Example #1
0
static void intel_workarounds(struct cpuinfo_x86 *c)
{
	unsigned long lo, hi;

#ifdef CONFIG_X86_F00F_BUG
	/*
	 * All current models of Pentium and Pentium with MMX technology CPUs
	 * have the F0 0F bug, which lets nonprivileged users lock up the
	 * system. Announce that the fault handler will be checking for it.
	 */
	clear_cpu_bug(c, X86_BUG_F00F);
	if (!paravirt_enabled() && c->x86 == 5) {
		static int f00f_workaround_enabled;

		set_cpu_bug(c, X86_BUG_F00F);
		if (!f00f_workaround_enabled) {
			printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
			f00f_workaround_enabled = 1;
		}
	}
#endif

	/*
	 * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
	 * model 3 mask 3
	 */
	if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
		clear_cpu_cap(c, X86_FEATURE_SEP);

	/*
	 * P4 Xeon errata 037 workaround.
	 * Hardware prefetcher may cause stale data to be loaded into the cache.
	 */
	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
		rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
		if ((lo & MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE) == 0) {
			printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
			printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
			lo |= MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE;
			wrmsr(MSR_IA32_MISC_ENABLE, lo, hi);
		}
	}

	/*
	 * See if we have a good local APIC by checking for buggy Pentia,
	 * i.e. all B steppings and the C2 stepping of P54C when using their
	 * integrated APIC (see 11AP erratum in "Pentium Processor
	 * Specification Update").
	 */
	if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
	    (c->x86_mask < 0x6 || c->x86_mask == 0xb))
		set_cpu_cap(c, X86_FEATURE_11AP);


#ifdef CONFIG_X86_INTEL_USERCOPY
	/*
	 * Set up the preferred alignment for movsl bulk memory moves
	 */
	switch (c->x86) {
	case 4:		/* 486: untested */
		break;
	case 5:		/* Old Pentia: untested */
		break;
	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
		movsl_mask.mask = 7;
		break;
	case 15:	/* P4 is OK down to 8-byte alignment */
		movsl_mask.mask = 7;
		break;
	}
#endif

#ifdef CONFIG_X86_NUMAQ
	numaq_tsc_disable();
#endif

	intel_smp_check(c);
}
Example #2
0
File: intel.c Project: ifilex/sensa
static void intel_workarounds(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_X86_F00F_BUG
	/*
	 * All models of Pentium and Pentium with MMX technology CPUs
	 * have the F0 0F bug, which lets nonprivileged users lock up the
	 * system. Announce that the fault handler will be checking for it.
	 * The Quark is also family 5, but does not have the same bug.
	 */
	clear_cpu_bug(c, X86_BUG_F00F);
	if (!paravirt_enabled() && c->x86 == 5 && c->x86_model < 9) {
		static int f00f_workaround_enabled;

		set_cpu_bug(c, X86_BUG_F00F);
		if (!f00f_workaround_enabled) {
			printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
			f00f_workaround_enabled = 1;
		}
	}
#endif

	/*
	 * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
	 * model 3 mask 3
	 */
	if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
		clear_cpu_cap(c, X86_FEATURE_SEP);

	/*
	 * PAE CPUID issue: many Pentium M report no PAE but may have a
	 * functionally usable PAE implementation.
	 * Forcefully enable PAE if kernel parameter "forcepae" is present.
	 */
	if (forcepae) {
		printk(KERN_WARNING "PAE forced!\n");
		set_cpu_cap(c, X86_FEATURE_PAE);
		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
	}

	/*
	 * P4 Xeon errata 037 workaround.
	 * Hardware prefetcher may cause stale data to be loaded into the cache.
	 */
	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
		if (msr_set_bit(MSR_IA32_MISC_ENABLE,
				MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE_BIT)
		    > 0) {
			pr_info("CPU: C0 stepping P4 Xeon detected.\n");
			pr_info("CPU: Disabling hardware prefetching (Errata 037)\n");
		}
	}

	/*
	 * See if we have a good local APIC by checking for buggy Pentia,
	 * i.e. all B steppings and the C2 stepping of P54C when using their
	 * integrated APIC (see 11AP erratum in "Pentium Processor
	 * Specification Update").
	 */
	if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
	    (c->x86_mask < 0x6 || c->x86_mask == 0xb))
		set_cpu_bug(c, X86_BUG_11AP);


#ifdef CONFIG_X86_INTEL_USERCOPY
	/*
	 * Set up the preferred alignment for movsl bulk memory moves
	 */
	switch (c->x86) {
	case 4:		/* 486: untested */
		break;
	case 5:		/* Old Pentia: untested */
		break;
	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
		movsl_mask.mask = 7;
		break;
	case 15:	/* P4 is OK down to 8-byte alignment */
		movsl_mask.mask = 7;
		break;
	}
#endif

	intel_smp_check(c);
}