linux/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/thread_info.h>
#include <linux/module.h>

#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/msr.h>
#include <asm/uaccess.h>
#include <asm/ptrace.h>
#include <asm/ds.h>
#include <asm/bugs.h>

#include "cpu.h"

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

#ifdef CONFIG_X86_INTEL_USERCOPY
/*
 * Alignment at which movsl is preferred for bulk memory copies.
 */
struct movsl_mask movsl_mask __read_mostly;
#endif

static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
{
	/* 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);
}

/*
 *	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;
}


/*
 * P4 Xeon errata 037 workaround.
 * Hardware prefetcher may cause stale data to be loaded into the cache.
 */
static void __cpuinit Intel_errata_workarounds(struct cpuinfo_x86 *c)
{
	unsigned long lo, hi;

	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
		rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
		if ((lo & (1<<9)) == 0) {
			printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
			printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
			lo |= (1<<9);	/* Disable hw prefetching */
			wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
		}
	}
}


/*
 * find out the number of processor cores on the die
 */
static int __cpuinit 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;
}

#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 init_intel(struct cpuinfo_x86 *c)
{
	unsigned int l2 = 0;
	char *p = NULL;

	early_init_intel(c);

#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

	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);
	}

	/* 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);

	/*
	 * Names for the Pentium II/Celeron processors
	 * detectable only by also checking the cache size.
	 * Dixon is NOT a Celeron.
	 */
	if (c->x86 == 6) {
		switch (c->x86_model) {
		case 5:
			if (c->x86_mask == 0) {
				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);

	c->x86_max_cores = num_cpu_cores(c);

	detect_ht(c);

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

#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

	if (cpu_has_xmm2)
		set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
	if (c->x86 == 15) {
		set_cpu_cap(c, X86_FEATURE_P4);
	}
	if (c->x86 == 6)
		set_cpu_cap(c, X86_FEATURE_P3);
	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);
		ds_init_intel(c);
	}

	if (cpu_has_bts)
		ptrace_bts_init_intel(c);

	/*
	 * 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_NUMAQ
	numaq_tsc_disable();
#endif
}

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;
}

static struct cpu_dev intel_cpu_dev __cpuinitdata = {
	.c_vendor	= "Intel",
	.c_ident	= { "GenuineIntel" },
	.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_early_init   = early_init_intel,
	.c_init		= init_intel,
	.c_size_cache	= intel_size_cache,
};

cpu_vendor_dev_register(X86_VENDOR_INTEL, &intel_cpu_dev);

#ifndef CONFIG_X86_CMPXCHG
unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
{
	u8 prev;
	unsigned long flags;

	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
	local_irq_save(flags);
	prev = *(u8 *)ptr;
	if (prev == old)
		*(u8 *)ptr = new;
	local_irq_restore(flags);
	return prev;
}
EXPORT_SYMBOL(cmpxchg_386_u8);

unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
{
	u16 prev;
	unsigned long flags;

	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
	local_irq_save(flags);
	prev = *(u16 *)ptr;
	if (prev == old)
		*(u16 *)ptr = new;
	local_irq_restore(flags);
	return prev;
}
EXPORT_SYMBOL(cmpxchg_386_u16);

unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
{
	u32 prev;
	unsigned long flags;

	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
	local_irq_save(flags);
	prev = *(u32 *)ptr;
	if (prev == old)
		*(u32 *)ptr = new;
	local_irq_restore(flags);
	return prev;
}
EXPORT_SYMBOL(cmpxchg_386_u32);
#endif

#ifndef CONFIG_X86_CMPXCHG64
unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new)
{
	u64 prev;
	unsigned long flags;

	/* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */
	local_irq_save(flags);
	prev = *(u64 *)ptr;
	if (prev == old)
		*(u64 *)ptr = new;
	local_irq_restore(flags);
	return prev;
}
EXPORT_SYMBOL(cmpxchg_486_u64);
#endif

/* arch_initcall(intel_cpu_init); */