arch/x86/kernel/cpu/intel.c

#include <linux/init.h>
#include <linux/kernel.h>

#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/smp.h>
#include <linux/sched.h>
#include <linux/thread_info.h>
#include <linux/module.h>
#include <linux/uaccess.h>

#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/msr.h>
#include <asm/bugs.h>
#include <asm/cpu.h>

#ifdef CONFIG_X86_64
#include <linux/topology.h>
#include <asm/numa_64.h>
#endif

#include "cpu.h"

#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/mpspec.h>
#include <asm/apic.h>
#endif

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);

	/*
	 * 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) {
		u32 ucode, junk;

		wrmsr(MSR_IA32_UCODE_REV, 0, 0);
		sync_core();
		rdmsr(MSR_IA32_UCODE_REV, junk, ucode);

		if (ucode < 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);
		}
	}
#endif

	/*
	 * If fast string is not enabled in IA32_MISC_ENABLE for any reason,
	 * clear the fast string and enhanced fast string CPU capabilities.
	 */
	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_FAST_STRING)) {
			printk(KERN_INFO "Disabled fast string operations\n");
			setup_clear_cpu_cap(X86_FEATURE_REP_GOOD);
			setup_clear_cpu_cap(X86_FEATURE_ERMS);
		}
	}
}

#ifdef CONFIG_X86_32
/*
 *	Early probe support logic for ppro memory erratum #50
 *
 *	This is called before we do cpu ident work
 */

int __cpuinit ppro_with_ram_bug(void)
{
	/* Uses data from early_cpu_detect now */
	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
	    boot_cpu_data.x86 == 6 &&
	    boot_cpu_data.x86_model == 1 &&
	    boot_cpu_data.x86_mask < 8) {
		printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
		return 1;
	}
	return 0;
}

#ifdef CONFIG_X86_F00F_BUG
static void __cpuinit trap_init_f00f_bug(void)
{
	__set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);

	/*
	 * Update the IDT descriptor and reload the IDT so that
	 * it uses the read-only mapped virtual address.
	 */
	idt_descr.address = fix_to_virt(FIX_F00F_IDT);
	load_idt(&idt_descr);
}
#endif

static void __cpuinit intel_smp_check(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_SMP
	/* calling is from identify_secondary_cpu() ? */
	if (!c->cpu_index)
		return;

	/*
	 * Mask B, Pentium, but not Pentium MMX
	 */
	if (c->x86 == 5 &&
	    c->x86_mask >= 1 && c->x86_mask <= 4 &&
	    c->x86_model <= 3) {
		/*
		 * Remember we have B step Pentia with bugs
		 */
		WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
				    "with B stepping processors.\n");
	}
#endif
}

static void __cpuinit 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.
	 * Note that the workaround only should be initialized once...
	 */
	c->f00f_bug = 0;
	if (!paravirt_enabled() && c->x86 == 5) {
		static int f00f_workaround_enabled;

		c->f00f_bug = 1;
		if (!f00f_workaround_enabled) {
			trap_init_f00f_bug();
			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);
}
#else
static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
{
}
#endif

static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_NUMA
	unsigned node;
	int cpu = smp_processor_id();

	/* Don't do the funky fallback heuristics the AMD version employs
	   for now. */
	node = numa_cpu_node(cpu);
	if (node == NUMA_NO_NODE || !node_online(node)) {
		/* reuse the value from init_cpu_to_node() */
		node = cpu_to_node(cpu);
	}
	numa_set_node(cpu, node);
#endif
}

/*
 * find out the number of processor cores on the die
 */
static int __cpuinit intel_num_cpu_cores(struct cpuinfo_x86 *c)
{
	unsigned int eax, ebx, ecx, edx;

	if (c->cpuid_level < 4)
		return 1;

	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
	if (eax & 0x1f)
		return (eax >> 26) + 1;
	else
		return 1;
}

static void __cpuinit detect_vmx_virtcap(struct cpuinfo_x86 *c)
{
	/* Intel VMX MSR indicated features */
#define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW	0x00200000
#define X86_VMX_FEATURE_PROC_CTLS_VNMI		0x00400000
#define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS	0x80000000
#define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC	0x00000001
#define X86_VMX_FEATURE_PROC_CTLS2_EPT		0x00000002
#define X86_VMX_FEATURE_PROC_CTLS2_VPID		0x00000020

	u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;

	clear_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
	clear_cpu_cap(c, X86_FEATURE_VNMI);
	clear_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
	clear_cpu_cap(c, X86_FEATURE_EPT);
	clear_cpu_cap(c, X86_FEATURE_VPID);

	rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
	msr_ctl = vmx_msr_high | vmx_msr_low;
	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
		set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
		set_cpu_cap(c, X86_FEATURE_VNMI);
	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
		rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
		      vmx_msr_low, vmx_msr_high);
		msr_ctl2 = vmx_msr_high | vmx_msr_low;
		if ((msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
		    (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
			set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT)
			set_cpu_cap(c, X86_FEATURE_EPT);
		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
			set_cpu_cap(c, X86_FEATURE_VPID);
	}
}

static void __cpuinit init_intel(struct cpuinfo_x86 *c)
{
	unsigned int l2 = 0;

	early_init_intel(c);

	intel_workarounds(c);

