c->x86 == 0x6 && c->x86_model >= 0x0e))
		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);

#ifdef CONFIG_X86_64
	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
#else
	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
	if (c->x86 == 15 && c->x86_cache_alignment == 64)
		c->x86_cache_alignment = 128;
#endif

	/* CPUID workaround for 0F33/0F34 CPU */
	if (c->x86 == 0xF && c->x86_model == 0x3
	    && (c->x86_mask == 0x3 || c->x86_mask == 0x4))
		c->x86_phys_bits = 36;

	/*
	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
	 * with P/T states and does not stop in deep C-states.
	 *
	 * It is also reliable across cores and sockets. (but not across
	 * cabinets - we turn it off in that case explicitly.)
	 */
	if (c->x86_power & (1 << 8)) {
		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
		set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE);
		sched_clock_stable = 1;
	}

	/*
	 * There is a known erratum on Pentium III and Core Solo
	 * and Core Duo CPUs.
	 * " Page with PAT set to WC while associated MTRR is UC
	 *   may consolidate to UC "
	 * Because of this erratum, it is better to stick with
	 * setting WC in MTRR rather than using PAT on these CPUs.
	 *
	 * Enable PAT WC only on P4, Core 2 or later CPUs.
	 */
	if (c->x86 == 6 && c->x86_model < 15)
		clear_cpu_cap(c, X86_FEATURE_PAT);
}

static void __cpuinit init_centaur(struct cpuinfo_x86 *c)
{
	if (c->x86 == 0x6 && c->x86_model >= 0xf) {
		c->x86_cache_alignment = c->x86_clflush_size * 2;
		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
	}
	set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
}

static void init_c3(struct cpuinfo_x86 *c)
{
	u32  lo, hi;

	/* Test for Centaur Extended Feature Flags presence */
	if (cpuid_eax(0xC0000000) >= 0xC0000001) {
		u32 tmp = cpuid_edx(0xC0000001);

		/* enable ACE unit, if present and disabled */
		if ((tmp & (ACE_PRESENT | ACE_ENABLED)) == ACE_PRESENT) {
			rdmsr(MSR_VIA_FCR, lo, hi);
			lo |= ACE_FCR;		/* enable ACE unit */
			wrmsr(MSR_VIA_FCR, lo, hi);
			pr_info("CPU: Enabled ACE h/w crypto\n");
		}

		/* enable RNG unit, if present and disabled */
		if ((tmp & (RNG_PRESENT | RNG_ENABLED)) == RNG_PRESENT) {
			rdmsr(MSR_VIA_RNG, lo, hi);
			lo |= RNG_ENABLE;	/* enable RNG unit */
			wrmsr(MSR_VIA_RNG, lo, hi);
			pr_info("CPU: Enabled h/w RNG\n");
		}

		/* store Centaur Extended Feature Flags as
		 * word 5 of the CPU capability bit array
		 */
		c->x86_capability[CPUID_C000_0001_EDX] = cpuid_edx(0xC0000001);
	}
#ifdef CONFIG_X86_32
	/* Cyrix III family needs CX8 & PGE explicitly enabled. */
	if (c->x86_model >= 6 && c->x86_model <= 13) {
		rdmsr(MSR_VIA_FCR, lo, hi);
		lo |= (1<<1 | 1<<7);
		wrmsr(MSR_VIA_FCR, lo, hi);
		set_cpu_cap(c, X86_FEATURE_CX8);
	}

	/* Before Nehemiah, the C3's had 3dNOW! */
	if (c->x86_model >= 6 && c->x86_model < 9)
		set_cpu_cap(c, X86_FEATURE_3DNOW);
#endif
	if (c->x86 == 0x6 && c->x86_model >= 0xf) {
		c->x86_cache_alignment = c->x86_clflush_size * 2;
		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
	}

	cpu_detect_cache_sizes(c);
}

static void probe_xeon_phi_r3mwait(struct cpuinfo_x86 *c)
{
	/*
	 * Ring 3 MONITOR/MWAIT feature cannot be detected without
	 * cpu model and family comparison.
	 */
	if (c->x86 != 6)
		return;
	switch (c->x86_model) {
	case INTEL_FAM6_XEON_PHI_KNL:
	case INTEL_FAM6_XEON_PHI_KNM:
		break;
	default:
		return;
	}

	if (ring3mwait_disabled)
		return;

	set_cpu_cap(c, X86_FEATURE_RING3MWAIT);
	this_cpu_or(msr_misc_features_shadow,
		    1UL << MSR_MISC_FEATURES_ENABLES_RING3MWAIT_BIT);

	if (c == &boot_cpu_data)
		ELF_HWCAP2 |= HWCAP2_RING3MWAIT;
}

/*
 * The earliest FPU detection code.
 *
 * Set the X86_FEATURE_FPU CPU-capability bit based on
 * trying to execute an actual sequence of FPU instructions:
 */
static void fpu__init_system_early_generic(struct cpuinfo_x86 *c)
{
	unsigned long cr0;
	u16 fsw, fcw;

	fsw = fcw = 0xffff;

	cr0 = read_cr0();
	cr0 &= ~(X86_CR0_TS | X86_CR0_EM);
	write_cr0(cr0);

	asm volatile("fninit ; fnstsw %0 ; fnstcw %1"
		     : "+m" (fsw), "+m" (fcw));

	if (fsw == 0 && (fcw & 0x103f) == 0x003f)
		set_cpu_cap(c, X86_FEATURE_FPU);
	else
		clear_cpu_cap(c, X86_FEATURE_FPU);

#ifndef CONFIG_MATH_EMULATION
	if (!cpu_has_fpu) {
		pr_emerg("x86/fpu: Giving up, no FPU found and no math emulation present\n");
		for (;;)
			asm volatile("hlt");
	}

int detect_extended_topology_early(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_SMP
	unsigned int eax, ebx, ecx, edx;

	if (c->cpuid_level < 0xb)
		return -1;

	cpuid_count(0xb, SMT_LEVEL, &eax, &ebx, &ecx, &edx);

	/*
	 * check if the cpuid leaf 0xb is actually implemented.
	 */
	if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE))
		return -1;

	set_cpu_cap(c, X86_FEATURE_XTOPOLOGY);

	/*
	 * initial apic id, which also represents 32-bit extended x2apic id.
	 */
	c->initial_apicid = edx;
	smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
#endif
	return 0;
}

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);
	}
}

static void early_init_centaur(struct cpuinfo_x86 *c)
{
	switch (c->x86) {
#ifdef CONFIG_X86_32
	case 5:
		/* Emulate MTRRs using Centaur's MCR. */
		set_cpu_cap(c, X86_FEATURE_CENTAUR_MCR);
		break;
#endif
	case 6:
		if (c->x86_model >= 0xf)
			set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
		break;
	}
#ifdef CONFIG_X86_64
	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
#endif
}

void __exit lguest_arch_host_fini(void)
{
	/* If we had PGE before we started, turn it back on now. */
	get_online_cpus();
	if (cpu_had_pge) {
		set_cpu_cap(&boot_cpu_data, X86_FEATURE_PGE);
		/* adjust_pge's argument "1" means set PGE. */
		on_each_cpu(adjust_pge, (void *)1, 1);
	}
	put_online_cpus();
}

void __exit lguest_arch_host_fini(void)
{
	
	get_online_cpus();
	if (cpu_had_pge) {
		set_cpu_cap(&boot_cpu_data, X86_FEATURE_PGE);
		
		on_each_cpu(adjust_pge, (void *)1, 1);
	}
	put_online_cpus();
}

static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
{
	/* Unmask CPUID levels if masked: */
	if (c->x86 == 6 && c->x86_model >= 15) {
		u64 misc_enable;

		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);

		if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
			misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
			wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
			c->cpuid_level = cpuid_eax(0);
		}
	}

	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
		(c->x86 == 0x6 && c->x86_model >= 0x0e))
		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);

#ifdef CONFIG_X86_64
	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
#else
	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
	if (c->x86 == 15 && c->x86_cache_alignment == 64)
		c->x86_cache_alignment = 128;
#endif