	/*
	 * Detect the extended topology information if available. This
	 * will reinitialise the initial_apicid which will be used
	 * in init_intel_cacheinfo()
	 */
	detect_extended_topology(c);

	l2 = init_intel_cacheinfo(c);
	if (c->cpuid_level > 9) {
		unsigned eax = cpuid_eax(10);
		/* Check for version and the number of counters */
		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
			set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
	}

	if (cpu_has_xmm2)
		set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
	if (cpu_has_ds) {
		unsigned int l1;
		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
		if (!(l1 & (1<<11)))
			set_cpu_cap(c, X86_FEATURE_BTS);
		if (!(l1 & (1<<12)))
			set_cpu_cap(c, X86_FEATURE_PEBS);
	}

	if (c->x86 == 6 && c->x86_model == 29 && cpu_has_clflush)
		set_cpu_cap(c, X86_FEATURE_CLFLUSH_MONITOR);

#ifdef CONFIG_X86_64
	if (c->x86 == 15)
		c->x86_cache_alignment = c->x86_clflush_size * 2;
	if (c->x86 == 6)
		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
#else
	/*
	 * Names for the Pentium II/Celeron processors
	 * detectable only by also checking the cache size.
	 * Dixon is NOT a Celeron.
	 */
	if (c->x86 == 6) {
		char *p = NULL;

		switch (c->x86_model) {
		case 5:
			if (l2 == 0)
				p = "Celeron (Covington)";
			else if (l2 == 256)
				p = "Mobile Pentium II (Dixon)";
			break;

		case 6:
			if (l2 == 128)
				p = "Celeron (Mendocino)";
			else if (c->x86_mask == 0 || c->x86_mask == 5)
				p = "Celeron-A";
			break;

		case 8:
			if (l2 == 128)
				p = "Celeron (Coppermine)";
			break;
		}

		if (p)
			strcpy(c->x86_model_id, p);
	}

	if (c->x86 == 15)
		set_cpu_cap(c, X86_FEATURE_P4);
	if (c->x86 == 6)
		set_cpu_cap(c, X86_FEATURE_P3);
#endif

	if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
		/*
		 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
		 * detection.
		 */
		c->x86_max_cores = intel_num_cpu_cores(c);
#ifdef CONFIG_X86_32
		detect_ht(c);
#endif
	}

	/* Work around errata */
	srat_detect_node(c);

	if (cpu_has(c, X86_FEATURE_VMX))
		detect_vmx_virtcap(c);

	/*
	 * Initialize MSR_IA32_ENERGY_PERF_BIAS if BIOS did not.
	 * x86_energy_perf_policy(8) is available to change it at run-time
	 */
	if (cpu_has(c, X86_FEATURE_EPB)) {
		u64 epb;

		rdmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
		if ((epb & 0xF) == 0) {
			printk_once(KERN_WARNING, "x86: updated energy_perf_bias"
				" to 'normal' from 'performance'\n"
				"You can view and update epb via utility,"
				" such as x86_energy_perf_policy(8)\n");
			epb = (epb & ~0xF) | ENERGY_PERF_BIAS_NORMAL;
			wrmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
		}
	}
}

#ifdef CONFIG_X86_32
static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
{
	/*
	 * Intel PIII Tualatin. This comes in two flavours.
	 * One has 256kb of cache, the other 512. We have no way
	 * to determine which, so we use a boottime override
	 * for the 512kb model, and assume 256 otherwise.
	 */
	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
		size = 256;
	return size;
}
#endif

static const struct cpu_dev __cpuinitconst intel_cpu_dev = {
	.c_vendor	= "Intel",
	.c_ident	= { "GenuineIntel" },
#ifdef CONFIG_X86_32
	.c_models = {
		{ .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
		  {
			  [0] = "486 DX-25/33",
			  [1] = "486 DX-50",
			  [2] = "486 SX",
			  [3] = "486 DX/2",
			  [4] = "486 SL",
			  [5] = "486 SX/2",
			  [7] = "486 DX/2-WB",
			  [8] = "486 DX/4",
			  [9] = "486 DX/4-WB"
		  }
		},
		{ .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
		  {
			  [0] = "Pentium 60/66 A-step",
			  [1] = "Pentium 60/66",
			  [2] = "Pentium 75 - 200",
			  [3] = "OverDrive PODP5V83",
			  [4] = "Pentium MMX",
			  [7] = "Mobile Pentium 75 - 200",
			  [8] = "Mobile Pentium MMX"
		  }
		},
		{ .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
		  {
			  [0] = "Pentium Pro A-step",
			  [1] = "Pentium Pro",
			  [3] = "Pentium II (Klamath)",
			  [4] = "Pentium II (Deschutes)",
			  [5] = "Pentium II (Deschutes)",
			  [6] = "Mobile Pentium II",
			  [7] = "Pentium III (Katmai)",
			  [8] = "Pentium III (Coppermine)",
			  [10] = "Pentium III (Cascades)",
			  [11] = "Pentium III (Tualatin)",
		  }
		},
		{ .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
		  {
			  [0] = "Pentium 4 (Unknown)",
			  [1] = "Pentium 4 (Willamette)",
			  [2] = "Pentium 4 (Northwood)",
			  [4] = "Pentium 4 (Foster)",
			  [5] = "Pentium 4 (Foster)",
		  }
		},
	},
	.c_size_cache	= intel_size_cache,
#endif
	.c_early_init   = early_init_intel,
	.c_init		= init_intel,
	.c_x86_vendor	= X86_VENDOR_INTEL,
};

cpu_dev_register(intel_cpu_dev);