	/*
	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
	 * with P/T states and does not stop in deep C-states
	 */
	if (c->x86_power & (1 << 8)) {
		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
	}

}

static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
{
	/* Unmask CPUID levels if masked: */
	if (c->x86 == 6 && c->x86_model >= 15) {
		u64 misc_enable;

		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);

		if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
			misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
			wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
			c->cpuid_level = cpuid_eax(0);
		}
	}

	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
	if (c->x86 == 15 && c->x86_cache_alignment == 64)
		c->x86_cache_alignment = 128;
	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
		(c->x86 == 0x6 && c->x86_model >= 0x0e))
		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
}

void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
{
	u32 max_level;
	u32 regs[4];
	const struct cpuid_bit *cb;

	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_count(cb->level, cb->sub_leaf, &regs[CPUID_EAX],
			    &regs[CPUID_EBX], &regs[CPUID_ECX],
			    &regs[CPUID_EDX]);

		if (regs[cb->reg] & (1 << cb->bit))
			set_cpu_cap(c, cb->feature);
	}
}

static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
{
	u64 misc_enable;

	/* Unmask CPUID levels if masked: */
	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);

		if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
			misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
			wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
			c->cpuid_level = cpuid_eax(0);
			get_cpu_cap(c);
		}
	}

	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
		(c->x86 == 0x6 && c->x86_model >= 0x0e))
		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);

	if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64)) {
		unsigned lower_word;

		wrmsr(MSR_IA32_UCODE_REV, 0, 0);
		/* Required by the SDM */
		sync_core();
		rdmsr(MSR_IA32_UCODE_REV, lower_word, c->microcode);
	}

	/*
	 * Atom erratum AAE44/AAF40/AAG38/AAH41:
	 *
	 * A race condition between speculative fetches and invalidating
	 * a large page.  This is worked around in microcode, but we
	 * need the microcode to have already been loaded... so if it is
	 * not, recommend a BIOS update and disable large pages.
	 */
	if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_mask <= 2 &&
	    c->microcode < 0x20e) {
		printk(KERN_WARNING "Atom PSE erratum detected, BIOS microcode update recommended\n");
		clear_cpu_cap(c, X86_FEATURE_PSE);
	}

#ifdef CONFIG_X86_64
	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
#else
	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
	if (c->x86 == 15 && c->x86_cache_alignment == 64)
		c->x86_cache_alignment = 128;
#endif

	/* CPUID workaround for 0F33/0F34 CPU */
	if (c->x86 == 0xF && c->x86_model == 0x3
	    && (c->x86_mask == 0x3 || c->x86_mask == 0x4))
		c->x86_phys_bits = 36;

	/*
	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
	 * with P/T states and does not stop in deep C-states.
	 *
	 * It is also reliable across cores and sockets. (but not across
	 * cabinets - we turn it off in that case explicitly.)
	 */
	if (c->x86_power & (1 << 8)) {
		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
		if (!check_tsc_unstable())
			sched_clock_stable = 1;
	}

	/*
	 * There is a known erratum on Pentium III and Core Solo
	 * and Core Duo CPUs.
	 * " Page with PAT set to WC while associated MTRR is UC
	 *   may consolidate to UC "
	 * Because of this erratum, it is better to stick with
	 * setting WC in MTRR rather than using PAT on these CPUs.
	 *
	 * Enable PAT WC only on P4, Core 2 or later CPUs.
	 */
	if (c->x86 == 6 && c->x86_model < 15)
		clear_cpu_cap(c, X86_FEATURE_PAT);

#ifdef CONFIG_KMEMCHECK
	/*
	 * P4s have a "fast strings" feature which causes single-
	 * stepping REP instructions to only generate a #DB on
	 * cache-line boundaries.
	 *
	 * Ingo Molnar reported a Pentium D (model 6) and a Xeon
	 * (model 2) with the same problem.
	 */
	if (c->x86 == 15) {
		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);

		if (misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING) {
			printk(KERN_INFO "kmemcheck: Disabling fast string operations\n");

			misc_enable &= ~MSR_IA32_MISC_ENABLE_FAST_STRING;
			wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
//.........这里部分代码省略.........